Selective intermolecular coupling of alkynes with nitriles and ketones via ββ′ carbon-carbon bond cleavage of zirconacyclopentenes

Article abstract of DOI:10.1021/jo980022s

Selective intermolecular coupling of alkynes with nitriles and ketones was performed by the reaction of a mixture of alkynes and Cp2ZrEt₂ with nitriles and ketones, respectively. Hydrolysis of the mixture gave α,β-unsaturated ketones and allylic alcohols in good to excellent yields, respectively. These reactions proceeded via zirconacyclopentenes which were prepared by the reaction of alkynes with Cp2ZrEt₂. The structure of zirconacyclopentene, which was prepared from diphenylacetylene and Cp2ZrEt₂, was determined by X-ray analysis. It clearly indicated that there is a single bond between the β- and β′-carbons of the zirconacyclopentene. The reaction of zirconacyclopentenes with nitriles or ketones proceeded via the β,β′ carbon-carbon bond cleavage of the zirconacyclopentenes. In a similar way, addition of PMes to the zirconacyclopentene afforded a zirconocenealkyne complex in 87% yield.

Full text of DOI:10.1021/jo980022s

6
802
J . Org. Chem. 1998, 63, 6802-6806
Selective In ter m olecu la r Cou p lin g of Alk yn es w ith Nitr iles a n d
Keton es via â,â′ Ca r bon -Ca r bon Bon d Clea va ge of
Zir con a cyclop en ten es
,
§
§
§
1a,§
Tamotsu Takahashi,* Chanjuan Xi, Zhenfeng Xi, Motohiro Kageyama,
Reinald Fischer,1 Kiyohiko Nakajima, and Ei-ichi Negishi*
b,§
†
,‡
Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University,
Kita-ku, Sapporo 060, J apan, Aichi University of Education, Igaya, Kariya, Aichi 444, J apan, and
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
Received J anuary 6, 1998
Selective intermolecular coupling of alkynes with nitriles and ketones was performed by the reaction
of a mixture of alkynes and Cp ZrEt with nitriles and ketones, respectively. Hydrolysis of the
2 2
mixture gave R,â-unsaturated ketones and allylic alcohols in good to excellent yields, respectively.
These reactions proceeded via zirconacyclopentenes which were prepared by the reaction of alkynes
with Cp
and Cp
2
ZrEt
ZrEt
2
. The structure of zirconacyclopentene, which was prepared from diphenylacetylene
2
, was determined by X-ray analysis. It clearly indicated that there is a single bond
2
between the â- and â′-carbons of the zirconacyclopentene. The reaction of zirconacyclopentenes
with nitriles or ketones proceeded via the â,â′ carbon-carbon bond cleavage of the zirconacyclo-
pentenes. In a similar way, addition of PMe
alkyne complex in 87% yield.
3
to the zirconacyclopentene afforded a zirconocene-
In tr od u ction
butene moiety of the zirconocene-butene complex in most
cases.2
,5,6
The ethylene ligand reacts with various un-
2 2 2 2
Dialkylzirconocenes such as Cp ZrBu and Cp ZrEt
are very useful reagents for organic synthesis. They are
saturated compounds and is incorporated in the reaction
products. We have preliminarily reported that Cp ZrEt
2
2
2
in situ converted into zirconocene-olefin complexes by
reacted with alkynes to give zirconacyclopentenes 1 by
â-hydrogen abstraction. For example, Cp
2
ZrBu
Zr(EtCHd
), which has been used as a zirconocene “Cp Zr”
equivalent, since the butene ligand is very labile. On
the other hand, Cp ZrEt gives zirconocene-ethylene
complex Cp Zr(CH dCH ) in a similar way; however, the
2
is con-
the coupling of an alkyne with ethylene derived from
verted into zirconocene-butene complex Cp
CH
2
5
Cp
2
ZrEt
2
.
The zirconacyclopentenes thus formed re-
2
2
acted with various unsaturated compounds to give cou-
3
pling products of alkynes with the unsaturated com-
2
2
pounds.5 Coupling reaction of alkynes with nitriles or
4
2
2
2
ketones using phosphine-stabilized zirconocene-alkyne
behavior of the ethylene ligand is very different from the
7-12
complexes has been reported.
From the point of view
§
Hokkaido University.
Aichi University of Education.
Purdue University.
(5) Takahashi, T.; Kageyama, M.; Denisov, V.; Hara, R.; Negishi,
E. Tetrahedron Lett. 1993, 34, 687-690.
†
‡
(6) (a) Fagan, P. J .; Nugent, W. A.; Calabrese, J . C. J . Am. Chem.
Soc. 1994, 116, 1880-1889. (b) Lipshutz, B. H.; Segi, M. Tetrahedron
1995, 51, 4407-4420.
(1) (a) Visiting research student at Purdue University, 1992. (b)
Visiting Associate Professor at IMS, 1995, on leave from J ena
University, Germany.
2 2
(7) In the case of enyne cyclization using Cp ZrBu , an intermo-
(
2) For reviews, see: (a) Negishi, E.; Takahashi, T. Aldrichim. Acta
lecular coupling of a nitrile with the triple bond in an enyne in a
competitive manner has been reported. See ref 3d.
