Reaction of Fischer carbene complexes with 1,3-butadiynes: A new strategem for biaryl synthesis with construction of the biaryl bond preceding synthesis of the arenes

Article abstract of DOI:10.1021/ja953146k

The first examples of the reactions of Fischer carbene complexes with 1,3-butadiynes are reported. These reactions are of interest since they provide new methods for the synthesis of acetylenic substituted arenes and also for the synthesis of biaryls. The reactions of the complexes (CO)₅Cr=C(OR¹)R² [R¹ = Me, n-Bu; R² = phenyl, 1-naphthyl, 1-cyclohexenyl] were investigated with the conjugated diynes R³C≡C-C≡CR³ [R³ = t-Bu, i-Pr, Ph]. All of the carbene complexes will react with 1 equiv of the diyne to give good yields of acetylenic arenes 5, 19, and 23, each with high selectivity for the regioisomer in which the substituent R³ on the diyne is incorporated adjacent to the phenol function. The reactions of the alkynylarenes 5, 19, and 23 with a second equivalent of carbene complexes, 4, 16, and 22, respectively, generate the bis-phenols 26, 31, and 33, with varying amounts of five-membered-ring annulated compounds as side products. These side products are not seen with the cyclohexenyl complex 22 and can be minimized to some extent for the phenyl complex 4a by proper control of the concentration and the temperature. Attempts to carry out benzannulations of both of the acetylenic functions in the 1,3-diyne concurrently by employing 2 equiv of the carbene complex were not successful, and this is suspected to be due to the presence of a chromium tricarbonyl group on the newly formed arene ring after the first benzannulation, such as in complex 34. The concurrent double benzannulation of a diyne can be achieved in an intramolecular fashion with the bis-carbene complex 39. The intramolecular process leads to a reversal in the regiochemistry of the second benzannulation producing the C₂-symmetrical 2,2'-binaphthol 40 from the reaction of complex 39 with the diyne 8 along with the indenylnaphthalene 41. The reaction of the optically pure bis-carbene complex 44 derived from (2R,3R)-butane-2,3-diol with diyne 8 gives a single diastereomer of the 2,2'-binaphthol 46. Chemical correlation with the known 2,2'-binaphthol 51 reveals that the biaryl axis in 46 has an S-configuration, which was predicted from an examination of models.

Full text of DOI:10.1021/ja953146k

2166
J. Am. Chem. Soc. 1996, 118, 2166-2181
Reaction of Fischer Carbene Complexes with 1,3-Butadiynes:
A New Strategem for Biaryl Synthesis with Construction of the
Biaryl Bond Preceding Synthesis of the Arenes
Jianming Bao, William D. Wulff,* Michael J. Fumo, Eugene B. Grant,
Douglas P. Heller, Mark C. Whitcomb, and Siu-Man Yeung
Contribution from the Searle Chemistry Laboratory, Department of Chemistry,
UniVersity of Chicago, Chicago, Illinois 60637
ReceiVed September 12, 1995X
Abstract: The first examples of the reactions of Fischer carbene complexes with 1,3-butadiynes are reported. These
reactions are of interest since they provide new methods for the synthesis of acetylenic substituted arenes and also
for the synthesis of biaryls. The reactions of the complexes (CO)5CrdC(OR1)R2 [R1 ) Me, n-Bu; R2 ) phenyl,
1-naphthyl, 1-cyclohexenyl] were investigated with the conjugated diynes R3CtCsCtCR3 [R3 ) t-Bu, i-Pr, Ph].
All of the carbene complexes will react with 1 equiv of the diyne to give good yields of acetylenic arenes 5, 19, and
23, each with high selectivity for the regioisomer in which the substituent R3 on the diyne is incorporated adjacent
to the phenol function. The reactions of the alkynylarenes 5, 19, and 23 with a second equivalent of carbene complexes,
4, 16, and 22, respectively, generate the bis-phenols 26, 31, and 33, with varying amounts of five-membered-ring
annulated compounds as side products. These side products are not seen with the cyclohexenyl complex 22 and can
be minimized to some extent for the phenyl complex 4a by proper control of the concentration and the temperature.
Attempts to carry out benzannulations of both of the acetylenic functions in the 1,3-diyne concurrently by employing
2 equiv of the carbene complex were not successful, and this is suspected to be due to the presence of a chromium
tricarbonyl group on the newly formed arene ring after the first benzannulation, such as in complex 34. The concurrent
double benzannulation of a diyne can be achieved in an intramolecular fashion with the bis-carbene complex 39.
The intramolecular process leads to a reversal in the regiochemistry of the second benzannulation producing the
C2-symmetrical 2,2′-binaphthol 40 from the reaction of complex 39 with the diyne 8 along with the indenylnaphthalene
41. The reaction of the optically pure bis-carbene complex 44 derived from (2R,3R)-butane-2,3-diol with diyne 8
gives a single diastereomer of the 2,2′-binaphthol 46. Chemical correlation with the known 2,2′-binaphthol 51 reveals
that the biaryl axis in 46 has an S-configuration, which was predicted from an examination of models.
The reaction of Fischer carbene complexes with alkynes is a
Scheme 1
synthetically important reaction for the preparation of oxygen-
ated benzenes.1 This methodology has been extended to
nonconjugated diynes, with significant study directed to cases
where polycyclic systems can be generated.2 In view of these
studies, which have taken place over an extended period of time,
it is surprising that the reactions of Fischer carbene complexes
with conjugated 1,3-diynes have never been reported.3 The
attractiveness of the potential of this class of reaction is
illustrated in Scheme 1, where it can be seen that, if the adjacent
benzannulations are carried out independently on each of the
X Abstract published in AdVance ACS Abstracts, February 15, 1996.
(1) For reviews on the synthetic applications of Fischer carbene
complexes, see: (a) Do¨tz, K. H.; Fischer, H.; Hofmann, P.; Kreissel, F. R.;
Schubert, U.; Weiss, K. Transition Metal Carbene Complexes; Verlag
Chemie: Deerfield Beach, FL, 1984. (b) Do¨tz, K. H., Angew. Chem., Int.
Ed. Engl. 1984, 23, 587. (c) Wulff, W. D. In AdVances in Metal-Organic
Chemistry; Liebeskind, L. S., Ed.; JAI Press Inc.: Greenwich, CT, 1989;
Vol. 1. (d) Wulff, W. D. In ComprehensiVe Organic Synthesis; Trost, B.
M., Fleming, I., Eds.; Pergamon Press: Oxford, UK, 1990; Vol 5. (e) Wulff,
W. D. In ComprehensiVe Organometallic Chemistry II; Abel, E. W., Stone,
F. G. A., Wilkinson, G., Eds.; Pergamon Press: Oxford, UK, 1995; Vol.
12. (f) Hegedus, L. S. In ComprehensiVe Organometallic Chemistry II; Abel,
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press: Oxford, UK,
1995; Vol. 12. (g) Doyle, M. In ComprehensiVe Organometallic Chemistry
II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press:
Oxford, UK, 1995; Vol. 12.
alkyne functions with the carbene complex 1, then a new route
to biaryls will result.4 This approach to biaryl synthesis
embodies the reverse of the normal strategy of biaryl synthe-
sis: the biaryl bond is constructed prior to the construction of
either of the two aryl rings. We report here the first examples
of the reactions of Fischer carbene complexes with conjugated
1,3-diynes and demonstrate that biaryls can be constructed from
this reaction with both inter- and intramolecular dispositions
of the two carbene complexes. It is further demonstrated in
the intramolecular case that high asymmetric induction in the
formation of the biaryl can be achieved if a chiral carbene
complex is employed.
(2) For citations to the literature, see: Bao, J.; Wulff, W. D.; Dragisich,
V.; Wenglowsky, S.; Ball, R. G. J. Am. Chem. Soc. 1994, 116, 7616.
(3) (a) Parts of this work have been reported in preliminary form: Wulff,
W. D.; Bao, J. Abstracts of Papers, 203rd ACS National Meeting, San
Francisco, April 5-10, 1992; (b) See also: Chan, K. S.; Mak, C. C.
Tetrahedron 1994, 50, 2003.
(4) For a review of biaryl synthesis, see: Bringmann, G.; Walter, R.;
Weirich, R. Angew. Chem., Int. Ed. Engl. 1990, 29, 977.
0002-7863/96/1518-2166$12.00/0 © 1996 American Chemical Society

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2167
Table 1. Monobenzannulation of 1,3-Diynes with the Aryl Complexes 4a
yield (%)b
entry
complex
R
solvent
[4a] (M)
temp (°C)
time (h)
5
6
1
2
3
4
5
6
7
8
9
4a
4a
4a
4a
4a
4a
4b
4b
4b
4b
Me
Me
Me
Me
Me
Me
n-Bu
n-Bu
n-Bu
n-Bu
THF
THF
THF
THF
THF
THF
THF
THF
0.03
0.03
0.5
60
70
70
105
105
105
50
70
70
70
24
23
24
2
3
3
17
24
24
24
20
44
16
21
nd
nd
nd
nd
nd
21
nd
nd
nd
0.1
42c,d
0.21
0.21
0.03
0.03
0.03
0.03
12c,e
ndc,f
53c
61
benzene
hexane
31 (40)g
25 (31)g
10
a All reactions carried out with 1 equiv of 8 under an argon atomosphere. b nd, not detected. c Isolated as the quinone (7) after an oxidative
workup with CeIV. d 41% after 24 h. e Slow addition of 8 over 1 h. f Slow addition of 4a over 1 h. g Yield based on recovered starting material.
Monobenzannulation of 1,3-Diynes. In our very first
attempt at reacting a carbene complex and a 1,3-diyne, we
examined the reaction of an excess of the phenylcarbene
complex 4a with the diyne 8 (3:1 stoichiometry) and observed
the formation of a complex reaction mixture that contained no
clear predominate product (the outcome was not significantly
different when carried out in the presence of 3 equiv of Bu3P).
While the disposition of this particular reaction was not further
pursued, the related reaction of excess complex 22 and diyne 8
was examined in more detail (Scheme 9). More readily
interpretable results for the reaction of complex 4 with diyne 8
were obtained with a 1:1 stoichiometry, and the results are
summarized in Table 1. The reaction of the phenyl complex
4a with 1 equiv of the commercially available 1,4-diphenyl-
1,3-butadiyne (8) gave the acetylenic naphthol 5a and the
cyclobutenone 6a in nearly equal amounts. Cyclobutenone
products have been previously reported from the reactions of
carbene complexes, and, while it is thought that in most cases
they are not intermediates on the pathway for the formation of
the normal phenol product, they will undergo thermal isomer-
ization to phenol products.5 This was demonstrated for cy-
clobutenone 6a, where the phenol 5a was obtained in 97% yield
upon thermolysis in hexane at 80 °C in 24 h (Scheme 2). This
is consistent with the fact that the reactions of 4a with 8 at 70
°C and 105 °C give only the naphthol 5a, but in the same overall
mass balance as the reaction at 60 °C which produced both 5a
and 6a. An increased mass balance for these reactions could
not be obtained with either slow addition of the carbene complex
4a to the diyne 8 or Vice Versa (entries 5 and 6).
Scheme 2
reasons that are not understood at this time, the reaction of
complex 4b with diyne 8 is slower and less efficient for the
formation of naphthol 5b in benzene and hexane solvent as
compared to the reactions in THF. Although the effects of
solvent on the product distribution from the reactions of carbene
complexes with monoalkynes have been observed, the effect
of the monoalkyne on the rate has not been examined.5a,6
The regiochemistry of alkyne incorporation has been exam-
ined for a number of alkynes, and in most situations the
regiochemical outcome is determined by the steric difference
between the two substituents of the alkyne, giving as the major
product the regioisomer in which the larger group is incorporated
adjacent to the phenol function.1c,7 Thus, it would be expected
that the structure of the product 5a from the reaction of complex
4a and diyne 8 would be that indicated in Table 1, where the
phenyl group is adjacent to the hydroxyl group. However, given
that electronic factors can reverse the regiochemistry in some
instances,7d it was deemed necessary to confirm the assignment
A significantly higher mass balance is observed for the
reaction of the (n-butyloxy)carbene complex 4b than for the
reaction of the methoxy complex 4a (Table 1, entry 2 vs entry
8). It is not known if this effect pertains for the reactions of
these complexes with simple alkynes. A 74% mass balance
can be obtained for the reaction of complex 4b at 50 °C, where
an oxidative workup with ceric ammonium nitrate was employed
to give the naphthoquinone 7 in 53% yield and the cyclobuten-
one 6b in 21% yield. At 70 °C, the naphthol 5b (no oxidative
workup) is formed to the exclusion of 6b in 61% yield. For
(6) (a) Bos, M. E.; Wulff, W. D.; Miller, R. A.; Brandvold, T. A.;
Chamberlin, S.; J. Am. Chem. Soc. 1991, 113, 9293. (b) Wulff, W. D.;
Bax, B. M.; Brandvold, T. A.; Chan, K. S.; Gilbert, A. M.; Hsung, R. P.;
Mitchell, J.; Clardy, J. Organometallics 1994, 13, 102. (c) Yamashita, A.
Tetrahedron Lett. 1986, 27, 5915. (d) Do¨tz, K. H. J. Organomet. Chem.
1977, 140, 177.
(7) (a) Yamashita, A.; Toy, A. Tetrahedron Lett. 1986, 27, 3471. (b)
Do¨tz, K. H.; Muhlemeier, J.; Schubert, U.; Orama, O. J. Organomet. Chem.
1983, 247, 187. (c) Wulff, W. D.; Tang, P. C.; McCallum, J. S. J. Am.
Chem. Soc. 1981, 103, 7677. (d) Chamberlin, S.; Wulff, W. D.; Waters,
M. L. J. Am. Chem. Soc. 1994, 116, 3113.
(5) (a) Chan, K. S.; Peterson, G. A.; Brandvold, T. A.; Faron, K. L.;
Challener, C. A.; Hyldahl, C.; Wulff, W. D. J. Organomet. Chem. 1987,
334, 9. (b) Yamashita, A.; Toy, A. Tetrahedron Lett. 1986, 27, 3471. (c)
Do¨tz, K. H. J. Organomet. Chem. 1977, 140, 177.

2168 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
Scheme 3
Table 2. Monobenzannulation of 1,3-Diynes with the Naphthyl
of 5a, and this was done by the synthesis of the other possible
regioisomer 13, as indicated in Scheme 3.
Complexes 16a
The benzannulation of the [(methyloxy)methoxy]carbene
complex 4c with phenylacetylene, followed by methylation of
the phenol function, gave the naphthalene 9. The regiochemistry
of 9 was determined by cleavage to the 3-phenyl-4-methoxy-
naphthol (10), which was shown not to be the 2-phenyl isomer
15 produced from the reaction of the phenylcarbene complex
14 with phenylacetylene. It has never been unambiguously
proven that the benzannulation reaction with phenylacetylene
gives the regiochemistry indicated in 15. Thus, the 13C-labeled
carbene complex 14 was prepared, and, upon reaction with
phenylacetylene, it was found that the labeled carbon is not
directly coupled to any aryl carbon that bears a proton. Since
an authentic sample of 10 was in hand, the opportunity was
provided to quantify the regioselectivity of the reaction of the
phenyl(methoxy)carbene complex with phenylacetylene, which
by capillary GC was found to be greater than or equal to 179:1
in favor of 15 over 10.
yield (%)
19 20
complex R1
R2 alkyne phenanthrol cyclobutenone
16a
16a
16b
16b
16b
16b
Me Ph
8
17
8
8
18
17
19a
19b
19c
19c
19d
19e
61
Me i-Pr
n-Bu Ph
n-Bu Ph
n-Bu t-Bu
n-Bu i-Pr
41 (53)b
82
20c
20d
86c
<2
72
6c
36 (65)b
a All reactions carried out at 0.03 M in 16 with 1 equiv of diyne
under an argon atmosphere. b Based on recovered 16. c Isolated as
quinones 21c,d after an oxidative workup with CeIV.
The completion of the synthesis of 13 was accomplished by
the metalation of the naphthalene 9 directed by the MOM group.
Quenching of the resulting aryl lithium with iodine provided a
sample of the aryl iodide 11, which upon coupling with
phenylacetylene under the conditions described by Sonogashira8
and cleavage of the MOM group provided 13. The spectral
data of 13 revealed that this compound is nonidentical with the
naphthol 5c obtained from the reaction of complex 4a with diyne
8.
Scheme 4
The benzannulations of the naphthylcarbene complex 16 give
higher yields of monobenzannulated product with diyne 8 (Table
2) than do those of the phenyl complex 4 (Table 1). As was
the case with the phenyl complexes, the benzannulation with
the n-butyloxy complexes give higher yields than the methoxy
complexes. Excellent yields of the alkynylphenanthrol 19c can
be obtained for the reaction of complex 16b and the diphen-
ylbutadiyne 8. The reaction of the di-tert-butyldiyne 18 with
complex 16b gives mainly the cyclobutenone 20d, but the
diisopropyldiyne 17 gives exclusively the phenanthrol 19e but
in a much reduced yield. The formation of 19e from 1 equiv
of the diyne was accompanied by a 45% recovery of carbene
complex 16b. It is suspected that either polymerization or
oligomerization of the diyne is responsible for the incomplete
conversion observed for the reaction of diyne 17 with both
complexs 16a,b.
The formations of 19 and 20 were found to occur with the
same sense of regiochemical incorporation of the alkyne. This
was confirmed by a chemical correlation in which both
phenanthrol 19d and the cyclobutenone 20d were converted to
the quinone 21d; the former by oxidation with cerium(IV) and
the latter by thermolysis and then oxidation, as indicated in
Scheme 4. It has been previously observed5a,b that the formation
of cyclobutenone products is more likely for sterically hindered
alkynes and carbene complexes, and this is consistent with the
fact that, for the reactions of the naphthyl complex 16b,
significant cyclobutenone formation is seen only with the di-
(8) (a) Rossi, R.; Carpita, A.; Bellina, F. Org. Prepr. Proc. Int. 1995,
27, 129. (b) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett.
1975, 4467.

