Facile synthesis of 7-dimethylamino-endo-tricyclo[5.2.2.01,6]undec-10-en-9-ones

Article abstract of DOI:10.1002/1099-0690(200107)2001:13<2501::AID-EJOC2501>3.0.CO;2-O

Pentacarbonyl[(2E)-3-cyclohexenyl-3-dimethylamino-1-ethoxy-2-propen-1- ylidene]chromium (2) yields 7-dimethylamino-endo-tricyclo[5.2.2.0^1,6]undec-10-en-9-ones 5 (15-88%, 12 examples) upon treatment with alkynes 3 in pyridine, most probably by a 6π-electrocyclization followed by a subsequent reductive elimination/intermolecular Diels-Alder reaction with the alkyne and eventual hydrolysis. The direct cyclization of 2 to the cyclohexane-annelated cyclopentadiene 6 is faster than the usual alkyne insertion of α,β-unsaturated Fischer carbene complexes. The [4+2] cycloadditions of 7 and the added alkynes 3 occur with high degrees of regio- and complete diastereoselectivity.

Full text of DOI:10.1002/1099-0690(200107)2001:13<2501::AID-EJOC2501>3.0.CO;2-O

FULL PAPER
1
,6
Facile Synthesis of 7-Dimethylamino-endo-tricyclo[5.2.2.0 ]-
undec-10-en-9-ones
[
a]
[a]
[a][‡]
and Armin de Meijere*[a]
Yao-Ting Wu, Heiko Schirmer, Mathias Noltemeyer,
Dedicated to Professor Herbert W. Roesky on the occasion of his 65th birthday
Keywords: Carbene complexes / Cyclization / Electrocyclic reactions / Alkynes
Pentacarbonyl[(2E)-3-cyclohexenyl-3-dimethylamino-1-eth- action with the alkyne and eventual hydrolysis. The direct
oxy-2-propen-1-ylidene]chromium (2) yields 7-dimethylam-
cyclization of
2 to the cyclohexane-annelated cyclo-
1
,6
ino-endo-tricyclo[5.2.2.0 ]undec-10-en-9-ones 5 (15−88%, pentadiene 6 is faster than the usual alkyne insertion of α,β-
1
2 examples) upon treatment with alkynes 3 in pyridine,
unsaturated Fischer carbene complexes. The [4+2] cycload-
most probably by a 6π-electrocyclization followed by a sub-
ditions of 7 and the added alkynes 3 occur with high degrees
sequent reductive elimination/intermolecular Diels−Alder re- of regio- and complete diastereoselectivity.
Introduction
There is now ample evidence that β-amino-substituted,
α,β-unsaturated Fischer carbene complexes can serve as
[1,2]
versatile reactive building blocks for organic synthesis.
Many of their reactions are unprecedented in that they do
Scheme 1. Preparation of the Fischer carbene complex 2 in a one-
pot sequence
not occur with other α,β-unsaturated Fischer carbenes and/
or lead to unusual structures.[
3Ϫ12]
Recently, this repertoire
of transformations has been enlarged by Aumann et al. with
yet another reaction mode in which β-cycloalkenyl-substi-
tuted β-dialkylaminopropenylidene metal complexes un-
dergo a rapid intramolecular insertion of the carbonϪ
carbon into the metalϪcarbon double bond leading to ring-
Upon heating the complex 2 with two equivalents of an
alkyne 3 in pyridine at 80 °C for two days, rather nonpo-
lar cycloaddition products 5 were obtained after purifica-
[14]
tion by chromatography (Scheme 2 and Table 1). From the
1
annelated pentacarbonyl-η -cyclopentadienyl metal com-
1
13
IR, H, C NMR and mass spectra, it was not possible to
assign the structures of these compounds unambiguously.
Slow diffusion crystallization of 5d and 5i from pentane/
diethyl ether afforded good quality single crystals for X-ray
structure analyses, and thus their structures were rigorously
plexes, which upon heating in pyridine at 70 °C did not
yield the uncomplexed alkoxydimethylaminocyclopenta-
diene, but eventually gave 4,5-ring-annelated 1-dimethyl-
aminocyclopent-1-en-3-ones.[ This prompted us to report
our own results on the reaction of pentacarbonyl(3-cyclo-
hexenyl-3-dimethylamino-1-ethoxypropenylidene)-chro-
mium (2) with various alkynes 3.
13]
[15]
established (Figure 1).
Results and Discussion
The β-dimethylamino-substituted, α,β-unsaturated com- Scheme 2. For details see Table 1
plex 2 was readily prepared by the new one-pot procedure[
4]
in excellent yield (overall 94%) from 1-ethynyl-1-cyclohex-
When the 1-chromahexa-1,3,5-triene 2 without an added
ene (1), hexacarbonylchromium, triethyloxonium tetra-
fluoroborate and dimethylamine in tetrahydrofuran solu-
tion (Scheme 1).
alkyne was kept in pyridine at room temperature for 16 h,
or at 80 °C for 1 h, it was completely converted into the
cyclohexane-annelated cyclopentadiene 8, the structure of
which was assigned on the basis of a NOESY-2D NMR
[
[
‡]
a]
X-ray crystal structure analysis
Institute für Organische und Anorganische Chemie der spectrum. No sign of the isomeric diene 9 arising from 8 by
Universität Göttingen
1
13
a 1,5-hydrogen shift could be detected by H and C NMR
spectroscopy, even at 80 °C.[ On the other hand, the
transformation of complex 2 with added phenylacetylene
Tammannstrasse 2Ϫ4, 37077 Göttingen, Germany
Fax: (internat.) ϩ49Ϫ551/399475
16]
E-mail: Armin.deMeijere@chemie.uni-goettingen.de
Eur. J. Org. Chem. 2001, 2501Ϫ2506
 WILEY-VCH Verlag GmbH, 69451 Weinheim, 2001
1434Ϫ193X/01/0713Ϫ2501 $ 17.50ϩ.50/0
2501

Y.-T. Wu, H. Schirmer, M. Noltemeyer, A. de Meijere
FULL PAPER
Table 1. Reaction of complex 2 with various alkynes in pyridine at
80 °C
Scheme 3. On the mechanism for the formation of cycloaddition
products 4; a: 1,5-cyclization; b: 6π-electrocyclization; c: reductive
elimination; d: 1,5-hydrogen shift; e: [4ϩ2] cycloaddition
NMR spectra of the crude products, but trace amounts
were observed in the thin layer chromatogram.
[
a]
Non-optimized isolated yields of purified products based on the
complex 2
Aumann et al. have shown that Fischer carbene com-
plexes of type 2 with tungsten undergo 1,5-cyclization to
1
yield η -cyclopentadienyl complexes of type 6, which upon
heating in pyridine at 70 °C do not liberate the cyclo-
pentadiene ligand of type 8. The formation of the cyclohex-
ane-annelated cyclopentadiene 8 from 2 in pyridine thus
most probably occurs by 6π-electrocyclization of monode-
carbonylated 2 to the pyridine-stabilized chroma-cyclo-
hexadiene 7, followed by reductive elimination.[ Pyridine
is essential as the solvent for this reaction mode of 2 to
occur: many by-products and only a trace amount of the
cycloadduct 5e from 2 and phenylacetylene (3e) were ob-
served after two days at 60 °C, either in benzene or in tetra-
hydrofuran, even in the presence of triphenylphosphane.
