7-(Dimethylamino)tricyclo[5.2.2.01,6]undecene derivatives from β-cyclohexenyl β-dimethylamino-substituted α,β-unsaturated fischer carbenes

Article abstract of DOI:10.1002/ejoc.200400471

When heated in pyridine at 80°C, pentacarbonyl[(2E)-3-cyclohexenyl-3- (dimethylamino)-1-ethoxy-2-propen-1-yl-idene]chromium (1-Cr) and -tungsten (1-W) complexes undergo 6π-electrocyclization and subsequent reductive elimination to yield the cyclohexane-an

Full text of DOI:10.1002/ejoc.200400471

FULL PAPER
7-(Dimethylamino)tricyclo[5.2.2.01,6]undecene Derivatives from β-Cyclohexenyl
β-Dimethylamino-Substituted α,β-Unsaturated Fischer Carbenes
Yao-Ting Wu,[a] Thomas Labahn,[b][‡] Attila Demeter,[c,d] Klaas A. Zachariasse,[c] and
Armin de Meijere*[a]
Keywords: Fischer carbene complexes / Organometallics / Sequential reactions / Pericyclic reactions / DielsϪAlder
reactions / Dual fluorescence / Radiative rate constants
When heated in pyridine at 80 °C, pentacarbonyl[(2E)-3-
cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-propen-1-yl-
idene]chromium (1-Cr) and -tungsten (1-W) complexes un-
tion. In this reaction, the tungsten complex 1-W consistently
gave lower yields than 1-Cr. Arylalkynes with strongly elec-
tron-withdrawing groups and minimal steric congestion are
dergo 6π-electrocyclization and subsequent reductive elim- particularly suitable reaction partners for 7. The formation of
ination to yield the cyclohexane-annelated cyclopentadiene
bis-cycloadducts 10 from suitable diynes largely depends
6, which equilibrates by 1,5-hydrogen shift with its more re-
upon the steric and electronic properties of the correspond-
active isomer 7. The latter molecule is efficiently trapped in ing alkynyl-substituted mono-cycloaddition products of type
Diels−Alder reactions with various alkynes 2 and styrenes 8
to give the cyclohexane-annelated norbornadiene 3 and nor-
bornene derivatives respectively, with high regio- and dias-
tereoselectivity in 15−91% yields. The enol ether moiety in
compound 3 is particularly easily hydrolyzed, probably due
to the through-space interaction between the two double
bond moieties, so that the norbornenone derivatives 4 are
isolated in all but one case after chromatographic purifica-
4 or 11. With the fluorenyl-substituted tricycle 4w in aceto-
nitrile at 25 °C, but not with 4y, dual fluorescence is ob-
served, with a red-shifted unstructured additional emission
band with a dipole moment of 32 D, originating from intra-
molecular charge transfer. The molecule 2y has an excep-
tionally large radiative rate constant of 13 × 108 s−1
.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2004)
Introduction
crude products. However, hydrolysis of the enol ether moi-
ety in 3 apparently occurred during chromatographic purifi-
cation, and the corresponding ketones 4 were the only iso-
lated products. In order to better understand this con-
venient access to these highly functionalized interesting tri-
cycles, we have continued our efforts in this area. Especially,
we have addressed the questions concerning the steric and
electronic effects of the substituents on the incorporated
alkynes 2, and the influence of the nature of the transition
metal in the carbene complexes 1 on this reaction. Here we
report on these aspects and the full scope of this method.
α,β-Unsaturated Fischer carbenes have established their
broad versatility in organic synthesis.[1] Among a wide spec-
trum of easily accessible products from such metal com-
plexes, 7-(dimethylamino)tricyclo[5.2.2.01,6]undec-10-en-9-
ones 4 were obtained from pentacarbonyl(3-cyclohexenyl-3-
(dimethylamino)-1-ethoxy-2-propen-1-ylidene)chromium
(1-Cr) and alkynes 2 in one step with high regio- and stereo-
selectivity (Scheme 1), as we communicated previously.[2]
The initial products were actually the cycloadducts 3 as as-
signed on the basis of 1H and 13C NMR spectra of the
[a]
Institut für Organische und Biomolekulare Chemie, Georg-
Results and Discussion
August-Universität Göttingen,
Tammannstrasse 2, 37077 Göttingen, Germany
[b]
Institut für Anorganische Chemie, Georg-August-Universität
β-(Dimethylamino)-substituted α,β-unsaturated Fischer
carbene complexes 1 were prepared from lithiated 1-ethy-
nyl-1-cyclohexene, the respective hexacarbonylmetal, tri-
ethyloxonium tetrafluoroborate and dimethylamine accord-
ing to the previously developed one-pot procedure in excel-
lent yields (94% for 1-Cr[1] and 87% for 1-W). As mentioned
previously,[2] the cyclohexane-annelated cyclopentadiene 6
is formed via a 6π-electrocyclization, and the observed re-
Göttingen,
Tammannstrasse 4, 37077 Göttingen, Germany
[c]
Max-Planck-Institut für biophysikalische Chemie,
Am Faßberg 11, 37077 Göttingen, Germany
[d]
Institute of Chemistry, Chemical Research Center, Hungarian
Academy of Sciences,
P. O. Box 17, 1525 Budapest, Hungary
[‡]
Crystal structure analysis.
Supporting information for this article is available on the
WWW under http://www.eurjoc.org or from the author.
Eur. J. Org. Chem. 0000, 4483Ϫ4491
DOI: 10.1002/ejoc.200400471
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FULL PAPER
Scheme 1. One-pot synthesis of 7-(dimethylamino)tricyclo[5.2.2.01,6]undec-10-en-9-ones 4 from complexes 1 and alkynes 2 as well as a
mechanistic rationalization. a: 6π-electrocyclization. b: reductive elimination. c: 1,5-hydrogen shift. d: [4ϩ2] cycloaddition. For details see
Table 1
gional and facial selectivities in the DielsϪAlder reactions with its two strong electron-donating groups is a particu-
of 7 with dienophiles 2 can be explained on the basis of a larly reactive diene. The arylacetylene 2j with its meth-
model proposed by Winterfeldt[3] (Scheme 2). The applied oxycarbonyl group afforded a much higher yield than 2h
alkynes add onto the more reactive 1,3-diene 7 with syn- with the electron-donating 4-ethoxy group (cf. entries 12
facial selectivity (with respect to the hydrogen in 7) and, as and 14 in Table 1). Apparently, alkynes containing electron-
far as the larger groups RL are concerned, the ortho-selec- withdrawing groups are more suitable reaction partners for
tivity rule (with respect to the dimethylamino group in 7) the cyclopentadiene 7. Whereas the symmetric diphenyl-
is obeyed.[2]
ethyne did not react with 7, ethyl 4-phenylethynylbenzoate
As listed in Table 1, 31 out of 32 examples gave only the (2k) gave the cycloadduct 4k in 66% yield (entry 15 in
hydrolysis products 4. However, the reaction of complex 1- Table 1).