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2169
Scheme 5
Scheme 6
tert-butyldiyne 18, and little is seen with the diphenyldiyne 8
and the diisopropyldiyne 17.
It has been generally observed that alkenyl complexes will
give cleaner reaction mixtures in the benzannulation with simple
alkynes than do arylcarbene complexes.6b This was found to
be true for the cyclohexenyl complex 22 and the phenyl complex
4a in their reactions with the diphenyldiyne 8 (Table 1 and
Scheme 5). The reaction of the cyclohexenyl complex gave
good yields of the phenol 23, and no cyclobutenone was
detected. The yield of the phenol product was also higher for
the cyclohexenyl complex under similar conditions (44% for
4a vs 73% for 22). Another difference is that the yield of the
phenol 23 is not dependent on the concentration of the reaction,
whereas the yield of 5a fell from 44% to 23% when the
concentration was raised from 0.03 to 0.5 M. A similarity in
the two complexes is the solvent dependence on efficiency of
phenol formation. The yields of the phenol product drop for
both complexes when the reaction solvent is changed from THF
to benzene. In the case of the aryl complex 4a, it is not clear
whether this is due to a decrease in the rate of the reaction or
the formation of undetected side products since significant
amounts of carbene complex were recovered in the reaction with
benzene (Table 1). For the cyclohexenyl complex 22, however,
it appears that this is due to a solvent-induced change in the
product distribution, since the yield of 23 drops by a factor of
2, even though the reaction goes to completion. In the case of
the reaction of the cyclohexenyl complex 22 with diyne 8, we
were able to isolate the regioisomeric phenol 24. Based on the
isolated yields for each isomer, the regioselectivity for this
reaction is approximately 28:1. Upon oxidation with cerium-
(IV), both of the phenols 23 and 24 gave the quinone 25,
confirming their regioisomeric relationship.
Biaryls from the Sequential Benzannulation of 1,3-Diynes.
Benzannulation of the diphenyldiyne 8 with the first equivalent
of phenylcarbene complex 4a produced phenol and cyclobuten-
one products (Table 1), and benzannulation of the second
equivalent gives phenol, cyclobutenone, and indene products,
as shown in Scheme 6. A single regioisomer of each of the
three products was observed. Since the phenol product obtained
was not C2 symmetric, the regioisomeric structure 29 could be
ruled out as the product of the reaction. Formation of the
regioisomer 26 is consistent with the general observation that
alkynes are incorporated with the largest group of the alkyne
into the position adjacent to the phenol function.7 In this case,
while both substituents of the alkyne in 5a are aryl groups, the
naphthyl groups bears two ortho substituents and thus, as
expected, is incorporated into the position ortho to the phenol
in the last-formed naphthalene ring in 26. The regiochemistry
of cyclobutenone 27 was assigned by its thermal conversion to
the phenol 26. The regiochemistry of the indene 28 was
assigned on the assumption that it has the same regiochemistry
as the phenol and cyclobutenone. Indene products are well
established primary products from the reactions of carbene
complexes with alkynes, and their formation is favored with
polar solvents, increased electron density on the carbene
complex, decreased concentration, and the presence of aryl
groups on the alkyne.6 A slight dependence of the product
distribution on the concentration was seen, as indicated in
Scheme 6, with the fraction of the indenyl product the highest
at the lowest concentration in THF. The one attempt made in
benzene as solvent led to a dramatic drop in the mass balance
and to less than detectable amounts of 27 and 28. This
observation was not further pursued, although a considerable
amount of insoluble material was observed for this reaction.
Nonetheless, the biaryl 26 can be obtained in 42-46% overall
yield from the reaction shown in Scheme 6, since the cy-
clobutenone 27 can be thermally converted to the biaryl 26.The
second step of the sequential benzannulation of the (butyloxy)-
carbene complex 16b with diphenyldiyne 8 gives the indene
product 30 as the only significant product of the reaction, along
with a 30% recovery of the phenanthrylacetylene 19c. This is
despite the fact that the first step is highly efficient giving the
phenanthrol 19c in 82% yield from the reaction of complex 16b
with 1 equiv of diyne 8 (Table 2). This reaction of the butyloxy
complex 16b with the 4-(butyloxy)phenanthrol 19c is to be
compared with the reaction of the methoxy complex 4a with
the 4-methoxynaphthol 5a. The fact that the reaction of 16b
with 19c gives a greater preference for indene over phenol
compared to the reaction of 4a with 5a is consistent with
observations that increased steric hindrance on the carbene
complex and in the alkyne can lead to increased proportions of
indene products.1,5,6 With this in mind, the reaction of the
methoxycarbene complex 16a with the phenanthrylacetylene
19b was investigated, and it was found that, as expected, this
reaction gave an increased preference for phenol products
relative to the reaction of 16b with 19c (Scheme 7).
The synthesis of biaryls by the sequential double benzannu-
lation of the diyne 8 was more successful with the cyclohex-
enylcarbene complex 22 than with either the phenylcarbene
complex 4a or the naphthylcarbene complex 16a. The first step
gave the arylacetylene 23 in 73% yield, and the second gave
the biaryl 33 in 56% yield. The increased facility of the biaryl
synthesis from the cyclohexenyl complex 22 compared to the

2170 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
Scheme 7
Scheme 8
Scheme 9
aryl complexes 4a and 16a is consistent with the well-established
observation that the benzannulations of alkenyl complexes are
less likely than those of aryl complexes to give indene or
cyclobutenone side products.6b The yield of the bis-quinone
32, obtained upon an oxidative workup, increases with increas-
ing concentration, giving a 60% yield when the reaction is
carried out at 1.7 M in carbene complex. In this reaction, there
is not a significant solvent effect, since the reactions in THF
and benzene give yields that are within experimental error.
In contrast to the finding that the double-benzannulation of
diyne 8 with the cyclohexenyl complex 22 can be successfully
performed if each benzannulation is carried out separately
(Scheme 8), no success has been realized for the one-pot double
benzannulation. The reaction of diyne 8 with an excess of
carbene complex 22 (3 equiv) in THF at 1.2 M in 22 and at 66
°C in 9 h gave a 67% yield of the monobenzannulated product
23 and a 4% yield of the double benzannulated product 33
(Scheme 9). This reaction cannot be driven further. Upon
heating the reaction mixture at 70 °C for 60 h, the yield of the
monobenzannulated product 23 drops to 5%, but the yield of
the double benzannulated product 33 is still negligible (0.6%).
One possible explanation for this is that, prior to workup and
exposure to air, the monobenzannulated product exists as the
chromium tricarbonyl complex 34, which is much less reactive
to the second benzannulation than the noncomplexed naphthol
23. This is supported by TLC of the reaction mixture, which,
after 4 h at 66 °C, reveals the presence of mainly one yellow
compound, which has an Rf value different from that of 23. In
the isolation of 23, the reaction mixture is stirred in air prior to
chromatography; however, if the reaction mixture is opened and
directly loaded onto a silica gel column and quickly eluted, a
small portion of yellow compound can be obtained. While this
material is air sensitive with respect to conversion to 23, its 1H
NMR and IR spectra are consistent with the arene complex 34.
If the unreactivity of the arene complex 34 is the problem, then
a solution would involve the in situ decomplexation of 34. While
such a solution has not yet been found, this was attempted by
carrying out the reaction in the presence of 3 equiv (per Cr) of
tri-n-butylphosphine, which, after 10 h at 70 °C, gave only a
74% yield of 23 (along with <1.3% of regioisomer 24) and no
detectable amount of the double benzannulated product 33.
Biaryls from the One-Pot Intramolecular Double Benz-
annulation of 1,3-Diynes. Given that the inability to realize a
one-pot double benzannulation with diyne 8 with either the
phenylcarbene complex 4a or the cyclohexenyl complex 22 was
due to the sluggishness in the second benzannulation, consid-
eration was given to strategies involving bis-carbene complexes
of the type 35 since the second benzannulation in the reactions
of these complexes with diynes would be intramolecular. In
addition to providing a possible solution to the one-pot double
benzannulation of diynes, this strategy would also serve to
expand the scope of these reactions and provide access to
symmetrical biaryls of the type 36 and would thus be comple-
mentary to the intermolecular version, which as was seen above
gives unsymmetrical biaryls (Scheme 6). It is expected that
bis-carbene complexes of the type 35 would give the sym-
metrical biaryl 36 in favor of the unsymmetrical biaryl 37
(Scheme 10). Although meta-cyclophanes containing six atoms
in the bridge are known,9 it is expected that the strain inherent

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2171
Scheme 10
Scheme 11
in the meta-cyclophane 37 would be sufficient so as to lead to
the predominant production of the symmetric biaryl 36, which
does not contain a meta-cyclophane bridge. Finally, the strategy
of employing an intramolecular double benzannulation of a 1,3-
diyne with a bis-carbene complex offers an opportunity for an
asymmetric synthesis of biaryls with an induction in the
stereochemistry of the newly formed biaryl axis from a chiral
diol that is used to tether the bis-carbene complex.
Scheme 12
The bis-methylene-tethered phenyl-substituted carbene com-
plex 39 was prepared by the Connors method for the preparation
of alkoxy complexes from alcohols.10,15 The mixed anhydride
from (hydroxyphenyl)carbene complex and acetic acid was
prepared by the treatment of the metal acylate 38 with acetyl
bromide. This anhydride was used to doubly acylate ethylene
glycol, which gave the bis-carbene complex 39 in 79% yield.
The reaction of the bis-carbene complex 39 with 0.9 equiv of
the diphenylbutadiyne 8 gave two predominant products, which
were identified as the desired 2,2′-binaphthol 40 and the
indenylnaphthalene 41. The latter resulted from the failure of
carbon monoxide to insert in one of the annulation steps. Based
on the results shown in Table 1 and Scheme 6, it is likely that
the naphthalene unit in 41 is constructed in the first annulation
followed by the formation of the indene unit in the second. The
indenylnaphthalene 41 was obtained as one diastereomer, but
the relative stereochemistry was not determined. The data in
Scheme 11 reveal that the partition between the binaphthalene
40 and the naphthylindene 41 is dependent on the concentration
and the temperature, although the low mass balance observed
for these reactions somewhat obscures the significance of these
observations. Higher concentration favors 40 over 41, consistent
with the general observations seen for reactions with simple
alkynes, where higher concentration favors the incorporation
of carbon monoxide-inserted products.6ab,11 In addition, it can
be seen that higher temperature shifts the partition in favor of
41, which is also consistent with previous studies on simple
alkynes which revealed that higher temperatures favor non-CO-
inserted products.6a
either of the two products seen with the unsubstituted ethylene-
tethered complex 39 (Scheme 11). Instead, this reaction
produced as the predominant product of the reaction the indenyl-
substituted cyclobutenone 43, which was obtained as a single
diastereomer in 22% yield. The relative stereochemistry in 43
was not assigned. It is not known why the presence of the
methyl groups in complex 42 causes such a dramatic change in
the reaction course. The fact that it is not known if the
cyclobutenone or the indene ring is formed in the first annulation
step makes it difficult to consider how the presence of the methyl
groups may affect the various intermediates that are likely
involved in the mechanism of this reaction and thus the product
distribution from this reaction.
The bis-carbene complex 44 was prepared in optically pure
form from (2R,3R)-butane-2,3-diol to probe the degree to which
the stereochemical information present in the chiral diol can be
used to induce a specific stereochemistry in the axis of chirality
generated when the two arene rings of the 2,2′-binaphthol 46
are generated from the double benzannulation of diyne 8. The
outcome of the reaction of the chiral bis-carbene complex 44
with diyne 8 was quite different from that of its meso
diastereomer 42. In fact, the reaction of complex 44 gave an
equal mixture of the 2,2′-binaphthol 46 and the indenyl
naphthalene 47, which is nearly identical to the outcome of the
reaction of the unsubstituted tethered complex 39 (Scheme 11).
This reaction also produced a 29% yield of the dihydrodioxane
48, which was found in a control experiment (51%) to result
from the thermal decomposition of the starting carbene complex
44. Such thermal dimerizations of carbene complexes are
known for both inter- and intramolecular situations.12 A single
diastereomer of the 2,2′-binaphthol 46 was formed in this
reaction as determined by 1H and 13C NMR. As will be shown
below, it has been determined that the 2R,3R configuration in
the diol led to the selective formation of the S-configuration of
Two bis-carbene complexes derived from substituted glycols
were investigated, and the results are summarized in Schemes
12 and 13. Complex 42 was prepared from the meso-2,3-
butanediol in 51% yield, as indicated in Scheme 12. The
reaction of complex 42 with the diphenyldiyne 8 did not give
(9) (a) Hirano, S.; Hiyama, T.; Fujita, S.; Nozaki, H. Chem. Lett. 1972,
707. (b) For citations to the literature, see: Nishimura, J.; Okada, Y.;
Inokuma, S.; Nakamura, Y.; Gao, S. R. Synlett 1994, 884.
(10) Connor, J. A.; Jones, E. M. J. Chem. Soc. A 1971, 3368.
(11) (a) Harvey, D. F.; Grenzer, E. M.; Gantzel, P. K. J. Am. Chem.
Soc. 1994, 116, 6719. (b) Gross, M. F.; Finn, M. G. J. Am. Chem. Soc.
1994, 116, 10921.

2172 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
Scheme 13
Scheme 14
this reaction led to oxidation to the 2,2′-naphthoquinone 50 in
44% yield. The optical rotation of the naphthoquinone 50
obtained from 49 was [R]D ) -76.4°, which represents material
that is only 28% optically pure, assuming that no optical activity
is lost when 51 is converted to 50. The 2,2′-binaphthol 46
1
appears to be a single diastereomer by H and 13C NMR, and
thus it is thought that the incomplete optical purity is due to
partial racemization caused by the treatment with ethanethiol
and aluminum chloride. Support for this possibility comes from
a control experiment performed on optically pure bis-naphtho-
quinone 50. When a sample of 50 ([R]D ) 275.5°) was
subjected to aluminum chloride and ethanethiol under the
reaction conditions, a material was recovered which was not
the bis-naphthoquinone 50. The structure of this compound was
not determined but could have been the hydroquinone since,
when this material was briefly treated with aqueous ceric
ammonium nitrate, the bis-quinone 50 was obtained with a 51%
recovery and had an optical rotation of 40.8°, which corresponds
to 15% optical purity. Control experiments showed that no loss
of optical purity occurs upon treatment of the bis-naphtho-
quinone 50 with ceric ammonium nitrate. These experiments
thus show the (2R,3R)-diol unit in the bis-carbene complex 44
will induce the formation of an S-configuration of the biaryl
axis in the 2,2′-binaphthol 46. The induction in the formation
of the biaryl axis in 46 produces exclusively a single compound
the chiral axis in the 2,2′-binaphthol 46. The indenylnaphthalene
47 was also obtained as a single diastereomer; however, the
relative stereochemistry was not assigned. The reaction of
complex 44 with diyne 8 has been attempted only with the
conditions indicated in Scheme 13. Further optimization
experiments will await the development of improved methods
for the synthesis of chiral bis-carbene complexes of the type
44.
The configuration of the biaryl chiral axis in the 2,2′-
binaphthol 46 was determined by chemical correlation with the
known optically pure 2,2′-binaphthol 5113 via the 2,2′-binaph-
thoquinone 50. Oxidation of the optically pure (R)-(+)-
enantiomer of the binaphthol 51 with salcomine and air gave
the bis-naphthoquinone 50, which had a specific rotation of [R]D
) 275.5°. The 2,2′-binaphthol 46 was inadvertently converted
to the bis-naphthoquinone 50 as indicated in Scheme 14. The
2,2′-binaphthol 46 was first converted to the bis-acetate 49 by
treatment with acetic anhydride, DMAP, and triethylamine in
71% yield. A direct chemical correlation was planned by the
conversion of the bis-acetate to the binaphthol 51 with aluminum
chloride and ethanethiol, which is known to effect transforma-
tions related to that indicated by 49 to 51.13 Quite unexpectedly,
1
(R,R,S-configuration) as indicated by H and 13C NMR spec-
troscopy, but since an authentic sample of the (R,R,R)-
diastereomer of 46 is not available, a precise quantitation of
the degree of induction cannot be determined.
The selective formation of 46 with a chiral axis with the
S-configuration from the (2R,3R)-butane-2,3-diol-derived car-
bene complex 44 was predicted from a consideration of models.
The Chem3D model of 46, which is produced when the S-biaryl
axis is generated from the carbene complex 44 that is derived
from (2R,3R)-butane-2,3-diol, is shown in Chart 1. This is to
be compared with the model of the diastereomer 52, which
would be generated in a situation where the S-biaryl axis was
generated from a carbene complex analogous to 44 which was
derived from (2S,3S)-butane-2,3-diol. From these models it can
be seen that the S-biaryl axis should be preferentially formed
from the (2R,3R)-diol auxiliary rather than from a (2S,3S)-diol
auxiliary. In the model of 46, it can be seen that the methyl
groups on the ethylene bridge between the oxygens are directed
away from the binaphthyl unit, and this would be a more
favorable situation than that for 52, where the methyl groups
(12) Several intermolecular examples have been described since the
original report by Fischer: (a) Fischer, E. O.; Heckel, B.; Do¨tz, K. H.;
Muller, J.; Merner, H. J. J. Organomet. Chem. 1969, 16, P29. For
intermolecular examples, see: (b) Huy, H. T.; Lefloch, P.; Louis, J. M.;
Fetizon, M. J. Organomet. Chem. 1986, 311, 79. (c) Macomber, D. W.;
Hung, M. H.; Verma, A. G. Organometallics 1988, 7, 2072.
(13) Bao, J.; Wulff, W. D.; Dominy, J. B.; Fumo, M. J.; Grant, E. B.;
Rob, A. C.; Whitcomb, M. C.; Yeung, S.-M.; Ostrander, R. L.; Rheingold,
A. L. J. Am. Chem. Soc. In press.