(
3e) in pyridine solution occurred even at room temper-
ature, and 36% of 5e could be isolated after 68 h, 57% after
8 h at 40 °C, and 71% after 68 h at 60 °C. Thus, 8 appar-
6
ently rapidly equilibrates with 9 even at room temperature,
and the latter preferentially reacts more rapidly than 8 with
1,4]
the added alkynes 3 to afford the [4ϩ2] cycloadducts 4[
17]
(Scheme 3). The ethoxy groups of the initial cycloadducts 4
1
13
could be clearly observed in the H and C NMR spectra
of the crude products; hydrolysis of 4 apparently occurred
during chromatography, and the ketones 5 were the only
isolated products. The other isomers or by-products, with
1
the exception of those of 5i, were not detected in the H
Figure 1. Structures of 5d (left) and 5i (right) in the crystals; 5d: C16
H
23NO, monoclinic crystals of space group P2
1
/c, unit cell dimensions:
˚
˚
3
a ϭ 9.618(2), b ϭ 10.817(2), c ϭ 13.411(3) A, β ϭ 98.75(3)°, V ϭ 1379.0(5) A , 3405 reflections; 5i: C27
H27NO, triclinic crystals of space
˚
˚
3
group P1, unit cell dimensions: a ϭ 10.13(3), b ϭ 15.01(4), c ϭ 15.10(3) A, α ϭ 99.2(2), β ϭ 107.8(2), γ ϭ 96.6(2)°, V ϭ 12125(9) A ,
9865 reflections
2502
Eur. J. Org. Chem. 2001, 2501Ϫ2506

Facile Synthesis of 7-Dimethylamino-endo-tricyclo[5.2.2.01,6]undec-10-en-9-ones
FULL PAPER
The regional and facial selectivities in the above 1,5-hydrogen shift, and the latter preferentially reacts with
DielsϪAlder reactions of 8 can be explained on the basis alkynes 3 to afford single [4ϩ2] cycloadducts 4 in a highly
of a model proposed by Winterfeldt (Scheme 4).[ The ap- regio- and diastereoselective manner.
plied alkynes 3 add to the more reactive 1,3-diene 9 with
18]
syn-facial selectivity (with respect to the hydrogen in 9) and
the larger groups R obey the ortho selectivity (with respect
L
to the dimethylamino group in 9).[ The energies, orbital Experimental Section
19]
phases and coefficients of LUMOs and HOMOs in the ap-
General: H and 13C NMR: Bruker AM 250 (250 and 62.9 MHz),
1
plied alkynes are similar to those in dienophiles with elec-
tron-withdrawing substituents.[
17]
Bruker AMX 300 (300 and 75 MHz) and Varian VXR 500 (500
and 125.7 MHz). Ϫ IR: Bruker IFS 66 (FT-IR). Ϫ Low-resolution
EI MS: Varian MAT CH 7, MAT 731, ionizing voltage 70 eV. Ϫ
High-resolution EI-MS (HR EIMS): Varian MAT 311 A. Ϫ X-ray
crystal structure determination: the data were collected on a Stoe-
Siemens-AED diffractometer. Ϫ Melting points were determined
with a Büchi melting point apparatus and are uncorrected. Ϫ Ele-
mental analysis: Mikroanalytisches Laboratorium der Georg-
August-Universität Göttingen. Ϫ Chromatography: Merck silica
gel 60 (230Ϫ400 mesh) or ICN neutral alumina (Super I, Activity
II). Solvents for chromatography were technical grade and freshly
distilled before use. Tetrahydrofuran was distilled from sodium
benzophenone ketyl and pyridine was distilled from calcium hy-
[
21]
dride. Ϫ 1-Ethynyl-1-cyclohexene (1),
1-ethynyl-1-cyclopentene
3b),[
21]
1-ethynyl-1-cycloheptene (3c),
[21]
2-methylbuten-3-yne
(
(
Scheme 4. Regional and facial selectivities in DielsϪAlder reac-
tions; Do: electron-donating group; R ,R : larger and smaller sub-
stituent; EWG: electron-withdrawing group
3d),[ 1,4-diphenylbuta-1,3-diyne (3i),
21]
[21]
p-phenylethynylbenzoic
L
S
[22]
[22]
acid ethyl ester (3k), (E)-1,2-di(phenylethynyl)ethene (3l) and
(
E)-1,2-di(cyclopropylethynyl)ethene (3m),[22] were prepared ac-
cording to published procedures. p-Propylphenylethyne (3f), p-
Unfortunately, the range of dienophiles applicable in the
cycloaddition to 9 appears to be limited to unsymmetrical ethoxyphenylethyne (3g) and 4-ethynyl-4Ј-propylbiphenyl (3h) were
alkenyl- and alkynyl-substituted alkynes. Several terminal generous gifts from Merck AG.
acetylenes [trimethylsilyl-, n-propyl-, isopropyl-, cyclopro-
Pentacarbonyl[(2E)-3-cyclohexenyl-3-dimethylamino-1-ethoxy-2-
pyl-, 2Ј-methoxyethenyl-, and (1Ј-trimethylsilyl)cyclopropyl-
propen-1-ylidene]chromium (2): Complex 2 was prepared adapting
acetylene] and the symmetrically disubstituted diphenylac-
[4]
a previously published procedure from 1-ethynyl-1-cyclohexene
etylene (3j) did not yield any cycloadduct of type 5. How-
(
1; 2.50 mL, 21.3 mmol), n-butyllithium (2.36  in n-hexane; 8.50
ever, the p-phenylethynyl benzoic acid ethyl ester (3k) did mL, 20.1 mmol), hexacarbonylchromium (4.60 g, 20.9 mmol), tri-
give the tricyclic product 5k in 66% yield. The enediyne 3m, ethyloxonium tetrafluoroborate (4.17 g, 21.9 mmol) and gaseous
even with a 2.2-fold excess of 2, only gave the monoadduct dimethylamine in THF (100 mL). Chromatography on silica gel
with pentane to pentane/Et
2
O (1:1) afforded 7.56 g (94%) of 2
5
m (46% yield), and none of the bisadduct 12 could be de-
(
R
f
ϭ 0.85, Et O) as a yellow solid, m.p. (dec.) 85 °C. Ϫ IR (KBr):
2
Ϫ1
tected. More typical dienophiles such as methyl propiolate,
dimethyl acetylenedicarboxylate and maleic anhydride
could not be employed as they react with the pyridine.
ν˜ ϭ 2940 cm (CϪH), 2045 (CϭO), 1893 (CϭO), 1426, 1259,
1
1
3
104, 931, 668. Ϫ H NMR (250 MHz, CDCl
3
): δ ϭ 1.47 (t, J ϭ
7
.0 Hz, 3 H, OCH CH ), 1.60Ϫ1.80 (m, 4 H, 4Ј,5Ј-H), 2.00Ϫ2.20
2
3
3
(
m, 4 H, 3Ј,6Ј-H), 3.05 [s, 6 H, N(CH
H, OCH CH ), 5.52Ϫ5.64 (br. s, 1 H, 2-H), 6.26 (s, 1 H, 2Ј-H). Ϫ
NMR (62.9 MHz, plus DEPT): 15.9 (ϩ,
OCH CH ), 21.6, 22.2, 24.8, 27.3 (Ϫ, C-3Ј,4Ј,5Ј,6Ј), 39.5 [ϩ,
N(CH ], 74.0 (Ϫ, OCH CH ), 117.8 (ϩ, C-2), 126.8 (ϩ, C-2Ј),
35.2 (Cquat, C-1Ј), 158.4 (Cquat, C-3), 220.3 (Cquat, CO), 225.0
quat, CO), 288.3 (Cquat, C-1). Ϫ MS (70 eV): m/z (%) ϭ 399 (16)
3 2
) ], 4.66 (q, J ϭ 7.0 Hz, 2
2
3
1
3
C
C
6
D
6
,
δ ϭ
2
3
3
)
2
2
3
1
(
C
ϩ
ϩ
ϩ
ϩ
[M ], 343 (7) [M Ϫ 2 CO], 315 (4) [M Ϫ 3 CO], 287 (50) [M
ϩ
Ϫ 4 CO], 259 (88) [M Ϫ 5 CO], 229 (18), 220 (32), 213 (78), 207
Conclusion
ϩ
ϩ
(
100) [M Ϫ 5 CO Ϫ Cr], 178 (72) [M Ϫ 5 CO Ϫ Cr Ϫ C
2
ϩ
H
5
],
60 (34), 150 (22), 135 (14), 108 (26), 80 (53), 52 (32) [Cr ]. Ϫ
21CrNO (399.4): calcd. C 54.14, H 5.30; found C 53.94, H
1
C
Alkyne insertion into the metalϪcarbon double bond is
18
H
6
generally considered to be the first important step in reac- 5.30.
