Synthesis of Si- and N-containing bicyclo[4.2.1]nona-2,4-dienes and bicyclo[4.2.1]nona-2,4,7-trienes

Article abstract of DOI:10.1007/s11172-013-0133-y

A [6π+2π] cycloaddition of Si- and N-containing alkynes and 1,2-dienes to cyclohepta-1,3,5-trienes in the presence of the two-component catalytic system (acac)₂TiCl₂-Et₂AlCl gives rise to the corresponding bicyclo[4.2.1]nona-2,4-diene and bicyclo[4.2.1]nona-2, 4,7-triene derivatives.

Full text of DOI:10.1007/s11172-013-0133-y

Russian Chemical Bulletin, International Edition, Vol. 62, No. 4, pp. 1016—1019, April, 2013
1016
Synthesis of Siꢀ and Nꢀcontaining bicyclo[4.2.1]nonaꢀ2,4ꢀdienes
and bicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienes*
V. A. D´yakonov, D. I. Kolokol´tsev, G. N. Kadikova, and U. M. Dzhemilev
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences,
141 prosp. Oktyabrya, 450075 Ufa, Russian Federation.
Fax: +7 (347) 284 2750. Eꢀmail: DyakonovVA@rambler.ru
A [6+2] cycloaddition of Siꢀ and Nꢀcontaining alkynes and 1,2ꢀdienes to cycloheptaꢀ
1,3,5ꢀtrienes in the presence of the twoꢀcomponent catalytic system (acac)2TiCl2—Et2AlCl
gives rise to the corresponding bicyclo[4.2.1]nonaꢀ2,4ꢀdiene and bicyclo[4.2.1]nonaꢀ2,4,7ꢀ
triene derivatives.
Key words: cycloheptaꢀ1,3,5ꢀtrienes, propargylamines, 1,2ꢀdienes, metal complex catalyꢀ
sis, medium size cycles, cycloaddition, organoaluminum compounds, organosilicon compounds.
Development of efficient methods for the construction
6 mol.%. The best yields of adducts 2 under the conditions
of choice (CHT : Si—alkyne : Ti(acac)2Cl2 : Et2AlCl =
= 1 : 2 : 0.06 : 0.4, benzene, 80 C, 8 h) were 84 (2a),
71 (2b), and 78% (2c) (see Scheme 1).
of medium size cycles is among the most important probꢀ
lems of organic chemistry because of their wide applicaꢀ
tion in the composition of medicines exhibiting antituꢀ
mor, antiviral, and other activities.1
Recently, we pioneered to show that 1,2ꢀdienes selecꢀ
tively underwent the [6+2] cycloaddition to cycloꢀ
heptaꢀ1,3,5ꢀtrienes (CHT) in the presence of the catalytic
system TiCl4—EtnAlCl3ꢀn (n = 1—3) with the formation
of practically important bicyclo[4.2.1]nonadienes in high
yields.2,3
Scheme 1
To continue this research and examine a possibility of
the [6+2] cycloaddition between functionally substitutꢀ
ed 1,2ꢀdienes and acetylenes to cycloheptaꢀ1,3,5ꢀtrienes,
we studied reactions of CHT and 7ꢀalkyl(phenyl)ꢀ
cycloheptaꢀ1,3,5ꢀtrienes with Siꢀcontaining allenes and
disubstituted acetylenes, as well as with propargylamines,
catalyzed by Ti complexes in combination with trialkylꢀ
and alkylhaloalanes.