Cr with 1,4-diphenyl-1,3-butadiyne (2q) did not only yield
Steric encumbrance in the applied alkynes may cause an-
the ketone 4q, but also the non-hydrolyzed enol ether 3q, other limitation in this cycloaddition. In the reactions of
even after chromatographic purification. Just like norbor- the complex 1-Cr with o-, m- and p-(trifluoromethyl)ethyn-
nadiene itself, the tricyclic norbornadiene derivatives 3 must ylbenzene (entries 16Ϫ18 in Table 1), the ortho-isomer gave
have a strong through-space electronic interaction,[4] which a much lower yield than the m- and the p-isomer. The cyclo-
leads to an elevation of the HOMO energy. The enol ether addition of 1-phenyl-4-(trimethylsilyl)buta-1,3-diyne (2p)
moieties in 3 therefore undergo more facile hydrolysis than onto 7 is an example for a high regioselectivity furnishing
ordinary enol ethers. The phenylethynyl substituent in 4q, 4p as the sole product, probably due to electronic as well as
however, exerts a stronger electron-withdrawing effect than steric reasons. The cycloaddition modes B and D (see Fig-
others and thus probably causes a decrease of the hydroly- ure 1) should be disfavored due to the stronger electron-
sis rate.
withdrawing ability of the phenylethynyl substituent as
With the tungsten complex 1-W, the same tricyclic com- compared to that of the trimethylsilyl and (trimethylsilyl)-
pounds were formed, but in lower yields in most cases. In ethynyl group. In addition, the steric demand of the tri-
order to rationalize this difference, the transformation of methylsilyl substituent disfavors the cycloaddition modes C
the tungsten complex 1-W in [D5]pyridine at room tempera- and D. This steric influence is also supported by the
ture was monitored by NMR spectroscopy and found to observation that 3-(trimethylsilylethynyl)benzotrifluoride as
proceed more slowly to 6 than that of 1-Cr. This must be a dienophile did not afford any tricyclic product in this re-
due to the enhanced bond strength between tungsten and action, whereas the cycloaddition product 4m was obtained
the carbene carbon. The conversion of 1-W to 6 was not in 84% yield from the unsilylated 3-ethynylbenzotrifluoride
complete within 2 days, yet during the whole period only 2m (entry 17 in Table 1).
the signals of the complex 1-W and the cyclization product
Styrene and substituted styrenes 8 also underwent cyclo-
6 were observed. Unfortunately, the highly labile molyb- addition with the diene 7 in situ formed from the complexes
denum analogue 1-Mo could not be isolated, therefore a 1-M to yield the cyclohexane-annelated ethoxy(dimethyla-
complete comparison of the transition metal effect in this mino)norbornene derivatives 9 (Scheme 2). These enol
transformation for all of the group VI metals cannot be ethers did not undergo rapid subsequent hydrolysis, such as
made.
all but one of the norbornadienes 3 do (see above). The
It is well-known that electronic as well as steric effects of yields of compounds 9 were consistently lower than those
substituents on both dienes and dienophiles play important of products 4 from alkynes. Since the LUMO energy of
roles in the DielsϪAlder reaction.[5] The cyclopentadiene 7 styrene is ca. 0.5 eV higher than that of phenylethyne (2e),
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Reactions of Fischer Carbene Complexes with Alkynes
FULL PAPER
Table 1. One-pot synthesis of 7-(dimethylamino)tricyclo-
[5.2.2.01,6]undec-10-en-9-ones 4 (see Scheme 1)
Figure 1. Four conceivable reaction modes of the intermediate
cyclohexane-annelated (dimethylamino)ethoxycyclopentadiene
with phenyl(trimethylsilyl)butadiyne 2q
7
Scheme 2. Synthesis of 7-(dimethylamino)-9-ethoxytricyclo-
[5.2.2.01,6]undec-8-enes 9 from the complexes 1-M and styrenes 8
[a]
See ref.[2] [b] 2.2 equiv. of complex 1a was used for this reaction.
its reaction with the same diene 7 probably proceeds more
slowly.[6] The constitution and the endo configuration of 9a
were rigorously proved by an X-ray crystal structure analy- Figure 2. Structure of the cyclohexane-annelated ethoxy(dimethyl-
amino)norbornene 9a in the crystal[7]
sis (Figure 2).[7]
Generally speaking, the alkynes and alkenes used above
are considered as being unreactive dienophiles in the formation, since they reacted with the solvent, pyridine, and
DielsϪAlder reaction. However, more reactive dienophiles produced dark-colored complicated mixtures.[8]
such as methyl propiolate, dimethyl acetylenedicarboxylate,
In all of the [4ϩ2] cycloadditions of a variety of diynes,
maleic anhydride etc. could not be employed in this trans- enediynes and oligoynes used, only the monoadducts 4 were
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Y.-T. Wu, T. Labahn, A. Demeter, K. A. Zachariasse, A. de Meijere
1
FULL PAPER
obtained, even when a 2.2-fold excess of complex 1-Cr was adducts could be detected in the mass spectrum. Their H-
employed (entry 25 in Table 1). In view of this result, the and 13C-NMR spectra each show five sets of signals with
possibilities of forming bisadducts 12 from not directly con- an approximate intensity ratio of 2:1:1:1:1 for the signals of
jugated diynes were investigated. Since phenyl-substituted dimethylamino as well as the carbonyl groups. According
monoalkynes consistently gave the highest yields, a number to these observations, the mixture of bisadducts consisted
of diynes of type 10 were employed for the reaction of the three regioisomers 14, 15 and 16 in a ratio of 1:1:1
(Scheme 3). Indeed, twofold adducts were obtained when (Scheme 4). Hence, the degree to which bisadducts are
more than 1.5 equivalents of the complex 1-Cr per triple formed, greatly depends upon the nature of the linkage Y
bond was employed, otherwise mainly the monoadducts of in 10, and it appears that they are only formed from alkyn-
type 4 were isolated. However, with 1,4-diethynylbenzene yl- and phenyl-substituted diynes.
10a (ϵ 2t) the bisadduct 12a was obtained in 8% yield, and
Recently,
oligo-(9,9-di-n-hexyl-2,7-fluorenethynylene)s
none of the monoadduct was observed (entry 1 in Table 2). were reported as potential candidates for light-emitting di-
This unsatisfactory result could arise from the much lower odes (LEDs), the fluorescence of which would possibly be
solubility of 12a in organic solvents. The directly conju- shifted towards blue light by way of an appropriate varia-
gated bis-dienophile, 1,4-diphenyl-1,3-butadiyne (2q), tion of the length of their conjugated systems.[9]
yielded only the monoadduct 11d (ϵ 4q), even when
3.5 equiv. of the complex 1-Cr was employed.