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2173
NMR data were obtained either on a University of Chicago-built DS-
1000 500 MHz instrument or on a General Electric QE-300 300 MHz
instrument. Carbon-13 spectra were obtained on the QE-300 instrument
at 75 MHz. GPC analyses were performed on a Varian Star 3600
instrument. High-resolution mass spectra were recorded on a VG 70-
250 instrument. Elemental analyses were done by Galbraith Labora-
tories in Knoxville, TN. Optical rotations were obtained on a Perkin-
Elmer 141 polarimeter at a wavelength of 589 nm (sodium D line)
using 1.0 dm cells. Specific rotations, [R]D, are reported in degrees
per decimeter at 25 °C, and the concentration (c) is given in grams per
100 mL.
Chart 1
Reaction of Phenyl(methoxy)chromium Carbene Complex 4a
with 1,4-Diphenyl-1,3-butadiyne (8). A solution of 0.265 g (0.85
mmol) of 1,4-diphenyl-1,3-butadiyne (8) and 0.172 g (0.85 mmol) of
phenyl(methoxy)chromium carbene complex 4a14 in 28.3 mL of THF
(0.03 M in 4a) was introduced into a 100 mL single-necked flask that
was modified by the replacement of the 14/20 joint with a threaded
high-vacuum stopcock. The resulting solution was deoxygenated by
the freeze-pump-thaw method (three cycles) and backfilled with
argon, and then the stopcock was closed at 25 °C and the flask placed
in a 60 °C oil bath for 24 h. After removal of the solvent, the two
products were separated from the crude reaction mixture on silica gel
by elution with a 1:1:8 mixture of ether/CH2Cl2/hexane and then with
a 1:1 mixture of CHCl3/hexane to give 6a (0.0622 g, 0.18 mmol, 21%)
and 5a (0.0593 g, 0.17 mmol, 20%). Spectral data for 5a: Rf ) 0.37
1
(1:1 CHCl3/hexane); white solid, mp 90-92 °C; H NMR (CDCl3) δ
4.14 (s, 3 H), 5.42 (s, 1 H), 7.15 (m, 2 H), 7.22 (m, 3 H), 7.48 (m, 1
H), 7.53 (m, 6 H), 8.20 (d, 1 H, J ) 7.6 Hz), 8.21 (d, 1 H, J ) 7.4
Hz); 13C NMR (CDCl3) δ 62.01, 85.68, 97.90, 112.35, 122.12, 122.76,
123.45, 124.99, 126.67, 126.90, 127.66, 127.99, 128.08, 128.17, 128.46,
129.11, 130.89, 131.14, 134.82, 144.23, 152.15; IR (neat) 3538 s, 3057
m, 2929 s, 2846 m, 1586 m, 1492 m, 1443 m, 1369 s, 1296 s, 1211 m,
1144 m, 1064 s, 1028 m, 1003 m, 829 w, 757 s, 690 s cm-1
spectrum, m/z, (relative intensity) 350 M+ (100), 335 (45), 318 (12),
307 (45), 289 (22), 276 (35), 202 (23), 138 (16), 105 (14), 97 (15);
high-resolution EI MS calcd for C25H18O2 m/z 350.1307, measd
350.1303. Anal. Calcd for C25H18O2: C, 85.69; H, 5.18. Found: C,
85.46; H, 5.21. Spectral data for 6a: Rf ) 0.41 (1:1:8 CH2Cl2/ether/
hexane); yellow oil; 1H NMR (CDCl3) δ 3.59 (s, 3 H), 7.33-7.51 (m,
9 H), 7.60-7.66 (m, 4 H), 8.14-8.17 (m, 2 H); 13C NMR (CDCl3) δ
53.76, 81.84, 102.00, 117.08, 121.54, 126.44, 128.02, 128.30, 128.51,
128.55, 128.70, 128.83, 130.52, 130.77, 132.26, 136.48, 150.68, 151.89,
192.93; IR (neat) 3062 w, 3030 w, 2953 w, 2931 w, 2184 m, 1758 s,
1586 w, 1495 m, 1442 m, 1360 m,1222 w, 1145 w, 1099 w, 1051 w,
1026 w, 756m, 689s cm-1; mass spectrum, m/z (relative intensity) 350
M+ (100), 335 (41), 307 (46), 289 (16), 279 (24), 202 (33), 105 (35),
77 (27); high-resolution EI MS calcd for C25H18O2 m/z 350.1307, measd
350.1321.
The outcome of this reaction under a variety of conditions is
summarized in Table 1. The deoxygenation procedure is not necessary,
as indicated by the data in entries 4-6. These reactions were carried
out by introduction of the reagents into an argon-flushed flask equipped
with a reflux condensor. The regiochemistry of the cyclobutenone was
shown by chemical correlation to be the same as that determined for
the naphthol 5a. A solution of the cyclobutenone 6a (0.039 g, 0.11
mmol) in 15 mL of hexane was heated in a sealed flask at 82 °C for
17 h under nitrogen. After purification by flash chromatography with
a 1:1:10 mixture of ether/CH2Cl2/hexane, 0.038 g (0.11 mmol, 97%)
of naphthol 5a was isolated.
generate close contacts with the bottom periphery of the
binaphthol unit.
; mass
This work has demonstrated the viability of a new approach
to the synthesis of biaryls via the double benzannulation of
conjugated 1,3-butadiynes with chromium carbene complexes.
In intermolecular reactions of diynes with 2 equiv of carbene
complex, the two benzannulations must be carried out sequen-
tially rather than concurrently. The first benzannulation occurs
with high regioselectivity and with the formation of few side
products for all of the complexes examined, which included
phenyl, naphthyl, and cyclohexenyl complexes. The second
benzannulation also occurs with high regioselectivity for all
complexes. However, the reactions of the phenyl and naphthyl
complexes (but not cyclohexenyl) occur with the formation of
five-membered-ring non-CO-inserted products as serious side
reactions. These side products can be suppressed to a degree
by controlling the concentration and the steric bulk of the
carbene complex and the diyne. The intramolecular double
benzannulation reactions of bis-carbene complexes with diynes
allows for the two benzannulations to be performed concurrently.
Additional advantages of the intramolecular reactions include
the generation of biaryls with symmetry complementary to that
possible with the intermolecular reactions and include the fact
that this biaryl synthesis can be rendered asymmetric by
incorporating a chiral diol in the tether in the bis-carbene
complexes. The success obtained in this work in establishing
the viability of a new approach to the asymmetric synthesis of
biaryls should stimulate the further consideration and investiga-
tions of the reaction of carbene complexes with 1,3-butadiynes.
The reaction of diyne 8 with 3 equiv of carbene complex 4a in THF
(0.06 M in 4a) at 110 °C for 14 h gave a complex mixture of products
in which none was significantly prominent. In light of the formation
of complex 34 from the reaction of complex 22 and the resistance of
34 to further reaction with 22, the reaction of 4a with diyne 8 was
performed in the presence of butylphosphine. A mixture of 0.055 g
(0.272 mmol) of 1,4-diphenyl-1,3-butadiyne, 0.255 g (0.817 mmol) of
Experimental Section
All reagents were obtained from commercial suppliers and used
without further purification unless otherwise indicated. Tetrahydro-
furan, ether, and benzene were distilled from benzophenone ketyl under
nitrogen. Cerium(IV) oxidation employed a 0.5 M solution of ceric
ammonium nitrate (CAN) in 0.1 M aqueous nitric acid. Dichlo-
romethane and hexane were distilled from calcium hydride. Proton
(14) Complex 4a was prepared as described by the literature procedure
with methyl triflate as the alkylating agent. (a) Fischer, E. O.; Maasbo¨l, A.
Chem. Ber. 1967, 100, 2445. (b) Fischer, E. O.; Kreiter, C. G.; Kollmeier,
H. J.; Muller, J.; Fischer, R. D. J. Organomet. Chem. 1971, 28, 237.
(15) Dumas, S.; Lastra, E.; Hegedus, L. S. J. Am. Chem. Soc. 1995, 117,
3368.

2174 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
phenyl(methoxy)chromium carbene complex 4a, and 0.61 mL (2.45
mmol) of tri-n-butylphoshine in 136 mL of THF was deoxygenated
and allowed to react at 80 °C for 23 h as described in the procedure
above. The resulting solution was degassed three times and was put
in an 80 °C oil bath for 23 h. The two major products produced were
separated on silica gel by elution with a 1:9 mixture of EtOAc/hexane
and then with a 1:1 mixture of CH2Cl2/hexane to give 5a (0.020 g,
0.057 mmol, 21%) and methoxy benzoate (8 mg, 0.059 mmol, 22%).
on unrecovered 4b). Spectral data for 5b: Rf ) 0.29 (1:15 EtOAc/
hexane); white solid, mp 73-74 °C; 1H NMR (CDCl3) δ 1.06 (t, 3 H,
J ) 7.4 Hz), 1.66-1.74 (m, 2 H), 1.98-2.02 (m, 2 H), 4.31 (t, 2 H, J
) 6.5 Hz), 5.46 (s, 1 H), 7.14-7.17 (m, 2 H), 7.26-7.28 (m, 3 H),
7.52-7.62 (m, 7 H), 8.18-8.28 (m, 2 H); 13C NMR (CDCl3) δ 14.09,
19.57, 32.68, 74.84, 86.13, 97.63, 112.49, 122.24, 122.69, 123.56,
124.98, 126.61, 126.78, 128.00, 128.18, 128.36, 128.42, 129.09, 130.91,
131.07, 134.93, 144.04, 151.45 (1 aryl C not located); IR (neat) 3544
bs, 3057 w, 2957 s, 2929 s, 2872 m, 1597 w, 1587 m, 1493 m, 1442
m, 1393 m, 1356 m, 1309 m, 1295 s, 1212 m, 1146 m, 1146 m, 1064
s, 1029 m, 972 m, 848 w, 755 s, 703 m, 690 s cm-1; mass spectrum,
m/z (relative intensity) 392 M+ (100), 336 (90), 318 (14), 307 (42),
289 (17), 276 (16), 231 (12), 202 (23), 105 (10); high-resolution EI
MS calcd for C28H24O2 m/z 392.1776, measd 392.1809. Anal. Calcd
for C28H24O2: C, 85.68; H, 6.16. Found: C, 85.00; H, 6.18.
Preparation of Phenyl(n-butyloxy)carbene Complex 4b. To a
solution of 1.33 g (3.58 mmol) of the tetramethylammonium metalate
3816 in 28 mL of dichloromethane at -20 °C was added 0.265 mL
(3.58 mmol) of acetyl bromide under nitrogen. After the mixture was
stirred at -20 °C for 1 h, 0.328 mL (3.58 mmol) of butanol was added,
and the resulting solution was stirred for an additional 2 h. The red
mixture was poured into an aqueous saturated NaHCO3 solution. The
organic layer was washed with water and brine and then dried with
anhydrous MgSO4. The solvent was removed, and the red residue was
loaded onto a silica gel column and eluted with a 1:1:30 mixture of
ether/CH2Cl2/hexane (Rf ) 0.61) to give 1.18 g (3.33 mmol, 93%) of
The regiochemistry of cyclobutenone 6b was shown by chemical
conversion to be the same as that determined for the naphthol 5b. The
cyclobutenone 6b (0.0291 g, 0.074 mmol) was dissolved in 10 mL of
hexane and heated at 80 °C for 17 h under argon. After removal of
the solvent, the residue was loaded onto a silica gel and eluted with a
1:9 mixture of EtOAc/hexane to give 0.0251 g (0.064 mmol, 86%) of
1
complex 4b as a red oil. Spectral data for 4b: H NMR (CDCl3) δ
1.01 (t, 3 H, J ) 7.2 Hz), 1.54-1.59 (m, 2 H), 1.95-2.05 (m, 2 H),
4.81 (s, 2 H), 7.20 (s, 2 H), 7.34-7.37 (m, 3 H); 13C NMR (CDCl3) δ
13.62, 19.18, 31.51, 81.02, 122.61, 128.14, 129.99, 153.68, 216.23,
224.27, 349.01; IR (neat) 3037 w, 2964 m, 2938 w, 2877 w, 2061 s,
1948 s, 1932 s, 1462 w, 1441 w, 1382 w, 1272 m, 1234 m, 1207 m,
1
5b as a white solid. This material was found to be identical by H
NMR and TLC to the major product from the reaction of complex 4b
with 1,4-diphenyl-1,3-butadiyne.
1168 m, 968 w, 938 w, 908 w, 877 w, 760 w, 656 s, 621 m cm-1
;
Preparation of Phenyl[(methoxymethyl)oxy]carbene Complex 4c.
To a solution of chromium hexacarbonyl (5.15 g, 23.3 mmol) in 100
mL of ether at 0 °C was added phenyllithium (25.7 mmol as a 1.8 M
solution in a 7:3 mixture of cyclohexane/ether). After 0.5 h, the ice
bath was removed, and the solution was allowed to stir for an additional
1 h. To this solution was then added chloromethyl methyl ether (5.32
mL, 70.0 mmol) at 0 °C. The solution was stirred at 0 °C for 1 h and
at 25 °C for 10 min and then washed twice with saturated aqueous
sodium bicarbonate. After removal of the solvent from the organic
layer, the product was purified by flash chromatography with a 1:1:16
mixture of ether/CH2Cl2/hexane. Complex 4c (3.70 g, 0.11 mmol, 46%)
was isolated as a red oil. Spectral data for 4c: Rf ) 0.37 (1:1:16 ether/
CH2Cl2/hexane); 1H NMR (CDCl3) δ 3.71 (s, 3 H), 5.75 (s, 2 H), 7.24-
7.27 (m, 2 H), 7.40-7.42 (m, 3 H); 13C NMR (CDCl3) δ 58.40, 103.37,
122.43, 128.19, 130.14, 153.41, 215.90, 224.37, 350.62; IR (neat) 3059
w, 3012 w, 2940 w, 2832 w, 2063 s, 1933 s, 1726 w, 1441 w, 1259 w,
1210 w, 1149 m, 1067 m, 930 m, 897 m, 837 w, 762 w, 697 m, 652
s cm-1; mass spectrum, m/z (relative intensity) 342 M+ (20), 314 (36),
286 (28), 258 (42), 230 (90), 202 (94), 172 (88), 157 (93), 129 (100),
105 (92), 80 (95); high-resolution EI MS calcd for C14H10O7Cr m/z
341.9832, measd 341.9858.
mass spectrum, m/z, (relative intensity) 354 M+ (1), 326 (1), 298 (1),
272 (1), 242 (1), 220 (36), 123 (53), 105 (96), 80 (100), 77 (44).
Reaction of Phenyl(n-butyloxy)carbene Complex 4b with Diphen-
yl-1,3-butadiyne (8). The reaction of carbene complex 4b (0.293 g,
0.83 mmol) and 1,3-butadiyne 8 (0.167 g, 0.83 mmol) in 27 mL of
THF was carried as described for the reaction 4a with 8 at 50 °C for
17 h. The crude reaction mixture was oxidized by stirring with 9.9
mL (0.5 M) of CAN solution for 45 min at 25 °C. The resulting mixture
was diluted with ether, and the organic layer was washed with water,
aqueous saturated sodium bicarbonate, water and brine. The two
products, quinone 7 (0.1465 g, 0.44 mmol, 53% as yellow solid, mp )
140-141 °C, Rf ) 0.18) and cyclobutenone 6b (0.0677 g, 0.17 mmol,
21% as yellow oil, Rf ) 0.41), could be isolated from the concentrate
after flash chromatography on silica gel with a 1:1:16 mixture of ether/
1
CH2Cl2/hexane. Spectral data for 6b: H NMR (CDCl3) δ 0.94 (t, 3
H, J ) 7.3 Hz), 1.44-1.52 (m, 2 H), 1.71 (pentet, 2 H, J ) 6.9 Hz),
3.72-3.80 (m, 2 H), 7.35-7.50 (m, 9 H), 7.61-7.67 (m, 4 H), 8.16-
8.19 (m, 2 H); 13C NMR (CDCl3) δ 13.82, 19.24, 31.98, 65.66, 81.96,
101.62, 116.93, 121.59, 126.41, 127.99, 128.17, 128.44, 128.69, 128.81,
128.96, 130.45, 130.68, 132.21, 136.92, 151.36, 151.49, 193.56; IR
(neat) 3082 w, 3061 m, 3032 w, 2958 s, 2932 s, 2872 s, 2184 s, 1760
vs, 1718 w, 1611 m, 1588 m, 1496 s, 1448 s, 1359 s, 1222 m, 1177 s,
Reaction of Phenyl[(methoxymethyl)oxy]carbene Complex 4c
with Phenylacetylene. A 250 mL single-necked flask equipped with
a high-vacuum threaded stopcock was charged with complex 4c (3.51
g, 10.3 mmol), phenylacetylene (1.13 mL, 10.4 mmol), and 51 mL of
THF to give a solution that was 0.2 M in complex 4c. The solution
was deoxygenated by the freeze-thaw method (three cycles) and then
backfilled with argon at 25 °C. The flask was sealed at 25 °C and
placed in a 48 °C oil bath for 12 h. Upon removal of the solvent and
chromatography on silica gel with a 1:15 mixture of EtOAc/hexane, a
total of 1.7972 g of an 8:1 mixture of two compounds was obtained,
identified as 2-phenylnaphthyl-1,4-hydroquinone 4-methoxymethyl ether
56 and 2-phenylnaphthyl-1,4-hydroquinone 1,4-bis(methoxymethyl)
ether 57. This mixture of compounds was dissolved in 45 mL of THF
and reacted with sodium hydride (1.67 g, 42 mmol as a 60% dispersion)
and dimethyl sulfate (5.46 mL, 58 mmol) under nitrogen at 0 °C for
2.5 h. The reaction was quenched with saturated aqueous HaHCO3,
and the organic layer was washed twice with water and stripped of
solvents. The two products were separated by flash chromatography
with a 1:1:16 mixture of CH2Cl2/ether/hexane to give 1.2988 g (4.41
mmol, 43%) of naphthalene 9 as a white solid and 0.1836 g (0.57 mmol,
5.5%) of the bis-ether 57. In a separate experiment at 0.1 M in 4c and
with 2 equiv of alkyn, naphthalene 9 was obtained in 58%, yield and
none of the bis-ether 57 was detected. Spectral data for 9: Rf ) 0.47
(1:9 EtOAc/hexane); mp ) 104-105 °C; 1H NMR (CDCl3, 500 MHz)
δ 3.52 (s, 3 H), 3.53 (s, 3 H), 5.35 (s, 2 H), 7.08 (s, 1 H), 7.32 (t, 1 H,
J ) 7.6 Hz), 7.41 (t, 2 H, J ) 7.5 Hz), 7.47 (t, 1 H, J ) 7.2 Hz), 7.52
1098 m, 1055 m, 1026 m, 938 w, 812 w, 773 m, 756 w, 690 s cm-1
;
mass spectrum, m/z (relative intensity) 392 M+ (7), 336 (11), 335 (12),
308 (8), 275 (10), 220 (15), 203 (17), 202 (76), 129 (22), 105 (100),
77 (52); high-resolution EI MS calcd for C28H24O2 m/z 392.1776, measd
392.1796. Anal. Calcd for C28H24O2: C, 85.68; H, 6.16. Found: C,
86.45; H, 5.94. Spectral data for 7: 1H NMR (CDCl3) δ 7.30-7.41
(m, 5 H), 7.50-7.55 (m, 3 H), 7.58-7.64 (m, 2 H), 7.76-7.82 (m, 2
H), 8.16-8.24 (m, 2 H); 13C NMR (CDCl3) δ 84.39, 106.25, 122.04,
126.59, 126.93, 127.65, 128.35, 129.48, 129.69, 130.40, 131.78, 132.22,
133.01, 133.77, 134.13, 148.46, 181.78, 183.42 (two carbons not
located); IR (neat) 3068 w, 2197 m, 1668 s, 1654 s, 1595 m, 1495 w,
1442 w, 1354 m, 1324 w, 12987 s, 1243 w, 1208 w, 1143 w, 1071 w,
961 w, 841 w, 758 s, 716 s, 690 s cm-1; mass spectrum, m/z (relative
intensity) 334 M+ (100), 306 (25), 278 (15), 277 (18), 276 (32), 151
(13), 104 (14), 76 (20); high-resolution EI MS calcd for C24H14O2 m/z
334.0994, measd 334.0999. Anal. Calcd for C24H14O2: C, 86.21; H,
4.22. Found: C, 85.98; H, 5.14.
The reaction was repeated at 0.03 M in 4b and heated at 70 °C for
24 h. The crude reaction mixture was directly loaded onto a silica gel
column without an oxidative workup with CAN to give a 61% yield
of the naphthol 5b upon elution from silica gel with a 1:1:16 mixture
of ether/CH2Cl2/hexane. As indicated in Table 1, the reaction under
the same conditions in benzene gave a 31% yield of 5b (40% based
on unrecovered 4b) and in hexane gave a 25% yield of 5b (40% based
(16) Fischer, E. O.; Maasbol, A. Chem. Ber. 1967, 100, 2445.