tions of Fischer carbene complexes with alkynes.[ In pyr-
20]
General Procedure for the Cocyclization of Complexes 2 with Al-
kynes 3: A thick-walled, screw-cap Pyrex bottle equipped with a
magnetic stirring bar was charged with a 0.05  solution of the
complex 2 in anhydrous pyridine. Dry nitrogen was bubbled
through the solution for 2 min, and two equiv. of the alkyne 3 were
idine solution, however, the cyclohexenyl-substituted β-di-
methylaminopropenylidenechromium complex 2 as a 1-
chromahexa-1,3,5-triene apparently undergoes 6π-electro-
cyclization more rapidly than alkyne insertion. A sub-
sequent reductive elimination then forms the cyclohexane- immediately added. The sealed bottle was kept in an oil bath at 80
annelated cyclopentadiene 8, which equilibrates with 9 by °C for 2Ϫ3 days. The solvent was removed under reduced pressure,
Eur. J. Org. Chem. 2001, 2501Ϫ2506
2503

Y.-T. Wu, H. Schirmer, M. Noltemeyer, A. de Meijere
FULL PAPER
the residue was diluted with Et
2
O, and the solution exposed to air 8-H), 5.42 (s, 1 H, 10-H), 6.71 (t, J ϭ 7.0 Hz, 1 H, 2Ј-H). Ϫ 13C
3
for 2 h. The mixture was then filtered, concentrated under reduced
pressure, diluted again with pentane/Et O (20:1), and kept at Ϫ20
C for 12Ϫ24 h in order to crystallize Cr(CO) and Cr(CO) Py
NMR (62.9 MHz, CDCl
26.6, 26.7, 28.5, 30.0, 32.6 (Ϫ, C-2,3,4,5,3Ј,4Ј,5Ј,6Ј,7Ј), 37.3 (Ϫ, C-
8), 40.0 [ϩ, N(CH ], 58.9 (ϩ, C-6), 61.3 (Cquat, C-1), 74.3 (Cquat,
3
, plus DEPT): δ ϭ 22.3, 23.1, 24.5, 26.2,
2
°
6
3
3
.
3
)
2
The solution was decanted, the solvents were removed under re-
duced pressure, and the H NMR spectra of these crude products
were recorded. Chromatography on aluminum oxide (II) (column [M ], 284 (100) [M Ϫ CH
C-7), 124.9 (ϩ, C-2Ј), 129.5 (ϩ, C-10), 139.0 (Cquat, C-11), 157.8
(Cquat, C-1Ј), 212.1 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 299 (60)
1
ϩ
ϩ
3
], 270 (14), 256 (49), 179 (23), 150 (10),
2
2.5 ϫ 30 cm) with pentane to pentane/Et O (3:1) afforded com- 84 (23). Ϫ C20H29NO: calcd. 299.2249; found 299.2249 (HR
pounds 5.
EIMS).
1
1-(1Ј-Cyclohexenyl)-7-dimethylaminotricyclo[5.2.2.01,6]undec-10-
7-Dimethylamino-11-(2Ј-propenyl)tricyclo[5.2.2.01,6]undec-10-en-9-
en-9-one (5a): 1-Ethynyl-1-cyclohexene (3a; 0.60 mL, 5.10 mmol) one (5d): 2-Methylbuten-3-yne (3d; 0.56 mL, 6.01 mmol) was ad-
was added to a solution of complex 2 (915 mg, 2.29 mmol) in 50 ded to a solution of complex 2 (1.21 g, 3.03 mmol) in 60 mL of
mL of pyridine, and the mixture was stirred at 80 °C for 60 h. pyridine, and the mixture was stirred at 80 °C for 45 h. After chro-
After chromatographic purification, 5a [257 mg (40%), R
pentane/Et O ϭ 1:1] was obtained as a pale-yellow solid, m.p. 63 Et
C. Ϫ IR (KBr): ν˜ ϭ 2938 cmϪ1 (CϪH), 2862 (CϪH), 2826 (KBr): ν˜ ϭ 2932 cm (CϪH), 1734 (CϭO), 1670 (CϭC), 1447,
f
ϭ 0.80, matographic purification, 5d [538 mg (73%), R
f
ϭ 0.80, pentane/
2
2
O ϭ 1:1] was obtained as a colorless solid, m.p. 79 °C. Ϫ IR
Ϫ1
°
1
1
(
CϪH), 1739 (CϭO), 1653 (CϭC), 1457, 1315, 1301, 1114. Ϫ H 1305, 1114, 1077, 900, 845. Ϫ H NMR (250 MHz, CDCl
NMR (250 MHz, CDCl ): 1.08Ϫ2.20 (m, 16 H, CH and HH COSY): δ ϭ 1.03Ϫ1.36 (m, 4 H, 2,3,4,5-H),
,3,4,5,3Ј,4Ј,5Ј,6Ј-H), 1.99 (ABM, dd, J ϭ 16.3, J ϭ 2.4 Hz, 1
H, 8-H), 2.25Ϫ2.35 (m, 1 H, 6-H), 2.35 [s, 6 H, N(CH ], 2.57 CH
3
, plus
3
δ
ϭ
2
4
2
1.51Ϫ1.59 (m, 1 H, 3-H), 1.59Ϫ1.66 (m, 1 H, 4-H), 1.77 (s, 3 H,
2
4
3
)
2
3
), 1.76Ϫ1.84 (m, 1 H, 5-H), 1.97 (ABM, dd, J ϭ 16.3, J ϭ
2
(
AB, d, J ϭ 16.3 Hz, 1 H, 8-H), 5.14 (s, 1 H, 10-H), 6.74 (m, 1 2.4 Hz, 1 H, 8-H), 2.15Ϫ2.21 (m, 1 H, 2-H), 2.28Ϫ2.36 (m, 1 H,
1
3
2
H, 2Ј-H). Ϫ C NMR (62.9 MHz, CDCl
3
, plus DEPT): δ ϭ 22.1,
2.3, 22.8, 23.1, 24.5, 25.72, 25.76, 26.3 (Ϫ, C-2,3,4,5,3Ј,4Ј,5Ј,6Ј),
7.4 (Ϫ, C-8), 40.1 [ϩ, N(CH ], 59.2 (ϩ, C-6), 61.2 (Cquat, C-
), 74.5 (Cquat, C-7), 124.5 (ϩ, C-2Ј), 125.7 (ϩ, C-10), 131.2 (Cquat
6-H), 2.36 [s, 6 H, N(CH
3
)
2
], 2.58 (AB, d, J ϭ 16.3 Hz, 1 H, 8-
H), 4.90 (AB, d, J ϭ 2.8 Hz, 1 H, 1Ј-H), 5.58 (s, 1 H, 10-H), 5.92
2
2
3
1
2
13
3
)
2
(AB, d, J ϭ 2.8 Hz, 1 H, 1Ј-H). Ϫ C NMR (62.9 MHz, CDCl
plus DEPT): δ ϭ 21.2 (ϩ, CH ), 22.0, 23.0, 24.4, 26.3 (Ϫ, C-
], 59.3 (ϩ, C-6), 61.6
(Cquat, C-1), 74.5 (Cquat, C-7), 114.1 (Ϫ, C-1Ј), 128.1 (ϩ, C-10),
2 5
H ], 228 (24), 214 (36), 200 (19), 179 137.2 (Cquat, C-11), 156.1 (Cquat, C-2Ј), 212.0 (Cquat, C-9). Ϫ MS
3
,
,
3
3 2
C-11), 156.5 (Cquat, C-1Ј), 212.1 (Cquat, C-9). Ϫ MS (70 eV): m/z 2,3,4,5), 37.0 (Ϫ, C-8), 40.1 [ϩ, N(CH )
ϩ
ϩ
ϩ
(
%) ϭ 285 (84) [M ], 270 (76) [M Ϫ CH
3
], 256 (26) [M
Ϫ
ϩ
C
2
H
5
], 242 (100) [M Ϫ NC
ϩ
ϩ
(
(
26), 162 (20), 150 (19), 129 (11), 115 (10), 91 (13), 56 (26), 41 (70 eV): m/z (%) ϭ 245 (64) [M ], 230 (58) [M Ϫ CH
43). Ϫ C19
3
], 216 (18)
], 188 (26), 174 (18), 150
H23NO (245.4): calcd. C 78.32, H
ϩ
ϩ
H
27NO (285.4): calcd. C 79.96, H 9.54; found C 80.00, [M Ϫ C
(16), 115 (10), 91 (14). Ϫ C16
.45; found C 78.26, H 9.52.
