[2σ + 2σ + 2π]-Cycloaddition of quadricyclane to partially methylated chlorosilylalkenes

Article abstract of DOI:10.1016/j.mencom.2015.09.008

[2σ + 2σ + 2π]-Cycloaddition of quadricyclane to trissilylated ethenes Cl_{3 - n}Me_nSiCH=CSiMe_nCl_{3 - n}(SiMe_{3 - n}Cl_n) (n = 1, 2) at 95 °C affords 3,3,4-trissilylated exo-tricyclo[4.2.1.0^2,5]non-7-enes. Tetrakis(trichlorosilyl)ethene does not react with quadricyclane.

Full text of DOI:10.1016/j.mencom.2015.09.008

Mendeleev
Communications
Mendeleev Commun., 2015, 25, 344–345
[2s+ 2 s+2p]-Cycloaddition of quadricyclane
to partially methylated chlorosilylalkenes
Pavel P. Chapala,a Maxim V. Bermeshev,a Valentin G. Lakhtin,b
Alexander M. Genaev,c Alexander N. Tavtorkina and Eugene Sh. Finkelshtein*a
a A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991 Moscow,
Russian Federation. E-mail: chapala@ips.ac.ru, fin314@gmail.com
b State Research Institute for Chemistry and Technology of Organoelement Compounds, 111123 Moscow,
Russian Federation
c N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences,
630090 Novosibirsk, Russian Federation
DOI: 10.1016/j.mencom.2015.09.008
[2s+ 2s+ 2p]-Cycloaddition of quadricyclane to trissilylated ethenes Cl3–nMenSiCH=CSiMenCl3–n(SiMe3–nCln) (n = 1, 2) at 95°C
affords 3,3,4-trissilylated exo-tricyclo[4.2.1.02,5]non-7-enes. Tetrakis(trichlorosilyl)ethene does not react with quadricyclane.
Discovery of [2s+ 2s+ 2p]-cycloaddition reaction of quadri-
cyclane (Q) with olefins opened a way for selective synthesis
of exo-norbornene derivatives (so-called tricyclononenes).1 These
Q
compounds turned out to be active monomers in addition and
95 °C
ring-opening metathesis polymerizations.2 Apparently, their activity
SiMeCl2
SiMe2Cl
can be attributed to the exo-configuration of the fused cyclobutane
ClMe2Si
SiMe2Cl
ring and remoteness of the bulky/electron-withdrawing substi-
tuents from the double bond. This results in lowering their sterical
hindrance effect in a polymerization process. Providing the
stereo/regioselectivity and distancing double bond of norbornene
fragment from substituents in 3,4 positions,1,3 the [2s+ 2s+ 2p]-
cycloaddition of Q became the extensively used tool in designing
new polymer materials such as photoresists,4 optical materials,4
membranes,5 etc.
Cl2MeSi
SiMeCl2
2
1
9
SiMeCl2
3
SiMe2Cl
SiMeCl2
1
8
2
SiMe2Cl
SiMe2Cl
5, 55 %
4
6
7
5
SiMeCl2
4, 85%
Earlier, we have shown that polymers bearing SiMe3 groups
synthesized from exo-tricyclononene type monomers possessed
high gas permeability.2(b),5(b) Furthermore, the gas permeability
values were getting higher with increasing a number of silicon-
containing substituents (e.g., SiMe3, SiPr3i) in a monomer unit
from one to two.2(b) These observations allowed for assumption
that synthesis of the corresponding polymers having three or
four SiMe3 groups per a monomer unit could improve their
membrane properties. The findings described below discuss a
possibility of synthesis of such exo-tricyclononene monomers
with three and four silyl groups based on the condensation of Q
and silylated alkenes 1–36 (Schemes 1, 2).†
Recently, we have demonstrated that some alkenes bearing
three silicon groups could react with Q.7 However, further
methylation of the corresponding products met difficulties due
to high sterical hindrance of starting chlorine-containing silicon
groups. Therefore, the initial use of partially methylated chloro-
silylalkenes in the reaction with Q seemed attractive in view of
the following exhaustive methylation of the cycloadducts.