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2175
(t, 1 H, J ) 7.2 Hz), 7.65 (d, 2 H, J ) 7.3 Hz), 8.14 (d, 1 H, J ) 8.4
Hz), 8.21 (d, 1 H, J ) 8.2 Hz); 13C NMR (CDCl3, 75 MHz) δ 56.26,
61.16, 95.25, 110.66, 122.10, 122.39, 125.72, 126.48, 126.65, 127.12,
128.31, 129.22, 129.43, 138.77, 147.72, 149.30 (1 C not located); IR
(neat) 3057 w, 2992 w, 2931 w, 2828 w, 1595 m, 1498 w, 1460 w,
1444 w, 1366 s, 1353 m, 1230 w, 1149 s, 1101 m, 1060 s, 989 s, 962
m, 926 w, 760 m, 698 m cm-1; mass spectrum, m/z (relative intensity)
294 M+ (100), 280 (17), 264 (26), 249 (98), 235 (36), 206 (58), 189
(90), 178 (85), 165 (18), 152 (27), 115 (28), 105 (88), 76 (87); high-
resolution EI MS calcd for C19H18O3 m/z 294.1256, measd 294.1285.
Spectral data for 56: Rf ) 0.30 (1:9 EtOAc/hexane); 1H NMR (CDCl3)
δ 3.52 (s, 3 H), 5.29 (s, 2 H), 5.54 (s, 1 H), 6.98 (s, 1 H), 7.36-7.48
(m, 7 H), 8.17-8.21 (m, 2 H); 13C NMR (CDCl3) δ 56.17, 95.60,
110.53, 120.50, 121.73, 122.36, 125.18, 126.01, 126.04, 126.56, 127.85,
129.37, 129.50, 137.58, 142.62, 146.78; IR (neat) 3542 m, 3058 w,
2955 w, 2901 w, 1631 w, 1598 m, 1497 w, 1458 m, 1446 w, 1423 w,
1387 m, 1297 m, 1250 w, 1229 m, 1210 w, 1146 s, 1101 m, 1057 s,
973 s, 920 w, 855 w, 760 s, 703 m cm-1; mass spectrum, m/z (relative
intensity) 280 M+ (90), 250 (42), 235 (100), 207 (26), 189 (40), 178
(97), 165 (20), 149 (27), 105 (91), 77 (92); high-resolution EI MS calcd
for C18H16O3 m/z 280.1099, measd 280.1148. Spectral data for 57: Rf
on silica gel with a 1:1:8 mixture of ether/CH2Cl2/hexane to give 0.142
g (0.36 mmol) of 58, the methoxymethyl ether of 13, as yellow oil in
100% yield. Spectral data for 58: Rf ) 0.33 (1:1:8 ether/CH2Cl2/
hexane); 1H NMR (CDCl3) δ 3.50 (s, 3 H), 3.71 (s, 3 H), 5.48 (s, 2 H),
7.11-7.12 (m, 2 H), 7.20-7.21 (m, 3 H), 7.39 (t, 1 H, J ) 7.5 Hz),
7.45 (t, 2 H, J ) 7.4 Hz), 7.52-7.54 (m, 4 H), 8.10-8.12 (m, 1 H),
8.21-8.23 (m, 1 H); 13C NMR (CDCl3) δ 58.12, 61.30, 86.16, 97.98,
100.28, 113.41, 122.63, 122.79, 123.31, 126.72, 127.34, 127.36, 127.70,
128.17, 128.22, 128.77, 128.98, 130.62, 131.08, 132.28, 136.58, 149.62,
152.16; IR (neat) 3058 m, 2993 m, 2932 m, 2828 m, 2250 w, 1948 w,
1597 w, 1583 m, 1492 m, 1442 m, 1411 w, 1351 m, 1308 w, 1209 w,
1159 m, 1062 m, 989 m, 931 m, 774 m, 690 m cm-1; mass spectrum,
m/z (relative intensity) 394 M+ (60), 375 (33), 362 (42), 347 (100),
334 (24), 305 (45), 293 (54), 276 (48), 262 (88), 248 (32), 219 (42),
189 (52), 134 (27), 105 (37); high-resolution EI MS calcd for C27H22O3
m/z 394.1569, measd 394.1571.
To a solution of 58 (0.156 g, 0.40 mmol) in 2 mL of ether was
added 10 mL of methanol and 0.1 mL of 6 N aqueous HCl. The
solution was stirred at 25 °C for 16 h. Extraction with ether and flash
chromatography on silica gel with a 1:15 mixture of EtOAc/hexane
gave 0.1021 g (0.29 mmol, 80% for two steps) of 13 as an off-white
solid. The phenol 13 has different spectral data than 5a obtained from
the reaction of phenyl(methoxy)chromium carbene 4a with 1,4-
diphenyl-1,3-diyne (8). Spectral data for 13: light yellow solid, mp
1
) 0.42 (1:1:8 CH2Cl2/ether/hexane); H NMR (CDCl3) δ 3.19 (s, 3
H), 3.55 (s, 3 H), 4.77 (s, 2 H), 5.38 (s, 2 H), 7.11 (s, 1 H), 7.35-7.67
(m, 7 H), 8.20-8.28 (m, 2 H); 13C NMR (CDCl3) δ 56.25, 57.46, 95.05,
99.68, 110.41, 122.05, 122.48, 125.71, 126.31, 126.72, 128.30, 129.49,
129.78, 129.77, 130.36, 139.17, 144.24, 149.50; IR (neat) 3061 w, 2933
w, 2825 w, 1596 m, 1498 w, 1444 w, 1362 s, 1229 w, 1148 s, 1083 w,
1059 s, 970 s, 761 m, 698 m cm-1; mass spectrum, m/z (relative
intensity) 324 M+ (34), 292 (72), 247 (100), 205 (27), 189 (22), 161
(95), 129 (52), 105 (20), 91 (18), 77 (22); high-resolution EI MS calcd
for C20H20O4 m/z 324.1362, measd 324.1317.
1
) 143-144 °C; Rf ) 0.42 (1:9 EtOAc/hexane); H NMR (CDCl3) δ
3.46 (s, 3 H), 6.39 (s, 1 H), 7.21 (br s, 5 H), 7.36 (t, 1 H, J ) 7.3 Hz),
7.43 (t, 2 H, J ) 7.4 Hz), 7.48 (t, 1 H, J ) 7.8 Hz), 7.52 (t, 1 H, J )
7.1 Hz), 7.57 (d, 2 H, J ) 7.5 Hz), 8.07 (d, 1 H, J ) 8.2 Hz), 8.22 (d,
1 H, J ) 8.2 Hz); 13C NMR (CDCl3) δ 61.27, 83.49, 100.03, 103.63,
122.37, 122.57, 122.71, 123.44, 126.06, 127.41, 127.72 (2 C), 128.32,
128.43, 129.03, 130.34, 130.45, 131.06, 136.47, 146.57, 150.48 (1 aryl
C not located); IR (neat) 3494 m, 3057 w, 2932 w, 2841 w, 1596 w,
1587 w, 1492 m, 1443 m, 1392 w, 1370 m, 1321 m, 1290 w, 1203 w,
Preparation of Naphthyl Iodide 11 by Metalation of Naphthalene
9. To a solution of 9 (0.791 g, 2.69 mmol) in 20 mL of ether at -78
°C was added butyllithium (4.03 mmol as a 1.6 M solution in hexane).
After 5 min, the solution was allowed warm to 25 °C for 12 h. The
solution was cooled to -78 °C, and a solution of iodine (1.36 g, 5.36
mmol) in 25 mL of ether was added via cannula. The reaction mixture
was warmed from -78 °C to 25 °C and stirred for 2.5 h and then
quenched with saturated aqueous sodium bicarbonate. After removal
of solvent from the organic layer, the two major products were purified
by flash chromatography on silica gel with a 1:9 mixture of EtOAc/
hexane to give 0.1643 g (0.39 mmol, 15%) of the naphthyl iodide 11
and 0.2067 g (0.38 mmol, 14%) of the naphthyl diiodide 12. In
addition, 0.3972 g (1.35 mmol, 50%) of the starting material 9 was
1154 w, 1077 s, 1027 w, 988 m, 947 w, 755 s, 690 s, 665 w cm-1
;
mass spectrum, m/z (relative intensity) 350 M+ (8), 332 (96), 317 (42),
287 (100), 273 (36), 259 (16), 245 (16), 229 (14), 213 (22), 73 (94);
high-resolution EI MS calcd for C25H18O2 m/z 350.1307, measd
350.1264.
Preparation of Naphthol 10 by Hydrolysis of 9. To a solution of
9 (0.147 g, 0.50 mmol) in 20 mL of methanol was added 0.3 mL of 6
N aqueous HCl. The solution was stirred at 25 °C for 36 h. Extraction
with ether and flash chromatography with a 1:9 mixture of EtOAc/
hexane gave 0.0726 g (0.29 mmol, 58%) of 10 as a semisolid. Naphthol
10 was found to be nonidentical with naphthol 15 obtained from the
reaction of carbene complex 4a with phenylacetylene. Spectral data
for 10: Rf ) 0.20 (1:9 EtOAc/hexane); 1H NMR (CDCl3) δ 3.52 (s, 3
H), 5.90 (s, 1 H), 6.75 (s, 1 H), 7.31-7.59 (m, 7 H), 8.15-8.19 (m, 2
H); 13C NMR (CDCl3) δ 61.27, 110.60, 121.94, 122.32, 124.79, 125.55,
126.78, 127.10, 128.29, 129.16, 129.22, 129.60, 138.25, 146.53, 147.81;
IR (neat) 3350 s, 3062 w, 2934 m, 2842 w, 1628 w, 1597 s, 1499 m,
1445 m, 1392 m, 1371 s, 1311 m, 1256 w, 1294 m, 1167 w, 1071 s,
981 m, 909 m, 855 w, 761 s, 698 m cm-1; mass spectrum, m/z (relative
intensity) 250 M+(100), 235 (84), 207 (54), 178 (36), 105 (12), 76
(16); high-resolution EI MS calcd for C17H14O2 m/z 250.0994, measd
250.0949.
1
recovered. Spectral data for 11: Rf ) 0.40 (1:9 EtOAc/hexane); H
NMR (CDCl3) δ 3.50 (s, 3 H), 3.76 (s, 3 H), 5.22 (s, 2 H), 7.28 (d, 2
H, J ) 7.3 Hz), 7.38-7.55 (m, 5 H), 8.07 (d, 1 H, J ) 7.7 Hz), 8.16
(d, 1 H, J ) 7.8 Hz); 13C NMR (CDCl3) δ 58.34, 61.62, 95.58, 100.45,
122.75, 122.93, 126.93, 126.98, 127.65, 127.87, 128.62, 130.18, 135.33,
140.89, 149.96, 150.70 (1 C not located); mass spectrum, m/z (relative
intensity) 420 M+ (86), 390 (14), 375 (95), 360 (16), 293 (100), 261
(37), 248 (88), 233 (83), 218 (54), 205 (92), 189 (86), 176 (82), 151
(57), 129 (56); high-resolution EI MS calcd for C19H17O3I m/z 420.0222,
measd 420.0258. Spectral data for 12: Rf ) 0.34 (1:9 EtOAc/hexane);
1H NMR (CDCl3) δ 3.63 (s, 3 H), 3.74 (s, 3 H), 5.24 (q, 2 H, J ) 7.2
Hz), 7.09 (t, 1 H, J ) 7.6 Hz), 7.24 (d, 1 H, J ) 7.5 Hz), 7.44 (t, 1 H,
J ) 7.4 Hz), 7.54-7.55 (m, 2 H), 7.95 (d, 1 H, J ) 7.4 Hz), 8.07-
8.09 (m, 1 H), 8.19-8.21 (m, 1 H); 13C NMR (CDCl3) δ 58.42, 61.76,
95.03, 100.62, 101.63, 122.93, 123.05, 127.01, 127.21, 128.01, 128.62,
129.09, 129.38, 130.87, 137.48, 138.88, 145.84, 149.90, 151.02; IR
(neat) 3069 w, 2954 m, 2931 m, 2828 w, 1663 w, 1586 w, 1564 m,
1491 m, 1470 w, 1449 m, 1431 w, 1347 s, 1263 w, 1210 m, 1161 s,
1077 s, 1046 s, 1018 m, 981 s, 929 s, 769 s, 741 s cm-1; mass spectrum,
m/z (relative intensity) 546 M+ (100), 516 (8), 501 (90), 419 (36), 375
(20), 292 (30), 234 (36), 176 (46), 69 (56); high-resolution EI MS calcd
for C19H16O3I2 m/z 545.9189, measd 545.9156.
Preparation of the 13C-Enriched Carbene Complex 14 and Its
Reaction with Phenylacetylene. A single-necked flask equipped with
a high-vacuum threaded stopcock was charged with phenyl(methoxy)-
chromium carbene complex 4a14 (0.270 g, 0.87 mmol) and 20 mL of
hexane. The solution was deoxygenated by the freeze-thaw method
(two cycles), and the flask was backfilled with an atmosphere of 13C-
enriched carbon monoxide (13C, 99%; 18O, 10.5%; Isotec Inc., Mi-
amisburg, OH), which was maintained with a balloon. The complex
was then heated at 45 °C in an oil bath for 48 h and then recovered
from the reaction mixture by flash chromatography on silica gel with
hexane (0.184 g, 0.59 mmol, 68%). The 13C NMR spectrum indicated
that 13C was introduced at the carbonyl ligands: trans, 30% enrichment,
δ ) 224.09 ppm; cis, 24% enrichment, δ ) 216.11 ppm.
Coupling of Naphthyl Iodide 11 with Phenylacetylene.8 A 50
mL flask was charged with iodide 11 (0.152 g, 0.36 mmol), phenyl-
acetylene (0.084 mL, 0.77 mmol), bis(triphenylphosphine)palladium
chloride (0.027 g, 0.038 mmol), cuprous iodide (0.0036 g, 0.019 mmol),
and diethylamine (1.5 mL). The resulting solution was stirred at 25
°C for 18 h. After the solvent was removed, the product was purified
A solution of the 13C-labeled complex 14 (0.184 g, 0.59 mmol) and
phenylacetylene (0.122 mL, 1.11 mmol) in 5.6 mL of THF was
deoxygenated as described above (three cycles) and backfilled with
13C-labeled carbon monoxide at 25 °C. The flask was sealed at 25 °C