2 5 2 5
H ], 202 (100) [M Ϫ NC H
H 9.47.
9
1
1-(1Ј-Cyclopentenyl)-7-dimethylaminotricyclo[5.2.2.01,6]undec-10-
en-9-one (5b): 1-Ethynyl-1-cyclopentene (3b; 0.51 g, 5.54 mmol) 7-Dimethylamino-11-phenyltricyclo[5.2.2.01,6]undec-10-en-9-one
was added to a solution of complex 2 (1.11 g, 2.78 mmol) in 50 (5e): Phenylethyne (3e; 0.78 mL, 7.10 mmol) was added to a solu-
mL of pyridine, and the mixture was stirred at 80 °C for 60 h.
After chromatographic purification, 5b [323 mg (43%), R ϭ 0.82, the mixture stirred at 80 °C for 68 h. After purification, 5e [869 mg
pentane/Et O ϭ 3:1] was obtained as a pale-yellow solid, m.p. 64 (88%), R ϭ 0.68, pentane/Et O ϭ 2:1] was obtained as a colorless
C. Ϫ IR (KBr): ν˜ ϭ 2934 cmϪ1 (CϪH), 2922 (CϪH), 2829 solid, m.p. 120 °C. Ϫ IR (KBr): ν˜ ϭ 2936 cm (CϪH), 1734 (Cϭ
tion of complex 2 (1.41 g, 3.53 mmol) in 70 mL of pyridine, and
f
2
f
2
Ϫ1
°
1
1
(
(
2
CϪH), 1734 (CϭO), 1653 (CϭC), 1457, 1309, 1115. Ϫ H NMR O), 1653 (CϭC), 1461, 1442, 1303, 1044, 754, 693. Ϫ H NMR
250 MHz, CDCl ): δ ϭ 1.00Ϫ1.39, 1.53Ϫ1.91, 2.15Ϫ2.25, (250 MHz, CDCl ): δ ϭ 1.13Ϫ1.47 (m, 4 H, 2,3,4,5-H), 1.60Ϫ1.70
(m, 1 H, 3-H), 1.70Ϫ1.78 (m, 1 H, 4-H), 1.82Ϫ1.91 (m, 1 H, 5-H),
3
3
2
.30Ϫ2.47 (m, 15 H, 2,3,4,5,6,3Ј,4Ј,5Ј-H), 1.92 (ABM, dd, J ϭ
4
2
4
1
6.3, J ϭ 2.3 Hz, 1 H, 8-H), 2.39 [s, 6 H, N(CH
3
)
2
], 2.51 (AB, d,
2.26 (ABM, dd, J ϭ 16.4, J ϭ 2.4 Hz, 1 H, 8-H), 2.30Ϫ2.38 (m,
], 2.46Ϫ2.57 (m, 1 H, 6-H), 2.74
3
, plus DEPT): δ ϭ 22.1, 22.3, (AB, d, J ϭ 16.4 Hz, 1 H, 8-H), 5.86 (s, 1 H, 10-H), 7.23Ϫ7.33
2
3 2
J ϭ 16.3 Hz, 1 H, 8-H), 5.42 (s, 1 H, 10-H), 6.57 (br. s, 1 H, 2Ј- 1 H, 2-H), 2.38 [s, 6 H, N(CH )
H). Ϫ 13C NMR (62.9 MHz, CDCl
2
1
3
2
4
3.1, 24.5, 26.4, 33.3, 34.0 (Ϫ, C-2,3,4,5,3Ј,4Ј,5Ј), 37.4 (Ϫ, C-8),
(m, 3 H, Ph-H), 7.60Ϫ7.64 (m, 2 H, Ph-H). Ϫ C NMR
(62.9 MHz, CDCl , plus DEPT): δ ϭ 22.1, 22.9, 24.3, 25.9 (Ϫ, C-
2,3,4,5), 37.1 (Ϫ, C-8), 40.0 [ϩ, N(CH ], 59.6 (ϩ, C-6), 62.0
quat, C-1Ј), 212.2 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 271 (Cquat, C-1), 74.3 (Cquat, C-7), 125.1 (ϩ, Ph-C), 127.3 (ϩ, Ph-C),
0.4 [ϩ, N(CH ], 59.5 (ϩ, C-6), 61.8 (Cquat, C-1), 74.3 (Cquat
3
)
2
,
3
C-7), 126.7 (ϩ, C-2Ј), 129.3 (ϩ, C-10), 136.4 (Cquat, C-11), 153.1
3 2
)
(
(
(
C
ϩ
100) [M ], 242 (29), 229 (45), 214 (22), 200 (32), 179 (14), 162 127.9 (ϩ, Ph-C), 129.2 (ϩ, C-10), 135.4 (Cquat, C-11), 156.3 (Cquat
12). Ϫ C18H25NO (271.4): calcd. C 79.66, H 9.28; found C 79.32, C-Ph), 211.8 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 281 (100) [M ],
,
ϩ
ϩ
ϩ
H 9.02.