With this information in mind, the electronic absorption
and fluorescence spectra (Figure 3) as well as the fluorence
decay times (Table 3) of the fluorenyl-substituted tricyclic
compounds 4w and 4y and their corresponding dienophilic
precursors 2w and 2y were measured.
The fluorescence spectra of 2w and 2y in diethyl ether
are structured and show only a small decrease in energy
between the lowest-energy absorption and the highest-en-
ergy fluorescence bands (small Stokes-shift), comparable to
that found for an alternating aromatic hydrocarbon such as
anthracene. This observation indicates that there is not an
appreciable change in molecular structure when going from
the electronic ground state S0 via the Franck-Condon ex-
cited state reached in absorption to the equilibrated fluor-
escing lowest singlet excited state S1. For 4w and 4y in
acetonitrile, in contrast, the Stokes shift is considerably
larger than that observed with 2w and 2y, similar to that
found e.g. with an aromatic amine such as aniline, which
means that the change in molecular structure of 4w and 4y
between S0 and S1 is larger than for the compounds 2w
and 2y.
Scheme 3. Synthesis of twofold cycloadducts 12 from the complex
1-Cr and diynes 10; for details see Table 2
The fluorescence spectrum of 4w in acetonitrile consists
of two emission bands (Figure 3, c). The structureless fluor-
escence band at lower energies is obtained by subtracting
from the total fluorescence spectrum that of 4w in n-hexane,
for which only a single fluorescence band is observed
(Table 4). The excitation spectrum of 4w in acetonitrile,
measured at 610 nm (low-energy emission band) is similar
to that determined at 460 nm, see part c in Figure 3, which
shows that both emission bands originate from 4w. This
dual fluorescence is due to an intramolecular charge trans-
fer (ICT) process, giving rise to an ICT band red-shifted
with respect to the locally excited (LE) emission.[10] This
conclusion is based on the observation that the ICT/LE flu-
orescence quantum yield ratio ΦICT/ΦLE increases when the
solvent polarity becomes larger (see Table 4). In the nonpo-
lar solvent n-hexane, dual fluorescence is not observed, as
Table 2. Synthesis of twofold cycloadducts 12 (see Scheme 4)
[a]
All reactions were carried out at 80 °C for 2 d.
In view of the thermal instability of the highly reactive mentioned above, whereas the second band is clearly pre-
1,8-diphenyl-1,3,5,7-octatetrayne (13), the cyclopentadiene sent in the more polar diethyl ether (ΦICT/ΦLE ϭ 0.24) and
6 was first generated by heating the complex 1-Cr in pyri- dual emission becomes progressively more important when
dine at 80 °C for 3 h. Then, the tetrayne 13 was introduced the solvent polarity increases (Table 4), with a value for
into the reaction medium, and the mixture was stirred at ΦICT/ΦLE of 0.40 (tetrahydrofuran), 0.82 (n-propyl cyanide)
ambient temperature for 3 days. After purification, only bis- and 1.15 (acetonitrile).
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Reactions of Fischer Carbene Complexes with Alkynes
FULL PAPER
Scheme 4. Synthesis of twofold cycloadducts 14, 15 and 16
Figure 3. Absorption and fluorescence spectra (at 25 °C) of the alkynes 2w and 2y and their cycloadducts 4w and 4y in diethyl ether
(DEE) and in acetonitrile (MeCN)
The maximum of the ICT fluorescence band ν˜max(ICT) employing a calculated (Hyperchem, PM3) ground state di-
of 4w undergoes a red-shift with increasing solvent polarity, pole moment µg of 3.4 D and assuming that 4w has a mo-
from 20080 cmϪ1 (diethyl ether) to 17000 cmϪ1 (aceto- lecular density of 1.0.[12] The fact that an ICT process does
nitrile, see Table 4). From these data, an ICT dipole mo- not occur in the case of 4y, may be caused by the presence
ment µe(ICT) of 32 D is estimated (Equations 1 and 2),[11] in this molecule of the phenylethynyl substituent which ap-
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Table 3. Absorption and fluorescence data (at 25 °C) of the alkynes 2w and 2y and their cycloadducts 4w and 4y in diethyl ether (DEE)
and in acetonitrile (MeCN)
Solvent
Extinction coefficient (ε)
[Ϫ1cmϪ1 [a]
Fluorescence
Quantum yield (Φ)
Fluorescence decay
Time (τ) [ns]
Radiative rate constant[b] (kf)
]
[108 sϪ1
]
2w
2y
DEE
DEE
10000 (375 nm)
66070 (369 nm),
0.19
0.60
0.23
0.46
8.2
13
4w
4y
MeCN
MeCN
17780 (361 nm)
112200 (340 nm), 380 (376 nm)
0.013 (Φ)[c]
0.138
1.84 (430, 560 nm)[d]
1.69
0.8
[a]
[b]
[c]
[d]
At selected wavelengths in the absorption spectrum above 340 nm, see Figure 3. kf ϭ Φ/τ. See Table 4. See Figure 3, c.
Table 4. ICT and LE fluorescence quantum yields ΦICT and ΦLE and the energy ν˜max(ICT) of the ICT emission band maximum of 4w
at 25 °C in five solvents of different polarity
Solvent
ε
n
f Ϫ1/2fЈ[a]
ΦICT/ΦLE
ΦICT
ΦLE
ν˜max(ICT)/ cmϪ1
n-hexane
1.88
4.27
7.39
24.2
36.1
1.372
1.361
1.405
1.382
1.342
0.092
0.252
0.307
0.375
0.393
0
0
0.48
0.13
0.03
0.008
0.006
diethyl ether
tetrahydrofuran
n-propyl cyanide
acetonitrile
0.24
0.40
0.82
1.15
0.03
0.013
0.006
0.007
20080
18520
17570
17000
[a]
f ϭ (ε Ϫ 1)/(2ε ϩ 1), fЈ ϭ (n2 Ϫ 1)/(2n2 ϩ 1), see Equation (2).
parently reduces the electron-donor character of the fluor- even towards moderately activated alkynes which act as di-
enyl moieties.
enophiles. The donor-acceptor substituted norbornadienes
3 thus formed exhibit strong through-space electronic inter-
actions and therefore undergo rapid hydrolysis at their enol
ether moieties to yield acceptor-substituted norbornenones
4. With 4w in sufficiently polar solvents (diethyl ether to
acetonitrile) dual fluorescence is observed. The red-shifted
new emission band originates from intramolecular charge
transfer in 4w, leading to an ICT state with a dipole mo-
ment of 32 D. In the case of 2y, especially, an exceptionally
large radiative rate constant is found.
(1)
(2)
In Equation (1), ρ is the Onsager radius of the solute, h
is the Planck constant, and c is the speed of light, whereas
ε and n are the dielectric constant and refractive index of
the solvent, respectively.