(8) An intramolecular coupling of 1-cyano-5-heptyne providing an
azazirconacyclopentadiene has been reported: Fagan, P. J .; Nugent,
W. A. J . Am. Chem. Soc. 1988, 110, 2310-2312.
1
(
(
985, 18, 31-47. (b) Negishi, E.; Takahashi, T. Synthesis 1988, 1-19.
c) Buchwald, S. L.; Nielsen, R. B. Chem. Rev. 1988, 88, 1047-1058.
d) Negishi, E. In Comprehensive Organic Synthesis; Trost, B. M.,
Fleming, I., Paquette, L. A., Eds.; Pergamon Press: Oxford, U.K., 1991;
Vol. 5, pp 1163-1184. (e) Binger, P.; Podubrin, S. In Comprehensive
Organometallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson,
G., Eds.; Pergamon Press: Oxford, U.K., 1995; Vol. 4, Chapter 8, pp
(9) Zirconocene-benzyne complexes have been reported to couple
with nitriles; see: (a) Buchwald, S. L.; Watson, B. T.; Huffman, J . C.
J . Am. Chem. Soc. 1986, 108, 7411-7413. (b) Buchwald, S. L.; Watson,
B. T.; Lum, R. T.; Nugent, W. A. J . Am. Chem. Soc. 1987, 109, 7137-
7141. See also reaction of zirconocene-cyclohexyne complex with
nitriles: (c) Buchwald, S. L.; Lum, R. T.; Dewan, J . C. J . Am. Chem.
Soc. 1986, 108, 7441-7442. Some reactions of benzynes with nitriles
were carried out without phosphine. However, the benzynes have to
be formed in situ. See: (d) Buchwald, S. L.; King, S. M. J . Am. Chem.
Soc. 1991, 113, 258-265. (e) Buchwald, S. L.; Sayers, A.; Watson, B.
T.; Dewan, J . C. Tetrahedron Lett. 1987, 28, 3245. (f) Hsu, D. P.; Lusas,
E. A.; Buchwald, S. L.Tetrahedron Lett. 1990, 31, 5563-5566.
(10) Recently, a coupling reaction of alkynes with ketones using a
zirconocene-disilylacetylene complex without phosphine has been
reported. However, only silylacetylenes or diphenylacetylene can be
used; see: (a) Rosenthal, U.; Ohff, A.; Baumann, W.; Tillack, A.; G o¨ rls,
H.; Burlakov, V. V.; Shur, V. B. J . Organomet. Chem. 1994, 484, 203-
207. (b) Penlecke, N.; Ohff, A.; Tillack, A.; Baumann, W.; Kempe, R.;
Burkov, V. V.; Rosenthal, U. Organometallics 1996, 15, 1340.
(11) Buchwald, S. L.; Watson, B. T. J . Am. Chem. Soc. 1987, 109,
2544-2546.
4
1
39-465. (f) Negishi, E.; Takahashi, T. Acc. Chem. Res. 1994, 27, 124-
30.
(3) (a) Negishi, E.; Holms, S. J .; Tour, J . M.; Miller, J . A. J . Am.
Chem. Soc. 1985, 107, 2568-2569. (b) Negishi, E.; Cederbaum, F. E.;
Takahashi, T.; Tetrahedron Lett. 1986, 27, 2829-2832. (c) Negishi, E.;
Swanson, D. R.; Cederbaum, F. E.; Takahashi, T. Tetrahedron Lett.
1
987, 28, 917-920. (d) Negishi, E.; Holms, S. J .; Tour, J . M.; Miller,
J . A.; Cederbaum, F. E.; Swanson, D. R.; Takahashi, T. J . Am. Chem.
Soc. 1989, 111, 3336-3346. (e) Lund E. C.; Livinghouse, T. J . Org.
Chem. 1989, 54, 4487-4490. (f) Wender, P. A.; Mcdonald, F. E.
Tetrahedron Lett. 1990, 31, 3691-3694. (g) Mori, M.; Uesaka, N.;
Shibasaki, M. J . Org. Chem. 1992, 57, 3519-3521.
(4) (a) Takahashi, T.; Seki, T.; Nitto, Y.; Saburi, M. 37th Symposium
on Organometallic Chemistry; Osaka, J apan, 1990; p 172. (b) Taka-
hashi, T.; Seki, T.; Saburi, M.; Negishi, E. XIVth International
Conference on Organometallic Chemistry; Detroit, 1990; p B17. (c)
Takahashi, T.; Seki, T.; Nitto, Y.; Saburi, M.; Rousset, C. J .; Negishi,
E. J . Am. Chem. Soc. 1991, 113, 6266-6268. (d) Takahashi, T.; Suzuki,
N.; Kageyama, M.; Nitto, Y.; Saburi, M.; Negishi, E. Chem. Lett. 1991,
(12) Takahashi, T.; Swanson, D. R.; Negishi, E. Chem. Lett. 1987,
623-626.
1
579-1582.
