Synthesis of tricyclononenes and tricyclononadienes containing MX3-groups (M=C, Si, Ge; X=Cl, Me)

Tetrahedron 68 (2012) 2166e2171

Contents lists available at SciVerse ScienceDirect

Tetrahedron journal homepage: www.elsevier.com/locate/tet

Synthesis of tricyclononenes and tricyclononadienes containing MX3-groups (M¼C, Si, Ge; X¼Cl, Me) B.A. Bulgakov a, M.V. Bermeshev a, D.V. Demchuk b, V.G. Lakhtin c, A.G. Kazmin d, E.Sh. Finkelshtein a, * a

A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospect, 119991 Moscow, Russia N.D. Zelinsky Institute of Organic Chemistry RAS, 47 Leninsky Prospect, 119991 Moscow, Russia c State Scientific Center of the Russian Federation “State Research Institute for Chemistry and Technology of Organoelement Compounds”, 38 Shosse Entuziastov, 111123 Moscow, Russia d Karpov Institute of Physical Chemistry, 3-1/12-6 Obukha sidest., 105064 Moscow, Russia b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 12 September 2011 Received in revised form 26 December 2011 Accepted 9 January 2012 Available online 13 January 2012

A series of new organoelement-substituted (Si-, Ge-) tricyclononenes and tricyclononadienes was obtained via the [2sþ2sþ2p]-cycloaddition reaction of the corresponding substituted ethylenes and acetylenes with quadricyclane. The chemical behavior of Si-, Ge-, Sn-containing olefins and acetylenes under the cycloaddition conditions was studied. Ó 2012 Elsevier Ltd. All rights reserved.

Keywords: Tricyclononenes Tricyclononadienes Norbornene derivatives

1. Introduction

2. Results and discussion

Previously we have shown that quadricyclane (Q) can be involved in the [2sþ2sþ2p]-cycloaddition with mono- and bis(trichlorosilyl)ethylene resulting in the corresponding trichlorosilylsubstituted exo-tricyclononenes.1,2 Methylation of these products led to monomers, which were more active in addition polymerization than their norbornene analogues due to the absence of an endo-isomer and greater distance between bulky substituents and the double bond. Me3Si-substituted tricyclononenes were polymerized to obtain promising polymer materials,2 with various interesting applications, e.g., membranes, adhesives etc. Once we discovered that the reaction of Q with trichlorosilylethylenes led to the precursors of active monomers, we decided to widen the study and investigate the scope of unsaturated organoelement compounds able to undergo the [2sþ2sþ2p]-cycloaddition reaction. The main goal of this work was to study the reaction of the [2sþ2sþ2p]-cycloaddition of Si-, Ge-, and Sn-containing ethylenes and acetylenes with Q. We considered that the resulting new organoelement-substituted tricyclononenes and tricyclononadienes would be interesting monomers for addition and ROMP polymerization.

The presence of an electron-withdrawing substituent in ethylene or acetylene is a necessary condition for the effective [2sþ2sþ2p]-cycloaddition with Q.3,4 Following this requirement we used MCl3-containing (M¼Si, Ge, Sn) derivatives of ethylene and acetylene as unsaturated substrates for the cycloaddition (Fig. 1). Compounds 1e3 and 5 reacted with Q in a regio- and stereospecific way resulting in only the corresponding [2sþ2sþ2p]cycloadducts: exo-tricyclo[4.2.1.02,5]nonenes and exo-tricyclo [4.2.1.02,5]nonadienes (Schemes 1 and 2). Whereas in the presence of acetylene 4 and ethylene 6 a fast isomerization of Q into norbornadiene-2,5 (NBD) occurred.

GeCl3 SiCl3 1

4 SiF3

SiCl3 5

0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.tet.2012.01.012

SnCl3

3

2

Cl3Si * Corresponding author. Tel.: þ7 495 9554379; fax: þ7 495 6338520; e-mail address: fi[email protected] (E.Sh. Finkelshtein).

GeCl3

F3Si

6

Fig. 1. Ethylenes and acetylenes used in the reaction with Q.

B.A. Bulgakov et al. / Tetrahedron 68 (2012) 2166e2171

2167

Scheme 1. Synthesis of compounds 7e12.

MCl3 MCl3

R 95 oC

R

M(CH3)3 CH3MgI Et2O

13 - 15 No 13 14 15 16 17 18

R' 16 - 18

Substituents

Yield, %

M = Si, R = H M = Si, R = SiCl3 M = Ge, R = H M = Si, R = H M = Si, R = SiMe3 M = Ge, R = H

75 92 78 60 55 60

Scheme 2. Synthesis of compounds 13e18.