The fluorescence decays of all four compounds are single
exponential (Table 3). For 4w this means that the ICT pro-
cess leading to the appearance of the second red-shifted em-
ission band is faster than the time resolution (around 3 ps)
of the SPC laser equipment used in the present experi-
ments.[13]
Experimental Section
1
General: H and 13C NMR: Bruker AM 250 (250 and 62.9 MHz).
IR: Bruker IFS 66 (FT-IR). Low-resolution EI-MS: Varian MAT
CH 7, MAT 731, ionizing voltage 70 eV. High-resolution EI-MS
(HR EI-MS): Varian MAT 311 A. X-ray crystal structure determi-
nation: The data were collected on a StoeϪSiemens-AED dif-
fractometer. Melting points were determined with a Büchi melting
point apparatus and are uncorrected. Elemental analysis: Mikroana-
lytisches Laboratorium der Georg-August-Universität Göttingen.
Chromatography: ICN neutral alumina (Super I, activity II). Sol-
vents for chromatography were technical grade and freshly distilled
before use. Tetrahydrofuran was distilled from sodium benzo-
phenone ketyl, and pyridine was distilled from calcium hydride.
Pentacarbonyl[(2E)-3-cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-
propen-1-ylidene]chromium (1-Cr),[2] 1-ethynyl-1-cyclopentene
(2a),[15] 1-ethynyl-1-cyclohexene (2b),[15] methyl p-ethynylbenzoate
(2j),[16] 2-ethynylthiophene (2f),[17] 2-ethynylbenzotrifluoride (2l),[17]
It is of interest to note that the radiative rate constant kf
of 2y, in particular, is exceptionally large, with a value of
13.0 ϫ 108 sϪ1 (Table 3). For comparison, the highly fluor-
escent molecule p-terphenyl, as an example, has a clearly
smaller kf of 9.8 ϫ 108 sϪ1 [14]
.
Conclusion
3-ethynylbenzotrifluoride
(2m),[17]
4-ethynylbenzotrifluoride
(2n),[17] 1-ethynylnaphthalene (2o),[17] 1-phenyl-4-(trimethylsilyl)-
The in situ generated cyclohexane-annelated cyclopen-
tadiene 7 shows a remarkably high DielsϪAlder reactivity 1,3-butadiyne (2p),[17,18] 1,4-diethynylbenzene (2t),[19] 1,3,5-triethy-
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Reactions of Fischer Carbene Complexes with Alkynes
FULL PAPER
nylbenzene (2u),[19] 2-ethynyl-9,9-di-n-hexylfluorene (2v),[9] 2,7-di- 7-(Dimethylamino)-11-[4Ј-(methoxycarbonyl)phenyl]tricyclo-
ethynyl-9,9-di-n-hexylfluorene (2 ؋),[9] 1,2-bis(4-ethynylphenyl)- [5.2.2.01,6]undec-10-en-9-one (4j): According to GP, a solution of
ethane (10c),[17,20] 1,8-diphenyl-1,3,5,7-octatetrayne (13),[21] 2- (1.04 g, 2.61 mmol) of complex 1-Cr in pyridine (52 mL) was
bromo-9,9-di-n-hexyl-7-(3Ј-hydroxy-3Ј-methylbut-1Ј-ynyl)-
treated with (500 mg, 3.12 mmol) of methyl p-ethynylbenzoate (2j),
and the mixture was stirred at 80 °C for 60 h. Chromatography on
aluminum oxide (activity II, 40 g) eluting with pentane/Et2O (from
1:0 to 3:1) gave 805 mg (91%) of 4j [Rf ϭ 0.26 (pentane/Et2O, 3:1)]
as a colorless solid, m.p. 151Ϫ152 °C. IR (KBr): ν˜ ϭ 2936 cmϪ1
(CϪH), 1745 (CϭO), 1715 (CϭO), 1607, 1432, 1321, 1284, 1113,
765, 701. 1H NMR (250 MHz, CDCl3): δ ϭ 1.00Ϫ1.45 (m, 4 H,
2,3,4,5-H), 1.50Ϫ1.70 (m, 2 H, 3,4-H), 1.80Ϫ1.90 (m, 1 H, 5-H),
2.10Ϫ2.30 (m, 2 H, 2,8-H), 2.33 [s, 6 H, N(CH3)2], 2.41Ϫ2.57 (m,
1 H, 6-H), 2.76 (AB, d, 2J ϭ 14.4 Hz, 1 H, 8-H), 3.86 (s, 3 H,
CO2CH3), 5.96 (s, 1 H, 10-H), 7.64 (d, 3J ϭ 8.0 Hz, 2 H, Ar-H),
7.92 (d, 3J ϭ 8.0 Hz, 2 H, Ar-H). 13C NMR (62.9 MHz, CDCl3,
plus DEPT): δ ϭ 22.2, 22.9, 24.3, 26.0 (Ϫ, C-2,3,4,5), 37.0 (Ϫ, C-
8), 40.1 [ϩ, N(CH3)2], 51.9 (ϩ, CO2CH3), 59.7 (ϩ, C-6), 62.5
(Cquat, C-1), 74.6 (Cquat, C-7), 125.1 (ϩ, Ar-C), 128.8 (Cquat, Ar-
C), 129.3 (ϩ, Ar-C), 131.7 (ϩ, C-10), 140.0 (Cquat, Ar-C), 155.6
(Cquat, C-11), 166.9 (Cquat, CO2CH3), 211.6 (Cquat, C-9). EI MS
(70 eV), m/z (%) ϭ 339 (100) [Mϩ], 311 (92) [Mϩ Ϫ CO], 297 (84)
[Mϩ Ϫ C3H6], 282 (12), 268 (24), 242 (10), 179 (23), 162 (22), 150
(16), 59 (10). C21H25NO3 (339.4): calcd. C 74.31, H 7.42; found
C 74.62, H 7.13.
fluorene[17,22] were prepared according to published procedures.