To search for the optimal catalyst for this reactions, we
studied a number of titanium complexes: (Cp2TiCl2,
(PriO)2TiCl2, (ButO)2TiCl2, Ti(acac)2Cl2, (PriO)4Ti) in
combination with such cocatalysts as Et3Al, Bui3Al,
Et2AlCl, Bui2AlCl, and Bui2AlH used previously for the
transformation of unsaturated compounds. The selection
was carried out for the model reaction of 1ꢀphenylꢀ2ꢀtriꢀ
methylsilylacetylene (1a) with CHT (Scheme 1). The
highest yields (>70%) of the [6+2]ꢀadducts 2a were
observed in the case of (RO)2TiCl2 and Ti(acac)2Cl2 reꢀ
duced with Et2AlCl or Bui2AlCl at 80 C, in the benzene
solution and at the concentration of the catalyst of
R = Ph (a), Hex (b), Oct (c)
The high efficiency of the Ti(acac)2Cl2—Et2AlCl cataꢀ
lytic system, in contrast to the catalyst TiCl4—Et2AlCl
reported in the literature4 for the use in the homodimerꢀ
ization of cycloheptaꢀ1,3,5ꢀtriene, was demonstrated for
the [6+2] cycloaddition of propargylamine 3a—c to
cycloheptaꢀ1,3,5ꢀtriene. Using of this catalytic system,
nitrogenꢀcontaining bicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienes 4a—c
were obtained in high yields 61—78% (Scheme 2). It
should be noted that in the case of TiCl4 and (RO)2TiCl2
in combination with organoaluminum reducing agents
mentioned above did not lead to the target cycloadducts
were not formed.
Note that no cycloaddition of propargylamine to CHT
was previously reported.
We also showed that Siꢀ and Nꢀcontaining acetylenes
similarly add to 7ꢀsubstituted CHT (CHT : Si—alkyne :
: Ti(acac)2Cl2 : Et2AlCl = 1 : 2 : 0.06 : 0.4, benzene, 80 C,
8 h; CHT : N—alkyne : Ti(acac)2Cl2 : Et2AlCl =
* Dedicated to Academician of the Russian Academy of Sciences
I. P. Beletskaya on the occasion of her anniversary.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1015—1018, April, 2013.
1066ꢀ5285/13/6204ꢀ1016 © 2013 Springer Science+Business Media, Inc.

Bicyclo[4.2.1]nonaꢀ2,4ꢀdienes
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 4, April, 2013
1017
Scheme 2
The structure of compounds obtained was confirmed
1
by D (1H, 13C) and 2D (COSY, NOESY) NMR specꢀ
troscopy and mass spectrometry.
In conclusion, we developed an efficient synthesis of
Siꢀ and Nꢀcontaining bicyclo[4.2.1]nonaꢀ2,4ꢀdienes and
bicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienes based on the [6+2]
cycloaddition of functionally substituted alkynes and alꢀ
lenes to cycloheptaꢀ1,3,5ꢀtrienes in the presence of the
new twoꢀcomponent catalytic system (acac)2TiCl2—
Et2AlCl. The results obtained show that such catalytic
systems seem promising for cycloaddition between heteroꢀ
cyclic analogs of CHT and for the preparation of practiꢀ
cally important natural compounds.
R = Bu (a), Oct (b), Ph (c)
= 1 : 1 : 0.07 : 0.5, benzene, 80 C, 8 h) in the presence of
Ti(acac)2Cl2—Et2AlCl to give products 5—7 in 74, 52,
and 81% yields, respectively (Scheme 3).