The cycloaddition of Q with trichlorosilyl-substituted acetylenes 2 and 5 was achieved with high yields. The corresponding monoand bis(trichlorosilyl)tricyclononadienes 13 and 14 were completely methylated to give the desired products 16 and 17 (Scheme 2). It was expected that 3,4-bis(trichlorosilyl)tricyclonona-3,7diene 14 containing a double bond activated by two electronwithdrawing substituents (SiCl3) would react with Q similarly to cyclobutenomaleimides.5 However, prolonged reaction of Q with 14 at elevated temperature did not lead to a polycyclic cycloaddition product (Scheme 3).

SiCl3 95-190 oC

SiCl3 SiCl3

+

14

SiCl3 Scheme 3. A possible [2sþ2sþ2p]-cycloaddition of Q with 14.

It is well known that vinyltrichlorogermane and ethynyltrichlorogermane readily enter in to DielseAlder reactions.6 Therefore it was expected that these compounds would also be active in a [2sþ2sþ2p]-cycloaddition with Q. Indeed it was found that 1 and 3 reacted with Q to form the desired cycloadducts 7 and 13 in moderate yields. However, the isomerization of Q into NBD and the formation of side product 19 were also observed. The isomerization was caused by the hard-to-remove impurity GeCl4 in the starting materials trichlorogermylethylene 1 and acetylene 3, which acted as a Lewis acid. It should be noted that trichlorogermyl-substituted organic compounds 7 and 15 do not cause the isomerization of Q, whereas GeCl4 does not only provoke transformation of Q into NBD but also reacts with Q resulting in compound 19 (Scheme 4).

GeCl4

GeCl3

95 oC

Cl 19, 25%

Scheme 4. The reaction between Q and GeCl4.

According to Schemes 1, 2 and Table 1 the yields of germaniumsubstituted tricyclononene and tricyclononadiene in the [2sþ2sþ2p]-cycloaddition were lower than those of the corresponding silicon-analogues. That was explained by considerable isomerization of Q into NBD caused by GeCl4 and the side reaction occurring. For example, in the reaction of vinyltrichlorogermane 1 and Q at 95  C the conversion of Q into NBD was 50% after 20 h while the conversion of 1 was just 15%. The problem of low yields of the target products was solved by use of a large excess of Q in the reaction with germanium-containing ethylene and acetylene. Utilizing a 2.5-fold excess of Q (in the case of vinyltrichlorogermane) allowed us to reach an olefin conversion comparable and even surpassing that obtained for the reaction with vinyltrichlorosilane.1,2,7 Conditions of the thermal cycloadditions used for Si-, Ge-, Sn-substituted ethylenes and acetylenes with Q are summarized in Table 1. Trichlorosilyl- and trichlorogermyl-substituted tricyclononenes and tricyclononadienes were fully methylated with CH3MgI to give potential monomers for addition and ROMP polymerization.8 It was also interesting to study a behavior of tin-containing olefins and acetylenes with Q under the same cycloaddition conditions. We tried to carry out a direct reaction to obtain alkyltinsubstituted tricyclononene from vinyl[tri(butyl)]tin. However, the latter did not react with Q even under continuous heating.

2168

B.A. Bulgakov et al. / Tetrahedron 68 (2012) 2166e2171

Table 1 The [2sþ2sþ2p]-cycloaddition between Q and organoelement olefins at 95  C Ethylene/acetylene

Mole ratio Q: ethylene/acetylene

Time, h

1.5:1

40

07

d

SiCl3

1.5:1

50

387

7

GeCl3

1.5:1 2.5:1

20 20

15 62

9 9

SnBu3

1.5:1

40

0

d

SiCl3

1.5:1

55

75

13

GeCl3

1.5:1 4.5:1

20 20

30 78

15 15

1.5:1

<1

0a

d

20

797

SiMe3

Yield, %

Cycloadduct

(2) was more active than vinyltrichlorosilane and 1,2bis(trichlorosilyl)acetylene (5) was more active than 1,2bis(trichlorosilyl)ethylene. Acetylene 5 containing two electronwithdrawing groups was more active than acetylene 2. Full conversion of 5 was reached after approximately 10 h, while for vinyltrichlorosilane it was not achieved even after 120 h under the same conditions. Obviously there was a competitive process of thermal isomerization of Q into NBD taking place under thermal conditions if the reaction time was long. This necessitated a limitation in the reaction time but caused the decrease in olefin conversion. The experiments described above (Table 1 and Fig. 2) enable us to estimate the sequence of reactivities for silyl-substituted ethylenes and acetylenes in the reaction of the [2sþ2sþ2p]-cycloaddition with Q (Fig. 3). Ge- and Sn-containing olefins and acetylenes were not included in the below rank because of the presence of different side processes.

Cl3Si

SiCl3

SiCl3

> Cl Si 3

SnCl3 SiCl3

1.5:1

1.5:1

<1

0a

d

1.5:1

12

92

14

F3Si

Cl3Si

a

SiCl3

SiCl3

>

SiCl3

Fig. 3. The sequence of reactivities of silicon-substituted ethylenes and acetylenes in the [2sþ2sþ2p]-cycloaddition with Q.