Pentacarbonyl[(2E)-3-cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-
propen-1-ylidene]tungsten (1-W): Following a previously published
protocol,[2,23] (2.50 mL, 21.3 mmol) of 1-ethynyl-1-cyclohexene (2b)
in THF (100 mL) was treated with n-butyllithium (9.00 mL, 2.36 
in
n-hexane,
21.2 mmol),
hexacarbonyltungsten
(8.01 g,
22.8 mmol), Et3OBF4 (4.18 g, 22.0 mmol), and gaseous dimethyl-
amine (1 equiv.). Flash chromatography on silica gel (120 g) eluting
with pentane/Et2O (from 10:1 to 4:1) gave 9.77 g (87%) of 1-W
[Rf  0.53 (pentane/Et2O, 1:1)] as a yellow solid, m.p. 92Ϫ94 °C
(dec.). IR (KBr): ν˜ ϭ 2938 cmϪ1 (CϪH), 2054 (CϭO), 1910 (Cϭ
O), 1888 (CϭO), 1653, 1558, 1520, 1261. 1H NMR (250 MHz,
3
CDCl3): δ ϭ 1.39 (t, J ϭ 7.1 Hz, 3 H, OCH2CH3), 1.60Ϫ1.80 (m,
4 H, 4Ј,5Ј-H), 2.00Ϫ2.20 (m, 4 H, 3Ј,6Ј-H), 3.06 [s, 6 H, N(CH3)2],
3
4.54 (q, J ϭ 7.1 Hz, 2 H, OCH2CH3), 5.58 (br. s, 1 H, 2Ј-H), 6.30
(s, 1 H, 2-H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ ϭ 15.8
(ϩ, OCH2CH3), 21.3, 22.0, 24.7, 27.2 (Ϫ, C-3Ј,4Ј,5Ј,6Ј), 40.5 [ϩ,
N(CH3)2], 76.3 (Ϫ, OCH2CH3), 120.0 (ϩ, C-2), 126.9 (ϩ, C-2Ј),
134.9 (Cquat, C-1Ј), 161.1 (Cquat, C-3), 199.9 (Cquat, CO), 204.3
(Cquat, CO), 267.8 (Cquat, C-1). MS (70 eV), m/z (%) ϭ 531 (1)
[Mϩ], 475 [Mϩ Ϫ CO], 443 (1) [Mϩ Ϫ 2 CO], 369 (2) [Mϩ Ϫ 5 CO],
207 (28), 179 (72), 150 (27), 124 (100), 69 (27), 43(28).
C18H21NO6W (531.2): calcd. C 40.70, H 3.98; found C 40.72, H
3.82.
7-(Dimethylamino)-11-[2Ј-(trifluoromethyl)phenyl]tricyclo-
[5.2.2.01,6]undec-10-en-9-one (4l): According to GP, to a solution of
(840 mg, 2.10 mmol) of complex 1-Cr in 42 mL of pyridine was
added (537 mg, 3.16 mmol) of 2-ethynylbenzotrifluoride (2l), and
the mixture was stirred at 80 °C for 48 h. Chromatography on
aluminum oxide (activity II, 40 g) eluting with pentane/Et2O (from
1:0 to 3:1) gave 320 mg (44%) of 4l [Rf ϭ 0.33 (pentane/Et2O, 3:1)]
as a colorless solid, m.p. 135Ϫ136 °C. IR (KBr): ν˜ ϭ 2935 cmϪ1
General Procedure for Cocyclizations of Complexes 1-M with
Alkynes 2 or Alkenes 8 (GP): A thick-walled, screw-cap Pyrex
bottle equipped with a magnetic stirring bar was charged with a
0.05  solution of the complex 1 in anhydrous pyridine. Dry nitro-
gen was bubbled through the solution for 5 min, and 2 equiv. of
the respective alkyne 2 (alkene 8 or diyne 10) were immediately
added. The sealed bottle was kept in an oil bath at 80 °C for
2Ϫ3 days. The solvent was removed under reduced pressure, the
residue was diluted with Et2O, and the solution exposed to air for
2 h. After filtration and removal of the solvents, the residue was
purified by column chromatography on aluminum oxide (activity
II).
1
(CϪH), 1741 (CϭO), 1444, 1312, 1160, 1110, 1034, 770. H NMR
(250 MHz, CDCl3): δ ϭ 1.12Ϫ1.47 (m, 4 H, 2,3,4,5-H), 1.59Ϫ1.72
(m, 2 H, 3,4-H), 1.80Ϫ1.88 (m, 1 H, 5-H), 2.24Ϫ2.30 (m, 1 H, 2-
H), 2.30 [s, 6 H, N(CH3)2], 2.50 (ABM, dd, 2J ϭ 16.5, 4J ϭ 2.5 Hz,
1 H, 8-H), 2.57Ϫ2.62 (m, 1 H, 6-H), 2.74 (AB, d, 2J ϭ 16.5 Hz,
1 H, 8-H), 5.88 (s, 1 H, 10-H), 7.26Ϫ7.44 (m, 3 H, Ar-H), 7.66 (d,
3J ϭ 7.8 Hz, 1 H, Ar-H). 13C NMR (62.9 MHz, CDCl3, plus
DEPT): δ ϭ 22.2, 22.9, 24.1, 25.4 (Ϫ, C-2,3,4,5), 39.0 (Ϫ, C-8), 40.1
[ϩ, N(CH3)2], 61.3 (ϩ, C-6), 63.5 (Cquat, C-1), 75.6 (Cquat, C-7),
7-(Dimethylamino)-11-(2Ј-thienyl)tricyclo[5.2.2.01,6]undec-10-en-9-
one (4f): According to GP, to a solution of (1.01 g, 2.53 mmol) of
complex 1-Cr in 45 mL of pyridine was added (412 mg, 3.81 mmol)
of 2-ethynylthiophene (2f), and the mixture was stirred at 80 °C for
48 h. Chromatography on aluminum oxide (activity II, 40 g) eluting
with pentane/Et2O (from 1:0 to 3:1) gave 245 mg (34%) of 4f [Rf ϭ
0.67 (pentane/Et2O, 3:1)] as a pale yellow solid, m.p. 104Ϫ105 °C.
3
126.5 (ϩ, q, JC,F ϭ 5.6 Hz, C-3Ј), 127.0, 127.1, 135.4 (ϩ, C-
2
4Ј,5Ј,6Ј), 127.5 (Cquat, q, JC,F ϭ 29.6 Hz, C-2Ј), 130.2 (ϩ, C-10),
134.2 (Cquat, q, 3J ϭ 4.2 Hz, C-1Ј), 152.7 (Cquat, C-11), 212.4 (Cquat
,
C-9). The signal of the CF3 carbon was not detected. EI MS
(70 eV), m/z (%) ϭ 349 (100) [Mϩ], 321 (58) [Mϩ Ϫ CO], 307 (64)
[Mϩ Ϫ C3H6], 292 (14), 278 (24), 252 (11), 179 (22), 162 (14).
C20H22NOF3 (349.4): calcd. C 68.75, H 6.35; found C 68.40,
H 6.02.