2176 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
and then heated at 45 °C in an oil bath for 21 h. After removal of the
volatiles, the naphthol 15 was isolated by flash chromatography with
a 1:15 mixture of EtOAc/hexane in 87% yield (0.1276 g, 0.51 mmol).
The 13C NMR spectrum of 15 revealed a 70% enrichment at the carbon
at δ ) 141.42 ppm, which is consistent with the mass spectrum (74%
enhancement) and indicates that additional incorporation of label occurs
during the benzannulation reaction. An APT experiment indicated that
the labeled carbon was one-bond coupled to two quaternary carbon
atoms. Spectral data for 15: Rf ) 0.45 (1:5 EtOAc/hexane); 1H NMR
(CDCl3) δ 3.97 (s, 3 H), 5.46 (s, 1 H), 6.70 (s, 1 H), 7.51-7.58 (m, 7
H), 8.22-8.25 (m, 2 H); 13C NMR (CDCl3, APT) δ 55.72 (CH3), 105.48
(CH), 120.18 (d, J ) 72.2 Hz), 121.74 (CH), 122.17 (CH), 125.16 (d,
J ) 68.0 Hz), 125.79 (CH), 125.85, 126.16 (CH), 127.77 (CH), 129.29
(CH), 129.45 (CH), 137.82, 141.42 (*C), 149.24; IR (neat) 3536 m,
3055 w, 2936 w, 1631 w, 1597 m, 1407 w, 1449 m, 1389 m, 1298 m,
The solvent was removed, and the residue was loaded onto a silica gel
column and eluted with a 1:15 mixture of EtOAc/hexane to give 0.1653
g (0.50 mmol, 41%) of 19b as a yellow oil along with 0.095 g (0.26
mmol, 22%) of complex 16a. Spectral data for 19b: Rf ) 0.38 (1:9
1
EtOAc/hexane); H NMR (CDCl3) δ 1.36 (d, 6 H, J ) 6.9 Hz), 1.52
(d, 6 H, J ) 7.2 Hz), 2.95 (heptet, 1 H, J ) 6.9 Hz), 3.84 (heptet, 1 H,
J ) 7.2 Hz), 3.93 (s, 3 H), 5.29 (s, 1 H), 7.52-7.63 (m, 2 H), 7.67 (d,
1 H, J ) 9.1 Hz), 7.81 (d, 1 H, J ) 6.7 Hz), 8.03 (d, 1 H, J ) 9.1 Hz),
9.56 (d, 1 H, J ) 8.4 Hz); 13C NMR (CDCl3) δ 20.91, 21.73, 22.92,
29.55, 59.75, 75.58, 104.89, 116.90, 119.57, 122.31, 124.02, 126.34,
126.96, 127.65, 128.23, 129.30, 130.78, 132.57, 145.59, 154.75 (1 aryl
C not located); IR (neat) 3440 m, 2966 s, 2930 m, 2871 w, 2218 w,
1582 w, 1484 w, 1445 m, 1390 m, 1361 w, 1310 m, 1276 w, 1247 m,
1202 w, 1127 w, 1080 w, 1015 m, 824 w, 758 m cm-1; mass spectrum,
m/z (relative intensity) 332 M+ (100), 317 (48), 301 (32), 289 (18),
261 (14), 215 (18), 202 (22), 155 (28), 127 (24); high-resolution EI
MS calcd for C23H24O2 m/z 332.1776, measd 332.1750.
1227 m, 1142 w, 1103 m, 1050 w, 984 w, 810 w, 760 m, 703 m cm-1
;
mass spectrum, m/z (relative intensity) 251 (100), 250 (36); high-
resolution EI MS calcd for C17H14O2 m/z 250.0994, measd 250.1024.
The regioselectivity of this reaction was determined on a run carried
out on the nonlabeled carbene complex with phenylacetylene. The
crude reaction mixture was analyzed by capillary GC, which indicated
that the ratio of 15 (unlabeled) to 10 is greater than or equal to 179:1.
This assignment was aided by an independent synthesis of 10 as
described above. The retention times of these two columns were 8.18
min for 15 and 8.50 min for 10 on a 30 m × 0.32 mm SE-54 column
at 200 °C for 1 min and then ramped at 10 °/min for 15 min with 1
mL/min helium as carrier gas. The ratio of 15:10 of g179:1 was judged
not to be in error as the result of a selective oxidation of one of the
isomers to the naphthoquinone since the GC trace of the crude reaction
mixture revealed no trace of the quinone as determined by an authentic
sample of the quinone, which had a retention time of 6.66 min.
Reaction of 1-Naphthyl(methoxy)carbene Complex 16a with 1,4-
Diphenyl-1,3-diyne (8). The reaction of 0.430 g (1.19 mmol) of freshly
prepared carbene complex 16a13,17 with 0.190 g (1.19 mmol) of 1,4-
diphenyl-1,3-butadiyne (8) in 31.3 mL of THF was carried out at 50
°C for 16 h according to the procedure described for the reaction of 4a
with 8. The solvent was removed, and the residue was loaded onto a
silica gel column and eluted with a 1:1:16 mixture of ether/CH2Cl2/
hexane to give 0.289 g (0.72 mmol, 61%) of 19a as a white solid.
Spectral data for 19a: Rf ) 0.52 (1:1:8 ether/CH2Cl2/hexane); white
Preparation of Tetramethylammonium 1-Naphthyl(pentacarbon-
yl)chromium Acylate 59. A solution of 5.0 mL (35.4 mmol) of
1-bromonaphthalene in 120 mL of ether was cooled to -78 °C and
treated with 24.4 mL of a 1.6 M solution of n-butyllithium in hexane
(39.0 mmol). After 10 min, the cold bath was removed, and the flask
was allowed to warm to 25 °C for 0.5 h. The flask was cooled to -10
°C, and 7.93 g (35.4 mmol) of chromium hexacarbonyl was added.
The mixture was cooled to -78 °C for 5 min, and then the flask was
allowed to warm to room temperature for 20 min. After the ether was
removed, the residue was dissolved in water and filtered through Celite.
To the filtrate was added 5.54 g (35.4 mmol) of tetramethylammonium
bromide. The resulting yellow precipitate was extracted into dichlo-
romethane. Upon addition of hexane, a yellow solid precipitated which
was collected and identified as the salt 59 (12.63 g, 30.0 mmol, 83%).
1
Spectral data for 59: yellow solid, mp ) 113-115 °C dec; H NMR
(CD3CN) δ 3.05 (s, 12 H), 7.11 (d, 1 H, J ) 7.0 Hz), 7.36-7.43 (m,
3 H), 7.59 (d, 1 H, J ) 8.1 Hz), 7.79 (d, 1 H, J ) 8.3 Hz), 7.92 (d, 1H,
J ) 8.2 Hz); 13C NMR (CD3CN) δ 56.08, 104.19, 118.90, 125.70,
125.87, 126.08, 126.27, 127.07, 128.60, 134.76, 159.22, 223.18, 228.76,
299.96; IR (neat) 3036 w, 2034 s, 1944 s, 1884 vs, 1588 w, 1532 m,
1484 m, 1450 w, 1386 w, 1201 w, 1155 w, 1065 w, 1011 w, 948 m,
878 w, 860 w, 787 m, 733 w, 686 m, 661 s cm-1. Anal. Calcd for
C20H19O6NCr: C, 57.01; H, 4.55. Found: C, 57.40; H, 4.41.
1
solid, mp ) 161-162 °C; H NMR (CDCl3) δ 4.07 (s, 3 H), 5.46 (s,
Preparation of 1-Naphthyl(butyloxy)carbene Complex 16b. To
a solution of 1.0 g (2.38 mmol) of the tetramethylammonium acylate
59 in 18.8 mL of dichloromethane at -20 °C was added 0.176 mL
(2.38 mmol) of acetyl bromide under argon. After the mixture was
stirred at -20 °C for 1 h, 0.217 mL (2.38 mmol) of 1-butanol was
added, and the resulting solution was stirred for 3.5 h at -20 °C. The
red mixture was then poured into a separatory funnel containing aqueous
saturated NaHCO3 and hexane. The organic layer was washed with
distilled water and brine then dried with anhydrous MgSO4. The
volatiles were removed by rotary evaporation, and the product was
isolated from the red residue via flash chromatography on silica gel
with a 1:1:8 mixture of ether/CH2Cl2/hexane to give 0.819 g (2.03
mmol, 85%) of 16b as a red solid. Spectral data for 16b: Rf ) 0.32
1 H), 7.16-7.23 (m, 5 H), 7.48 -7.65 (m, 7 H), 7.74 (d, 1 H, J ) 9.1
Hz), 7.86 (d, 1 H, J ) 7.5 Hz), 8.18 (d, 1 H, J ) 9.1 Hz), 9.61 (d, 1
H, J ) 8.5 Hz); 13C NMR (CDCl3) δ 60.56, 86.12, 97.82, 115.95,
120.71, 123.53, 123.66, 123.88, 125.25, 126.82, 127.18, 127.80, 128.11,
128.20, 128.50, 128.64, 129.20, 129.37, 130.80, 131.25, 133.18, 134.67,
144.87, 154.30 (1 aryl C not located); IR (neat) 3539 s, 3079 w, 3054
m, 2929 w, 1595 m, 1485 m, 1444 m, 1393 m, 1326 m, 1308 m, 1239
m, 1219 m, 1147 w, 1135 m, 1073 w, 1028 w, 1007 s, 908 m, 825 m,
752 s, 690 s cm-1; mass spectrum, m/z (relative intensity) 400 M+
(100), 385 (30), 357 (58), 339 (12), 326 (20), 163 (16); high-resolution
EI MS calcd for C29H20O2 m/z 400.1463, measd 400.1468. Anal. Calcd
for C29H20O2: C, 86.98; H, 5.03. Found: C, 86.55; H, 5.33.
Reaction of 1-Naphthyl(methoxy)carbene Complex 16a with 1,4-
Diisopropyl-1,3-diyne (17). The diisopropyl diyne 17 was prepared
by the Glasser reaction.18 To a solution of CuCl (3.84 g, 17.6 mmol)
and NH4Cl (6.73 g, 126 mmol) in 36 mL of water was added a solution
of isopropylacetylene (1.2 g, 17.6 mmol) and CuCl2 (0.035 g, 0.14
mmol) in 21 mL of ethanol. After being stirrred at 25 °C in air for16
h, the solution was exacted with ether, and the combined organic layer
was washed with saturated aqueous sodium bicarbonate, water, and
brine. Distillation at 70 °C and 8 mmHg gave 1,4-diisopropyl-1,3-
butadiyne (17, 0.50 g, 3.73 mmol, 42%) as a colorless liquid. Spectral
data for 17: 1H NMR (CDCl3) δ 1.17 (d, 12 H, J ) 7.0 Hz), 2.60
(septet, 2 H, J ) 6.8 Hz).
1
(1:1:60 ether/CH2Cl2/hexane); mp ) 44-45 °C; H NMR (CDCl3) δ
0.92 (t, 3 H, J ) 7.4 Hz), 1.46-1.53 (m, 2 H), 1.84 (br s, 2H), 4.21
(br s, 2 H), 7.01 (d, 1 H, J ) 7.1 Hz), 7.40-7.53 (m, 4 H), 7.74 (d, 1
H, J ) 8.2 Hz), 7.74-7.84 (m, 1 H); 13C NMR (CDCl3) δ 13.51, 18.94,
31.43, 79.90, 118.35, 123.69, 124.13, 124.90, 125.35, 126.56, 127.08,
128.30, 128.71, 133.07, 216.07, 224.81, 356.44; IR (neat) 3061 w, 2963
w, 2936 w, 2876 w, 2063 s, 1989 s, 1929 vs, 1589 w, 1505 w, 1466
w, 1382 w, 1279 m, 1244 m, 1199 m, 1158 m, 1076 m, 1045 m, 925
m, 788 m, 702 m, 650 s, 609 m cm-1; mass spectrum, m/z (relative
intensity) 404 M+ (4), 376 (10), 348 (10), 320 (12), 292 (27), 264
(100), 196 (27), 179 (64), 167 (64), 155 (22), 137 (20), 128 (27); high-
resolution EI MS calcd for C20H16O6Cr m/z 404.0352, measd 404.0334.
Anal. Calcd for C20H16O6Cr: C, 59.41; H, 3.99. Found: C, 59.71;
H, 4.07.
The reaction of 0.434 g (1.20 mmol) of freshly prepared carbene
complex 16a13,17 with 0.241 g (1.80 mmol) of 1,4-diisopropyl-1,3-
butadiyne (17) in 40 mL of THF was carried out at 50 °C for 24 h
according to the procedure described for the reaction of 4a with 8.
Reaction of 1-Naphthyl(butyloxy)carbene Complex 16b with 1,4-
Diphenyl-1,3-butadiyne (8). The reaction of 0.232 g (0.57 mmol) of
freshly prepared carbene complex 16b and 0.116 g (0.57 mmol) of
1,4-diphenyl-1,3-butadiyne (8) was carried out at 50 °C for 16 h
according to the procedure described above for the reaction of complex
(17) Fischer, E. O.; Kreiter, C. G.; Kollmeier, H. J.; Muller, J.; Fischer,
R. D. J. Organomet. Chem. 1971, 28, 237.
(18) Eglinton, G.; McCrae, W. AdV. Org. Chem. 1963, 4, 225.