8

Cl3Si

SiF3

>

25  C, full isomerization of Q.

In previous work we reported that vinylsilanes containing SiCH3-groups were not active in the reaction with Q.7 However, the incorporation of a strong electron-withdrawing sulfone substituent (TolSO2-) into trimethylsilylacetylene allowed us to involve the acetylene containing a bulky electron-donating group (Si(CH3)3) into the reaction with Q (Scheme 5). Moreover, in this case the cycloaddition proceeded even at room temperature unlike all other ethylenes and acetylenes described above.

SO2Tol

In the case of trichlorostannylacetylene 4 the immediate isomerization of Q into NBD took place instead of the cycloaddition. This was considered to be due to the Lewis acidity of 4 initiating the isomerization of Q into NBD. Silicon-substituted acetylenes were found to be more active than the corresponding ethylenes (Fig. 2): 1-trichlorosilylacetylene

Scheme 5. The [2sþ2sþ2p]-cycloaddition of Q with the acetylene containing Si(CH3)3-group.

Fig. 2. Conversion of chlorosilylethylenes and acetylenes on reaction with Q [Q:ethylene/acetylene ratio¼1.5:1 (mol:mol)], 95  C.

The X-ray analysis of compound 20 confirmed the suggested structure, namely the formation of only exo-tricyclononadiene (Fig. 4a). A special synthetic problem was the synthesis of a hydrocarbon analogue of (CH3)3Si- and (CH3)3Ge-substituted tricyclononene or tricyclononadiene. A direct reaction between tert-butylacetylene as well as tert-butylethylene and Q did not proceed because of the absence of electron-withdrawing substituents (Scheme 6). The difficulty in nucleophilic substitution of a CeCl bond for a formation of CeCH39 bond did not allow us to use in this case the scheme applied for the synthesis of compounds 12, 16 or 18. So we performed an indirect synthesis of the hydrocarbon analogue of (CH3)3Si- and (CH3)3Ge-substituted tricyclononene (23) instead. The replacement of the AreSO2-group for the introduction of tertbutyl substituent in tricyclononadienes is described in the literature.10 Based on that ethynyl-(4-methylphenyl)sulfone underwent a [2sþ2sþ2p]-cycloaddition with Q. The treatment of product 21 with tBuLi resulted in the formation of 22 (Scheme 6). The addition of tBuLi to 21 proceeded to less steric hindered sidedanti, and was confirmed by X-ray analysis of 22 (Fig. 4b). The desulfonation of 22 with sodium amalgam gave the target hydrocarbon compound (23) as the only isomer where the tert-butyl substituent was in the anti-position as it was in 22.

(CH3)3Si

SO2Tol 25 oC

Si(CH3)3 20, 21%

B.A. Bulgakov et al. / Tetrahedron 68 (2012) 2166e2171

2169

Fig. 4. General view of compounds 20 (a) and 22 (b) in representation of atoms via thermal ellipsoids at 50% probability level.

t

t

Bu

Bu

95 oC

SO2Tol

SO2Tol

SO2Tol 95 oC 21, 95%

t BuLi THF-hexane 0 oC

Na/Hg t

22, 70%

Bu

MeOH 0-25 oC

t

Bu

23, 40%

Scheme 6. Synthesis of 3-tert-butyltricyclononene-7.

Thus we succeeded in the synthesis of a series of new tricyclononenes and tricyclononadienes containing substituents based on elements of XIV-group. 3. Conclusions We have shown that different trichlorosilyl- and trichlorogermylsubstituted ethylenes and acetylenes are active in a [2sþ2sþ2p]cycloaddition with Q. The relative reactivities of the used silylderivatives in this reaction were estimated. The reaction products trichlorosilyl- and trichlorogermyl-substituted tricyclononenes and tricyclononadienes were obtained with good yields and were used as intermediates for further syntheses of potential monomers for ROMP and addition polymerization. 4. Experimental 4.1. General All manipulations involving air- and moisture-sensitive compounds were carried out under dried and purified argon using standard Schlenk and vacuum-line techniques. All monomers were stored under inert atmosphere. Q was synthesized as described in the literature11 and distilled over sodium metal under argon before use. Vinyltrichlorogermane (1),12 trichlorosilylacetylene (2),13 trichlorogermylacetylene (3),14 trichlorostannylacetylene (4),15 1,2bis-(trichlorosilyl)acetylene (5),16 1,2-bis-(triflourosilyl)ethylene (6),17 1-(4-methylphenyl)sulfonyl-2-trimethylsilylacetylene,18 and