In fact, tris-silylated alkenes 1 and 2 readily react with Q
at 95°C (Scheme 1). The reactivity of 1 containing in total
four Me groups at Si atoms was noticeably higher than that of
alkene 2 with five Me groups. Thus, 50% conversion of 1 was
achieved within 15 h, whereas in case of 2 the same conversion
was reached only within 90 h. At the same time, both alkenes
120–140 °C
SiMe3
MeMgI
SiMe3
SiMe3
6, 60–65%
Scheme 1
1 and 2 were less active than 1,1,2-tris(trichlorosilyl)ethylene
because of weaker electron-withdrawing ability of SiMeCl2 and
SiMe2Cl groups. Therefore, they reacted with Q only at elevated
temperature (95°C).
New cycloadducts 4 and 5 were successfully obtained as
thermally stable compounds in 55–85% yields, both being formed
as individual anti-isomers with no admixture of syn-isomers.
Their configuration was confirmed by 1H and 13C NMR spectro-
scopy. The possible reason for this is a steric hindrance between
Cl
Cl3Si
Cl3Si
Cl2
UV
HSiCl3
Pr3N
Cl3Si
Cl3Si
Cl3Si
Cl3Si
Cl3Si
SiCl3
SiCl3
Cu
CCl2
220 °C, 6 h
3
†
The cycloaddition reactions were performed according to the earlier
developed procedures.7
Scheme 2
© 2015 Mendeleev Communications. Published by ELSEVIER B.V.
on behalf of the N. D. Zelinsky Institute of Organic Chemistry of the
Russian Academy of Sciences.
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Mendeleev Commun., 2015, 25, 344–345
C9H2 moiety and a silyl group at C4 driving the process to syn-
isomer. The further methylation of the obtained cycloadducts 4‡
and 5§ afforded the desired monomer7 6 bearing three SiMe3
groups.
Table 1 DFT calculations of activation energies for the reactions of
different alkenes with Q.
Activation energy/
Activation energy/
kcal mol–1
Alkene
Alkene
kcal mol–1
The reaction of Q with tetrakis(trichlorosilyl)ethene 3 was
anticipated to give a tetrasubstituted cycloadduct. Compound 3¶
was cleanly synthesized according to Scheme 2.8 Note that direct
synthesis9 of this compound is accompanied by formation of
hardly separable by-products which could also react with Q.
Taking into consideration the fact that reactivity of alkenes
gradually increased from vinyltrichlorosilane to 1,1-bis(trichloro-
silyl)ethene and then to 1,1,2-tris(trichlorosilyl)ethene,7,10 we
suggested that olefin 3 would be sufficiently active in the reaction
with Q. Unexpectedly, no reaction between 3 and Q was observed
at both room and elevated temperatures (Scheme 3).
SiCl3
H2C CH2
29.8
15.8
Cl3Si
Cl3Si
SiCl3
SiCl3
22.3
16.8
33.4
34.3
SiCl3
SiCl3
SiCl3
Cl3Si
Cl3Si
SiCl3
SiCl3
Cl3Si
SiMe3
increased by more than twice (from 15.8 up to 33.4 kcal mol–1).
This barrier is even higher than that for unsubstituted ethylene
(29.8 kcal mol–1). A possible reason of this fact lies in a high
steric hindrance of four SiCl3 substituents. Indeed, according to
X-ray data, C and Si atoms of alkene 3 are not in the same
plane. The double bond showed the twist with dihedral angles
Si1–C=C–Si3 of 28.0° and Si2–C=C–Si4 of 28.2°.8 Non-planar
structure of 1 resulted in the creation of a critical hindrance for
the desired reaction. Replacement of one SiCl3 group by SiMe3
group makes double bond more polar. However, in this case a
growth of activation barrier was observed (see Table 1). This can
be attributed to electron-donating properties of SiMe3 group, and
this fact evidenced that steric hindrance is the principal factor.