S0022-3263(98)00022-X CCC: $15.00 © 1998 American Chemical Society
Published on Web 09/12/1998

Selective Intermolecular Coupling of Alkynes
J . Org. Chem., Vol. 63, No. 20, 1998 6803
Ta ble 1. In ter m olecu la r Cou p lin g Rea ction of Alk yn es
w ith Nitr iles on Zir con ocen e
Sch em e 1
alkyne
R tR
nitrile
RCN
1
2
zirconacycle product yield, %a
run
1
2
3
4
5
6
7
PhtPh
ButBu
PrtPr
ButBu
PhtMe
PhtMe
PrCN
PrCN
PrCN
MeCN
MeCN
PrCN
2a
2b
2c
2d
2e
2f
4a
4b
4c
4d
4e
4f
70 (94)
68 (91)
50 (80)
74 (95)
54 (78)
b
80 (95)c
71 (88)
Me3SitMe PhCN
2g
4g
a
Isolated yields. GC yields are given in parentheses. b Two
c
isomers in a ratio of 1:1 were obtained. Two isomers in a ratio of
Sch em e 2
1
.5:1 were obtained.
of organic synthesis, the phosphine-free procedure is
more practical, convenient, and useful. In our reactions,
zirconacyclopentenes behaved as zirconocene-alkyne
complexes without phosphine. In this paper we would
like to report selective intermolecular coupling of alkynes
with nitriles or ketones, and we also report the structure
of a zirconacyclopentene having a single carbon-carbon
bond between the â- and â′-carbons in it. This clearly
shows that the coupling reaction of zirconacyclopentenes
with nitriles or ketones proceeds via the â,â′ carbon-
carbon bond cleavage of the zirconacyclopentenes.1
good yield of 4g after hydrolysis. When terminal alkynes
were used, the corresponding products were not obtained
in good yields.
Coupling of alkynes with nitriles or ketones using
phosphine-stabilized zirconocene-alkyne complexes has
3-17
7-12
been reported.
In our reaction described here, a
zirconacyclopentene 1 was initially formed via a pair-
selective coupling between an alkyne and ethylene of
Cp Zr(CH dCH ) generated in situ from Cp ZrEt . Treat-
2 2 2 2 2
Resu lts a n d Discu ssion
In ter m olecu la r Cou p lin g of Alk yn es w ith Nitr iles
Zr E t . When alkynes were treated with
2 2
Cp ZrEt and nitriles in this order, hydrolysis of the
reaction mixture with 3 N HCl afforded R,â-unsaturated
ketones 4 in good to excellent yields (eq 1, Table 1). As
ment of the zirconacyclopentene 1 with a nitrile at 50 °C
for 1 h afforded an azazirconacyclopentadiene 2 along
Usin g Cp
5
2
2
with elimination of the ethylene moiety of 1. This
reaction provides direct intermolecular coupling products
of an alkyne with a nitrile via a facile cleavage of the
â,â′ carbon-carbon bond of 1.
Formation of azazirconacyclopentadienes 2 was char-
acterized by NMR spectroscopy. Azazirconacyclopenta-
dienes 2d , 2h , and 2i were formed in 89%, 95%, and 91%
1
NMR yield, respectively. Their H NMR spectra showed
a singlet peak assigned to Cp at 5.76 ppm for 2d , 5.92
ppm for 2h , and 5.88 ppm for 2i. Their 13C NMR spectra
revealed characteristic signals for Cp, Zr-C, and C-N
at 108.25, 188.99, and 217.50 ppm for 2d , 109.53, 187.86,
and 214.46 ppm for 2h , and 110.52, 190.16, and 216.89
ppm for 2i.
shown in Table 1, alkyl-, aryl-, and silyl-substituted R,â-
unsaturated ketones are all formed in satisfactory yields.
In the cases of unsymmetrical alkynes such as 1-phenyl-
propyne (runs 5 and 6), regioisomers were formed. The
ratio of two regioisomers was 1:1 or 1.5:1. The regiose-
lectivity of the 1-phenylpropyne moiety in this reaction
is not the same as that observed in the formation of the
zirconacyclopentene, where the selectivity was 20:1 (vide
infra). In the case of silylated alkynes (run 7), although
the formation of several species was observed by the
2 2
reaction with Cp ZrEt , addition of benzonitrile gave a
(
13) (a) Takahashi, T.; Suzuki, N.; Kageyama, M.; Kondakov, D. Y.;
Two paths, a dissociative path and an associative path,
should be considered from 1 to 2 as shown in Scheme 3.
In ter m olecu la r Cou p lin g of Alk yn es w ith Ke-
Hara, R. Tetrahedron Lett. 1993, 34, 4811-4814. (b) Takahashi, T.;
Kotora, M.; Kasai, K.; Suzuki, N. Tetrahedron Lett. 1994, 35, 5685-
5
688. (c) Takahashi, T.; Kondakov, D. Y.; Xi, Z.; Suzuki, N. J . Am.
Chem. Soc. 1995, 117, 5871-5872. (d) Suzuki, N.; Kondakov, D. Y.;
Kageyama, M.; Kotora, M.; Hara, R.; Takahashi, T. Tetrahedron 1995,
1, 4519-4540. (e) Takahashi, T.; Fischer, R.; Xi, Z.; Nakajima, K.
Chem. Lett. 1996, 357-358.
2 2
ton es Usin g Cp Zr Et . Similar reactions proceeded
2 2
when alkynes were treated with Cp ZrEt and ke-
5
tones (eq 2).18 Hydrolysis of the reaction mixture pro-
(
14) (a) Xi, Z.; Hara, R.; Takahashi, T. J . Org. Chem. 1995, 60, 4444-
4
1
448. (b) Takahashi, T.; Xi, Z.; Rousset, C. J .; Suzuki, N. Chem. Lett.