ethynyl-(4-methylphenyl)sulfone18 were obtained according to the published procedures. Methyl iodide (Aldrich) was distilled over CaH2. tBuLi (Aldrich) and tributylvinylstannane (Aldrich) was used as a commercial product without any purification. Solvents were purified and distilled before their use by standard methods.19 NMR-spectra were recorded on a Bruker Avance DRX 400 spectrometer at 400.1 MHz (1H NMR) and 133.3 MHz (13C NMR) in CDCl3 solution. Chemical shifts d are reported in parts per million relative to an internal reference (residual CHCl3 signal). FTIR spectra for 12, 16e18, 23 were recorded as KBr thin films or neat on a Bruker FS-66 v/s Fourier spectrometer. FTIR spectra for 20e22 were recorded on a FTIR-Microscope HYPERION 2000 Bruker associated with IFS-66 v/s Fourier spectrometer as ATR. Mass spectra were recorded on a Thermo Focus DSQ II (ionization energy 70 eV, source temperature 230  C). CCDC 837568 and CCDC 854544 contain supplementary crystallographic data for 20 and 22 correspondingly. These data can be obtained free of charge via http:// www.ccdc.cam.ac.uk/conts/retrieving.html. 4.2. Synthesis of products of [2sD2sD2p]-cycloaddition 9, 13e15 General procedure: An oven-dried ampoule equipped with a magnetic stir bar was charged with Q and the appropriate substituted ethylene/acetylene (Table 1). Then the mixture was degassed. The ampoule was sealed and heated at 95  C. The conversion was monitored by 1H NMR spectroscopy. The ampoule was cracked and the volatile reagents were removed under reduce

2170

B.A. Bulgakov et al. / Tetrahedron 68 (2012) 2166e2171

pressure (2e5 mmHg, 20e90  C) to give the desired products as residual viscous oils. Yields were calculated based on ethylene/ acetylene used. 4.2.1. 3-Trichlorogermyltricyclo[4.2.1.02,5]nonene-7 (9). To achieve better conversion of the ethylene into the desired product 2.5-fold excess of Q was used. The desired product was obtained as a moisture-sensitive colorless liquid. Yield 62%. 1H NMR: d¼5.50e5.43 (m, 2H, CH]CH), 2.68 (br s, 0.4H, C(1)H, C(6)H), 2.30e2.20 (m, 1.6H, C(1)H, C(6)H), 1.98e1.73 (m, 3.6H), 1.45e1.24 (m, 2.4H), 0.93e0.91 (m, 1H, C(9)H2); 13C NMR: d¼135.4, 135.0, 134.9, 134.1 (C(7), C(8)), 44.5, 44.4, 43.8, 43.3, 41.6, 40.2, 38.8, 37.5, 37.2, 35.7 (C(1), C(2), C(3), C(5), C(6)), 40.5, 39.7 (C(9)), 24.9, 22.9 (C(4)). (13). The 4.2.2. 3-Trichlorolsilyltricyclo[4.2.1.02,5]nona-3,7-diene desired product was obtained as a moisture-sensitive colorless liquid. Yield 75%. 1H NMR: d¼6.98 (s, 1H, CH]CSiCl3), 5.94e5.86 (m, 2H, CH]CH), 2.46e2.22 (m, 4H), 1.27e1.15 (m, 2H, CH2); 13C NMR: d¼158.9, 146.2, 135.5, 135.0 (C(3), C(4), C(7), C(8)), 47.4, 47.1, 38.3, 38.1 (C(1), C(2), C(5), C(6)), 39.2 (C(9)). 