253 (72) [M Ϫ CO], 239 (77) [M Ϫ C
3
H
6
], 224 (18), 210 (38),
1
79 (22), 162 (24), 150 (18), 115 (14), 91 (10). Ϫ C19
H23NO (281.4):
1
1-(1Ј-Cycloheptenyl)-7-dimethylaminotricyclo[5.2.2.01,6]undec-10-
calcd. C 81.10, H 8.24; found C 81.06, H 8.03.
en-9-one (5c): 1-Ethynyl-1-cycloheptene (3c; 0.67 g, 5.57 mmol) was
added to a solution of complex 2 (1.13 g, 2.83 mmol) in 50 mL 7-Dimethylamino-11-(4Ј-propylphenyl)tricyclo[5.2.2.01,6]undec-10-
of pyridine, and the mixture was stirred at 80 °C for 60 h. After en-9-one (5f): p-Propylphenylethyne (3f; 0.90 mL, 5.62 mmol) was
chromatographic purification, 5c [220 mg (26%), R
ane/Et O ϭ 3:1] was obtained as a pale-yellow solid, m.p. 59 °C. pyridine, and the mixture stirred at 80 °C for 64 h. After purifica-
Ϫ IR (KBr): ν˜ ϭ 2930 cm (CϪH), 2918 (CϪH), 2845 (CϪH), tion, 5f [810 mg (87%), R
O ϭ 2:1] was ob-
2
f
ϭ 0.56, pent-
added to a solution of complex 2 (1.15 g, 2.88 mmol) in 60 mL of
2
Ϫ1
f
ϭ 0.70, pentane/Et
734 (CϭO), 1653 (CϭC), 1457, 1304, 1114. Ϫ H NMR tained as a colorless solid, m.p. 52 °C. Ϫ IR (KBr): ν˜ ϭ 2835 cm
1
Ϫ1
1
(
1
250 MHz, CDCl
3
):
δ ϭ 1.04Ϫ1.80, 2.19Ϫ2.32 (m, 19 H, (CϪH), 1738 (CϭO), 1503, 1458, 1306, 1237, 905, 814, 804. Ϫ H
2
4
3
2
1
,3,4,5,6,3Ј,4Ј,5Ј,6Ј,7Ј-H), 1.99 (ABM, dd, J ϭ 16.3, J ϭ 2.2 Hz, NMR (250 MHz, CDCl ): δ ϭ 0.95 (t, J ϭ 7.5 Hz, 3 H, Pr-CH ),
3
3
2
H, 8-H), 2.36 [s, 6 H, N(CH
504
)
3 2
], 2.58 (AB, d, J ϭ 16.3 Hz, 1 H, 1.25Ϫ1.45 (m, 4 H, 2,3,4,5-H), 1.57Ϫ1.74 (m, 2 H, 3,4-H), 1.65
2
Eur. J. Org. Chem. 2001, 2501Ϫ2506

Facile Synthesis of 7-Dimethylamino-endo-tricyclo[5.2.2.01,6]undec-10-en-9-ones
FULL PAPER
3
ϩ
(
(
2
7
(
8
sex, J ϭ 7.4 Hz, 2 H, Pr-CH
2
), 1.80Ϫ1.90 (m, 1 H, 5-H), 2.24 CO], 357 (73) [M Ϫ C
3
H
6
], 328 (18), 279 (10), 191 (18), 179 (32),
2
4
ABM, dd, J ϭ 16.5, J ϭ 2.2 Hz, 1 H, 8-H), 2.27Ϫ2.35 (m, 1 H, 162 (32), 149 (75), 91 (10), 74 (14), 59 (22), 41 (18). Ϫ C28H33NO
-H), 2.39 [s, 6 H, N(CH
.4 Hz, 2 H, Pr-CH ), 2.73 (AB, d, J ϭ 16.5 Hz, 1 H, 8-H), 5.82
s, 1 H, 10-H), 7.11 (d, J ϭ 8.2 Hz, 2 H, Ph-H), 7.57 (d, J ϭ
3
3 2
) ], 2.49Ϫ2.55 (m, 1 H, 6-H), 2.57 (t, J ϭ (399.6): calcd. C 84.17, H 8.32; found C 84.07, H 8.33.
2
2
7-Dimethylamino-10-phenyl-11-phenylethinyltricyclo[5.2.2.01,6]-
undec-10-en-9-one (5i): 1,4-Diphenylbuta-1,3-diyne (3i; 825 mg,
.08 mmol) was added to a solution of complex 2 (1.05 g,
.63 mmol) in 50 mL of pyridine, and the mixture was stirred at 80
C for 72 h. After chromatography, a mixture of 4i, 5i and their
regioisomers [814 mg (81%)] was obtained as a pale yellow oil.
Crystallization from pentane/Et O (20:1) at Ϫ20 °C afforded
603 mg (60%) of 5i (R ϭ 0.09, pentane/Et O ϭ 10:1) as colorless
crystals (m.p. 119 °C). Ϫ IR (KBr): ν˜ ϭ 2927 cm (CϪH), 1741
CϭO), 1598 (CϭC), 1442, 1310, 1131, 1026, 767, 756, 691. Ϫ H
NMR (250 MHz, CDCl ): δ ϭ 1.06Ϫ1.39 (m, 4 H, 2,3,4,5-H),
1.62Ϫ1.78 (m, 3 H, 3,4,5-H), 2.46 (AB, d, J ϭ 16.4 Hz, 1 H, 8-
3
3
.2 Hz, 2 H, Ph-H). Ϫ 1 C NMR (62.9 MHz, CDCl
δ ϭ 13.6 (ϩ, Pr-CH ), 22.0, 22.8, 24.2 ϫ 2, 25.9 (Ϫ, C-2,3,4,5, Pr-
CH ), 36.9 (Ϫ, Pr-CH ), 37.6 (Ϫ, C-8), 39.9 [ϩ, N(CH ], 59.4 (ϩ,
C-6), 61.7 (Cquat, C-1), 74.1 (Cquat, C-7), 124.9, 127.8 (ϩ, C-2Ј,3Ј),
28.1 (ϩ, C-10), 132.6 (Cquat, C-11), 141.7 (Cquat, C-4Ј), 156.1
quat, C-1Ј), 211.3 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 323 (94)
M ], 295 (100) [M Ϫ CO], 281 (82) [M Ϫ C
23), 162 (30), 154 (25), 150 (13), 70 (18). Ϫ C22
calcd. C 81.69, H 9.04; found C 80.77, H 9.09.
3
3
, plus DEPT):
4
2
°
3
2
2
3 2
)
1
(
[
(
2
C
ϩ
ϩ
ϩ
f
2
3
H
6
], 252 (27), 209
Ϫ1
H29NO (323.5):
1
(
3
2
-Dimethylamino-11-(4Ј-ethoxyphenyl)tricyclo[5.2.2.01,6]undec-10-
7
2
4
H), 2.50Ϫ2.56 (m, 2 H, 2,6-H), 2.59 (ABM, dd, J ϭ 16.4, J ϭ
.1 Hz, 1 H, 8-H), 2.81 [s, 6 H, N(CH ], 7.24Ϫ7.46 (m, 10 H, Ph-
, plus DEPT): δ ϭ 22.6, 22.7,
3.6, 23.7 (Ϫ, C-2,3,4,5), 39.8 (Ϫ, C-8), 40.1 [ϩ, N(CH ], 61.8
(ϩ, C-6), 65.2 (Cquat, C-1), 74.0 (Cquat, C-7), 85.8 (Cquat, C-1Ј),
00.0 (Cquat, C-2Ј), 123.3 (ϩ, Ph-C), 127.6 (ϩ, Ph-C), 127.8 (ϩ,
Ph-C), 127.9 (ϩ, Ph-C), 128.3 (ϩ, Ph-C), 128.4 (Cquat, C-10), 131.0
(ϩ, Ph-C), 132.3 (Cquat, Ph-C), 133.9 (Cquat, Ph-C), 151.4 (Cquat
en-9-one (5g): p-Ethoxyphenylethyne (3g; 0.45 mL, 4.77 mmol) was
added to a solution of complex 2 (0.99 g, 2.48 mmol) in 50 mL of
pyridine, and the mixture stirred at 80 °C for 52 h. After purifica-
2
3 2
)
1
3
H). Ϫ C NMR (62.9 MHz, CDCl
2
3
3 2
)
tion, 5g [401 mg (50%), R
tained as a yellow solid, m.p. 101 °C. Ϫ IR (KBr): ν˜ ϭ 2928 cm
f 2
ϭ 0.60, pentane/Et O ϭ 2:1] was ob-
Ϫ1
1
(
8
2
CϪH), 1738 (CϭO), 1609 (CϭC), 1565 (CϭC), 1508, 1249, 1046,
11. Ϫ 1H NMR (250 MHz, CDCl
3
): δ ϭ 1.16Ϫ1.47 (m, 4 H,
CH ), 1.55Ϫ1.64 (m, 1
3
,
,3,4,5-H), 1.39 (t, J ϭ 7.0 Hz, 3 H, OCH
2
3
ϩ
C-11), 212.0 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 381 (25) [M ],
H, 3-H), 1.64Ϫ1.75 (m, 1 H, 4-H), 1.80Ϫ1.91 (m, 1 H, 5-H), 2.22
ϩ
ϩ
2
4
353 (11) [M Ϫ CO], 339 (100) [M Ϫ C
3 6
H ], 178 (10). Ϫ
(
ABM, dd, J ϭ 16.4, J ϭ 2.3 Hz, 1 H, 8-H), 2.24Ϫ2.32 (m, 1 H,
27
C H
27NO (381.5): calcd. C 85.00, H 7.13; found C 85.35, H 7.06.