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2177
4a with 8. To the crude reaction mixture was then added 18.7 mL of
a 0.5 M solution of CAN. After being stirred at 25 °C for 1 h, the
resulting mixture was extracted with ether, and the organic layer was
washed with water, saturated aqueous sodium bicarbonate, water, and
brine. The quinone 21c (0.189 g, 0.49 mmol, 86%) was isolated after
flash chromatography on silica gel with a 1:15 mixture of EtOAc/hexane
as a red solid. Spectral data for 21c: Rf ) 0.24 (1:15 EtOAc/hexane);
1H NMR (CDCl3) δ 7.30-7.81 (m, 12 H), 7.93 (d, 1 H, J ) 7.5 Hz),
8.19 (d, 1 H, J ) 8.6 Hz), 8.25 (d, 1 H, J ) 8.6 Hz), 9.61 (d, 1 H, J
) 8.7 Hz); 13C NMR (CDCl3) δ 84.82, 106.08, 122.15, 122.29, 127.34,
127.70, 128.18, 128.39, 128.65, 128.72, 129.45, 129.66, 129.80, 130.19,
130.47, 130.52, 131.68, 132.24, 132.65, 135.34, 136.33, 146.07, 184.38,
184.49; IR (neat) 3072 w, 2199 m, 1658 vs, 1646 s, 1597 w, 1493 w,
1459 w, 1442 w, 1381 w, 1359 w, 1333 w, 1305 s, 1232 m, 1204 w,
1145 m, 1096 s, 1061 m, 1027 w, 985 m, 771 s, 756 s cm-1; mass
spectrum, m/z (relative intensity) 384 M+ (100), 326 (28), 307 (29),
192 (8), 151 (22), 126 (30); high-resolution EI MS calcd for C28H16O2
m/z 384.1151, measd 384.1146.
299 (15), 287 (12), 273 (13), 259 (12), 245 (12), 215 (14), 202 (15),
149 (21), 126 (24), 83 (15), 71 (24); high-resolution EI MS calcd for
C24H24O2 m/z 344.1776, measd 344.1715. Spectral data for 20d: yellow
1
oil; Rf ) 0.26 (1:2 CHCl3/hexane); H NMR (CDCl3) δ 0.85 (t, 3 H,
J ) 7.3 Hz), 1.28 (s, 9 H), 1.32 (s, 9 H), 1.30-1.50 (m, 2 H), 1.51-
1.66 (m, 2 H), 3.53-3.66 (m, 2 H), 7.38 (t, 1 H, J ) 7.4 Hz), 7.40-
7.54 (m, 2 H), 7.71 (d, 1 H, J ) 7.1 Hz), 7.79 (d, 2 H, J ) 8.1 Hz),
8.73 (d, 1 H, J ) 8.1 Hz); 13C NMR (CDCl3) δ 13.75, 19.22, 27.61,
29.24, 30.01, 32.02, 33.25, 65.38, 72.69, 101.42, 102.53, 124.74, 124.84,
125.43, 125.49, 125.80, 127.85, 129.24, 131.72, 133.86, 134.24, 154.50,
164.75, 193.61; IR (neat) 3049 w, 2966 s, 2932 m, 2903 m, 2870 s,
2211 m, 1757 vs, 1599 m, 1511 w, 1475 m, 1459 m, 1395 w, 1366 m,
1326 m, 1258 m, 1201 m, 1135 m, 1094 m, 1069 m, 1024 m, 778 s,
700 w cm-1; mass spectrum, m/z (relative intensity) 402 M+ (6), 346
(46), 331 (3), 317 (6), 290 (5), 155 (100), 127 (66), 83 (18); high-
resolution EI MS calcd for C28H34O2 m/z 402.2559, measd 402.2539.
It was shown that the cyclobutenone 20d had the same regiochem-
istry of alkyne incorporation as quinone 21d by chemical correlation.
The cyclobutenone 20d (0.0671 g, 0.17 mmol) was dissolved in 30
mL of hexane, and the resulting solution was deoxygenated (two cycles).
The flask was sealed at 25 °C under argon and heated at 85 °C for 18
h. The reaction mixture was oxidized with 1.3 mL of aqueous CAN
(0.5 M, 0.65 mmol) in air for 1 h. After flash chromatography on
silica gel with a 1:30 mixture of EtOAc/hexane, 0.036 g (0.10 mmol,
64%) of quinone 21d was isolated as a yellow oil, along with 0.0165
g (0.042 mmol, 25%) of the starting material 20d.
The reaction was repeated under the conditions described above,
but an oxidative workup was not employed. The solvent was removed
from the crude reaction mixture, and the residue was loaded onto a
silica gel column which was eluted with a 1:15 mixture of ethyl acetate/
hexane to give 0.341 g (0.77 mmol, 82%) of phenanthrol 19c as a
yellow oil. Spectral data for 19c: Rf ) 0.27 (1:15 EtOAc/hexane); 1H
NMR (CDCl3) δ 1.02 (t, 3 H, J ) 7.4 Hz), 1.64-1.69 (m, 2 H), 2.03-
2.056 (m, 2 H), 4.13 (t, 2 H, J ) 6.6 Hz), 5.43 (s, 1 H), 7.13-7.14 (m,
2 H), 7.21-7.47 (m, 4 H), 7.47-7.64 (m, 6 H), 7.73 (d, 1 H, J ) 9.1
Hz), 7.85 (d, 1 H, J ) 7.6 Hz), 8.17 (d, 1 H, J ) 9.2 Hz), 9.67 (d, 1
H, J ) 8.4 Hz); 13C NMR (CDCl3) δ 14.14, 19.57, 32.68, 73.77, 86.63,
97.59, 116.12, 120.71, 123.61, 123.64, 124.18, 125.39, 126.75, 126.88,
127.89, 128.01, 128.07, 128.19, 128.38, 128.57, 129.17, 129.48, 130.80,
131.17, 133.08, 134.81, 144.70, 153.38; IR (neat) 3541 s, 3052 w, 2957
m, 2932 m, 2871 m, 1596 m, 1484 m, 1412 s, 1379 m, 1325 m, 1309
s, 1242 m, 1220 m 1138 m, 1098 w, 1070 w, 1028 w, 977 w, 908 w,
824 m, 734 s, 701m, 690 s cm-1; mass spectrum, m/z (relative intensity)
442 M+ (100), 386 (80), 357 (48), 339 (15), 326 (17); high-resolution
EI MS calcd for C32H26O2 m/z 442.1933, measd 442.1992.
Reaction of 1-Naphthyl(butyloxy)carbene Complex 16b with 1,4-
Diisopropyl-1,3-butadiyne (17). The reaction of carbene complex 16b
(0.370 g, 0.92 mmol) with 1,4-diisopropyl-1,3-diyne (17) (0.135 g, 1.01
mmol) in 30.5 mL of THF was carried out at 50 °C for 18 h according
to the procedure described above for the reaction of complex 4a with
diyne 8. A single product observed by TLC was purified by flash
chromatography on silica gel with a 1:9 mixture of EtOAc/hexane,
which gave 0.1231 g (0.33 mmol, 36%) of the phenanthrol 19e as an
oil, along with 0.165 g (0.41 mmol, 45%) of the starting carbene
complex 16b. Spectral data for 19e: Rf ) 0.37 (1:9 EtOAc/hexane);
1H NMR (CDCl3) δ 1.02 (t, 3 H, J ) 7.4 Hz), 1.36 (d, 6 H, J ) 6.9
Hz), 1.53 (d, 6 H, J ) 7.2 Hz), 1.55-1.61 (m, 2 H), 1.98 (pentet, 2 H,
J ) 7.4 Hz), 2.94 (m, 1 H), 3.84 (m, 1 H), 3.96 (t, 2 H, J ) 6.8 Hz),
5.10 (s, 1 H), 7.51 (t, 1 H, J ) 7.1 Hz), 7.56 (t, 1 H, J ) 8.0 Hz), 7.65
(d, 1 H, J ) 9.1 Hz), 7.79 (d, 1 H, J ) 7.7 Hz), 7.99 (d, 1 H, J ) 9.1
Hz), 9.58 (d, 1 H, J ) 8.4 Hz); 13C NMR (CDCl3) δ 14.16, 19.43,
20.91, 21.78, 22.97, 29.53, 32.60, 72.85, 75.96, 104.51, 117.04, 119.58,
122.62, 124.00, 126.29, 126.67, 127.53, 127.77, 128.12, 129.45, 130.94,
132.50, 145.45, 153.81; IR (neat) 3470 m, 3051 w, 2962 s, 2932 s,
2871 m, 1948 w, 1635 w, 1589 w, 1462 w, 1412 w, 1359 w, 1309 m,
1245 w, 1195 w, 1081 w, 1001 w, 906 w, 822 w, 757 cm-1; mass
spectrum, m/z (relative intensity) 374 M+ (100), 317 (96), 301 (33),
289 (18), 275 (16), 261 (16), 215 (12), 202 (14), 155 (27), 127 (20);
high-resolution EI MS calcd for C26H30O2 m/z 374.2246, measd
374.2238.
Reaction of Cyclohexenyl(methoxy)carbene Complex 22 with 1,4-
Diphenyl-1,3-butadiyne (8). The reaction of 0.338 g (1.069 mmol)
of carbene complex 22 and 0.256 g (1.069 mmol) of 1,4-diphenyl-1,3-
butadiyne (8) in 2.1 mL of THF (0.5 M in 22) was carried out at 55 °C
for 20 h according to the procedure described for complex 4a with 8.
The mixture was diluted with THF (miniumum of 20 mL), and a
solution of p-toluenesulfonic acid monohydrate (0.3 equiv) in water
(25 mL for 0.1 g of carbene complex used) was added. The mixture
stirred at 25 °C in air for 1 h. The reaction mixture was diluted with
water, and the organic components were extracted into ether which
was washed with aqueous NaHCO3, water, and brine and dried over
MgSO4. After filtration and removal of the solvents, CH2Cl2 and a
small amount of silica gel were added, and the resulting solution was
stirred at 25 °C in air for 1-2 days until the yellow compound on
TLC with Rf ) 0.18 (1:1 CH2Cl2/hexane) was no longer present. The
crude reaction mixture was filtered, stripped of solvent, and loaded
onto a silica gel column and eluted with a 1:1 mixture of CH2Cl2/
hexane to give a 73% yield (0.278 g, 0.784 mmol) of the phenol 23
and a 2.8% yield (10.5 mg, 0.03 mmol) of its regioisomer 24. The
regioisomeric relationship of the phenols 23 and 24 was established
by chemical correlation, in which each was shown to be oxidized by
Reaction of 1-Naphthyl(butyloxy)carbene Complex 16b with 1,4-
Di-tert-butyl-1,3-butadiyne (18). The di-tert-butyl diyne 18 was
prepared by the Glasser reaction.18,19 To a solution of CuCl (10 g,
100 mmol) and NH4Cl (17 g, 318 mmol) in 150 mL water was added
a solution of tert-butylacetylene (5 mL, 40.6 mmol) and CuCl2 (0.5 g,
2.0 mmol) in 50 mL of ethanol. After being stirred at 25 °C for 48 h
in air, the solution was exacted with ether and was washed with sodium
bicarbonate, water, and brine. A total of 1.99 g (12.3 mmol, 60%) of
1,4-di-tert-butyl-1,3-butadiyne (18) was isolated as a white solid after
flash chromatography with a 1:1:30 mixture of CH2Cl2/ether/hexane.
Spectral data for 18:19 1H NMR (CDCl3) δ 1.23; 13C NMR (CDCl3, 75
MHz) δ 27.95, 30.58, 63.61, 86.27.
The reaction of 0.276 g (0.64 mmol) of freshly prepared complex
16b and 0.103 g (0.64 mmol) of 1,4-di-tert-butyl-1,3-butadiyne (18)
in 21 mL of THF was carried out at 53 °C for 16 h according to the
procedure described above for the reaction of complex 4a with diyne
8. The crude reaction mixture was then stirred with 8.0 mL of a 0.5
M solution of CAN, and after 1 h the resulting mixture was extracted
with ether and washed with water, saturated aqueous sodium bicarbon-
ate, water, and brine. The two products of this reaction were separated
by flash chromatography on silica gel with a 1:2 mixture of CHCl3/
hexane to give the quinone 21d (0.0139 g, 0.040 mmol, 6%) and the
cyclobutenone 20d (0.1854 g, 0.46 mmol, 72%). Spectral data for
1
21d: yellow oil; Rf ) 0.33 (1:2 CHCl3/hexane); H NMR (CDCl3) δ
1.41 (s, 9 H), 1.57 (s, 9 H), 7.62 (t, 1 H, J ) 7.0 Hz), 7.70 (t, 1 H, J
) 7.2 Hz), 7.88 (d, 1 H, J ) 7.2 Hz), 8.00 (d, 1 H, J ) 8.5 Hz), 8.11
(d, 1 H, J ) 8.5 Hz), 9.34 (d, 1 H, J ) 8.7 Hz); 13C NMR (CDCl3) δ
29.06, 30.19, 30.37, 36.97, 75.18, 119.40, 121.81, 127.09, 128.00,
128.31, 128.53, 129.21, 129.65, 131.17, 134.37, 134.61, 135.73, 156.74,
184.49, 187.55; IR (neat) 3056 w, 2968 s, 2929 m, 2867 w, 2213 m,
1662 s, 1653 vs, 1595 w, 1554 w, 1461 m, 1304 s, 1283 s, 1266 m,
1249 s, 1209 m, 1167 m, 1118 m, 847 m, 817 m, 764 s cm-1; mass
spectrum, m/z (relative intensity) 344 M+ (30), 329 (100), 314 (27),
(19) Smith, E. H.; Whittall, J. Organometallics 1994, 13, 5169.

2178 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
CAN to the quinone 25. If upon opening to air the reaction mixture is
immediately chromatographed on silica gel, a sample of the compound
that appears as a yellow spot on TLC with Rf ) 0.18 can be obtained
as an orange solid. While this compound is sensitive to air with respect
to oxidation to phenol 23, the spectral data collected on this compounds
allow for a tentative assignment as the chromium tricarbonyl complexed
naphthalene 34. The outcome of the reactions at 0.05 M in THF and
benzene is summarized in Scheme 5. Spectral data for 23: white solid,
mp 106.5-107.5 °C; Rf ) 0.30 (1:1 CH2Cl2/hexane); 1H NMR (CDCl3)
δ 1.80 (br s, 4 H), 2.70 (br s, 2 H), 2.78 (br s, 2 H), 3.92 (s, 3 H), 4.90
(s, 1 H), 7.09-7.20 (m, 5 H), 7.39-7.49 (m, 5 H); 13C NMR (CDCl3)
δ 22.21, 23.74, 23.84, 60.64, 85.56, 95.94, 113.36, 123.66, 126.43,
126.82, 127.82, 128.10, 128.26, 128.99, 130.63, 131.08, 131.45, 134.96,
146.25, 152.70 (1 C not located); IR (neat) 3548 s, 2981 s, 1450 s,
1411 s, 1303 s, 755 s cm-1; mass spectrum, m/z (relative intensity)
355 (35), 354 M+ (100), 353 (95), 339 (10), 311 (12), 250 (35), 235
(12). Spectral data for 24: white solid, mp 144-145.5 °C; Rf ) 0.37
(1:1 CH2Cl2/hexane); 1H NMR (CDCl3) δ 1.84 (br s, 4 H), 2.75-2.81
(m, 4 H), 3.29 (s, 3 H), 5.89 (s, 1 H), 7.22-7.53 (m, 10 H); 13C NMR
(CDCl3) δ 22.14, 22.33, 23.49, 24.04, 59.96, 83.40, 98.51, 106.34,
122.74, 123.90, 127.20, 127.65, 128.30, 130.30, 131.09, 133.19, 133.93,
136.67, 148.68, 150.68 (1 C not located); IR (neat) 3500 s, 2930 s,
1450 s, 1410 s cm-1; mass spectrum, m/z (relative intensity) 355 (25),
354 M+ (100), 340 (25), 339 (85), 321 (12), 311 (15), 149 (25).
Spectral data for 25: bright yellow solid, mp 145-163 °C (soften); Rf
(87), 77 (43); high-resolution EI MS calcd for C34H26O4 m/z 498.1831,
measd 498.1819. Spectral data for 28: white solid, mp ) 256-258
°C; Rf ) 0.51 (1:5 EtOAc/hexane); 1H NMR (CDCl3) δ 3.58 (s, 3 H),
4.21 (s, 3 H), 4.59 (s, 1 H), 5.74 (s, 1 H), 5.93 (d, 1 H, J ) 7.6 Hz),
6.61 (d, 1 H, J ) 7.3 Hz), 6.71 (t, 1 H, J ) 7.5 Hz), 7.03-7.20 (m, 8
H), 7.44 (t, 1 H, J ) 7.4 Hz), 7.52-7.57 (m, 4 H), 8.08 (d, 1 H, J )
8.28 Hz), 8.16 (d, 1 H, J ) 8.5 Hz); 13C NMR (CDCl3) δ 45.47, 59.00,
63.49, 118.87, 121.57, 122.26, 122.84, 123.77, 124.35, 125.40, 125.48,
126.11, 126.49, 126.56, 127.36, 127.61, 127.83, 127.94, 128.07, 128.46,
130.69, 131.43, 132.14, 134.48, 140.43, 145.31, 146.43, 148.64, 154.81;
IR (neat) 3522 m, 3059 w, 2926 m, 2851 w, 1720 m, 1596 m cm-1
;
mass spectrum, m/z (relative intensity) 470 M+ (75), 423 (17), 179
(21), 165 (28), 151 (34), 137 (41), 123 (62), 111 (100).
The regiochemistry of alkyne incorporation for the cyclobutenone
27 was shown to be the same as that for 26 by chemical conversion.
A 25 mL flask equipped with a threaded stopcock that was flushed
with nitrogen was charged with cyclobutenone 27 (0.0072 g, 0.014
mmol) and 5 mL of benzene. The flask was sealed by closing the
stopcock at 25 °C and placed in an 80 °C oil bath for 48 h. The starting
material was consumed at this point, and the only product obtained
was 0.0051 g (0.010 mmol, 71% yield) of phenol 26, which was isolated
after flash chromatography with1:1:8 ether/CH2Cl2/hexane.
Reaction of 1-Naphthyl(butyloxy)carbene Complex 16b with
Phenanthrylacetylene 19c. A mixture of 0.194 g (0.48 mmol) of
carbene complex 16b and 0.161 g (0.36 mmol) of alkyne 19c in 12
mL of THF was reacted according to the procedure described above
for the reaction of complex 4a with diyne 8. After the mixture was
heated at 67 °C for 3 days and then at 85 °C for 1 day, the solvent was
removed and residue was loaded onto a silica gel column and eluted
with a 1:15 mixture of ethyl acetate/hexane to give 0.0478 g (0.11
mmol, 30%) of recovered alkyne 19c and 0.1148 g (0.176 mmol, 48%)
of the five-membered-ring annulated product 30 as an off-white
semisolid. Spectral data for 30: Rf ) 0.33 (1:15 ethyl acetate/hexane);
1H NMR (CDCl3) δ 0.90 (t, 3 H, J ) 7.3 Hz), 0.95 (t, 3 H, J ) 7.4
Hz), 1.20-1.75 (m, 6 H), 2.00-2.09 (m, 2 H), 3.69-3.72 (m, 2 H),
4.06 (q, 1 H, J ) 8.7 Hz), 4.24-4.25 (m, 1 H), 4.64 (s, 1 H), 5.82 (d,
1 H, J ) 7.0 Hz), 5.97 (s, 1 H), 6.11 (t, 1 H, J ) 7.1 Hz), 6.72 (d, 1
H, J ) 7.1 Hz), 6.86 (t, 1 H, J ) 7.3 Hz), 7.04 (t, 1 H, J ) 7.4 Hz),
7.16-7.24 (m, 3 H), 7.32 (d, 1 H, J ) 8.1 Hz), 7.40-7.41 (m, 2 H),
7.58-7.61 (m, 2 H), 7.64-7.70 (m, 2 H), 7.75-7.82 (m, 3 H), 7.86
(d, 1 H, J ) 7.8 Hz), 8.02 (d, 1H, J ) 9.0 Hz), 8.40-8.42 (m, 1 H),
9.76 (d, 1 H, J ) 8.5 Hz); 13C NMR (CDCl3) δ 13.94, 14.06, 19.23,
19.50, 32.36, 32.57, 45.66, 71.91, 74.30, 120.83, 122.06, 122.43, 124.12,
124.21, 124.36, 124.96, 125.46, 125.93, 126.04, 126.45, 126.52, 126.84,
126.86, 127.26, 127.76, 127.99, 128.03, 128.10, 128.18, 128.37, 129.31,
129.60, 130.20, 131.18, 133.05, 133.09, 134.89, 135.79, 144.71, 145.36,
150.24, 156.72 (1 aryl C not located); IR (neat) 3533 s, 3052 m, 3033
w, 2957 s, 2933 s, 2872 m, 1594 s, 1516 w, 1493 m, 1409 m, 1363 w,
1332 m, 1309 m, 1255 m, 1214 s, 1133 m, 1064 m, 1002 w, 946 m,
909 s, 803 s, 758 m, 733 s, 700s cm-1; mass spectrum, m/z (relative
intensity) 654 M+ (100), 597 (8), 580 (14), 541 (8), 524 (20), 423
(32), 257 (20), 155 (34), 105 (26); high-resolution EI MS calcd for
C47H42O3 m/z 654.3134, measd 654.3152. Anal. Calcd for C47H42O3:
C, 86.20; H, 6.47. Found: C, 86.21; H, 6.84.
Reaction of 1-Naphthyl(methoxy)carbene Complex 16a with
Phenanthrylacetylene 19b. The reaction of 0.161 g (0.44 mmol) of
16a13,17 with 0.1475 g (0.44 mmol) of alkyne 19b in 14.8 mL of THF
was carried out at 75 °C for 40 h according to the procedure described
for the reaction of complex 4a with diyne 8. The solvent was removed,
and the residue was loaded onto a silica gel column and eluted with a
1:1 mixture of benzene/hexane to give 0.0744 g (0.14 mmol, 32%) of
the bis-phenanthrol 31 and 0.0936 g of a mixture of several compounds
that were not identified. Spectral data for 31: Rf ) 0.21 (1:9 EtOAc/
hexane); 1H NMR (CDCl3) δ 1.40 (d, 6 H, J ) 7.0 Hz), 1.49 (d, 6 H,
J ) 7.0 Hz), 2.89-2.94 (m, 2 H), 3.42 (br s, 3 H), 3.81 (s, 3 H), 4.81
(s, 1 H), 5.35 (s, 1 H), 7.57-7.92 (m, 8 H), 8.15 (d, 1 H, J ) 9.1 Hz),
8.16 (d, 1 H, J ) 9.0 Hz), 9.47 (d, 1 H, J ) 8.3 Hz), 9.55 (d, 1 H, J
) 8.3 Hz); 13C NMR (CDCl3) δ 21.06, 21.58, 22.17, 29.54, 32.20,
59.69, 61.42, 119.18, 120.85, 120.97, 121.38, 123.54, 124.34, 125.06,
126.07, 126.36, 126.41, 126.72, 127.21, 127.69, 127.83, 127.90, 128.04,
128.25, 128.40, 129.03, 129.55, 129.68, 132.66, 132.98, 138.78, 144.52,
147.56, 151.40, 152.30; IR (neat) 3623 w, 3532 m, 3053 w, 2961 m,
1
) 0.23 (1:1 CH2Cl2/hexane); H NMR (CDCl3) δ 1.77 (br s, 4 H),
2.53-2.56 (br s, 4 H), 7.25-7.33 (br s, 5 H), 7.41-7.50 (br s, 5 H);
13C NMR (CDCl3) δ 21.03, 21.09, 21.40, 21.47, 83.97, 104.90, 122.17,
127.58, 127.76, 128.33, 129.33, 129.49, 130.42, 132.13, 132.71, 142.32,
143.16, 145.88, 183.79, 185.72; IR (neat) 2936 m, 2199 m, 1648 vs,
1343 m, 1298 s, 1275 m, 1219 m, 1142 m, 758 m cm-1; mass spectrum,
m/z (relative intensity) 340 (60), 339 (35), 338 M+ (100), 310 (45),
309 (25), 281 (17), 252 (17), 202 (15). Anal. Calcd for C24H18O2: C,
85.18; H, 5.36. Found: C, 84.78; H, 5.35. Spectral data for 34: orange
solid; Rf ) 0.18 (1:1 CH2Cl2/hexane); 1H NMR (CDCl3) δ 1.65-1.82
(m, 3 H), 1.82-1.95 (m, 3 H), 2.55-2.92 (m, 4 H), 3.85 (s, 3 H), 4.62
(s, 1 H), 6.96-7.28 (m, 5 H), 7.28-7.56 (m, 5 H); IR (neat) 3505 w,
2939 w, 1951 s, 1876 s, 1491 w, 1449 m, 1396 m, 1323 m, 1210 m,
996 m, 757 m cm-1
.
Reaction of Phenyl(methoxy)carbene Complex 4a with Naph-
thylacetylene 5a. A mixture of 0.186 g (0.53 mmol) of alkyne 5a
and 0.275 g (1.59 mmol) of carbene complex 4a14 in 88.5 mL of THF
was reacted at 80 °C for 24 h according to the procedure described
above for 4a with diyne 8. The reaction mixture was opened and stirred
in the presence of air for 24 h at room temperature. The separation of
the products was accomplished on silica gel with a 1:9 mixture of
EtOAc/hexane to give 0.051 g (0.10 mmol, 19%) of 26, 0.086 g (0.17
mmol, 32%) of 27, and 0.0562 g (0.12 mmol, 23%) of 28. Spectral
data for 26: white solid, mp 99-123 °C (soften); Rf ) 0.35 (1:5 EtOAc/
hexane); 1H NMR (CDCl3) δ 3.31 (s, 3 H), 3.81 (s, 3 H), 5.34 (s, 1 H),
5.45 (s, 1 H), 6.97-7.10 (m, 10 H), 7.47-7.58 (m, 4 H), 8.03 (d, 1 H,
J ) 7.3 Hz), 8.13 (d, 1 H, J ) 8.3 Hz), 8.19 (d, 1 H, J ) 8.2 Hz), 8.26
(d, 1 H, J ) 8 Hz); 13C NMR (CDCl3) δ 60.98, 61.80, 117.40, 121.83,
122.19, 122.39, 122.81, 123.02, 123.42, 124.16, 125.36, 125.45, 126.31,
126.49, 126.62, 126.92, 127.01, 128.02, 128.11, 128.57, 130.28, 130.32,
130.38, 130.78, 133.51, 136.01, 145.17, 145.40, 146.98, 148.16; IR
(neat) 3528 s, 3059 m, 2933 m, 2842 m, 1719 w, 1662 m, 1587 m,
1495 m, 1450 m, 1365 s, 1289 s, 1211 m, 1143 m, 1074 s, 1028 w,
986 m, 909 m, 762s, 731 s, 701 s cm-1; mass spectrum, m/z (relative
intensity) 498 M+ (100), 482 (94), 467 (28), 421 (15), 289 (10), 276
(12), 249 (11), 233 (32), 163 (50), 121 (19); high-resolution EI MS
calcd for C34H26O4 m/z 498.1831, measd 498.1829. Spectral data for
27: yellow solid, mp 112-114 °C; Rf ) 0.26 (1:5 EtOAc/hexane); 1H
NMR (CDCl3) δ 2.05-3.92 (4 br s, 6 H), 5.31 (s, 1 H), 6.72-6.74 (br
s, 1 H), 7.08-7.67 (m, 16 H), 8.13-8.18 (m, 1 H), 8.33-8.37 (m, 1
H); 13C NMR (CDCl3) δ 52.61, 63.18, 100.81, 119.42, 120.17, 122.30,
123.08, 125.38, 126.10,126.24, 126.59, 127.04, 127.65, 128.10, 128.22,
128.75, 128.99, 129.41, 129.87, 130.19, 130.29, 131.23, 132.14, 134.35,
137.50, 145.48, 147.26, 192.10; IR (neat) 3530 m, 3059 m, 2931 m,
2849 w, 1754 s, 1616 m, 1447 m, 1390 m, 1369 m, 1296 m, 1197 w,
1140 m,1066 m cm-1; mass spectrum, m/z (relative intensity) 498 M+
(100), 483 (3), 466 (4), 423 (8), 249 (12), 233 (18), 163 (12), 105