4.2.3. 3,4-Bis-(Trichlorosilyl)tricyclo[4.2.1.0 2,5 ]nona-3,7-diene (14). The desired product was obtained as a moisture-sensitive colorless liquid. Yield 92%. 1H NMR: d¼5.80e5.77 (m, 2H, CH] CH), 2.36e2.23 (m, 4H), 1.08 (d, 2J¼9.7 Hz, 1H, CH2), 1.01 (d, 2 J¼9.7 Hz, 1H, CH2). 13C NMR: d¼164.9, 134.8 (C(3), C(4), C(7), C(8)), 49.3, 38.3 (C(1), C(2), C(5), C(6)), 38.8 C(9). (15). To 4.2.4. 3-Trichlorogermyltricyclo[4.2.1.02,5]nona-3,7-diene achieve better conversion of the acetylene into the desired product 4.5-fold excess of Q was used. The desired product was obtained as a moisture-sensitive colorless liquid. Yield 78%. 1H NMR: d¼6.65 (s, 1H, CH]CGeCl3), 5.70e5.60 (m, 2H, CH]CH), 2.31 (br s, 1H), 2.27 (br s, 1H), 2.11 (br s, 1H), 2.04 (br s, 1H), 1.82e1.70 (m, 1H, C(9)H2), 0.97e0.89 (m, 1H, C(9)H2); 13C NMR: d¼157.6 (C(4)), 145.3 (C(3)), 135.6, 135.1 (C(7), C(8)), 49.7, 48.2, 37.9, 37.7 (C(1), C(2), C(5), C(6)), 39.0 (C(9)). 4.3. Methylation of products 9, 13e15 General procedure. To a solution of CH3MgI prepared from Mg (12.4 g, 0.51 mol) and methyl iodide (71.1 g, 0.50 mol) in diethyl ether (200 mL), 3-(trichlorosilyl)tricyclononadiene-7 (13) (20.5 g, 81.5 mmol) in diethyl ether (20 mL) was added dropwise during 1 h as the mixture gently refluxed. The reaction mixture was then refluxed for an additional 8 h, cooled to room temperature and allowed to stand overnight. The diethyl ether was evaporated and the residue was extracted with absolute hexane (580 mL). The combined extracts were concentrated under reduced pressure (15 mmHg) until a viscous oil was formed. The products were purified by flash chromatography (eluentdhexane). During methylation of products 9 and 15 with methylmagnesium iodide compound 19 probably underwent b-elimination resulting in NBD, which was easily removed from the desired products under reduced pressure. The formation of NBD was confirmed by GCeMS. 4.3.1. 3-Trimethylgermyltricyclo[4.2.1.02,5]nonene-7 (12). The desired product was obtained as a colorless liquid. Yield 75%. The monomer corresponds to a mixture of syn- and anti-isomers (ratio of the isomers is 35:65). 1H NMR: d¼5.95e5.86 (m, 2H, CH]CH), 2.69 (br s, 0.35H, C(1)H, C(6)H), 2.61e2.52 (m, 1.65H, C(1)H, C(6)H), 2.18e2.10 (m, 1.35H), 1.91e1.70 (m, 2.65H), 1.52e1.46 (m, 0.65H), 1.32e1.24 (m, 1.7H), 1.12e1.10 (m, 0.65H), 0.12, 0.10 (s, 9H, Ge(CH3)3); 13C NMR: d¼135.7, 134.9, 134.7, 134.6 (C(7), C(8)), 45.6, 44.7, 44.6, 44.3 (C(1), C(6)), 40.8, 40.0 (C(9)), 40.3, 39.2, 37.3, 35.7