2
-H), 2.38 [s, 6 H, N(CH ], 2.44Ϫ2.53 (m, 1 H, 6-H), 2.71 (AB,
3 2
)
2
3
d, J ϭ 16.4 Hz, 1 H, 8-H), 4.01 (q, J ϭ 7.0 Hz, 2 H, OCH
2
CH
3
),
.75 (s, 1 H, 10-H), 6.81 (d, J ϭ 8.6 Hz, 2 H, Ph-H), 7.58 (d, J ϭ
.6 Hz, 2 H, Ph-H). Ϫ 13C NMR (62.9 MHz, CDCl
, plus DEPT):
CH ), 22.2, 23.0, 24.4, 26.1 (Ϫ, C-2,3,4,5), 37.2
Ϫ, C-8), 40.0 [ϩ, N(CH ], 59.6 (ϩ, C-6), 61.7 (Cquat, C-1), 63.2
Ϫ, OCH CH ), 74.2 (Cquat, C-7), 113.9, 126.5 (ϩ, C-2Ј,3Ј), 126.9
ϩ, C-10), 127.8 (Cquat, C-4Ј), 155.9 (Cquat, C-1Ј), 158.5 (Cquat, C-
7
-Dimethylamino-11-(4Ј-ethoxycarbonylphenyl)-10-phenyltricyclo-
3
3
5
8
1,6
[5.2.2.0 ]undec-10-en-9-one (5k): p-Phenylethynyl benzoic acid
3
ethyl ester (3k; 705 mg, 2.82 mmol) was added to a solution of
complex 2 (815 mg, 2.04 mmol) in 40 mL of pyridine, and the mix-
ture stirred at 80 °C for 56 h. After purification, 5k [581 mg (66%),
δ ϭ 14.7 (ϩ, OCH
2
3
(
(
(
3 2
)
2
3
R
f
ϭ 0.25, pentane/Et
2
O ϭ 3:1] was obtained as a colorless solid,
Ϫ1
m.p. 78 °C. Ϫ IR (KBr): ν˜ ϭ 2934 cm (CϪH), 1738 (CϭO),
ϩ
1
2
2
1), 211.9 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 325 (100) [M ],
1
1
714 (CϭO), 1603 (CϭC), 1280, 1107, 701. Ϫ H NMR (250 MHz,
ϩ
ϩ
97 (66) [M Ϫ CO], 283 (66) [M Ϫ C
07 (18), 179 (26), 162 (26), 149 (24), 91 (16), 84 (26), 57 (13), 41
(325.5): calcd. C 77.50, H 8.36; found C 77.16,
3
H
6
], 268 (18), 254 (20),
3
CDCl
H, CH
3 2
H), 2.01Ϫ2.10 (m, 1 H, 2-H), 2.36 [s, 6 H, N(CH )
3
): δ ϭ 1.14Ϫ1.35 (m, 4 H, 2,3,4,5-H), 1.32 (t, J ϭ 7.1 Hz,
CH ), 1.60Ϫ1.78 (m, 2 H, 3,4-H), 1.85Ϫ1.95 (m, 1 H, 5-
], 2.55 (ABM,
dd, J ϭ 16.5, J ϭ 2.3 Hz, 1 H, 8-H), 2.68Ϫ2.73 (m, 1 H, 6-H),
3
2
3
(13). Ϫ C21
H
27NO
2
H 8.10.
2
4
2
3
2
.76 (AB, d, J ϭ 16.5 Hz, 1 H, 8-H), 4.30 (q, J ϭ 7.1 Hz, 2 H,
CH CH ), 6.85Ϫ6.92 (m, 2 H, Ph-H), 7.10Ϫ7.16 (m, 3 H, Ph-H),
.22Ϫ7.28 (m, 2 H, Ph-H), 7.80Ϫ7.85 (m, 2 H, Ph-H). Ϫ C NMR
62.9 MHz, CDCl , plus DEPT): δ ϭ 14.2 (ϩ, CH CH ), 22.3,
2.7, 24.1, 25.4 (Ϫ, C-2,3,4,5), 38.2 (Ϫ, C-8), 40.0 [ϩ, N(CH ],
0.1 (ϩ, C-6), 60.7 (Ϫ, CH CH ), 65.9 (Cquat, C-1), 74.6 (Cquat, C-
7
-Dimethylamino-11-(4ЈЈ-propylbiphenyl-4Ј-yl)tricyclo[5.2.2.01,6]-
undec-10-en-9-one (5h): 4-Ethynyl-4Ј-propylbiphenyl (3h; 898 mg,
2
3
13
7
(
2
6
7
1
4
2
.08 mmol) was added to a solution of complex 2 (1.10 g,
.75 mmol) in 55 mL of pyridine, and the mixture stirred at 80 °C
3
2
3
3 2
)
f
for 60 h. After purification, 5h [165 mg (15%), R ϭ 0.73, pentane/
2
3
Et O ϭ 10:1] was obtained as a yellow solid, m.p. 113 °C. Ϫ IR
2
), 127.3, 128.0 ϫ 2, 128.67, 128.70 (ϩ, Ph-C), 133.9 (Cquat, C-10),
40.5 (Cquat, Ph-C), 143.2 (Cquat, Ph-C), 151.5 (Cquat, C-11), 166.3
Ϫ1
(
(
1
1
KBr): ν˜ ϭ 2933 cm (CϪH), 1734 (CϭO), 1653 (CϭC), 1496
CϭC), 1457, 1306, 1245, 804. Ϫ H NMR (250 MHz, CDCl
.00 (t, J ϭ 7.3 Hz, 3 H, CH
.66Ϫ1.78 (m, 2 H, 3,4-H), 1.70 (sex, J ϭ 7.3 Hz, 2 H,
1
3
): δ ϭ
(
(
1
2
Cquat, CO Et), 211.8 (Cquat, C-9). Ϫ MS (70 eV): m/z (%) ϭ 429
3
2
CH
3
), 1.15Ϫ1.46 (m, 4 H, 2,3,4,5-H),
ϩ
ϩ
ϩ
22) [M ], 401 (17) [M Ϫ CO], 387 (100) [M Ϫ C
50 (7), 91 (9). Ϫ C28 : calcd. 429.2304; found 429.2303
HR EIMS).