993, 1001-1004.
(15) For previous reports on the cleavage of zirconacyclopentenes,
see: (a) McDade, C.; Bercaw, J . E. J . Organomet. Chem. 1985, 279,
81-315. For cleavage of hafnacyclopentenes, see: (b) Erker, G.; Dorf,
U.; Rheingold, A. L. Organometallics 1988, 7, 138-143.
16) Hara, R.; Xi, Z.; Kotora, M.; Xi, C.; Takahashi, T. Chem. Lett.
996, 1003-1004.
17) (a) Buchwald, S. L.; Nielsen, R. B. J . Am. Chem. Soc. 1989,
11, 2870-2874. (b) Hill, J . E.; Balaich, G.; Fanwick, P. E.; Rothwell,
2
(
1
(
1
(18) Coperet, C.; Negishi, E.; Xi, Z.; Takahashi, T. Tetrahedron Lett.
1994, 35, 695-698.
I. P. Organometallics 1993, 12, 2911-2924.

6
804 J . Org. Chem., Vol. 63, No. 20, 1998
Takahashi et al.
Sch em e 3
Ta ble 3. F or m a tion of Zir con a cyclop en ten es fr om
Cp 2Zr Cl2, 2 equ iv of EtMgBr , a n d Alk yn e
alkyne
R tR
dimer of
1
2
zirconacycle product yield, %a alkyne, %
b
run
1
2
3
4
5
PhtPh
PrtPr
ButBu
PhtMe
1a
1b
1c
1d
1e
7a c
7b
(95)
<1
0
3
3
12
86(94)
(91)
c
7c
7d
c
(92)d
(60)
c
Me3SitMe
7e
a
Isolated yields. GC yields are in parentheses. b Maximum yield
of alkyne dimer is 50%. c Reference 14a. d A mixture of two isomers
in a ratio of 20:1.
is interesting that the stability of 1 in THF could be
controlled by the presence of ethylene gas.
Recently, we have reported a highly selective prepara-
2 2
tive method of zirconacyclopentenes using Cp ZrBu ,
ethylene gas, and alkynes.1 In most cases the amount
of the dimer of alkynes is negligible when zirconacyclo-
pentenes are formed by the reaction of Cp ZrEt with
2 2
4a
Ta ble 2. In ter m olecu la r Cou p lin g Rea ction of Alk yn es
w ith Keton es on Zir con ocen e
alkyne
R tR
alkynes. For the coupling of alkynes with nitriles or
ketones described here, the use of ethylene gas is practi-
cally not necessary. The small amount of the dimer of
alkynes can be separated.
1
2
zirconacycle product yield, %a
run
ketone
1
2
3
4
ButBu
PrtPr
ButBu PhCOMe
PhtPh Et2CO
Et2CO
Et2CO
3a
3b
3c
3d
6a
6b
6c
6d
75 (93)
53 (83)
77
There have been several reports on cross-coupling of
an alkyne with an alkene using zirconium complexes. In
those procedures, either phosphine-stabilized zirconocene-
61 (85)
a
Isolated yields. GC yields are given in parentheses.
2
0
alkene or -alkyne complexes or intramolecular cou-
Sch em e 4
pling3 is involved. Cp
ZrEt provided a convenient
2
2
preparative method of 1 without phosphines.
The characterization of 2,3-diphenyl-1-zirconacyclo-
1
2
pentene 1a (R ) R ) Ph) was initially done by (a)
deuteriolysis with DCl in D O to form 8 in 92% yield with
98% D incorporation, (b) iodinolysis with I
in 90% yield, and (c) carbonylation-iodinolysis to afford
2
2
1
>
2
to give 9
2
2
Sch em e 5
10 in 64% yield. All these results indicated that the
five-membered zirconacyclopentene was formed. The
structure of 1a was determined by X-ray analysis and is
shown in Figure 1. Erker and co-workers have reported
its hafnium analogue by the reaction of hafnacyclopen-
tane with diphenylacetylene.1 The distance of the â,â′
carbon-carbon bond is 1.507 Å, which is in the range
for a normal C-C single bond. This bond is cleaved in
further reactions with unsaturated substrates, such as
nitriles and ketones as described above.
5b
videdallylic alcohols 6 in high yields (Table 2).19 The
reaction path is essentially the same as that described
above for the intermolecular coupling of alkynes with
nitriles.
F or m a tion a n d Ch a r a cter iza tion of Zir con a cy-
clop en ten es. We have reported the formation of zir-
3
Treatment of 1a with 1 equiv of PMe afforded zir-
conocene-alkyne complex 5 in 87% NMR yield when
zirconacyclopentene 1a was heated in the presence of 1.5
conocene-ethylene complex Cp
2
Zr(CH
2
dCH
2
) in situ
12
when zirconocene dichloride was treated with 2 equiv of
EtMgBr.4 When the zirconocene-ethylene complex thus
formed was treated with alkynes, zirconacyclopentenes
3
equiv of PMe at 50 °C for 3 h, as shown in eq 3. This
5
1
were formed in >90% yields (Scheme 5, Table 3).