Experimental
Chromatographic analysis was carried out on a Shimadzu
GCꢀ9A instrument, using a 2000×2ꢀmm column, silicon SEꢀ30
(5%) on Chromaton NꢀAWꢀHMDS (0.125—0.160 mm) as the
stationary phase, carrier gas helium (30 mL min–1), the temperꢀ
ature regime from 50 to 300 C at the rate of 8 deg min–1. 1H and
13C NMR spectra were recorded on a Bruker Avanceꢀ400
spectrometer (100 MHz for 13C and 400 MHz for 1H) in CDCl3
relative to Me4Si. Mass spectrometric analysis was carried out
on a Shimadzu GCMSꢀQP2010 Plus spectrometer (glass capilꢀ
lary column SLBꢀ5ms 60000×0.25mm×0.25 m (Supelco, USA),
carrier gas helium, the temperature regime from 40 to 280 C at
the rate of 5 deg min–1, the injector temperature 280 C, the
source of ions temperature 200 C, 70 eV). Elemental analysis
was performed on a Carlo Erba model 1108 analyzer. The yields
of the products were determined by GLC. The catalytic cycloꢀ
addition was carried out under dry argon. Aromatic solvents
were dried with Na. Commercial Et2AlCl (90%) and Bui3Al
(92%) were available from Redkino Experimental Factory Inc.,
cycloheptaꢀ1,3,5ꢀtriene was purchased from Aldrich. Titanium
chlorobis(acetylacetonate), trimethylsilylacetylenes, propargylꢀ
amines, and 1,2ꢀdienes were synthesized as described.5,6 7ꢀEthylꢀ
cycloheptaꢀ1,3,5ꢀtriene and 7ꢀphenylcycloheptaꢀ1,3,5ꢀtriene
were obtained according to the literature.7
Cycloaddition of Siꢀcontaining acetylenes to cycloheptaꢀ1,3,5ꢀ
trienes (general procedure). Cycloheptatriene (1 mmol), acetylꢀ
ene compound 1 (2 mmol), Ti(acac)2Cl2 (0.06 mmol), and dry
benzene (3 mL) were placed into a temperature controlled
(~0 C) glass tube under dry argon. The tube was cooled to
temperature of liquid nitrogen, Et2AlCl (0.4 mmol) was added,
and the tube was sealed. After heating at 80 C for 8 h, the tube
was unsealed, the content was treated with EtOH. The light
solvents were evaporated in vacuo, the residue was subjected to
chromatography on a column with silica gel (eluent light petroꢀ
leum, 100%).
Scheme 3
R = Et (5, 7), Ph (6)
The systems selected also catalyzed [6+2] cycloadꢀ
dition of CHT to allenes (Scheme 4). Thus, the Siꢀconꢀ
taining 1,2ꢀdienes 7a,b added to CHT in the presence of
the catalyst Ti(acac)2Cl2—RnAlCl3ꢀn (R = Et, Bui; n = 2, 3)
affording alkylideneꢀsubstituted bicyclo[4.2.1]nonaꢀ2,4ꢀ
dienes 8a,b in 60—87% yields.
Scheme 4
Trimethyl(8ꢀphenylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)silꢀ
ane (2a). Rf 0.52 (SiO2, light petroleum, 100%). 1H NMR,
: –0.73 (s, 9 H, SiMe3); 1.69 (d, 1 H, C(9)H2, J = 12 Hz); 2.33
(dt, 1 H, C(9)H2, Jd = 12 Hz, Jt = 7 Hz); 3.31 (t, 1 H, C(1)H,
J = 7 Hz); 3.54 (t, 1 H, C(6)H, J = 7 Hz); 5.84—5.91 (m, 2 H,
C(3,4)H); 5.99—6.04 (m, 1 H, C(5)H); 6.20—6.24 (m, 1 H,
C(2)H); 7.17—7.30 (m, 5 H, Ph). 13C NMR, : 0.60 (SiMe3),
31.64 (C(9)), 49.22 (C(1)), 51.62 (C(6)), 123.63 (C(3)), 124.70
(C(4)), 126.89 (C(13)), 127.49 (C(12), C(14)), 129.10 (C(11),
7a, 8a: R1 = CH2TMS, R2 = H
7b, 8b: R1 = Bu, R2 = CH2TMS

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D´yakonov et al.
C(15)), 135.20 (C(10)), 138.01 (C(5)), 139.00 (C(2)), 147.24
(C(7), C(8)). MS, m/z: 266 [M]+. Found (%): C, 80.91; H, 8.33.
C18H22Si. Calculated (%): C, 81.14; H, 8.32.
and the tube was sealed. After heating at 80 C for 8 h, the tube
was unsealed, the content was treated with aqueous KOH (25%).