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2179
2930 m, 2875 m, 2239 w, 1594 w, 1513 w, 1445 m, 1393 m, 1331 m,
1311 w, 1242 s, 1216 w, 1178 m, 1141 w, 1117 w, 1086 w, 1043 m,
1010 m, 987 m, 908 m, 826 m, 805 m, 757 m, 734 s cm-1; mass
spectrum, m/z (relative intensity) 530 M+ (100), 456 (8), 441 (12), 199
(11), 120 (53), 69 (56); high-resolution EI MS calcd for C36H34O4 m/z
530.2457, measd 530.2452.
out at 70 °C for 10 h in the manner described above for the reaction of
complex 4a with diyne 8. The reaction mixture was diluted with CH2-
Cl2 and allowed to stir with silica gel at 25 °C for 12 h. After flash
chromatography on silica gel with 1:5 EtOAc/hexane, a 74% yield of
the single benzannulated product 23 (57 mg, 0.161 mmol) and <1.3%
yield of the regioisomer 24 (3.6 mg, 0.007 mmol) were isolated, along
with small amounts of some unidentified compounds.
Reaction of cyclohexenyl(methoxy)carbene Complex 22 with
Arylacetylene 23. (i) In Benzene with an Oxidative Workup. The
reaction of carbene complex 2220 (0.25 g, 0.791 mmol) and alkyne 23
(0.1 g, 0.282 mmol) in 0.47 mL of benzene (1.7 M in 22) was carried
out at 70-74 °C for 10 h according to the procedure described above
for the reaction of complex 4a with diyne 8. The reaction mixture
was oxidized by stirring with a 0.5 M aqueous solution of CAN for 2
h. The organic layer was separated, diluted with CH2Cl2, washed with
water and brine, and then dried over Na2SO4. Upon flash chromatog-
raphy on silica gel with a 1:5 mixture of EtOAc/hexane, the quinone
32 was isolated as a yellow solid in 60% yield (0.0797 g, 0.168 mmol).
Small amounts of other compounds were observed which were not
identified. As indicated in Scheme 8, the same reaction at 0.016 M in
22 gave a 16% yield of 32, and the reaction at 0.16 M gave a 42%
yield of 32. Spectral data for 32: yellow solid, mp 145-164 °C
Preparation of the Ethylene-Bridged Bis-Carbene Complex 39.
To a solution of 1.02 g (2.75 mmol) of tetramethylammonium metalate
3816 in 30 mL of dichloromethane at -20 °C was added 0.233 mL
(3.0 mmol) of acetyl bromide. After the solution was stirred at -20
°C for 1 h, 0.077 mL (1.38 mmol) of ethylene glycol was added, and
the resulting solution was stirred for an additional 16 h at -20 °C.
The red reaction mixture was quenched by pouring into saturated
aqueous NaHCO3. The organic layer was washed with water and brine
then dried with anhydrous MgSO4. The solvent was removed, and the
product was separated from the red residue by flash chromatography
on silica gel with a 1:1:8 mixture of CH2Cl2/ether/hexane to give 0.67
g (1.08 mmol, 79%) of the bis-carbene complex 39. Spectral data for
39: red solid, mp 106-107 °C; Rf ) 0.48 (1:1:8 CH2Cl2/ether/hexane);
1H NMR (CDCl3) δ 5.22 (br s, 4 H), 7.18 (br s, 4 H), 7.36 (br s, 6 H);
13C NMR (CDCl3) δ 76.77, 122.55, 128.36, 130.40, 153.23, 215.77,
224.02, 351.59; IR (neat) 3063 m, 2950 w, 2063 s, 1929 vs, 1721 w,
1593 w, 1441 w, 1254 w, 1222 w, 1199 w, 1145 w, 1102 w, 902 w,
759 w, 652 s, 619 w cm-1; mass spectrum, m/z (relative intensity) 622
M+ (1), 534 (1), 426 (1), 374 (6), 290 (35), 262 (8), 238 (17), 220
(43), 178 (100), 105 (70), 80 (61). Anal. Calcd for C26H14O12Cr2: C,
50.17; H, 2.27. Found: C, 50.42; H, 2.42.
1
(soften); Rf ) 0.30 (1:5 EtOAc/hexane); H NMR (CDCl3) δ 1.68-
1.73 (m, 8 H), 2.36-2.55 (m, 8 H), 6.50 (d, 4 H, J ) 7.4 Hz), 7.13 (t,
4 H, J ) 7.6 Hz), 7.22 (d, 2 H, J ) 6.4 Hz); 13C NMR (CDCl3) δ
20.90, 20.99, 22.59, 22.80, 127.57, 128.75, 129.07, 131.78, 138.83,
142.41, 142.67, 143.71, 185.60, 186.79; IR (neat) 2940 m, 1646 vs
cm-1; mass spectrum, m/z (relative intensity) 478 (55), 476 (60), 474
M+ (97), 430 (100), 429 (70), 415 (67), 401 (40), 105 (60), 79 (72).
Anal. Calcd for C32H26O4: C, 80.99; H, 5.52. Found: C, 79.68; H,
6.11.
Reaction of Bis-Carbene Complex 39 with 1,4-Diphenyl-1,3-
butadiyne (8). The reaction of carbene complex 39 (100 mg, 0.16
mmol) with 0.9 equiv of 1,4-diphenyl-1,3-butadiyne (8) was carried
out as described above for the reaction of complex 4a with diyne 8.
The reaction times, temperatures, concentrations, and yields for the
various runs are indicated in Scheme 11. After the mixture cooled to
room temperature, 200 mg of silica gel was added, the volatiles were
removed, and the residue was loaded on the top of a silica gel column.
The products were eluted first with a 5:1 mixture of hexane/ethyl acetate
and then with a 3:1 mixture. The only two predominate products
observed for each run were the 2,2′-binaphthol 40 and the indenyl-
naphthol 41. Purer samples of each product could be obtained if a
16:1:1 mixture of hexane/CH2Cl2/ether was used as eluant. Spectral
data for 40: whitish-yellow film; Rf ) 0.16 (16:1:1 hexane/CH2Cl2/
(ii) In THF without an Oxidative Workup. The reaction of
carbene complex 2220 (0.244 g, 0.772 mmol) and alkyne 23 (0.1 g,
0.282 mmol) in 0.47 mL of THF was carried out as described above
for the reaction in benzene. The reaction mixture was diluted with
CH2Cl2 and allowed to stir with silica gel at 25 °C for 2 h. After flash
chromatography on silica gel with a 1:5 mixture of EtOAc/hexane, a
56% yield of phenol 33 (80.6 mg, 0.159 mmol) was isolated as a white
solid. Small amounts of other compounds were observed which were
not identified. Spectral data for 33: white solid, mp 192.5-194 °C; Rf
) 0.35 (1:5 EtOAc/hexane); 1H NMR (CDCl3) δ 1.74-1.85 (m, 8 H),
2.59-2.81 (m, 8 H), 3.08 (s, 3 H), 3.61 (s, 3 H), 4.72 (s, 1 H), 4.86 (s,
1 H), 6.87-6.88 (m, 2 H), 7.06-7.17 (m, 8 H); 13C NMR (CDCl3) δ
22.31, 22.37, 22.43, 22.50, 23.62, 23.69, 23.84, 24.18, 59.56, 60.23,
120.04, 123.48, 124.06, 125.30, 125.67, 126.03, 126.78, 127.61, 128.47,
130.05, 130.58, 130.88, 131.18, 134.05, 136.74, 146.89, 147.06, 148.68,
149.90 (1 C not located); IR (neat) 3527 s, 2933 s, 1449 s, 1403 s
cm-1; mass spectrum, m/z (relative intensity) 508 (8), 507 (35), 506
M+ (100).
(iii) With Excess Carbene Complex 22. The reaction of carbene
complex 2220 (0.1933 g, 0.611 mmol) and 1,4-diphenyl-1,3-butadiyne
(0.0412 g, 0.204 mmol) in 0.5 mL of THF was carried out at 66 °C for
9 h as described above for the reaction of complex 4a with diyne 8.
The reaction mixture was opened to air and diluted with CH2Cl2. The
major compound present as indicated by TLC was the arene complex
34 (see above, Rf ) 0.38 in 1:5 EtOAc/hexane). Silica gel was added,
and the mixture was allowed to stir in air at 25 °C for 1-2 days until
34 had dissappeared. After flash chromatography on silica gel with a
1:5 mixture of EtOAc/hexane, a 67% yield of monobenzannulated
product 23 (48.3 mg, 0.136 mmol, Rf ) 0.40) and a 4% yield of the
double benzannulated product 33 (3.6 mg, 0.007 mmol, Rf ) 0.35)
were isolated, along with small amounts some unidentified compounds.
The reaction was repeated at 70 °C for 60 h, with an additional 2 equiv
of 22 being added after 20 and 40 h. The crude reaction mixture was
stirred for 30 min at room temperature with 0.5 M aqueous CAN to
give the quinones 32 and 25 in 5% and 0.6% yields, respectively.
(iv) With Excess Carbene Complex 22 in the Presence of Bu3P.
The reaction of carbene complex 2220 (0.205 g, 0.648 mmol),
1,4-diphenyl-1,3-butadiyne (0.0437 g, 0.216 mmol), and tri-n-bu-
tylphosphine (0.48 mL, 1.945 mmol) in 0.5 mL of THF was carried
1
ether); H NMR (CDCl3, -20 °C) δ 4.20 (d, 2 H, J ) 8.5 Hz), 4.57
(d, 2 H, J ) 8.5 Hz), 5.63 (s, 2 H), 6.41 (d, 2 H, J ) 7.3 Hz), 6.67 (d,
2 H, J ) 7.6 H z), 6.96 (t, 2 H, J ) 7.6 Hz), 7.14 (t, 2 H, J ) 7.4 Hz),
7.20 (t, 2 H, J ) 7.4 Hz), 7.53 (t, 2 H, J ) 7.7 Hz), 7.62 (t, 2 H, J )
7.1 Hz), 8.14 (d, 2 H, J ) 8.4 Hz), 8.19 (d, 2 H, J ) 8.3 Hz); 13C
NMR (CDCl3) δ 73.26, 120.61, 122.03, 123.10, 125.08, 125.73, 125.85,
126.81, 127.19, 127.52, 128.18, 129.00, 130.17, 132.07, 134.33, 144.40,
148.51; IR (neat) 3526 m, 3332 w, 3061 w, 2923 m, 2851 w, 1720 m,
1391 m, 1359 m, 1296 m, 1064 s, 761 s cm-1; mass spectrum, m/z
(relative intensity) 496 M+ (100), 468 (7), 450 (2), 423 (2), 105 (12),
73 (22); high-resolution EI MS calcd for C34H24O4 m/z 496.1675, measd
496.1643. Spectral data for 41: whitish-yellow film; Rf ) 0.09 (16:
1
1:1 hexane/CH2Cl2/ether); H NMR (CDCl3) δ 3.44 (s, 1 H), 3.96 (t,
2 H, J ) 11.5 Hz), 4.67 (td, 1 H, J ) 11.3, 2.8 Hz), 4.92-5.00 (m, 1
H), 5.41 (s, 1 H), 6.72-6.75 (m, 3 H), 6.85-6.90 (m, 4 H), 7.14 (t, 1
H, J ) 7.5 Hz), 7.21 -7.59 (m, 8 H), 8.00 (d, 1 H, J ) 8.3 Hz), 8.08
(d, 1 H, J ) 8.2 Hz); 13C NMR (CDCl3) δ 54.67, 64.25, 68.77, 118.30,
119.94, 121.62, 122.82, 123.01, 124.39, 125.46, 126.00, 126.19, 126.32,
126.89, 127.87, 128.20, 128.46, 129.05, 129.80, 130.35, 130.38, 132.00,
136.13, 138.87, 139.42, 141.53, 144.53, 147.68, 155.57; IR (neat) 3531
s, 3059 m, 3026 w, 2938 w, 1723 w, 1599 s, 1584 s, 1499 s,, 1451 s,
1391 s, 1358 s, 1319 m, 1296 m, 1265 m, 1211 w, 1112 m, 1067 s,
1016 w, 892 w, 763 s, 737 s, 702 s cm-1; mass spectrum, m/z (relative
intensity) 468 M+ (100), 440 (4), 422 (4), 262 (6), 105 (5), 77 (3);
high-resolution EI MS calcd for C33H24O3 m/z 468.1725, measd
468.1676.
Preparation of meso-2,3-Butanediol-Bridged Bis-Carbene Com-
plex 42. To a solution of tetramethylammonium metalate 3816 (0.426
g, 1.15 mmol) in 6 mL of a 1:1 mixture of dichloromethane/DMF at
-20 °C was added acetyl bromide (0.093 mL, 1.26 mmol). After the
(20) Chan, K. S.; Peterson, G. A.; Brandvold, T. A.; Faron, K. L.;
Challener, C. A.; Hyldahl, C.; Wulff, W. D. J. Organomet. Chem. 1987,
334, 9.