Homo-coupled products of alkynes were formed in a
small amount (1-3%) in most cases, as shown in Table
. These results are in striking contrast with the case
of Cp ZrBu , which quantitatively gave zirconacyclopen-
3
2
2
3
b
tadienes by dimerization of alkynes. The zirconacyclo-
pentenes gradually decomposed at room temperature. It
result also clearly indicates that zirconacyclopentenes
(
19) For formation of allylic alcohols by intermolecular coupling of
(20) (a) Alt, H. G.; Denner, C. E. J . Organomet. Chem. 1989, 368,
C15-C17; 1990, 390, 53. (b) Fisher, R. A.; Buchwald, S. L. Organo-
metallics 1990, 9, 871-873.
(21) Xi, C.; Huo, S.; Afifi, T. H.; Hara, R.; Takahashi, T. Tetrahedron
Lett. 1997, 38, 4099-4102.
alkynes with aldehydes or ketones using tantalum, see: (a) Takai, K.;
Kataoka, Y.; Uchimoto, K. J . Org. Chem. 1990, 55, 1707. For titanium,
see: (b) Harada, K.; Urabe, H.; Sato, F. Tetrahedron Lett. 1995, 36,
3
203-3206.

Selective Intermolecular Coupling of Alkynes
J . Org. Chem., Vol. 63, No. 20, 1998 6805
F igu r e 1. Str u ctu r e of 2,3-d ip h en yl-1-zir con a cyclop en ten e (1a ). Selected bond distances [Å] and bond angles [deg]: Zr-
C1 2.276(4), Zr-C4 2.271(5), C1-C2 1.336(5), C1-C5 1.490(5), C2-C3 1.507(7), C2-C11 1.502(6), C3-C4 1.443(7); C1-Zr-C4
7
9.1(2), Zr-C1-C2 111.6(3), C1-C2-C3 121.0(4), C2-C3-C4 118.9(4), Zr-C4-C3 109.1(3).
provide a straightforward and convenient source of
zirconocene-alkyne complexes via a facile cleavage of the
â,â′ carbon-carbon bond. Such properties of the â,â′
carbon-carbon bond of zirconacyclopentenes 1 may be
attributable to the existence of the formal equilibrium
between a zirconacyclopentene and a zirconocene-alkyne-
ethylene complex.
127.89, 128.56, 128.63, 129.07, 137.60, 141.63, 144.93. HRMS
calcd for C16 14 210.1375, found 210.1388.
Rep r esen ta tive P r oced u r e for th e P r ep a r a tion of
Aza zir con a cyclop en ta d ien es via Zir con a cyclop en -
ten es: Syn th esis of (Z)-1,2-Dip h en yl-1-h exen -3-on e (4a ).
,3-Diphenylzirconacyclopentene (1a ) was generated as de-
scribed above and could be obtained as yellow single crystals
2
D H
2
2
1
suitable for X-ray crystal analysis. H NMR (C
6
D
6
, Me
4
Si): δ
1
.47 (t, J ) 6.7 Hz, 2H), 3.05 (t, J ) 6.7 Hz, 2H), 5.91 (s, 10
13
Exp er im en ta l Section 25
H), 6.62-7.11 (m, 10H).
6 6 4
C NMR (C D , Me Si): δ 34.50,
4
1
2.88, 111.91, 122.82, 125.72, 126.78, 127.63, 128.06, 129.01,
45.13, 145.82, 149.77, 186.59. To the reaction mixture of
Rep r esen ta tive P r oced u r e for th e P r ep a r a tion of
Zir con a cyclop en ten es: Syn th esis of (Z)-4-Eth yl-4-octen e
zirconacyclopentene 1a was added n-butyronitrile (0.35 mL,
mmol), and the mixture was stirred at 50 °C for 3 h. The
4
(
7b). A 50 mL Schlenk tube under dried nitrogen was charged
above reaction mixture was quenched with 3 N HCl, stirred
at room temperature for 9 h, and then extracted with ether.
The extract was washed with water and brine and dried over
MgSO . The solvent was evaporated in vacuo to give a light
4
brown liquid. Chromatography using a mixture of hexane and
with Cp ZrCl (1.46 g, 5 mmol) and THF (25 mL). To this
2
2
solution was added ethylmagnesium bromide (1.0 M THF
solution, 10 mmol, 10 mL) at -78 °C. After stirring for 1 h,
4
-octyne (0.59 mL, 4 mmol) was added and the reaction
mixture was stirred at 0 °C for 3 h. The above reaction
mixture was then quenched with 3 N HCl and extracted with
ether. The extract was washed with water and brine and dried
ether (5%) as the eluent provided the product 4a as a colorless
1
liquid, 0.70 g (isolated yield 70%, GC yield 94%). H NMR
(
2
7
CDCl
3
, Me
4
Si): δ 0.89 (t, J ) 7.4 Hz, 3H), 1.60-1.69 (m, 2H),
over MgSO
4
. The solvent was evaporated in vacuo to give a
.48 (t, J ) 7.2 Hz, 2H), 7.00-7.25 (m, 5H), 7.28-7.40 (m, 5H),
.62 (s, 1H). C NMR (CDCl , Me Si): δ 13.65, 17.68, 41.71,
3 4
light yellow liquid. Distillation provided the title compound
1
3
7
9
b as a colorless liquid, 0.48 g (isolated yield 86%, purity >
1
127.69, 128.07, 128.87, 129.48, 130.67, 134.66, 136.98, 137.54,
40.77, 201.92. Anal. Calcd for C18 18O: C, 86.36; H, 7.25.