The reaction products were extracted with benzene, dried with
KOH, the target compounds were isolated by fractional distilꢀ
lation.
(8ꢀHexylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)trimethylsilane
(2b). Rf 0.59 (SiO2, light petroleum, 100%). 1H NMR, : 0.17
(s, 9 H, SiMe3); 0.91 (t, 3 H, CH3, J = 6 Hz); 1.20—1.46 (m, 8 H,
C(11—14)H2); 1.56 (d, 1 H, C(9)H2, J = 12 Hz); 2.08—2.14
(m, 2 H, C(10)H2); 2.23—2.32 (m, 1 H, C(9)H2); 3.08 (t, 1 H,
C(1)H, J = 7 Hz); 3.26 (t, 1 H, C(6)H, J = 7 Hz); 5.70—5.83
(m, 2 H, C(3,4)H); 6.05—6.17 (m, 2 H, C(2,5)H). 13C NMR,
: 0.63 (3 C, SiMe3), 14.07 (C(15)), 22.64 (C(14)), 29.49 (C(11)),
29.57 (C(12)), 30.30 (C(13)), 31.44 (C(9)), 31.83 (C(10)), 48.31
(C(1)), 48.36 (C(6)), 123.05 (C(3)), 124.32 (C(4)), 132.61 (C(7)),
138.62 (C(5)), 139.91 (C(2)), 149.87 (C(8)). MS, m/z: 274 [M]+.
Found (%): C, 78.49; H, 10.99. C18H30Si. Calculated (%):
C, 78.75; H, 11.02.
Trimethyl(8ꢀoctylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)silane
(2c). Rf 0.63 (SiO2, light petroleum, 100%). 1H NMR, : 0.17
(s, 9 H, SiMe3); 0.91 (t, 3 H, CH3, J = 6 Hz); 1.21—1.48 (m,
12 H, C(11—16)H2); 1.56 (d, 1 H, C(9)H2, J = 12 Hz); 2.05—2.14
(m, 2 H, C(10)H2); 2.22—2.33 (m, 1 H, C(9)H2); 3.08 (t, 1 H,
C(1)H, J = 7 Hz); 3.25 (t, 1 H, C(6)H, J = 7 Hz); 5.70—5.83
(m, 2 H, C(3,4)H); 6.05—6.17 (m, 2 H, C(2,5)H). 13C NMR,
: 0.64 (3 C, SiMe3), 14.10 (C(17)), 22.67 (C(16)), 29.48 (C(11)),
29.91 (C(13)), 29.57 (C(12)), 29.91 (C(13)), 30.33 (C(15)), 31.44
(C(9)), 31.88 (C(10)), 48.30 (C(1)), 48.35 (C(6)), 123.03 (C(3)),
124.31 (C(4)), 132.61 (C(7)), 138.65 (C(5)), 139.94 (C(2)).
MS, m/z: 302 [M]+. Found (%): C, 79.15; H, 11.30. C20H34Si.
Calculated (%): C, 79.39; H, 11.33.
(8ꢀButylꢀ9ꢀethylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)trimethꢀ
ylsilane (5). Rf 0.66 (SiO2, light petroleum, 100%). 1H NMR,
: 0.13 (s, 9 H, SiMe3); 0.84 (t, 3 H, C(11)H3, J = 7 Hz); 0.93
(t, 3 H, C(15)H3, J = 7 Hz); 1.11—1.33 (m, 2 H, C(10)H2);
1.34—1.57 (m, 4 H, C(13,14)H2); 2.05—2.28 (m, 3 H, C(9)H,
C(12)H2); 2.87 (t, 1 H, C(1)H, J = 7 Hz); 3.10 (t, 1 H, C(6)H,
J = 7 Hz); 5.83—5.91 (m, 4 H, C(2—5)H). 13C NMR, : 0.71 (3 C,
SiMe3), 13.16 (C(11)), 14.09 (C(15)), 20.87(C(10)), 22.98
(C(14)), 29.76 (C(12)), 32.58 (C(13)), 40.68 (C(9)), 50.67 (C(1)),
50.74 (C(6)), 124.96 (C(3)), 126.26 (C(4)), 134.76 (C(7)), 136.09
(C(2)), 137.33 (C(5)), 151.82(C(8)). MS, m/z: 274 [M]+.