3 6
H ], 178 (30),
3
H31NO
3
2
CH
2
CH
2
CH
3
), 1.89Ϫ1.95 (m, 1 H, 5-H), 2.29 (ABM, dd, J ϭ
(
4
1
6.4, J ϭ 2.3 Hz, 1 H, 8-H), 2.33Ϫ2.43 (m, 1 H, 2-H), 2.44 [s, 6
3
H, N(CH
CH CH CH
0-H), 7.26 (d, J ϭ 8.2 Hz, 2 H, Ph-H), 7.54 (d, J ϭ 8.2 Hz, 2 yl)ethene (3l; 535 mg, 2.34 mmol) was added to a solution of com-
3 2
) ], 2.50Ϫ2.62 (m, 1 H, 6-H), 2.65 (t, J ϭ 7.3 Hz, 2 H, 7-Dimethylamino-10-phenyl-11-(4Ј-phenyl-1Ј-buten-3Ј-ynyl)-
2
1,6
2
2
3
), 2.79 (AB, d, J ϭ 16.4 Hz, 1 H, 8-H), 5.93 (s, 1 H,
tricyclo[5.2.2.0 ]undec-10-en-9-one (5l): (E)-1,2-Di(phenylethyn-
3
3
1
3
3
H, Ph-H), 7.55 (d, J ϭ 8.2 Hz, 2 H, Ph-H), 7.59 (d, J ϭ 8.2 Hz, plex 2 (958 mg, 2.40 mmol) in 50 mL of pyridine, and the mixture
2
1
H, Ph-H). Ϫ 13C NMR (62.9 MHz, CDCl
3.9 (ϩ, CH CH CH ), 22.3, 23.1, 24.5, 26.2 (Ϫ, C-2,3,4,5), 24.6 0.55, pentane/Et
CH CH ), 37.1 (Ϫ, C-8), 37.7 (Ϫ, CH CH CH
), 40.3 [ϩ, 132 °C. Ϫ IR (KBr): ν˜ ϭ 2930 cm (CϪH), 1737 (CϭO), 1488,
3
], 59.8 (ϩ, C-6), 62.2 (Cquat, C-1), 74.5 (Cquat, C-7), 125.7 1443, 1314, 964, 753, 712, 687. Ϫ H NMR (250 MHz, CDCl ):
3
, plus DEPT): δ ϭ stirred at 80 °C for 56 h. After purification, 5l [461 mg (48%), R
f
ϭ
2
2
3
2
O ϭ 3:1] was obtained as a pale-yellow solid, m.p.
Ϫ1
(
Ϫ, CH
2
2
3
2
2
3
1
3
N(CH )
2
(
1
ϩ, Ph-C), 126.5 (ϩ, Ph-C), 126.7 (ϩ, Ph-C), 128.9 (ϩ, Ph-C), δ ϭ 1.04Ϫ1.31 (m, 4 H, 2,3,4,5-H), 1.58Ϫ1.72 (m, 2 H, 3,4-H),
29.2 (ϩ, C-10), 134.2 (Cquat, Ph-C), 138.1 (Cquat, Ph-C), 140.2 1.87Ϫ1.92 (m, 1 H, 5-H), 2.15 (ABM, dd, J ϭ 16.5, J ϭ 4.0 Hz,
2
4
(
C
quat, Ph-C), 141.9 (Cquar, Ph-C), 156.1 (Cquat, C-11), 212.0 (Cquat
,
3 2
1 H, 8-H), 2.31Ϫ2.36 (m, 1 H, 2-H), 2.52 [s, 6 H, N(CH ) ],
2.52Ϫ2.60 (m, 1 H, 6-H), 2.78 (AB, d, J ϭ 16.5 Hz, 1 H, 8-H),
ϩ
ϩ
2
C-9). Ϫ MS (70 eV): m/z (%) ϭ 399 (100) [M ], 371 (90) [M
Ϫ
Eur. J. Org. Chem. 2001, 2501Ϫ2506
2505

Y.-T. Wu, H. Schirmer, M. Noltemeyer, A. de Meijere
FULL PAPER
3
[3]
6
.78 (d, J ϭ 15.9 Hz, 1 H, 1Ј-H), 7.10Ϫ7.42 (m, 11 H, 2Ј-H, Ph-
M. Duetsch, R. Lackmann, F. Stein, A. de Meijere, Synlett
1991, 324Ϫ326.
B. L. Flynn, F. J. Funke, C. C. Silveira, M. Duetsch, A. de
Meijere, Synlett 1995, 1007Ϫ1010.
F. Stein, M. Duetsch, R. Lackmann, M. Noltemeyer, A. de
Meijere, Angew. Chem. 1991, 103, 1669Ϫ1671; Angew. Chem.
Int. Ed. Engl. 1991, 30, 1658Ϫ1660.
1
3
H). Ϫ C NMR (62.9 MHz, CDCl
3.8, 26.0 (Ϫ, C-2,3,4,5), 36.9 (Ϫ, C-8), 39.9 [ϩ, N(CH
ϩ, C-6), 64.5 (Cquat, C-1), 73.5 (Cquat, C-7), 90.3 (Cquat, C-4Ј), 93.3
quat, C-3Ј), 111.1 (ϩ, C-1Ј), 123.3 (Cquat, Ph-C), 127.4, 127.8,
28.0, 128.1 ϫ 2, 131.2 (ϩ, Ph-C), 133.8 (Cquat, Ph-C), 133.9 (ϩ,
C-2Ј), 144.5 (Cquat, C-10), 145.8 (Cquat, C-11), 211.1 (Cquat, C-9).
3
, plus DEPT): δ ϭ 22.0, 22.2,
[
[
4]
5]
2
3 2
)
], 58.4
(
(
C
1
[6]
F. Stein, M. Duetsch, M. Noltemeyer, A. de Meijere, Synlett
993, 486Ϫ488.
ϩ
ϩ
Ϫ MS (70 eV): m/z (%) ϭ 407 (53) [M ], 365 (100) [M Ϫ C
36 (14), 178 (48), 150 (12). Ϫ C29 29NO (407.6): calcd. C 85.47,
H 7.17; found C 85.60, H 7.04.
3 6
H ],
1
[
[
7]
8]
3
H
H. Schirmer, T. Labahn, B. L. Flynn, Y.-T. Wu, A. de Meijere,
Synlett 1999, 2004Ϫ2006.
M. Duetsch, S. Vidoni, F. Stein, F. Funke, M. Noltemeyer, A.
de Meijere, J. Chem. Soc., Chem. Commun. 1994, 1679Ϫ1680.
B. L. Flynn, C. C. Silveira, A. de Meijere, Synlett 1995,
812Ϫ814.
B. L. Flynn, F. J. Funke, M. Noltemeyer, A. de Meijere, Tetra-
hedron 1995, 51, 11141Ϫ11148.
H. Schirmer, M. Duetsch, F. Stein, T. Labahn, B. Knieriem, A.
de Meijere, Angew. Chem. 1999, 111, 1364Ϫ1367; Angew.
Chem. Int. Ed. 1999, 38, 1285Ϫ1287.
1
0-Cyclopropyl-11-(4Ј-cyclopropyl-1Ј-buten-3Ј-ynyl)-7-dimethyl-
1,6
aminotricyclo[5.2.2.0 ]undec-10-en-9-one (5m): (E)-1,2-Di(cyclo-
propylethynyl)ethene (3m; 247 mg, (1.58 mmol) was added to a so-
lution of complex 2 (1.41 g, 3.53 mmol) in 40 mL of pyridine, and
the mixture stirred at 80 °C for 60 h. After purification, 5m [251 mg
[9]
[10]
[
[
11]
(47%), R
f 2
ϭ 0.45, pentane/Et O ϭ 3:1] was obtained as a colorless
Ϫ1
solid, m.p. 187 °C. Ϫ IR (KBr): ν˜ ϭ 2934 cm (CϪH), 1732 (Cϭ
O), 1458, 1311, 1026, 966, 891. Ϫ H NMR (250 MHz, CDCl
δ ϭ 0.40Ϫ0.55 (m, 2 H, cPr), 0.62Ϫ0.85 (m, 6 H, cPr), 1.02Ϫ1.29
1
3
):
12]
H. Schirmer, B. Flynn, A. de Meijere, Tetrahedron 2000, 56,
977Ϫ4984.