In summary, it was shown that partially methylated chloro-
silylalkanes bearing three Si-containing substituents at the double
bond and up to five Me groups at Si atoms can successfully
give [2s+ 2s+ 2p]-cycloadducts with Q, while the alkene with
four strong electron-withdrawing SiCl3 groups turned out to be
inactive at all due to greater steric hindrance.
SiCl3
Cl3Si
Cl3Si
SiCl3
SiCl3
SiCl3
SiCl3
+
25–95 °C
SiCl3
Q
3
Scheme 3
The origin of such inactivity can in principle arise from a
steric hindrance of substituents and low polarization of the double
bond. The possibility of such reaction was evaluated applying
density functional theory (DFT)†† (Table 1). According to cal-
culations, the lowest activation barrier was attributed to tris-
(trichlorosilyl)ethene which showed the highest activity in the
studied reaction.7 The rise in number of SiCl3 groups up to
four dramatically influenced the activation barrier: it suddenly
‡
3-Dimethylchlorosilyl-3,4-bis(methyldichlorosilyl)tricyclo[4.2.1.02,5]-
1
non-7-ene 4: yield 85%, mp 152–155°C. H NMR (499.8 MHz, C6D6)
d: 5.80–5.71 (m, 2H, C7H, C8H), 3.19 (br.s, 1H, C1H/C6H), 2.72 (br.s,
1H, C1H/C6H), 2.56 (d, 1H, C2H, 3J 10.1 Hz), 2.47–2.41 (m, 1H, C5H),
2.28–2.21 (m, 2H, C9H, C4H), 1.31 (d, 1H, C9H, 2J 9.6 Hz), 0.84 (br.s,
3H, MeSiCl2), 0.77 (br.s, 3H, MeSiCl2), 0.55 (br.s, 3H, Me2SiCl), 0.52
(br.s, 3H, Me2SiCl). 13C NMR (125.7 MHz, C6D6) d: 136.53, 134.95 (C7,
C8), 45.43 (C1, C6), 43.73 (C4), 42.26 (C9), 39.23 (C5), 35.20 (C2), 28.37
(C3), 7.79 (MeSiCl2), 6.58 (MeSiCl2), 6.29 (Me2SiCl), 5.84 (Me2SiCl).
References
1 V. A. Petrov and N. V. Vasil’ev, Curr. Org. Synth., 2006, 3, 215.
2 (a) R. H. Grubbs, in Handbook of Metathesis, Wiley-VCH, Weinheim,
2008, p.1; (b) E. S. Finkelshtein, M. V. Bermeshev, M. L. Gringolts,
L. E. Starannikova and Yu. P. Yampolskii, Russ. Chem. Rev., 2011, 80,
341 (Usp. Khim., 2011, 80, 362).
3 I. Tabushi, K. Yamamura and Z. Youshida, J. Am. Chem. Soc., 1972,
94, 787.
4 A. E. Feiring, M. K. Crawford, W. B. Farnham, J. Feldman, R. H. French,
C. P. Junk, K. W. Leffew, V. A. Petrov, W. Qiu, F. L. Schadt, H. V. Tran
and F. C. Zumsteg, Macromolecules, 2006, 39, 3252.
§
3,4-Bis(dimethylchlorosilyl)-3-methyldichlorosilyltricyclo[4.2.1.02,5]-
non-7-ene 5: yield 55%. 1H NMR (499.8 MHz, C6D6) d: 5.80–5.71 (m,
2H, C7H, C8H), 3.20 (br.s, 1H, C1H/C6H), 2.72 (br.s, 1H, C1H/C6H),
2.35 (d, 1H, C9H2, 2J 10.1 Hz), 2.32–2.29 (m, 2H), 2.11 (d, 1H, 3J 5.2 Hz),
2
1.35 (d, 1H, C9H, J 10.1 Hz), 0.77 (m, 3H, MeSiCl2), 0.58 (br.s, 3H,
5 (a) M. Bermeshev, B. Bulgakov, L. Starannikova, G. Dibrov, P. Chapala,
D. Demchuk,Y.Yampolskii and E. Finkelshtein, J. Appl. Pol. Sci., 2015,
132, 41395; (b) M.V. Bermeshev,A.V. Syromolotov, L. E. Starannikova,
M. L. Gringolts, V. G. Lakhtin, Y. P. Yampolskii and E. S. Finkelshtein,
Macromolecules, 2013, 46, 8973.