Found (%): C, 78.69; H, 11.00. C18H30Si. Calculated (%):
C, 78.75; H, 11.02.
(8ꢀButylꢀ9ꢀphenylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)triꢀ
methylsilane (6). Rf 0.59 (SiO2, light petroleum, 100%). 1H NMR,
: 0.26 (s, 9 H, SiMe3); 1.02 (t, 3 H, CH3, J = 6 Hz); 1.39—1.51
(m, 2 H, C(12)H2); 1.59—1.70 (m, 2 H, C(10)H2); 2.23—2.44
(m, 2 H, C(11)H2); 3.51—3.60 (m, 2 H, C(1,6)H); 3.72—3.81
(m, 1 H, C(9)H); 5.67—5.76 (m, 2 H, C(3,4)H); 6.14—6.23
(m, 2 H, C(2,5)H); 7.43—7.44 (m, 5 H, Ph). 13C NMR, : 0.80
(3 C, SiMe3), 14.21 (C(13)), 23.09 (C(12)), 29.80 (C(11)), 32.67
(C(10)), 44.18 (C(6)), 49.98 (C(9)), 50.01 (C(1)), 125.14 (C(3)),
125.22 (C(17)), 126.35 (C(4)), 127.19 (C(15), C(19)), 128.40
(C(16), C(18)), 133.66 (C(14)), 136.57 (C(2)), 137.69 (C(5)),
141.64 (C(7)), 150.57 (C(8)). MS, m/z: 322 [M]+. Found (%):
C, 81.74; H, 9.34. C22H30Si. Calculated (%): C, 81.92; H, 9.37.
Cycloaddition of Nꢀcontaining acetylenes to cycloheptaꢀ1,3,5ꢀ
trienes (general procedure). Cycloheptaꢀ1,3,5ꢀtriene (1 mmol),
propargylamine 3 (1 mmol), Ti(acac)2Cl2 (0.07 mmol), and dry
benzene (3 mL) were placed into a temperature controlled
(~0 C) glass tube under dry argon. The tube was cooled to
temperature of liquid nitrogen, Et2AlCl (0.5 mmol) was added,
Nꢀ[(8ꢀButylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)methyl]ꢀ
N,Nꢀdimethylamine (4a). 1H NMR, : 0.91 (t, 3 H, CH3, J = 7 Hz);
1.28—1.46 (m, 6 H, C(10,11,12)H2); 1.62 (d, 1 H, C(9)H2,
J = 11 Hz); 2.19 (s, 6 H, (CH3)2N); 2.23—2.30 (m, 1 H, C(9)H2);
2.69 (d, 1 H, C(14)H2, J = 13 Hz); 3.13 (t, 1 H, C(6)H, J = 7 Hz);
3.19 (d, 1 H, C(14)H2, J = 13 Hz); 3.29 (t, 1 H, C(1)H, J = 7 Hz);
5.73—5.78 (m, 2 H, C(3,4)H); 6.14—6.18 (m, 1 H, C(5)H);
6.24—6.27 (m, 1 H, C(2)H). 13C NMR, : 14.03 (C(13)), 22.71
(C(12)), 25.87 (C(11)), 30.61 (C(9)), 31.84 (C(10)), 45.43
((CH3)2N)), 45.47 (C(6)), 46.75 (C(1)), 54.59 (C(14)), 123.76
(C(4)), 124.06 (C(3)), 132.86 (C(7)), 139.02 (C(8)), 139.81
(C(5)), 140.80 (C(2)). MS, m/z: 231 [M]+. Found (%): C, 82.92;
H, 10.87; N, 6.01. C16H25N. Calculated (%): C, 83.06; H, 10.89;
N, 6.05.