1
IR (KBr): ν˜ ϭ 2928 cmϪ1 (CϪH), 1728 (CϭO), 1315, 850, 831. H
NMR (250 MHz, CDCl3): δ ϭ 1.11Ϫ1.47 (m, 4 H, 2,3,4,5-H),
1.60Ϫ1.74 (m, 2 H, 3,4-H), 1.83Ϫ1.88 (m, 1 H, 5-H), 2.05 (ABM,
dd, 2J ϭ 16.3, 4J ϭ 2.4 Hz, 1 H, 8-H), 2.24Ϫ2.31 (m, 1 H, 2-H), 7-(Dimethylamino)-11-[4Ј-(trifluoromethyl)phenyl]tricyclo-
2.40Ϫ2.43 (m, 1 H, 6-H), 2.46 [s, 6 H, N(CH3)2], 2.63 (AB, d, 2J ϭ [5.2.2.01,6]undec-10-en-9-one (4n). Variant A: Following GP, to a
3
3
16.3 Hz, 1 H, 8-H), 5.91 (s, 1 H, 10-H), 6.98 (dd, J ϭ 5.1, J ϭ
solution of complex 1-Cr (958 mg, 2.40 mmol) in 48 mL of pyridine
3.5 Hz, 1 H, 4Ј-H), 7.24 (dd, 3J ϭ 5.1, 4J ϭ 1.0 Hz, 1 H, 3Ј-H), was added (612 mg, 3.60 mmol) of 4-ethynylbenzotrifluoride (2n),
7.45 (dd, 3J ϭ 3.5, J ϭ 1.0 Hz, 1 H, 5Ј-H). 13C NMR (62.9 MHz, and the mixture was stirred at 80 °C for 2 days. Chromatography
4
CDCl3, plus DEPT): δ ϭ 22.2, 22.9, 24.2, 25.7 (Ϫ, C-2,3,4,5), 37.1 on aluminum oxide (activity II, 40 g) eluting with pentane/Et2O
(Ϫ, C-8), 40.4 [ϩ, N(CH3)2], 59.5 (ϩ, C-6), 62.1 (Cquat, C-1), 74.0
(from 1:0 to 3:1) gave 714 mg (85%) of 4n [Rf ϭ 0.25 (pentane/
(Cquat, C-7), 124.4, 125.0, 126.5, 126.8 (ϩ, C-10,3Ј,4Ј,5Ј), 136.1 Et2O, 6:1)] as a colorless solid, m.p. 88Ϫ89 °C. IR (KBr): ν˜ ϭ 2930
(Cquat, C-2Ј), 150.3 (Cquat, C-11), 211.0 (Cquat, C-9). EI MS (70 eV), cmϪ1 (CϪH), 1744 (CϭO), 1616, 1327, 1162, 1126, 1068, 1017,
m/z (%) ϭ 287 (100) [Mϩ], 259 (39) [Mϩ Ϫ CO], 245 (52) 851, 819. 1H NMR (250 MHz, CDCl3): δ ϭ 1.10Ϫ1.45 (m, 4 H,
[Mϩ Ϫ C3H6], 230 (12), 215 (19), 179 (17), 162 (34), 150 (14). 2,3,4,5-H), 1.57Ϫ1.72 (m, 2 H, 3,4-H), 1.84Ϫ1.91 (m, 1 H, 5-H),
C17H21NOS (287.4): calcd. C 71.04, H 7.36; found C 70.78, H 7.23.
2.14Ϫ2.35 (m, 2 H, 2,8-H), 2.34 [s, 6 H, N(CH3)2], 2.44Ϫ2.54 (m,
Eur. J. Org. Chem. 2004, 4483Ϫ4491
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Y.-T. Wu, T. Labahn, A. Demeter, K. A. Zachariasse, A. de Meijere
FULL PAPER
2
1 H, 6-H), 2.75 (AB, d, J ϭ 16.4 Hz, 1 H, 8-H), 5.96 (s, 1 H, 10-
7-(Dimethylamino)-9-ethoxy-11-phenyltricyclo[5.2.2.01,6]undec-8-
3
3
H), 7.51 (m, J ϭ 8.2 Hz, 2 H, Ar-H), 7.70 (d, J ϭ 8.2 Hz, 2 H, ene (9a): Following GP, to a solution of (813 mg, 2.04 mmol) of
Ar-H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ ϭ 22.1, 22.9, complex 1-Cr in 40 mL of pyridine was added (0.47 mL,
24.3, 26.0 (Ϫ, C-2,3,4,5), 36.9 (Ϫ, C-8), 40.0 [ϩ, N(CH3)2], 59.7
4.06 mmol) of styrene (8a), and the mixture was stirred at 80 °C
(ϩ, C-6), 62.5 (Cquat, C-1), 74.5 (Cquat, C-7), 124.2 (Cquat, q, 1JC,F ϭ for 48 h. Chromatography on aluminum oxide (activity II, 40 g)
273.3 Hz, CF3), 124.9 (ϩ, q, 3JC,F ϭ 3.7 Hz, C-3Ј,5Ј), 125.4 (ϩ, C-
eluting with pentane/Et2O (from 1:0 to 3:1) gave 374 mg (59%) of
2
2Ј,6Ј), 129.2 (Cquat, q, JC,F ϭ 32.3 Hz, C-4Ј), 131.6 (ϩ, C-10), 9a [Rf ϭ 0.60 (pentane/Et2O, 3:1)] as a colorless solid, m.p. 57 °C.
138.9 (Cquat, C-1Ј), 155.1 (Cquat, C-11), 211.6 (Cquat, C-9). EI MS IR (KBr): ν˜ ϭ 2924 cmϪ1 (CϪH), 1621 (CϭC), 1446, 1347, 1245,
(70 eV), m/z (%) ϭ 349 (100) [Mϩ], 321 (79) [Mϩ Ϫ CO], 307 (66)
[Mϩ Ϫ C3H6], 292 (12), 278 (24), 270 (38), 179 (14), 162 (17), 150
1081, 1036, 754. 1H NMR (250 MHz, CDCl3, plus CH COSY and
HH NOESY): δ ϭ 0.95Ϫ1.36 (m, 3 H, 2,3,4-H), 1.45 (t, 3J ϭ
(7). C20H22NOF3 (349.4): calcd. C 68.75, H 6.35; found C 68.43, 7.0 Hz, 3 H, CH2CH3), 1.47Ϫ1.72 (m, 5 H, 3,4,5,10-H), 1.87 (t,
2
3
H 6.28. Variant B: Following GP, to a solution of (531 mg,
1.00 mmol) of complex 1-W in 20 mL of pyridine was added
(255 mg, 1.50 mmol) of 4-ethynylbenzotrifluoride (2n), and the
3J ϭ 7.7 Hz, 1 H, 6-H), 2.02 (dd, J ϭ 11.9, J ϭ 9.5 Hz, 1 H, 10-
endo), 2.16Ϫ2.22 (m, 1 H, 2-H), 2.43 [s, 6 H, N(CH3)2], 3.70 (dd,
3J ϭ 9.5, 3J ϭ 4.8 Hz, 1 H, 11-H), 3.94 (q, 3J ϭ 7.0 Hz, 2 H,
H
mixture was stirred at 80 °C for 2 days. After chromatography on CH2CH3), 4.46 (s, 1 H, 8-H), 7.13Ϫ7.28 (m, 5 H, Ph-H). 13C NMR
aluminum oxide (activity II, 20 g), 204 mg (58%) of 4n was ob-
tained.