(C(2), C(5)), 23.7, 23.1 (C(4)), 22.3, 21.4 (C(3)), 1.2, 4.3 (Ge(CH3)3); IR: n¼3120, 3057, 1598, 1551, 1315, 1276, 1240, 1229, 830, 752, 710, 590, 580; m/z (EI): 238, Mþ (2%), 119, Ge(CH3)3 (100%). Elemental analysis calculated for C12H20Ge: C, 60.84; H, 8.51. Found: C, 60.70; H, 8.42. (16). The 4.3.2. 3-Trimethylsilyltricyclo[4.2.1.02,5]nona-3,7-diene desired product was obtained as a colorless liquid. Yield 60%. 1H NMR: d¼6.67 (s, 1H, CH]CSi(CH3)3), 6.12e6.03 (m, 2H, CH]CH), 2.43e2.30 (m, 4H), 1.42 (d, 2J¼8.7 Hz, 1H, CH2), 1.20 (d, 2J¼8.7 Hz, 1H, CH2), 0.06 (s, 9H, Si(CH3)3); 13C NMR: d¼156.4 (C(3)), 149.4 (C(4)), 135.5, 135.2 (C(7), C(8)), 46.6, 46.5 (C(1), C(6)), 39.4 (C(9)), 38.6, 38.3 (C(2), C(5)), 1.7 (Si(CH3)3); IR: n¼3127, 3059, 3011, 1604, 1562, 1552, 1364, 1288, 1248, 1226, 1199, 885, 837, 817, 746, 701, 676, 629, 498, 484; m/z (EI): 190, Mþ (1%), 73, Si(CH3)3 (100%). Elemental analysis calculated for C12H18Si: C, 75.71; H, 9.53. Found: C, 75.85; H, 9.62. 4.3.3. 3,4-Bis-(trimethylsilyl)tricyclo[4.2.1.0 2,5 ]nona-3,7-diene (17). The desired product was obtained as a colorless liquid. Yield 55%. 1H NMR: d¼6.07e6.02 (m, 2H, CH]CH), 2.35 (br s, 2H), 2.28 (br s, 2H), 1.30 (d, 2J¼8.7 Hz, 1H, CH2), 1.13 (d, 2J¼8.7 Hz, 1H, CH2), 0.10 (s, 18H, Si(CH3)3); 13C NMR: d¼167.8 (C(3), C(4)), 134.6 (C(7), C(8)), 47.1 (C(1), C(6)), 39.1 (C(9)), 38.7 (C(2), C(5)), 0.6 (Si(CH3)3); IR: n¼3125, 3058, 1607, 1562, 1524, 1320, 1281, 1248, 1192, 885, 833, 750, 703, 691, 625, 498, 485; m/z (EI): 262, Mþ (2%), 73, Si(CH3)3 (100%). Elemental analysis calculated for C15H26Si2: C, 68.62; H, 9.98. Found: C, 68.79; H, 10.14. 4.3.4. 3-Trimethylgermyltricyclo[4.2.1.02,5]nona-3,7-diene (18). The desired product was obtained as a colorless liquid. Yield 60%. 1H NMR: d¼6.58 (s, 1H, CH]CGe(CH3)3), 6.10e6.03 (m, 2H, CH]CH), 2.45e2.39 (m, 1H), 2.36e2.29 (m, 3H), 1.43 (d, 2J¼7.7 Hz, 1H, CH2), 1.21 (d, 2J¼7.7 Hz, 1H, CH2), 0.19 (s, 9H, Ge(CH3)3); 13C NMR: d¼156.7 (C(3)), 147.7 (C(4)), 135.5, 135.3 (C(7), C(8)), 47.6, 46.9 (C(1), C(6)), 39.4 (C(9)), 38.5, 38.2 (C(2), C(5)), 2.2 (Ge(CH3)3); IR: n¼3125, 3058, 3012, 1603, 1563, 1549, 1319, 1288, 1238, 1225, 1200, 825, 751, 700, 600, 571, 493, 473; m/z (EI): 236, Mþ (1%), 119, Ge(CH3)3 (100%). Elemental analysis calculated for C12H18Ge: C, 61.36; H, 7.72. Found: C, 61.09; H, 7.60. 4.3.5. 5-Trichlorogermyl-6-chloronorbornene-2 (19). Freshly distilled GeCl4 (1.20 g, 5.59 mmol) and Q (0.98 g, 10.7 mmol) were mixed in an ampoule under an argon atmosphere. Thereafter the ampoule was sealed and heated at 95  C for 12 h. Then the ampoule was opened and the volatile fractions were removed under reduced pressure (2 mmHg). Compound 19 (0.43 g) was isolated as a moisture-sensitive colorless transparent liquid. Yield 25%. 1H NMR: d¼5.74e5.72 (m, 1H, CH]CH), 5.55e5.52 (m, 1H, CH]CH), 3.51 (d, 3 J¼6.5 Hz, 1H, CHCl) 2.71 (br s, 1H), 2.56 (br s, 1H), 2.01 (d, 2 J¼6.5 Hz, 1H), 1.62 (d, 2J¼9.5 Hz, 1H, CH2), 1.13 (d, 2J¼9.5 Hz, 1H, CH2); 13C NMR: 140.2, 135.2 (C(2), C(3)), 57.1, 55.2, 51.8, 43.9 (C(1), C(4), C(5), C(6)), 44.8 (C(7)); m/z (EI): 306, Mþ (0.5%), 179, GeCl3 (2%), 66, C5H6 (100%). 4.3.6. 3-Trimethylsilyl-4-(p-methylphenyl)sulfonyltricyclo[4.2.1.02,5] nona-3,7-diene (20). 1-Trimethylsilyl-2-(p-methylphenyl)sulfonylacetylene (2.86 g, 11.3 mmol) was mixed with Q (1.56 g, 17.0 mmol) and sealed in an ampoule under an atmosphere of argon. Then the ampoule was stored for 240 h at 25  C. After that the mixture was dried under reduced pressure (2 mmHg) to remove norbornadiene and Q. The solid residue was purified by flash chromatography (eluentdhexane/ethylacetate 19:1) and recrystallized from ethanol. The desired product was obtained as a white powder (0.82 g, 2.48 mmol). Yield 21%. Melting point 83e85  C. Monocrystal of 20 was obtained from hexane/ethylacetate mixture (9:1). 1H NMR:

B.A. Bulgakov et al. / Tetrahedron 68 (2012) 2166e2171

d¼7.77 (d, 3J¼8.0 Hz, 2H), 7.32 (d, 3J¼8.0 Hz, 2H), 6.09e6.06 (m, 1H, CH]CH), 6.00e5.98 (m, 1H, CH]CH), 2.54 (d, 3J¼3.4 Hz, 1H), 2.47 (br s, 1H), 2.42 (s, 3H, ArCH3), 2.26 (d, 3J¼3.4 Hz, 1H), 2.23 (br s, 1H), 1.18 (d, 2J¼9.5 Hz, 1H, C(9)H2), 1.12 (d, 2J¼9.5 Hz, 1H, C(9)H2), 0.26 (s, 9H, Si(CH3)3); 13C NMR: d¼168.0, 154.5, 144.3, 137.4 (C(3), C(4), CCH3, C(Ar)eSO2R) 135.9, 134.8 (C(7), C(8)), 129.8, 128.1 (o-CH(Ar), m-CH(Ar)), 47.0, 44.9, 39.6, 37.8 (C(1), C(2), C(5), C(6)), 39.3 (C(9)), 21.6 (ArCH3), 1.37 (Si(CH3)3). IR: n¼3220, 3068, 3057, 1725, 1683, 1598, 1563, 1296, 1247, 1155, 842, 762, 714, 682; m/z (EI): 344, Mþ (6%), 73, Si(CH3)3 (100%). Elemental analysis calculated for C19H24O2SSi: C, 66.23; H, 7.02. Found: C, 66.70; H, 7.40. 4.3.7. 3-[(p-Methylphenyl)sulfonyl]tricyclo[4.2.1.02,5]nona-3,7-diene (21). 1-(p-Methylphenyl)sulfonylacetylene (8.69 g, 48.3 mmol) was mixed with Q (8.79 g, 95.6 mmol) and then sealed in an ampoule under an argon atmosphere. Then the ampoule was stored for 24 h at 95  C. After that the volatile compounds were removed from the reaction mixture under reduced pressure. The solid residue was purified by flash chromatography (eluentdhexane/ethylacetate 19:1) and recrystallized from ethanol. The desired product was obtained as a transparent viscous colorless oil (12.5 g, 45.6 mmol). Yield 95%. 1H NMR: d¼7.78 (d, 3 J¼8.0 Hz, 2H), 7.32 (d, 3J¼8.0 Hz, 2H), 6.82 (s, 1H, CH]C (SO2Tol)), 6.08e6.04 (m, 2H, CH]CH), 2.67 (br s, 1H), 2.49 (br s, 1H), 2.43e2.37 (m, 5H), 1.23e1.19 (m, 2H, CH2); 13C NMR: d¼147.6, 144.6, 136.5 (C(3), C(Ar)CH3, C(Ar)eSO2R), 146.0, 136.3, 135.2, 129.8, 128.0 (C(4), C(7), C(8), o-CH(Ar), m-CH(Ar)), 47.3, 43.6, 39.2, 37.6 (C(1), C(2), C(5), C(6)), 39.4 (C(9)), 21.6 (ArCH3); IR: n¼3124, 3057, 1615, 1566, 705, 687; m/z (EI): 272, Mþ (5%), 117, C9H9 (100%). Elemental analysis calculated for C16H16O2S: C, 70.56; H, 5.92. Found: C, 70.81; H, 5.83. 4.3.8. 3-(p-Methylphenyl)sulfonyl-4-tert-butyltricyclo[4.2.1.02,5]nonene-7 (22). Compound 21 (6.50 g, 23.9 mmol) was dissolved in absolute THF (80 mL). The solution was cooled up to 20  C and t BuLi (115 mL solution in hexane, 1.34 M) were added dropwise under stirring during 1 h. The solution was stirred for an hour at 10  C following by keeping 1 h at room temperature. Then water (75 mL) was added dropwise (during half an hour) into the mixture under cooling and the solution was extracted with diethyl ether (325 mL). The organic layer was isolated, dried over MgSO4 and then the volatile fractions were separated by vacuum drying. The resulting oil was crystallized from ethanol. The desired product was isolated as a white powder (5.51 g, 16.7 mmol). Yield 70%. Melting point 142e146  C. 1H NMR: d¼7.77 (d, 3J¼8.1 Hz, 2H), 7.30 (d, 3 J¼8.1 Hz, 2H), 6.00e5.90 (m, 2H, CH]CH), 3.74e3.64 (m, 1H, C(3)), 3.16, 2.71 (br s, 2H, C(1), C(6)), 2.42 (s, 3H, ArCH3), 2.32e2.24 (m, 2H), 1.97e1.88 (m, 1H), 1.79e1.72 (m, 1H), 1.29 (d, 1H, 2J¼9.9 Hz), 0.77 (s, 9H, C(CH3)3); 13C NMR: d¼144.1, 138.1 (C(Ar)CH3, C(Ar)e SO2R), 136.4, 136.3 (C(7), C(8)), 129.7, 128.0 (o-CH(Ar), m-CH(Ar)), 57.4, 49.4, 45.6, 42.6, 38.1, 36.3 (C(1)eC(6)), 42.4 (C(9)), 31.6 (C(CH3)3), 26.8 (C(CH3)3), 21.6 (ArCH3); IR: n¼3125, 3068, 3057, 1617, 1605, 1566, 1364, 1304, 1148, 815, 705, 687, 672; m/z (EI): 330,