Found: C, 86.51; H, 7.45.
(E)-5-Bu tyl-5-d ecen -4-on e (4b): Yield 91%. 1H NMR
(CDCl , Me Si): δ 0.80-0.87 (m, 9H), 1.18-1.57 (m, 10H),
2.14-2.22 (m, 4H), 2.52 (t, J ) 7.4 Hz, 2H), 6.48 (t, J ) 7.3
3 4
8%, GC yield 94%). H NMR (CDCl , Me Si): δ 0.82-0.86
1
H
(
m, 6H), 0.93 (t, J ) 7.3 Hz, 3H), 1.25-1.37 (m, 4H), 1.89-
1
3
1
.96 (m, 6H), 5.06 (t, J ) 7.0 Hz, 1H).
Si): δ 13.00, 13.88, 14.21, 21.68, 23.33, 29.60, 29.86, 32.33,
23.58, 141.04. Anal. Calcd for C10 20: C, 85.63; H, 14.37.
Found: C, 85.90; H, 14.02.
Compounds 7a , 7c, 7d , and 7e are the same as those
3
C NMR (CDCl ,
Me
1
4
H
3
4
1
3
Hz, 1H).
18.35, 22.41, 22.75, 25.34, 28.44, 31.08, 31.46, 39.21, 142.02,
42.04, 201.78. Anal. Calcd for C14 26O: C, 79.94; H, 12.46.
Found: C, 80.04; H, 12.42.
(E)-5-P r op yl-5-n on en -4-on e (4c): Yield 80%. 1H NMR
CDCl , Me Si): δ 0.79-0.90 (m, 9H), 1.20-1.30 (m, 2H), 1.38-
.59 (m, 4H), 2.12-2.21 (m, 4H), 2.53 (t, J ) 7.3 Hz, 2H), 6.48
3 4
C NMR (CDCl , Me Si): δ 13.74, 13.78, 13.88,
1
4a
reported previously according to NMR data.
1
H
Ch a r a cter iza tion of 8. Deuteriolysis of 1a prepared in
situ as described above followed by usual workup afforded 8
1
in 92% yield with >99% deuterium incorporation. H NMR
(
1
3
4
6 6 4
(C D , Me Si): δ 1.01(tt, J ) 8.0 Hz, 1.9 Hz, 2H), 2.55 (t, J )
8
.0 Hz, 2H), 6.96-6.99 (m, 2H), 7.07-7.13 (m, 3H), 7.19-7.22
1
3
13
(t, J ) 7.3 Hz, 1H). C NMR (CDCl
3
, Me
3.90, 18.30, 22.01, 22.32, 27.51, 30.70, 39.14, 141.90, 141.95,
01.62. Anal. Calcd for C12 22O: C, 79.06; H, 12.16. Found:
4
Si): δ 13.65, 13.69,
(m, 2H), 7.26-7.35 (m, 3H). C NMR (CDCl3, Me
4
Si): δ 12.70
1
2
(t, J ) 19.6 Hz), 33.52, 125.06 (t, J ) 23.8 Hz), 126.13, 126.90,
H
C, 78.57; H, 12.09.
(
22) Takahashi, T.; Xi, Z.; Nishihara, Y.; Huo, S.; Kasai, K.; Aoyagi,
K.; Denisov, V.; Negishi, E. Tetrahedron 1997, 53, 9123-9134.
23) Sheldrick, G. M. SHELXS-86, Program for Crystal Structure
Determination; University of Gottingen, Germany, 1986.
24) Hall, S. R.; Flack, H. D.; Stewart, J . M. Xtal 3.2, Program for
E)-3-Bu tyl-3-octen -2-on e (4d ): Yield 95%. 1H NMR
CDCl , Me Si): δ 0.85-0.96 (m, 6H), 1.25-1.51 (m, 8H), 2.22-
2.30 (m, 7H), 6.59 (t, J ) 7.3 Hz, 1H).
(
(
3
4
(
1
3
C NMR (CDCl
3
,
(
Me
Si): δ 13.93, 13.98, 22.57, 22.91, 25.28, 25.68, 28.70, 31.16,
4
X-ray Crystal Structure Analysis; Universities of Western Australia,
Geneva, and Maryland, 1992.
3
7
1.57, 142.44, 143.88, 199.66. Anal. Calcd for C12H22O: C,
9.06; H, 12.06. Found: C, 78.91; H, 12.14.
(25) For general Experimental Section, see our recent paper: Ta-
(
E)-1-P h en yl-2-m et h yl-1-b u t en -3-on e/(E)-3-P h en yl-3-
kahashi, T.; Xi, Z.; Yamazaki, A.; Liu, Y.; Nakajima, K.; Kotora, M. J .
Am. Chem. Soc. 1998, 120, 1672-1680.
p en ten -2-on e (4e). Two regioisomers, (E)-1-phenyl-2-methyl-

6
806 J . Org. Chem., Vol. 63, No. 20, 1998
Takahashi et al.