(62.9 MHz, CDCl3, plus DEPT): δ ϭ 14.5 (ϩ, CH2CH3), 23.4,
23.6, 24.5, 27.7 (Ϫ, C-2,3,4,5), 39.9 [ϩ, N(CH3)2], 44.2 (Ϫ, C-10),
45.5 (ϩ, C-11), 50.8 (Cquat, C-1), 59.9 (ϩ, C-6), 64.1 (Ϫ, CH2CH3),
80.5 (Cquat, C-7), 93.3 (ϩ, C-8), 125.4, 127.2, 129.1 (ϩ, Ph-C), 144.9
(Cquat, Ph-C), 161.9 (Cquat, C-9). DCI MS (70 eV), m/z (%) ϭ 329
(2) [M ϩ NH4ϩ], 312 (100) [M ϩ Hϩ]. C21H29NO (311.5): calcd. C
80.98, H 9.38; found C 80.92, H 9.09.
7-(Dimethylamino)-11-[2Ј-(trimethylsilyl)ethynyl]-10-phenyltricyclo-
[5.2.2.01,6]undec-10-en-9-one (4p): Following GP, to a solution of
complex 1-Cr (1.38 g, 3.46 mmol) in pyridine (40 mL) was added
(655 mg, 3.30 mmol) of 1-phenyl-4-(trimethylsilyl)-1,3-butadiyne
(2p), and the mixture was stirred at 80 °C for 48 h. Chromatogra-
phy on aluminum oxide (activity II, 60 g) eluting with pentane/
Et2O (from 1:0 to 3:1), gave 613 mg (49%) of 4p [Rf ϭ 0.26 (pen-
tane/Et2O, 3:1)] as a colorless solid, m.p. 92Ϫ94 °C. IR (KBr): ν˜ ϭ
2937 cmϪ1 (CϪH), 2132 (CϭC), 1744 (CϭO), 1248, 843, 761, 696.
1H NMR (250 MHz, CDCl3): δ ϭ 0.15 [s, 9 H, Si(CH3)3],
1.00Ϫ1.34 (m, 4 H, 2,3,4,5-H), 1.61Ϫ1.74 (m, 3 H, 3,4,5-H),
2.33Ϫ2.57 (m, 4 H, 2,6,8-H), 2.73 [s, 6 H, N(CH3)2], 7.19Ϫ7.39 (m,
5 H, Ph-H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ ϭ Ϫ0.52
ppm[ϩ, Si(CH3)3], 22.6, 22.7, 23.57, 23.62 (Ϫ, C-2,3,4,5), 39.7 (Ϫ,
C-8), 39.8 [ϩ, N(CH3)2], 62.0 (ϩ, C-6), 65.1 (Cquat, C-1), 73.8
(Cquat, C-7), 101.2, 107.3 (Cquat, C-1Ј,2Ј), 127.5, 127.7, 127.8 (ϩ,
Ph-C), 132.1, 133.5 (Cquat, C-10, Ph-C), 152.5 (Cquat, C-11), 211.9
(Cquat, C-9). EI MS (70 eV), m/z (%) ϭ 377 (26) [Mϩ], 349 (7)
[Mϩ Ϫ CO], 335 (100) [Mϩ Ϫ C3H6], 178 (11), 150 (6), 73 (10).
C24H31NOSi (377.6): calcd. C 76.34, H 8.28; found C 76.07,
H 8.59.
4,4Ј-Bis[7ЈЈ-(dimethylamino)-9"-oxotricyclo[5.2.2.01,6]undec-10ЈЈ-en-
11ЈЈ-yl]biphenyl (12b): Following GP,
a solution of (2.27 g,
5.68 mmol) of complex 1-Cr in pyridine (40 mL) was treated with
(344 mg, 1.70 mmol) of 4,4Ј-diethynylbiphenyl (10b), and the mix-
ture was stirred at 80 °C for 48 h. Chromatography on aluminum
oxide (activity II, 60 g) eluting with pentane/Et2O (from 1:0 to 1:1)
gave 476 mg (50%) of 12b [Rf ϭ 0.56 (pentane/Et2O, 1:1)] as a col-
orless solid, m.p. Ͼ230 °C. IR (KBr): ν˜ ϭ 2936 cmϪ1 (CϪH), 1736
1
(CϭO), 1492, 1305, 1114, 904, 810. H NMR (250 MHz, CDCl3):
δ ϭ 1.13Ϫ1.48 (m, 8 H, 2ЈЈ,3ЈЈ,4ЈЈ,5ЈЈ-H), 1.65Ϫ1.76 (m, 4 H,
3ЈЈ,4ЈЈ-H), 1.82Ϫ1.92 (m, 2 H, 5"-H), 2.27 (ABM, dd, 2J ϭ 16.3,
4J ϭ 2.3 Hz, 2 H, 8ЈЈ-H), 2.29Ϫ2.40 (m, 2 H, 2ЈЈ-H), 2.41 [s, 12 H,
2
N(CH3)2], 2.52Ϫ2.70 (m, 2 H, 6ЈЈ-H), 2.77 (AB, d, J ϭ 16.3 Hz,
2 H, 8ЈЈ-H), 5.92 (s, 2 H, 10ЈЈ-H), 7.54 (d, 3J ϭ 8.5 Hz, 4 H, Ar-
H), 7.77 (d, 3J ϭ 8.5 Hz, 4 H, Ar-H). 13C NMR (62.9 MHz,
CDCl3, plus DEPT): δ ϭ 22.2, 23.0, 24.4, 26.1 (Ϫ, C-2ЈЈ,3ЈЈ,4ЈЈ,5ЈЈ),
37.2 (Ϫ, C-8ЈЈ), 40.2 [ϩ, N(CH3)2], 59.7 (ϩ, C-6ЈЈ), 62.2 (Cquat, C-
1ЈЈ), 74.5 (Cquat, C-7ЈЈ), 125.7, 126.4 (ϩ, Ar-C), 129.3 (ϩ, C-10"),
134.5, 139.7 (Cquat, Ar-C), 156.0 (Cquat, C-11"), 212.1 (Cquat, C-9").
EI MS (70 eV), m/z (%) ϭ 560 (72) [Mϩ], 532 (50) [Mϩ ϪCO], 518
(100) [Mϩ Ϫ C3H6], 490 (17), 179 (24), 162 (24), 150 (32).
C38H44N2O2 (560.8): calcd. C 81.39, H 7.91; found C 81.37, H 8.21.
7-(Dimethylamino)-11-(9Ј,9Ј-dihexyl-2Ј-fluorenyl)-10-phenyltri-
cyclo[5.2.2.01,6]undec-10-en-9-one (4v): Following GP, to a solution
of complex 1-Cr (798 mg, 2.00 mmol) in pyridine (40 mL) was ad-
ded (850 mg, 2.37 mmol) of 9,9-dihexyl-2-ethynylfluorene (2v), and
the mixture was stirred at 80 °C for 48 h. Chromatography on
aluminum oxide (activity II, 50 g) eluting with pentane/Et2O (from
1:0 to 3:1) gave 546 mg (51%) of 4v [Rf ϭ 0.46 (pentane/Et2O, 9:1)]
as a pale yellow oil. IR (oil): ν˜ ϭ 2930 cmϪ1 (CϪH), 1742 (Cϭ
Supporting Information: Preparation and full characterization of
compounds 2w, 2x, 2y, 4m, 4o, 4q, 4t, 4u, 4w, 4y, 9b, 9c, 12a, 12c,
14, 15, 16 (see also the footnote on the first page of this article).