N,NꢀDimethylꢀNꢀ[(8ꢀoctylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀ
yl)methyl]amine (4b). 1H NMR, : 0.90 (t, 3 H, CH3, J = 7 Hz);
1.28—1.46 (m, 14 H, C(10—16)H2); 1.61 (d, 1 H, C(9)H2,
J = 12 Hz); 2.20 (s, 6 H, (CH3)2N); 2.22—2.29 (m, 1 H, C(9)H2);
2.66 (d, 1 H, C(18)H2, J = 13 Hz); 3.12 (t, 1 H, C(6)H, J = 7 Hz);
3.19 (d, 1 H, C(18)H2, J = 13 Hz); 3.28 (t, 1 H, C(1)H, J = 7 Hz);
5.72—5.75 (m, 2 H, C(3,4)H); 6.13—6.17 (m, 1 H, C(5)H);
6.22—6.26 (m, 1 H, C(2)H). 13C NMR, : 14.09 (C(17)), 22.66
(C(16)), 26.11 (C(11)), 29.28 (C(14)), 29.50 (C(13)), 29.62
(C(12)), 30.61 (C(9)), 31.83 (C(10)), 31.88 (C(15)), 45.52
((CH3)2N), 44.11 (C(6)), 46.77 (C(1)), 54.69 (C(18)), 123.71
(C(4)), 124.06 (C(3)), 132.85 (C(7)), 139.00 (C(8)), 139.78
(C(5)), 140.79 (C(2)). MS, m/z: 287 [M]+. Found (%): C, 83.29;
H, 11.53; N, 4.84. C20H33N. Calculated (%): C, 83.56; H, 11.57;
N, 4.87.
N,NꢀDimethylꢀNꢀ[(8ꢀphenylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ
7ꢀyl)methyl]amine (4c). 1H NMR, : 1.75 (d, 1 H, C(9)H2,
J = 12 Hz); 2.18 (s, 6 H, (CH3)2N); 2.40—2.43 (m, 1 H, C(9)H2);
2.75 (d, 1 H, C(16)H2, J = 12 Hz); 3.31 (d, 1 H, C(16)H2,
J = 16 Hz); 3.50 (t, 1 H, C(6)H, J = 7 Hz); 3.55 (t, 1 H, C(1)H,
J = 7 Hz); 5.81—5.90 (m, 2 H, C(3,4)H); 6.17 (t, 1H, C(5)H,
J = 8 Hz); 6.31 (t, 1 H, C(2)H, J = 8 Hz); 7.24—7.39 (m, 5 H, Ph).
13C NMR, : 30.61 (C(9)), 45.55 ((CH3)2N), 45.93 (C(1)), 48.96
(C(6)), 55.01 (C(16)), 124.40 (C(3), C(4)), 126.69 (C(13)),
127.94 (C(12), C(14)), 129.28 (C(11), C(15)), 135.16 (C(10)),
136.44 (C(8)), 137.60 (C(7)), 139.59 (C(5)), 139.93 (C(2)). MS,
m/z: 251 [M]+. Found (%): C, 85.81; H, 8.39; N, 5.59. C18H21N.
Calculated (%): C, 86.01; H, 8.42; N, 5.57.