1
-buten-3-one and (E)-3-phenyl-3-pentene-2-one, were obtained
(E)-3-Eth yl-4-p r op yl-4-octen -3-ol (6b): Yield 83%. 1H
in a ratio of 1:1. Yield (combined): 78%. (E)-1-Phenyl-2-
NMR (CDCl
8H), 1.80-1.99 (m, 5H), 5.30 (t, J ) 7.2 Hz, 1H). C NMR
(CDCl , Me Si): δ 7.67, 13.74, 14.72, 23.07, 23.10, 30.05, 30.41,
31.94, 78.33, 125.64, 141.66. Anal. Calcd for C13
78.72; H, 13.21. Found: C, 78.61; H, 13.10.
3 4
, Me Si): δ 0.69-0.86 (m, 12H), 1.27-1.55 (m,
1
13
methyl-1-butene-3-one: H NMR (CDCl
3 4
, Me Si): δ 1.85 (d, J
)
0.9 Hz, 3H), 2.06 (s, 3H), 6.90-6.91 (m, 1H), 7.06-7.32 (m,
3
4
1
3
5
1
2
3
H); C NMR (CDCl
3
, Me
4
Si): δ 15.81, 27.44, 127.23, 128.07,
H26O: C,
28.37, 136.15, 137.97, 139.78, 198.61. (E)-3-Phenyl-3-penten-
-one: H NMR (CDCl
H), 2.25 (s, 3H), 6.80 (q, J ) 7.0 Hz, 1H), 7.06-7.32 (m, 5H);
1
3 4
, Me Si): δ 1.52-1.54 (d, J ) 7.1 Hz,
(
E)-2-P h en yl-3-bu tyl-3-octen -2-ol (6c): Isolated yield
1
7
0
2
7%. H NMR (CDCl
.92 (t, J ) 6.9 Hz, 3H), 1.10-1.4 1 (m, 8H), 1.64 (s, 3H), 1.78-
3 4
, Me Si): δ 0.79 (t, J ) 6.9 Hz, 3H),
1
3
C NMR (CDCl
3 4
, Me Si): δ 13.11, 25.99, 128.28, 129.42,
1
29.52, 136.03, 139.18, 144.43, 200.35. HRMS calcd for
13
.15 (m, 5H), 5.62 (t, J ) 7.3 Hz, 1H), 7.15-7.42 (m, 5H).
, Me Si): δ 13.80, 14.07, 22.61, 23.40, 27.74, 28.36,
9.43, 32.11, 32.70, 77.95, 125.59, 125.69, 126.56, 127.89,
C
C
11
H
12O 160.0888, found 160.0889.
NMR (CDCl
3
4
(
E)-3-P h en yl-2-h ep ten e-4-on e/(E)-1-P h en yl-2-m eth yl-1-
2
1
2
h exen -3-on e (4f). Two regioisomers, (E)-3-phenyl-2-hepten-
-one and (E)-1-phenyl-2-methyl-1-hexen-3-one, were obtained
44.38, 147.04. HRMS calcd for C18
60.2145.
H28O 260.2140, found
4
1
in a ratio of 1.5:1. Yield (combined): 95%. H NMR (CDCl
Me Si) for the two regioisomers: δ 0.89 (t, J ) 7.3 Hz), 0.98
t, J ) 7.6 Hz), 1.55-1.76 (m), 2.06 (d, J ) 1.2 Hz), 2.51 (t, J
7.3 Hz), 2.78 (t, J ) 7.3 Hz), 6.93-7.00 (q, J ) 7.3 Hz), 7.08-
3
,
(
Z)-1,2-Dip h en yl-3-eth yl-1-p en ten -3-ol (6d ): Yield 85%.
H NMR (CDCl , Me Si): δ 1.01 (t, J ) 7.3 Hz, 6H), 1.57-
.73 (m, 5H), 6.78-7.30 (m, 11H). C NMR (CDCl
δ 7.83, 31.63, 78.35, 126.29, 127.02, 127.16, 127.69, 128.43,
29.11, 129.42, 136.86, 139.20, 145.55. HRMS calcd for
22O 266.1678, found 266.1681.
X-r a y Cr ysta llogr a p h ic An a lysis of 2,3-Dip h en ylzir -
4
1
3
4
(
)
7
4
1
1
3
1
3 4
, Me Si):
1
3
.52 (m). C NMR (CDCl
3 4
, Me Si) for (E)-3-phenyl-2-hepten-
-one: δ 13.78, 15.49, 17.86, 41.37, 127.35, 128.26, 129.63,
3 4
36.06, 137.63, 143.93, 200.90. C NMR (CDCl , Me Si) for
1
1
3
19
C H
(
3
E)-1-phenyl-2-methyl-1-hexaten-3-one: δ 13.15, 13.96, 18.36,
9.57, 127.35, 128.42, 129.68, 137.46, 138.34, 143.93, 202.49.
HRMS calcd for C13 16O 188.1201, found 188.1209.