1
O), 1454, 1131, 1114, 817, 739. H NMR (250 MHz, CDCl3): δ ϭ
0.70Ϫ0.84 (m, 10 H, hexyl-H), 1.00Ϫ1.49 [m, 16 H, 2,3,4,5-H
(4 H), hexyl-H (12 H)], 1.64Ϫ1.78 (m, 2 H, 3,4-H), 1.89Ϫ2.02 [m,
5 H, 5-H (1 H), hexyl-H (4 H)], 2.43 (m, 2 H, 2,8-H), 2.43 [s, 6 H,
Acknowledgments
2
This work was supported by the State of Niedersachsen and the
Fonds der Chemischen Industrie. Generous gifts of chemicals by
the companies BASF, Bayer, Degussa-Hüls AG and Chemetall
GmbH are gratefully acknowledged. The authors are indebted to
Dr. Sergey Druzhinin (MPI für Biophysikalische Chemie) for fluor-
escence measurements, and to Dr. Burkhard Knieriem, Göttingen,
for his careful proofreading of the final manuscript.
N(CH3)2], 2.57Ϫ2.62 (m, 1 H, 6-H), 2.84 (d, J ϭ 16.4 Hz, 1 H, 8-
H), 5.95 (s, 1 H, 10-H), 7.26Ϫ7.38 (m, 3 H, Ar-H), 7.57Ϫ7.71 (m,
4 H, Ar-H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ ϭ 13.86,
13.87 (ϩ, hexyl CH3), 22.2, 23.0, 24.3, 26.0 (Ϫ, C-2,3,4,5), 22.4,
22.5, 23.5, 23.6, 29.5, 29.7, 31.3, 31.4, 40.2 ϫ 2 (Ϫ, C-hexyl), 37.2
(Ϫ, C-8), 40.0 [ϩ, N(CH3)2], 54.8 (Cquat, C-9Ј), 59.7 (ϩ, C-6), 62.0
(Cquat, C-1), 74.3 (Cquat, C-7), 119.1, 119.5, 119.6, 121.6, 124.1,
126.6, 126.8 (ϩ, Ar-C), 128.4 (ϩ, C-10), 134.2, 140.4, 140.7, 150.1,
150.8 (Cquat, Ar-C), 157.0 (Cquat, C-11), 211.8 (Cquat, C-9). EI MS
(70 eV), m/z (%) ϭ 537 (100) [Mϩ], 509 (37) [Mϩ Ϫ CO], 495 (44)
[Mϩ Ϫ C3H6], 179 (12). HRMS (EI) calcd. for C38H51NO:
537.3971 (correct HRMS).
[1]
For recent reviews on reactions of α,β-unsaturated β-dialkyl-
amino-substituted Fischer carbene complexes with alkynes, see:
[1a]
H. Schirmer, M. Duetsch, A. de Meijere, Angew. Chem.
2000, 112, 4124Ϫ4162; Angew. Chem. Int. Ed. 2000, 39,
4490
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
Eur. J. Org. Chem. 2004, 4483Ϫ4491

Reactions of Fischer Carbene Complexes with Alkynes
FULL PAPER
Am. Chem. Soc. 2004, 126, 1705Ϫ1715 and references cited
there.
[1b]
3964Ϫ4002.
61Ϫ72.
A. de Meijere, Pure Appl. Chem. 1996, 68,
[1c]
Y.-T. Wu, A. de Meijere, ‘‘The Multifaced Chemis-
[11]
[12]
try of Variously Substituted α,β-Unsaturated Fischer Metalcar-
benes’’, Topics in Organometallic Chemistry (Ed.: K. H. Dötz),
Springer, Heidelberg 2004, 13, 21Ϫ57.
Y.-T. Wu, H. Schirmer, M. Noltemyer, A. de Meijere, Eur. J.
Org. Chem. 2001, 2501Ϫ2506.
A. Demeter, S. Druzhinin, M. George, E. Haselbach, J.-L. Rou-
lin, K. A. Zachariasse, Chem. Phys. Lett. 2000, 323, 351Ϫ360.
The dipole moment µe(ICT) was in fact determined by plotting
the ν˜max(ICT) data of 4w (Table 4) against those of 4-(dimeth-
ylamino)benzonitrile (DMABN) in the corresponding solvents
and using for DMABN µe(ICT) ϭ 17 D and µg ϭ 6.6 D (see
ref.[11]). Such a procedure, based on Equation (1), reduces the
scatter in the data points caused by specific solute/solvent in-
teractions.
S. I. Druzhinin, A. Demeter, V. A. Galievsky, T. Yoshihara, K.
A. Zachariasse, J. Phys. Chem. A 2003, 107, 8075Ϫ8085.
J. B. Birks, Photophysics of Aromatic Molecules, Wiley-Intersci-
ence, London, 1970.
L. Brandsma, Preparative Acetylenic Chemistry, 2nd. ed., Elsev-
ier, Amsterdam 1988.
S. J. Havens, P. M. Hergenroter, J. Org. Chem. 1985, 50,
1763Ϫ1765.
L. Brandsma, S. F. Vasilevsky, H. D. Verkruijsse, Application
of Transition Metal Catalysts in Organic Synthesis, Springer,
Berlin, 1999.
M. Alami, B. Grousse, G. Linstrumelle, Tetrahedron Lett. 1995,
36, 3687Ϫ3690.
[2]
[3]
[4]
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Compound 9a: C21H29NO, triclinic crystals of space group P1,
unit cell dimensions: a ϭ 8.4438(8), b ϭ 9.9685(9), c ϭ
˚
11.8828(11) A, α ϭ 97.698(7), β ϭ 91.575(7), γ ϭ 115.012(7)°,
3
˚
V ϭ 894.28(14) A . Crystallographic data (excluding structure
factors) for the structure reported in this paper have been de-
posited with the Cambridge Crystallographic Data Centre as
supplementary publication no. CCDC-239241. Copies of the
data can be obtained free of charge on application to CCDC,
12 Union Road, Cambridge CB2 1EZ, UK [Fax: ϩ44-1223-
336033; E-mail: deposit@ccdc.cam.ac.uk].
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K. A. Zachariasse, S. I. Druzhinin, W. Bosch, R. Machinek, J.
Received July 5, 2004
Eur. J. Org. Chem. 2004, 4483Ϫ4491
www.eurjoc.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4491