R. Aumann, R. Fröhlich, J. Prigge, O. Meyer, Organometallics
999, 18, 1369Ϫ1380.
4
(m, 4 H, 2,3,4,5-H), 1.33Ϫ1.45 (m, 2 H, cPr), 1.57Ϫ1.67 (m, 2 H,
[13]
[14]
2
4
3
2
6
,4-H), 1.75Ϫ1.80 (m, 1 H, 5-H), 1.93 (ABM, dd, J ϭ 16.2, J ϭ
.2 Hz, 1 H, 8-H), 2.21Ϫ2.27 (m, 1 H, 2-H), 2.30Ϫ2.34 (m, 1 H,
1
It is remarkable that pyridine can be used as a solvent not
only for formal cycloadditions of alkynes to α,β-unsaturated
carbenechromium complexes (see: H. Schirmer, F. J. Funke, S.
Müller, M. Noltemeyer, B. Flynn, A. de Meijere, Eur. J. Org.
Chem. 1999, 2025Ϫ2031), but also for the direct cyclization of
2
-H), 2.37 [s, 6 H, N(CH
3
)
2
], 2.55 (AB, d, J ϭ 16.2 Hz, 1 H, 8-
3
5
H), 6.57 (ABM, dd, J ϭ 16.2, J ϭ 1.8 Hz, 1 H, 2Ј-H), 6.77 (AB,
d, J ϭ 16.0 Hz, 1 H, 1Ј-H). Ϫ C NMR (62.9 MHz, CDCl , plus
3
3
13
DEPT): δ ϭ 0.5 (ϩ, cPr-C), 5.0, 5.9 (Ϫ, cPr-C), 8.1 (ϩ, cPr-C), 8.7
ϫ 2 (Ϫ, cPr-C), 22.25, 22.29, 24.3, 26.2 (Ϫ, C-2,3,4,5), 37.3 (Ϫ, C-
1
C
-chroma-1,3,5-hexatrienes of type 2. When other solvents (e.g.
6
H
6
, THF or THF ϩ 1 equiv. PPh ) were applied in this reac-
3
3 2
8), 40.0 [ϩ, N(CH ) ], 58.3 (ϩ, C-6), 65.5 (Cquat, C-1), 72.9 (Cquat,
tion, only trace amounts of DielsϪAlder adducts and many
by-products were detected.
C-7), 76.6 (Cquat, C-4Ј), 96.6 (Cquat, C-3Ј), 110.2 (ϩ, C-1Ј), 132.4
(ϩ, C-2Ј), 142.7 (Cquat, C-10), 147.0 (Cquat, C-11), 211.6 (Cquat, C-
[15]
Crystallographic data (excluding structure factors) for the
structures reported in this paper have been deposited with the
Cambridge Crystallographic Data Centre as supplementary
publication nos. CCDC-142652 (5d) and -149648 (5i). Copies
of the data can be obtained free of charge on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK [Fax: (in-
ternat.) ϩ44-1223/336-033; E-mail: deposit@ccdc.cam.ac.uk].
It is well-known that the 1,5-hydrogen shift in many substituted
cyclopentadienes is fast even at room temperature. For a de-
tailed discussion of thermal sigmatropic rearrangements, in-
cluding 1,5-hydrogen shifts, see: C. W. Spangler, Chem. Rev.
ϩ
ϩ
9
). Ϫ MS (70 eV): m/z (%) ϭ 335 (43) [M ], 320 (14), 293 (53) [M
], 278 (46), 178 (100), 150 (26). Ϫ C23 29NO (335.5): calcd.
C 82.34, H 8.71; found C 82.58, H 8.66.
Ϫ C
3
H
6
H
1
-Dimethylamino-3-ethoxy-3aH-tetrahydroindene (8): A solution of
complex 2 (10 mg) in 0.5 mL of [D ]pyridine under nitrogen was
kept at room temp. for 16 h. Ϫ H NMR (500 MHz, [D ]pyridine,
5
1
[16]
5
2
3
plus CH COSY and HH NOESY): δ ϭ 1.02 (‘‘q’’d, J ϭ 12.5, J ϭ
3
1
2.5, J ϭ 3.0 Hz, 1 H, 4-H), 1.08Ϫ1.19 (m, 1 H, 6-H), 1.24 (t,
3
J ϭ 7.0 Hz, 3 H, OCH
2 3
CH ), 1.27Ϫ1.33 (m, 1 H, 5-H), 1.63Ϫ1.78
1
976, 76, 187Ϫ217.
(m, 2 H, 5,6-H), 1.90Ϫ2.03 (m, 1 H, 7-H), 2.25Ϫ2.33 (m, 1 H, 4-
[17]
3
3
It is well documented that a donor substituent activates a 1,3-
diene more when placed in the 1-position than in the 3-posi-
tion, and a dimethylamino group is a more efficient donor than
an ethoxy group. For a detailed discussion, see: I. Fleming,
Frontier Orbitals and Organic Chemical Reactions, Wiley, Lon-
don, 1976.
3 2
H), 2.60 [s, 6 H, N(CH ) ], 2.67 (dd, J ϭ 12.5, J ϭ 4.5 Hz, 1 H,
3
3
a-H), 2.92Ϫ3.00 (m, 1 H, 7-H), 3.90 (q, J ϭ 7.0 Hz, 2 H,
OCH CH ]pyrid-
), 5.12 (s, 1 H, 2-H). Ϫ 13C NMR (75 MHz, [D
ine, plus APT): δ ϭ 15.7 (ϩ, OCH CH ), 24.4, 26.3, 28.9, 32.6 (Ϫ,
C-4,5,6,7), 41.1 [ϩ, N(CH ], 47.2 (ϩ, C-3a), 65.4 (Ϫ, OCH CH ),
4.6 (ϩ, C-2), 107.5 (Ϫ, C-7a), 150.0 (Ϫ, C-1), 160.9 (Ϫ, C-3).
2
3
5
2
3
3
)
2
2
3
[
[
18]
19]
9
E. Winterfeldt, Chem. Rev. 1993, 93, 827Ϫ843.
Both the steric and the electronic effects play an important role
for the facial stereoselectivity of the DielsϪAlder reaction of
substituted cyclopentadienes with dienophiles. For a detailed
discussion, see: R. Gleiter, L. A. Paquette, Acc. Chem. Res.
983, 16, 328Ϫ334.
H. Fischer, J. Mühlemeier, R. Markl, K. H. Dötz, Chem. Ber.
982, 115, 1355Ϫ1362.
L. Brandsma, Preparative Acetylenic Chemistry, 2nd ed., Elsev-
ier, Amsterdam, 1988.
L. Brandsma, S. F. Vasilevsky, H. D. Verkruijsse, Application
of Transition Metal Catalysts in Organic Synthesis, Springer,
Berlin, 1999.
Acknowledgments
This work was supported by the Volkswagen-Stiftung and the
Fonds der Chemischen Industrie. Generous gifts of chemicals by
BASF, Bayer, Degussa-Hüls and Merck AG have been provided.
The authors are grateful to Dr. Burkhard Knieriem for his careful
proofreading of the final manuscript.
1
[
[
[
20]
21]
22]
1
[
[
1]
2]
Review: A. de Meijere, Pure & Appl. Chem. 1996, 68, 61Ϫ72.
Review: H. Schirmer, M. Duetsch, A. de Meijere, Angew.
Chem. 2000, 112, 4124Ϫ4162; Angew. Chem. Int. Ed. 2000,
Received January 18, 2001
39, 3964Ϫ4002.
[O01023]
2506
Eur. J. Org. Chem. 2001, 2501Ϫ2506