1ꢀ[(8ꢀButylꢀ9ꢀethylbicyclo[4.2.1]nonaꢀ2,4,7ꢀtrienꢀ7ꢀyl)ꢀ
methyl]piperidine (7). 1H NMR, : 0.83 (t, 3 H, C(15)H3,
J = 7 Hz); 0.92 (t, 3 H, C(13)H3, J = 7 Hz); 1.26—1.48 (m, 8 H,
C(10—12,14)H2); 1.66—1.70 (m, 1 H, C(9)H); 2.00—2.12
(m, 10 H, C(17—21)H2); 2.78 (d, 2 H, C(16)H2, J = 7 Hz);
2.85—2.95 (m, 1 H, C(1)H); 3.00—3.12 (m, 1 H, C(6)H);
5.65—5.72 (5.80—5.87) (m, 2 H, C(3,4)H); 5.94—5.99 (6.09—6.12)
(m, 1 H, C(5)H); 6.14—6.18 (6.28—6.33) (m, 1 H, C(2)H).
13C NMR, : 12.40 (C(15)), 12.91 (C(13)), 20.61 (C(14)), 22.72
(C(12)), 22.77 (C(19)), 25.81 (C(11)), 26.28 (C(18)), 26.67
(C(20)), 31.55 (C(10)), 31.88 (C(9)), 48.22 (49.11) (C(6)), 50.92
(51.86) (C(1)), 53.68 (C(16)), 54.26 (C(17)), 54.62 (C(21)),
123.29 (124.00) (C(4)), 125.61 (126.24) (C(3)), 134.12 (C(7)),
136.62 (138.40) (C(5)), 137.59 (C(8)), 138.82 (140.61) (C(2)).

Bicyclo[4.2.1]nonaꢀ2,4ꢀdienes
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 4, April, 2013
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MS, m/z: 299 [M]+. Found (%): C, 84.01; H, 11.07; N, 4.62.
C21H33N. Calculated (%): C, 84.22; H, 11.11; N, 4.68.
Cycloaddition of Siꢀcontaining allenes to cycloheptaꢀ1,3,5ꢀ
triene (general procedure). Cycloheptaꢀ1,3,5ꢀtriene (1 mmol),
allene 7 (1.1 mmol), Ti(acac)2Cl2 (0.06 mmol), and dry benzene
(3 mL) were placed into a temperature controlled (~0 C) glass
tube under dry argon. The tube was cooled to temperature of
liquid nitrogen, RnAlCl3ꢀn (R = Et, Bui; n = 2, 3) (0.2 mmol) was
added, and the tube was sealed. After heating at 80 C for 8 h, the
tube was unsealed, the content was treated with EtOH. The light
solvents were evaporated in vacuo, the residue was subjected to
chromatography on a column with silica gel (eluent light petroꢀ
leum, 100%) to separate a mixture of Eꢀ and Zꢀisomers from the
minor reaction products.
EꢀIsomer. 13C NMR, : –0.32 (SiMe3), 14.13 (C(14)), 22.77
(C(13)), 24.59 (C(15)), 30.34 (C(12)), 32.79 (C(9)), 36.29
(C(11)), 39.28 (C(1)), 42.95 (C(6)), 45.13 (C(8)), 122.92 (C(4)),
123.46 (C(3)), 127.65 (C(10)), 138.14 (C(2)), 137.31 (C(5)),
141.56 (C(7)).
ZꢀIsomer. 13C NMR, : –0.26 (SiMe3), 14.07 (C(14)), 22.20
(C(13)), 23.01 (C(15)), 30.04 (C(12)), 33.02 (C(9)), 33.99
(C(11)), 39.35 (C(1)), 42.38 (C(6)), 43.93 (C(8)), 123.35 (C(4)),
123.53 (C(3)), 127.65 (C(10)), 136.63 (C(5)), 138.06 (C(2)),
141.56 (C(7)). MS, m/z: 274 [M]+. Found (%): C, 78.60;
H, 11.00. C18H30Si. Calculated (%): C, 78.75; H, 11.02.
This work was finacially supported by the Russian
Foundation for Basic Research (Project No. 13ꢀ03ꢀ00167).
[2ꢀ(Bicyclo[4.2.1]nonaꢀ2,4ꢀdienꢀ7ꢀylidene)ethyl]trimethylꢀ
silane (E : Z = 1 : 1) (8a). Rf 0.62 (SiO2, light petroleum, 100%).