6 V. D. Scheludyakov, V. I. Zhun’, V. G. Lakhtin, V. V. Scherbinin and
E. A. Chernyshev, Zh. Obshch. Khim., 1982, 53, 1192 (in Russian).
7 M. Bermeshev, P. Chapala, V. Lakhtin, A. Genaev, M. Filatova, A. Peregudov,
K. Utegenov, N. Ustynyuk and E. Finkelshtein, Silicon, 2015, 7, 117.
8 C. Rüdinger, H. Beruda and H. Schmidbaur, Z. Naturforsch., 1994, 49b,
1348.
9 A. D. Petrov, S. I. Sadykh-Zade, E. A. Chernyshev and V. F. Mironov,
Zh. Obshch. Khim., 1956, 26, 1248 (in Russian).
10 M. V. Bermeshev, A. V. Syromolotov, M. L. Gringolts, V. G. Lakhtin and
E. S. Finkelshtein, Tetrahedron Lett., 2011, 52, 6091.
11 D. N. Laikov, Chem. Phys. Lett., 1997, 281, 151.
Me2SiCl), 0.54 (br.s, 3H, Me2SiCl), 0.46 (br.s, 3H, Me2SiCl), 0.42 (br.s,
3H, Me2SiCl). 13C NMR (125.7 MHz, C6D6) d: 136.55, 134.92 (C7, C8),
45.65, 45.37, 43.03, 42.35 (C9), 39.24, 33.35, 27.84 (C3), 10.11 (MeSiCl2),
4.34 (Me2SiCl), 3.98 (Me2SiCl), 2.85 (Me2SiCl), 2.76 (Me2SiCl).
¶
1
Bis(trichlorosilyl)methane. H NMR (499.8 MHz, CDCl3) d: 1.37 (s,
2H). 13C NMR (125.7 MHz, CDCl3) d: 22.07. 29Si NMR (99.3 MHz,
CDCl3) d: 1.9.
Dichlorobis(trichlorosilyl)methane. 13C NMR (125.7 MHz, CDCl3) d:
63.98. 29Si NMR (99.3 MHz, CDCl3) d: –9.2.
Tetrakis(trichlorosilyl)ethene 3. Copper powder (50 mm) (3.5 g, 55 mmol)
and dichlorobis(trichlorosilyl)methane (7.5 g, 21 mmol) were placed in a
two-necked flask equipped with magnetic stirrer and reflux condenser.
The mixture was heated at 220°C for 6 h. The crude mixture was extracted
with warm hexane (3×15 ml). The solvent was removed under reduced
pressure (2 Torr) and the crude product was sublimed (0.1 Torr, 70°C).
Then it was recrystallized twice from hexane and obtained as a moisture
sensitive white solid; mp 150–153°C. Yield: 3.6 g (60%). 13C NMR
(125.7 MHz, CDCl3) d: 178.10. 29Si NMR (99.3 MHz, CDCl3) d: –12.2.
†† The Cluster of the Novosibirsk University Scientific Computing Center
(http://www.nusc.ru/) was used for calculation. Visualization and xyz-
coordinates of all structures are available from http://limor1.nioch.nsc.ru/
quant/222/. DFT calculations were performed with the PRIRODA pro-
gram,11 functional PBE,12 basis L113 (L01, cc-pVDZ analog).
12 J. P. Perdew, K. Burke and M. Ernzerhof, Phys. Rev. Lett., 1996, 77,
3865.
13 D. N. Laikov, Chem. Phys. Lett., 2005, 416, 116.
Received: 17th April 2015; Com. 15/4605
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