2171

Mþ (0.5%). Elemental analysis calculated for C20H26O2S: C, 72.69; 7.93. Found: C, 72.81; H, 8.23. 4.3.9. 3-tert-Butyltricyclo[4.2.1.02,5]nonene-7 (23). Desulfonylation20 was carried out by treating of 22 (2.41 g, 7.30 mmol) dissolved in 60 mL of absolute methanol containing Na2HPO4 with excess of 6% Na/Hg amalgam (43.5 g) at 0  C following by warming up to 25  C. The mixture stirred for 24 h and then was diluted with of saturated NaCl solution (50 mL), extracted by hexane (325 mL). Organic fraction was collected, dried over MgSO4 following with solvent removal by rotation evaporator. Residual oil was recondensed under 0.5 mmHg and dried over sodium metal. The product (0.51 g, 2.89 mmol) was obtained as a colorless oil. Yield 40%. 1H NMR: d¼5.96e5.92 (m, 2H, CH]CH), 2.57 (br s, 1H), 2.47 (br s, 1H), 1.75e1.68 (m, 3H), 1.35e1.17 (m, 4H), 0.87 (s, 9H, C(CH3)3); 13C NMR: d¼135.4, 135.3 (C(7), C(8)), 45.0, 44.5, 44.1, 38.8, 33.1 (C(1)eC(3), C(5), C(6)), 40.72 (C(9)), 31.7 (C(CH3)3), 26.3 (C(CH3)3), 21.4 (C(4)); IR: n¼3124, 3057, 1615, 1566, 1364, 705, 687; m/z (EI): 176, Mþ (5%), 66, C5H6 (100%), 57, C4H9 (12%). Elemental analysis calculated for C13H20: C, 88.57; H, 11.43. Found: C, 88.33; H, 11.67.

Acknowledgements The authors are grateful for support from Ministry of Education and Science of the Russian Federation (GK No. 16.740.11.0338).

References and notes 1. Gringolts, M. L.; Bermeshev, M. V.; Makovetsky, K. L.; Finkelshtein, E. S. Eur. Polym. J. 2009, 45, 2142e2149. 2. Gringolts, M.; Bermeshev, M.; Yampolskii, Y. P.; Starannikova, L.; Shantarovich, V.; Finkelshtein, E. S. Macromolecules 2010, 43, 7165e7172. 3. Petrov, V. A. Curr. Org. Synth. 2006, 3, 175e213. 4. Tabushi, I.; Yamamura, K.; Yoshida, Z. J. Am. Chem. Soc. 1972, 94, 787e792. 5. Warrener, R. N.; Maksimovic, L.; Pitt, I. G.; Mahadevan, I.; Russell, R. A.; Tiekink, E. R. T. Tetrahedron Lett. 1996, 37, 3773e3776. 6. Dubac, J.; Mazerolles, P.; Laporterie, A.; et Lix, P. Bull. Soc. Chim. Fr. 1971, 1, 125e131. 7. Bermeshev, M. V.; Syromolotov, A. V.; Gringolts, M. L.; Lakhtin, V. G.; Finkelshtein, E. S. Tetrahedron Lett. 2011, 52, 6091e6093. 8. Finkelshtein, E. S.; Bermeshev, M. V.; Gringolts, M. L.; Starannikova, L. E.; Yampolskii, Y. P. Russ. Chem. Rev. (Engl. Transl.) 2011, 80, 341e361. 9. Fusion, R. C.; Ross, W. E. J. Am. Chem. Soc. 1933, 55, 720e723. 10. Riddell, N.; Tam, W. J. Org. Chem. 2006, 71, 1934e1937. 11. Smith, C. D. Org. Synth. 1971, 6, 962e963. 12. Brickman, F. E.; Stone, F. G. A. J. Inorg. Nucl. Chem. 1959, 11, 24e32. 13. Scheludyakov, V. D.; Lakhtin, V. G.; Zhun’, V. I.; Scherbin, V. V.; Chernyshev, E. A. Zh. Obshch. Khim. 1981, 51, 1829e1834. 14. Zavgorodnyi, V. S.; Sharanina, L. G.; Petrov, A. A. Zh. Obshch. Khim. 1967, 38, 1150e1154. tail, V.; Pfister-Guillouzo, G.; Guillemin, J.-C. J. Organomet. 15. Chrostowska, A.; Me Chem. 1998, 570, 175e182. 16. Scheludyakov, V. D.; Zhun’, V. I.; Lakhtin, V. G.; Scherbinin, V. V.; Chernyshev, E. A. Zh. Obshch. Khim. 1982, 53, 1192e1193. 17. Mironov, V. F. Izv. Akad. Nauk, Ser. Khim. 1962, 10, 1884e1886. 18. Chen, Z.; Trudell, M. L. Synth. Commun. 1994, 24, 3149e3155. 19. Armarego, W. L. F.; Chai, C. L. L. Purification of the Laboratory Chemicals, 5th ed.; Elsevier: New York, NY, 2003. 20. Gowland, B. D.; Durst, T. Can. J. Chem. 1979, 57, 1462e1467.