1H NMR, : 0.01 (s, 9 H, SiMe3); 1.35 (d, 2 H, C(11)H2,
J = 8 Hz); 1.54 (d, 1 H, C(9)H2, J = 11 Hz); 1.97 (d, 1 H,
C(9)H2, J = 12 Hz); 2.42—2.53 (m, 2 H, C(8)H2); 2.71—2.75
(m, 1 H, C(1)H); 3.19—3.29 (m, 1 H, C(6)H); 5.18 (t, 1 H,
C(10)H, J = 8 Hz); 5.56—5.88 (m, 2 H, C(3,4)H); 5.96—6.24
(m, 2 H, C(2,5)H).
EꢀIsomer. 13C NMR, : –1.55 (SiMe3), 22.60 (C(11)), 31.69
(C(9)), 38.85 (C(1)), 42.31 (C(6)), 45.52 (C(8)), 118.16 (C(10)),
122.85 (C(3)), 123.58 (C(4)), 138.74 (C(5)), 139.49 (C(2)),
149.21 (C(7)).
References
1. N. A. Petasis, M. A. Patane, Tetrahedron, 1992, 48, 5757.
2. V. A. D´yakonov, G. N. Kadikova, U. M. Dzhemilev, Tetraꢀ
hedron Lett., 2011, 52, 2780.
3. V. A. D´yakonov, G. N. Kadikova, L. M. Dzhemilev, Russ.
Chem. Bull. (Int. Ed.), 2011, 60, 499 [Izv. Akad. Nauk, Ser.
Khim., 2011, 489].
4. K. Mach, H. Antropiusová, F. Tureèek, V. Hanuš, P. Sedꢀ
mera, Tetrahedron Lett., 1980, 21, 4879.
ZꢀIsomer. 13C NMR, : –1.65 (SiMe3), 20.16 (C(11)), 32.41
(C(9)), 39.22 (C(1)), 43.04 (C(6)), 46.06 (C(8)), 116.64 (C(10)),
123.41 (C(3)), 124.35 (C(4)), 134.46 (C(5)), 139.36 (C(2)),
144.15 (C(7)). MS, m/z: 218 [M]+. Found (%): C, 76.84;
H, 10.12. C14H22Si. Calculated (%): C, 76.99; H, 10.15.
[2ꢀ(Bicyclo[4.2.1]nonaꢀ2,4ꢀdienꢀ7ꢀylidene)hexꢀ1ꢀyl]triꢀ
methylsilane (E : Z = 1 : 1) (8b). Rf 0.64 (SiO2, light petroleum,
5. U. M. Dzhemilev, N. R. Popod´ko, E. V. Kozlova, Metalꢀ
lokompleksnyi kataliz v organicheskom sinteze [Metal Complex
Catalysis in Organic Synthesis], Khimiya, Moscow, 1999,
631 pp. (in Russian).
6. Best Synthetic Methods: Acetilenes, Allenes and Cumulenes,
Ed. L. Brandsma, Elsevier, Amsterdam, 2003, p. 502.
7. K. Conrow, J. Am. Chem. Soc., 1961, 83, 2343.
1
100%). H NMR, : 0.05 (s, 9 H, SiMe3); 0.93—0.99 (m, 2 H,
C(14)H2); 1.30—1.64 (m, 6 H, C(12,13,15)H2); 1.93—2.13
(m, 1 H, C(11)H2); 2.17—2.27 (m, 2 H, C(9)H2); 2.42—2.63
(m, 1 H, C(8)H2); 2.72—2.74 (m, 1 H, C(1)H); 3.45—3.49
(m, 1 H, C(6)H); 5.57—5.68 (m, 2 H, C(3,4)H); 5.97—6.14
(m, 2 H, C(2,5)H).
Received January 25, 2013;
in revised form February 22, 2013