E)-1-(Tr im et h ylsilyl)-2-m et h yl-3-p h en yl-1-p r op en -3-
con a cyclop en ten e (1a ). A crystal of dimensions 0.2 × 0.4
3
H
× 0.5 mm was sealed in a capillary tube and mounted on an
(
Enraf-Nonius CAD4 diffractometer. The cell dimensions and
crystal orientation matrixes were obtained from least-squares
refinement of 25 well-centered strong reflections. Crystal-
lographic data: fw ) 427.70, monoclinic, space group C2/c, Z
) 8, a ) 9.1942(6) Å, b ) 17.692(1) Å, c ) 25.383(2) Å, â )
1
on e (4g): Yield 88%. H NMR (CDCl
1
Me
1
2
3
, Me
4
Si): δ 0.01 (s, 9H),
1
3
3
.92 (s, 3H), 6.04 (s, 1H), 7.21-7.52 (m, 5H). C NMR (CDCl ,
4
Si): δ -0.59, 17.69, 128.03, 129.52, 131.83, 137.43, 142.12,
50.67, 199.00. HRMS calcd for C13
18.1123.
H18OSi 218.1127, found
3
-3
92.670(7)°, V ) 4126.2(8) Å , D ) 1.38 g cm , and µ(Mo KR)
x
-1
Observation of Formation of Azazirconacyclopentadienes (2)
by NMR.
Aza zir con a cyclop en ta d ien e 2d : NMR yield 89%. Char-
) 5.30 cm . Diffraction data were collected at room temper-
ature by using graphite-monochromatized Mo KR radiation (λ
) 0.710 73 Å) and a ω scan technique. Intensities were
corrected for the gain (14%) observed in the intensities of the
three standard reflections, monitored periodically during data
collection. A total of 6365 reflections (2θmax ) 60°) were
1
acteristic NMR peaks: H NMR (C
6
D
6
-THF, Me
4
4
Si): δ 5.76
1
3
(
1
s, 10H, 2 Cp); C NMR (C
88.99, 217.50.
Aza zir con a cyclop en ta d ien e 2h : NMR yield 95%. Iso-
lated yield: 89%. H NMR (C
s, 10H, 2 Cp), 6.97-7.13 (m, 10H). C NMR (C
δ 30.77, 109.53, 122.80, 124.99, 125.56, 127.11, 127.29, 130.45,
43.91, 146.68, 153.02, 187.86, 214.46. Anal. Calcd for C26
NZr: C, 70.86; H, 5.26; N, 3.18. Found: C, 70.60; H, 5.39; N,
.17.
Aza zir con a cyclop en ta d ien e 2i: NMR yield 91%. 1H
6
D
6
-THF, Me Si): δ 108.25, 143.89,
measured, of which 3061 reflections were unique with |F | >
o
1
6
D
6
, Me
4
1
Si): δ 2.13 (s, 3H), 5.92
3σ(|F |). The structure was solved by direct methods (SHELXS-
o
3
23
(
6
D
6
, Me
4
Si):
86) and subsequently completed by Fourier recycling. All
non-hydrogen atoms were refined anisotropically by full-matrix
1
23
H -
least-squares techniques using Xtal3.2 software.24 All the
hydrogen atoms were located at the calculated positions with
isotropic displacement parameters of their parent carbon
atoms. Refinement of positional and thermal parameters
3
NMR (C
6
D
6
, Me
4
3
Si): δ 1.23 (s, 9H), 5.88 (s, 10H, 2 Cp), 6.68-
converged at R ) 0.048, R ) 0.045, and GOF ) 1.42.
w
1
7
1
1
.26 (m, 14H). C NMR (C
6
D
6
, Me
4
3
Si): δ 31.18 (3 CH ), 34.51,
10.52, 123.31, 123.65, 123.74, 126.33, 127.16, 127.39, 128.65,
31.97, 143.36, 144.33, 148.84, 149.47, 153.55, 190.16, 216.89.
Rep r esen ta tive P r oced u r e for th e P r ep a r a tion of
Ack n ow led gm en t. We thank the Ministry of Edu-
cation, Science, Sports and Culture, J apan, for support
of this study.
Allylic Alcoh ols 6 fr om th e Rea ction of Zir con a cyclo-
p en ten es 1 w ith Keton es. The procedure for synthesis of
allylic alcohols 6 was the same as that for 4. Hydrolysis was
fast (at room temperature for 30 min with 3 N HCl) in this
case.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data, positional and thermal parameters, and lists of bond
1
13
lengths and angles for 1a and H and C NMR spectra of 4a -
g, 6a -d , and 7b (18 pages). This material is contained in
libraries on microfiche, immediately follows this article in the
microfilm version of the journal, and can be ordered from the
ACS; see any current masthead page for ordering information.
(
E)-3-Eth yl-4-bu tyl-4-n on en -3-ol (6a ): Yield 93%. 1H
NMR (CDCl
3 4
, Me Si): δ 0.78 (t, J ) 7.3 Hz, 6H), 0.83-1.0 (m,
6
H), 1.25-1.65 (m, 12H), 1.89-2.12 (m, 5H), 5.35 (t, J ) 7.3
1
3
Hz, 1H). C NMR (CDCl
3
, Me
4
Si): δ 7.89, 13.93, 14.07, 22.52,
2
3.63, 27.76, 27.98, 32.02, 32.18, 32.33, 78.60, 125.82, 141.56.
HRMS calcd for C15
H
30O 226.2295, found 226.2297.
J O980022S