2180 J. Am. Chem. Soc., Vol. 118, No. 9, 1996
Bao et al.
mixture was stirred at -20 °C for 0.5 h, 2,3-butanediol (0.035 mL,
0.38 mmol, >90% meso) was added, and the resulting solution was
stirred for 2 h at -20 °C and 2 h at 0 °C. The red mixture was poured
into a sepratory funnel containing aqueous saturated NaHCO3 and
hexane. The organic layer was washed with water and brine and then
dried with anhydrous MgSO4. The solvent was removed by rotary
evaporation. The product was isolated from the red residue by flash
chromatography on silica gel with a 1:1:16 mixture of ether/CH2Cl2/
hexane to give 0.126 g (0.59 mmol, 51%) of complex 42. Spectral
binaphthol 46 (0.0196 g, 23%, white solid), and the thermal dimerization
product 48 (0.0099 g, 29%, white solid). Spectral data for 48: Rf )
1
0.61 (1:9 EtOAc/hexane); H NMR (CDCl3) δ 1.37 (d, 6 H, J ) 5.1
Hz), 3.88-3.90 (m, 2 H), 7.11-7.14 (m, 6 H), 7.19-7.22 (m, 4 H);
13C NMR (CDCl3) δ 16.89, 74.81, 127.25, 127.81, 128.91, 133.96,
135.30; IR (neat) 3038 w, 2971 m, 2927 m, 2890 w, 1644 m, 1495 w,
1446 m, 1271 s, 1155 m, 1094 s, 1020 w, 947 w, 764 s, 697 s cm-1
;
mass spectrum, m/z (relative intensity) 266 M+ (28), 178 (3), 165 (4),
105 (100), 77 (40); high-resolution EI MS calcd for C18H18O2 m/z
266.1307, measd 266.1351. Spectral data for 47: Rf ) 0.24 (1:9
1
data for 42: red solid, mp ) 114-115 °C; H NMR (CDCl3) δ 1.70
(br s, 6 H), 5.55 (br s, 2 H), 7.03 (br s, 4 H), 7.33 (br s, 6 H); 13C
NMR (CDCl3) δ 16.24, 87.38, 122.29, 128.34, 130.15, 152.90, 215.84,
224.04, 349.65; IR (neat) 3065 w, 2990 w, 2943 w, 2062 s, 1933 vs,
1721 w, 1574 w, 1442 w, 1384 w, 1313 w, 1269 m, 1207 m, 1162 m,
1087 m, 1070 m, 979 w, 933 w, 900 m, 834 w, 759 w, 703 m, 690 m,
652 s cm-1; mass spectrum, m/z (relative intensity) 402 (5), 318 (33),
266 (16), 220 (32), 178 (46), 105 (100), 80 (97). Anal. Calcd for
C28H18O12Cr2: C, 51.70; H, 2.79. Found: C, 51.87; H, 2.72.
EtOAc/hexane); H NMR (CDCl3) δ 1.53 (d, 3 H, J ) 5.9 Hz), 1.71
1
(d, 3 H, J ) 5.8 Hz), 3.45 (s, 1 H), 3.96-3.99 (m, 2 H), 5.27 (s,1 H),
6.80-6.99 (m, 8 H), 7.23-7.60 (m, 8 H), 8.11 (d, 1 H, J ) 8.1 Hz),
8.20 (d, 1 H, J ) 8.4 Hz); 13C NMR (CDCl3) δ 18.90, 19.31, 53.15,
78.85, 83.06, 117.73, 119.82, 122.65, 122.93, 123.73, 124.14, 124.58,
125.39, 125.68, 126.32, 126.39, 126.48, 128.09, 128.28, 128.50, 128.60,
128.85, 129.91, 130.06, 130.16, 131,94, 135.66, 138.31, 138.81, 144.20,
147.38, 147.98, 156.39; IR (neat) 3595 m, 3054 w, 3017 w, 2975 m,
2933 w, 2869 m, 1601 w, 1586 m, 1495 m, 1442 m, 1381 s, 1354 m,
1313 m, 1296 m, 1266 m, 1210 w, 1177 w, 1138 w, 1122 s, 1092 w,
1063 s, 1029 s, 769 s, 761 s, 737 s, 700 s, 683 s cm-1; mass spectrum,
m/z (relative intensity) 496 M+ (45), 440 (21), 422 (14), 336 (23), 306
(16), 289 (14), 276 (16), 202 (17) 177 (56), 165 (12), 105 (100), 77
(34); high-resolution EI MS calcd for C35H28O3 m/z 496.2038, measd
496.2102. Anal. Calcd for C35H28O3: C, 84.65; H, 5.68. Found: C,
84.88; H, 6.34. Spectral data for 46: Rf ) 0.19 (1:9 EtOAc/hexane);
white solid, mp ) 184 °C dec; 1H NMR (CDCl3) δ 1.59 (d, 6 H, J )
5.7 Hz), 4.00 (m, 2 H), 5.59 (s, 2 H), 6.43 (s, 2 H), 6.74 (s, 2 H), 7.00
(br s, 2 H), 7.16 (m, 4 H), 7.54 (t, 2 H, J ) 8.2 Hz), 7.64 (t, 2 H, J )
8.1 Hz), 8.13 (d, 2 H, J ) 8.2 Hz), 8.26 (d, 2 H, J ) 8.1 Hz); 13C
NMR (CDCl3) δ 19.13, 83.30, 120.48, 122.13, 123.26, 124.99, 125.44,
126.15, 126.63, 127.32, 127.39, 128.12, 129.12, 130.06, 132.10, 134.35,
144.12, 148.04; IR (neat) 3484 m, 3067 w, 2957 m, 2929 m, 2858 m,
1726w, 1588 w, 1448 w, 1387 m, 1380 m, 1360 w, 1298 s, 1276 s,
1125 m, 1064 s, 1031 m, 761 s cm-1; mass spectrum, m/z (relative
intensity) 524 M+ (6), 496 (2), 468 (2), 408 (2), 380 (16), 336 (12),
308 (30), 291 (8), 276 (8), 231 (12), 202 (11), 177 (22), 105 (100), 91
(26), 77 (34); high-resolution EI MS calcd for C36H28O4 m/z 524.1988,
measd 524.2002.
Reaction of the meso-2,3-Butanediol-Bridged Bis-Carbene Com-
plex 42 with 1,4-Diphenyl-1,3-butadiyne (8). The reaction of carbene
complex 42 (0.1256 g, 0.19 mmol) with 0.9 equiv (0.0326 g, 0.16
mmol) of 1,4-diphenyl-1,3-butadiyne (8) in 6.4 mL of THF was carried
out at 75 °C for 5 h according to the procedure described for the reaction
of complex 4a with diyne 8. The product was isolated from the crude
reaction on silica gel with a 1:1:8 mixture of ether/CH2Cl2/hexane to
give 14.6 mg (0.029 mmol) of 43 as a white solid in 22% yield as a
single diastereomer. Spectal data for 43: Rf ) 0.25 (1:9 EtOAc/
hexane); 1H NMR (CDCl3) δ 1.29 (d, 3 H, J ) 6.7 Hz), 1.31 (d, 3 H,
J ) 6.8 Hz), 4.12 (q, 1 H, J ) 6.7 Hz), 4.65 (q, 1 H, J ) 7.0 Hz), 5.13
(s, 1 H), 6.42 (d, 2 H, J ) 7.5 Hz), 6.96 (t, 2 H, J ) 7.3 Hz), 7.02 (t,
1 H, J ) 7.2 Hz), 7.06 (d, 1 H, J ) 7.4 Hz), 7.19-7.40 (m, 12 H),
7.48 (d, 1 H, J ) 7.4 Hz); IR (neat) 3060 w, 3023 w, 2974 w, 2917 m,
2847 w, 1756 vs, 1613 w, 1587 s, 1542 s, 1489 m, 1447 m, 1409
m,1386 w, 1297 w, 1173 m, 1148 w, 1116 w, 1098 m, 1073 m, 1006
m, 909 m, 730 s, 697 s cm-1; mass spectrum, m/z (relative intensity)
496 M+ (100), 440 (20), 424 (21), 363 (12), 336 (8), 307 (8), 289
(14), 276 (12), 247 (20) 236 (18), 194 (18), 105 (45), 77 (18); high-
resolution EI MS calcd for C35H28O3 m/z 496.2038, measd 496.2047.
Anal. Calcd for C35H28O3: C, 84.65; H, 5.68. Found: C, 84.85; H,
6.52.
In a control experiment, it was shown that 48 is a thermal
decompostion product of the carbene complex 44. A solution of 0.025
g (0.038 mmol) of 44 in 1.5 mL of THF was heated at 80 °C under
argon for 16 h. After removal of the volatiles, the residue was loaded
onto a silica gel column and eluted with a 1:30 mixture of EtOAc/
hexane to give 0.052 g (0.02 mmol, 51%) of 48, which was found to
be identical with the major product from the thermolysis of complex
44 with 1,4-diphenyl-1,3-butadiyne.
Preparation of (2R,3R)-Butane-2,3-diol-Bridged Bis-Carbene
Complex 44. To a solution of 1.216 g (3.28 mmol) of tetramethyl-
ammonium metalate 3816 in 10 mL of dichloromethane at -20 °C under
argon was added 0.24 mL (3.28 mmol) of acetyl bromide. After the
mixture was stirred at -20 °C for 1 h, 0.15 mL (1.64 mmol) of (2R,3R)-
butane-2,3-diol was added, and the resulting solution was stirred at
-15 °C for 7.5 h. The red mixture was poured into saturated aqueous
NaHCO3 solution. The organic layer was washed with water and brine
and then dried with anhydrous MgSO4. The solvent was removed, and
the products were purified by flash chromatography on silica gel to
give 0.193 g (0.30 mmol, 18%) of bis-carbene complex 44 (with a
1:1:30 mixture of ether/CH2Cl2/hexane) and 0.342 g (0.92 mmol, 28%)
of a compound tentatively identified as the monocarbene complex 45
(with a 1:1:4 solvent mixture; Rf ) 0.06 with a 1:1:16 solvent mixture)
as red oils. Spectral data for 44: Rf ) 0.38 (1:1:16 ether/CH2Cl2/
Preparation of 2,2′-Binaphthyl Diacetate 49. A solution of
binaphthol 46 (0.0813 g, 0.16 mmol), acetic anhydride (0.088 mL, 0.93
mmol), triethylamine (0.13 mL, 0.93 mmol) and DMAP (5 mg) in 10
mL of THF was introduced into a 25 mL single-necked flask that was
modified by replacement of the 14/20 joint with a threaded high-vacuum
stopcock. The flask was closed at 25 °C and placed in a 65 °C oil
bath for 12 h. The solution was diluted with ether and washed with
aqueous saturated sodium bicarbonate. The product was purified on
silica gel with a 1:1:4 mixture of ether/CH2Cl2/hexane to give 0.0672
g (0.11 mmol) of the diacetate 49 in 71% yield. Spectral data for 49:
Rf ) 0.36 (1:1:4 ether/CH2Cl2/hexane); 1H NMR (CDCl3) δ 1.63 (d, 6
H, J ) 5.8 Hz), 1.94 (s, 6 H), 4.10-4.12 (m, 2 H), 6.48-6.55 (br s,
4 H), 6.83 (br s, 2 H), 7.06 (br s, 4 H), 7.51-7.76 (m, 6 H), 8.16 (d,
2 H, J ) 8.0 Hz); 13C NMR (CDCl3) δ 19.01, 20.43, 83.53, 102.62,
122.26, 122.80, 126.46, 126.77, 126.86, 127.30, 128.12, 131.34, 131.41,
134.87, 140.01, 152.79, 168.57 (1 aryl C not located); IR (neat) 3072
w, 3026 w, 2982 w, 2935 w, 2914 w, 2256 w, 1765 s, 1591 w, 1566
w, 1494 w, 1444 w, 1380 w, 1355 s, 1200 s, 1177 m, 1152 m, 1110 w,
1059 m, 1032 m, 1006 w, 966 w, 912 m, 844 w, 762 m, 711 s, 698 m
cm-1; mass spectrum, m/z (relative intensity) 608 M+ (38), 566 (88),
524 (100), 468 (18), 451 (6), 421 (3), 289 (2), 233 (6), 105 (14); high-
resolution EI MS calcd for C40H32O6 m/z 608.2199, measd 608.2190.
1
hexane), H NMR (CDCl3) δ 1.60 (br s, 6 H), 5.66 (br s, 2 H), 7.14
(br s, 4 H), 7.37 (br s, 6 H); 13C NMR (CDCl3) δ 17.96, 87.63, 122.22,
128.25, 130.01, 153.04, 215.79, 224.40, 350.37; IR (neat) 3060 w, 2986
w, 2939 w, 2062 s, 1929 vs, 1717 w, 1438 w, 1380 w 1268 w, 1201
m, 1159 w, 1073 m, 932 w, 900 w, 760 w, 676 m, 652 s, 619 m cm-1
;
mass spectrum, m/z (relative intensity) 650 M+ (8), 594 (2), 566 (3),
539 (2), 510 (7), 403 (58), 318 (16), 281 (18), 267 (100), 253 (22),
197 (11), 177 (16).
Reaction of the (2R,3R)-Butane-2,3-diol-Bridged Bis-Carbene
Complex 44 with 1,4-Diphenyl-1,3-Butadiyne (8). The reaction of
0.126 g (0.19 mmol) of complex 44 and 0.026 g (0.16 mmol) of 1,4-
diphenyl-1,3-butadiyne (8) in 6.05 mL of THF was carried as described
for the reaction of complex 4a with 8 at 75 °C for 17 h. The solvent
was removed slowly under vacuum, and the residue was loaded onto
a silica gel column and eluted with a 1:9 mixture of ethyl acetate/
hexane. The three products that were isolated were identified as the
indenylnaphthalene 47 (0.0168 g, 21%, light yellow oil), the 2,2′-
Reaction of 2,2′-Binaphthyl Diacetate 49 with Ethanethiol and
Aluminum Chloride. To a solution of the diacetate 49 (0.0404 g,
0.066 mmol) and aluminum chloride (0.151 g, 1.1 mmol) in 2 mL of

Fischer Carbene Complexes with 1,3-Butadiynes
J. Am. Chem. Soc., Vol. 118, No. 9, 1996 2181
CH2Cl2 was added 2 mL of ethanethiol at 25 °C, and the solution was
stirred 16 h at 25 °C. The solution was quenched with brine and
extracted with ether. The organic layer was washed with aqueous
saturated NaHCO3 and water. Quinone 50 (0.0135 g, 0.029 mmol,
44%) was isolated by elution from a silica gel column with a 1:1:4
mixture of CH2Cl2/ether/hexane. The bis-quinone 50 from this reaction
had an optical rotation of [R]D ) -76.4°(c ) 0.5, THF). As described
below, the optical rotation of optically pure bis-quinone 50 was shown
to be [R]D ) 275.5° (c ) 0.54, THF) for the R isomer, and therefore
the compound 46 has S-configuration. Spectral data for 50: yellow
The brown solution was stirred at 25 °C for 40 h, and then the volatiles
were removed by vacuum. Brine and ether were added to the residue,
and the aqueous layer was extracted with ether. The combined organic
layer was washed with saturated aqueous NaHCO3, water, and brine
1
and dried with anhydrous MgSO4. The H NMR spectrum and TLC
both indicated that no bis-quinone 50 was present in the crude reaction
mixture and that the major product was not the bis-naphthol 51. The
crude reaction mixture was dissolved in 5 mL of THF and 1.2 mL of
0.5 M aqueous CAN was added. After the mixture was stirred at 25
°C for 25 min, brine was added. The organic layer was washed with
saturated aqueous NaHCO3, water, and brine and then dried with
anhydrous MgsO4. After removal of solvent, the residue was loaded
onto a silica gel column and eluted with a 1:5 mixture of EtOAc/hexane
to give 0.0685 g (0.16 mmol, 51% yield) of bis-quinone 50. This
compound was found to have an optical rotation of [R] ) 40.8° (c )
0.48, THF). This bis-quinone product (0.028 g, 0.065 mmol) was then
dissolved in 2 mL of THF, and to this solution was added 0.3 mL of
0.5 M aqueous CAN (0.15 mmol). The mixture was stirred in air at
25 °C for 25 min, and then workup as described above afforded 0.0292
g (0.067 mmol, 100%) of bis-quinone 50, which had an optical rotation
of [R]D ) 43.3° (c ) 0.61, THF).
1
solid, mp ) 253-255 °C; Rf ) 0.24 (1:5 EtOAc/hexane); H NMR
(CDCl3) δ 6.69 (d, 4 H, J ) 7.2 Hz), 7.18 (t, 4 H, J ) 7.9 Hz), 7.28-
7.31 (m, 2 H), 7.75-7.83 (m, 4 H), 8.09-8.12 (m, 2 H), 8.18-8.21
(m, 2 H); 13C NMR (CDCl3) δ 126.68, 126.92, 127.65, 129.13, 129.25,
131.85, 131.96, 132.02, 133.91, 134.15, 142.02, 146.35, 183.40, 184.65;
IR (neat) 3060 w, 2914 w, 1665 s, 1595 m, 1322 w, 1287 s, 759 w,
724 m, 708 m, 664 m cm-1; mass spectrum, m/z (relative intensity)
466 M+ (95), 422 (100), 361 (22), 276 (21), 105 (54), 76 (58); high-
resolution EI MS calcd for C32H18O4 m/z 466.1205, measd 466.1193.
A mixture of 0.112 g (0.26 mmol) of (R)-(+)-4813 (optical purity
g99% by HPLC measurement) and 0.025 g (0.077 mmol) of salcomine
was dissolved in 30 mL of THF, and the solution was purged with
oxygen for 4 h. After chromatography on silica gel with a 1:5 mixture
of EtOAc/hexane, 0.1019 g (0.22 mmol, 85%) of quinone (R)-(+)-50
was isolated. This material has a optical rotation of [R]D) 275.5° (c
) 0.54, THF). The same reaction was also carried out with racemic
51, and racemic 50 was isolated in 71% yield.
Acknowledgment. This work was supported by the National
Institutes of Health (PHS-GM 45326) and the National Science
Foundation (CHE-8821326). We thank the NSF for summer
fellowships for M.C.W. and M.J.F. The NMR instruments used
were funded in part by the NSF Chemical Instrumentation
Program.
Racemization of the Bis-2,2′-Naphthoquinone 50 with Ethanethiol
and Aluminum Chloride. A flask was charged with 0.134 g (0.31
mmol) of (R)-(+)-5013 [([R]D ) 275.5° at (c ) 0.54)], 0.689 g (5.17
mmol) of AlCl3, 3 mL of EtSH, and 3 mL of CH2Cl2 under nitrogen.
JA953146K