Synthesis of unsymmetrical 1,2-bis(diorganochlorosilyl)ethanes

Article abstract of DOI:10.1134/S1070363208090053

Unsymmetrical 1,2-bis(diorganylsilyl)ethanes were synthesized by two procedures. Hydrosilylation of chloro(vinyl)silanes were used to obtain compounds of the general formula ClMe₂SiCH₂CH ₂SiRMeCl with different substituents (R = Et, Vin, Ph) on the silicon atom. Chlorodealkylation of 1,2-bis(trialkylsilyl)ethanes gave compounds of the general formula ClAlk₂SiCH₂CH₂SiAlk ₂Cl (Alk = Me, Et, Pr). It is established that the latter reaction provides high yields only with Me-and Et-substituted compounds, whereas Pr-substituted products are formed in poor yields. The mechamism of this reaction based on quantum-chemical calculations is offered.

Full text of DOI:10.1134/S1070363208090053

ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 9, pp. 1668–1674. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © V.G. Lakhtin, S.P. Knyazev, L.E. Gusel’nikov, E.N. Buravtseva, N.A. Kuyantseva, I.A. Zalomnova, L.A. Parshkova, V.G. Bykovchenko,
A.V. Kisin, E.A. Chernyshev, 2008, published in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 9, pp. 1435–1441.
Synthesis of Unsymmetrical 1,2-Bis(diorganochlorosilyl)ethanes
V. G. Lakhtina, S. P. Knyazevb, L. E. Gusel’nikovc, E. N. Buravtsevac, N. A. Kuyantsevab,
I. A. Zalomnovaa, L. A. Parshkovaa, V. G. Bykovchenkoa, A. V. Kisina, and E. A. Chernysheva
a State Research Institute of Chemistry and Technology of Organoelement Compounds,
sh. Entuziastov 38, Moscow, 111123 Russia
e-mail: eos2004@inbox.ru
b Lomonosov State Academy of Fine Chemical Technology, Moscow, Russia
c Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia
Received May 4, 2008
Abstract―Unsymmetrical 1,2-bis(diorganylsilyl)ethanes were synthesized by two procedures. Hydrosilylation
of chloro(vinyl)silanes were used to obtain compounds of the general formula ClMe2SiCH2CH2SiRMeCl with
different substituents (R = Et, Vin, Ph) on the silicon atom. Chlorodealkylation of 1,2-bis(trialkylsilyl)ethanes
gave compounds of the general formula ClAlk2SiCH2CH2SiAlk2Cl (Alk = Me, Et, Pr). It is established that the
latter reaction provides high yields only with Me- and Et-substituted compounds, whereas Pr-substituted
products are formed in poor yields. The mechamism of this reaction based on quantum-chemical calculations is
offered.
DOI: 10.1134/S1070363208090053
One of the most interesting and promising
directions of polycarbosilane chemistry [1–3] is
synthesis of polymers with a (–Si–Si-C–C–)n main
chain [4–9]. Such polymers are prepared by
spontaneous polymerization of 1,2-disilacyclobutanes,
proceeding through ring opening [4–9]. 1,2-
Disilacyclobutanes are synthesized by gas-phase
dehalogenation of 1,2-bis(diorganylchlorosilyl)ethanes
with alkali metals [10–12]. In this connection of
importance is to develop procedures for preparing of
the starting 1,2-bis(diorganylchlorosilyl)ethanes.
ethanes involved in the gas-phase or liquid-phase
dehalogenation with alkali metals are few in number
and include 1,2-bis(chlorodimethylsilyl)ethane, 1-
(chlorodimethylsilyl)-2-[butylchloro(methyl)silyl)]-
ethane, and 1,2-(chlorodimethylsilyl)propane [7].
This work presents an attempt to make use of the
hydrosilylation and chlorodealkylation reactions for
preparing 1,2-bis(diorganylchlorosilyl)ethanes with a
more diverse surrounding of the silicon atom,
including ethyl, propyl, vinyl, and silyl substituents
together methyls.
1,2-Bis(diorganylchlorosilyl)ethanes are commonly
prepared by two procedues. The first one is based on
hydrosilylation [13, 14] of vinyldiorganylchlorosilanes
or acetylene with diorganylchlorosilanes [15]. This
procedure usually provides high yields. The second
procedure involves chlorodealkylation of hexa-
alkyldisilylethanes [16] with acetyl chloride in the
presence of aluminum chloride. 1,2-Bis(chlorosilyl)-
In the synthesis of 1,2-bis(diorganylchlorosilyl)
ethanes we used two chloro(vinyl)silanes: chloro-
dimethyl(vinyl)silane and chloromethyldivinylsilane.
Chlorodimethylsilane and chloro(methyl)phenylsilane
were chosen as hydrosilylating agents. In presence of
the Speier catalyst, the following reactions were
carried out.
ClMe2SiCH=CH2 + HSiMe2Cl → ClMe2SiCH2CH2SiMe2Cl,
(1)
(2)
I
ClMe2SiCH=CH2 + HSiMePhCl → ClMe2SiCH2CH2SiMePhCl,
II
ClMeSi(CH=CH2)2 + HSiMe2Cl → ClMeVinSiCH2CH2SiMe2Cl + ClMe2SiCH2CH2Si(Me)(Cl)CH2CH2SiMe2Cl. (3)
III IV
1668

SYNTHESIS OF UNSYMMETRICAL 1,2-BIS(DIORGANOCHLOROSILYL)ETHANES
1669
Reactions (1)–(3) gave 1,2-bis(chlorodimethylsilyl)
ethane (I), 1-(chlorodimethylsilyl)-2-[chloro(methyl)
phenylsilyl]ethane (II), and 1-[chloro(methyl)vinyl-
silyl]-2-(chlorodimethylsilyl)ethane (III). Their yields
and properties are listed Table 1.
[diethyl(methyl)silyl]-2-(triethylsilyl)ethane (X), 1,2-
bis(triethylsilyl)ethane (XI), and 2-(dimethyl-
propylsilyl)-1-(trimethylsilyl)ethane (XII).
V + MeMgCl → Me3SiCH2CH2SiEtMe2,
(8)
IX
As seen form Table 1, unlike reactions (1) and (2)
which occur in high yields, reaction (3) is
accompanied by addition of the hydrosilylating agent
HSiMe2Cl to the second vinyl group to form
compound IV. As a result, the yield of compound III
decreases to 35%.
VI + EtMgCl → MeEt2SiCH2CH2SiEt3,
(9)
X
VII + EtMgCl → Et3SiCH2CH2SiEt3,
(10)
(11)
XI
VIII + PrMgCl → Me3SiCH2CH2SiMe2Pr.
Hydrosilylation reactions generally proceed easily
and in high yields. However, for their performing and
synthesizing 1,2-bis(diorganylchlorosilyl)ethanes one
needs monochlorinated vinylsilanes and organylchlo-
rosilylhydrides, which are difficult to synthesize.
XII
The yields and properties of the synthesized
compounds are listed in Table 2.
As shown previously [16], chlorodealkylation of
alkylsilanes with acetyl chloride and aluminum
chloride is a convenient method for preparing
alkylchlorosilanes. The reactions proceed under mild
conditions. By varying the reagent ratio one can
selectively substitute one or more alkyl groups by
chlorine atoms.
Further we made use of hydrosilylation to prepare
the starting materials for their subsequent chloro-
dealkylation. The hydrosilylation of trimethyl(vinyl)-
silane, dichloro(methyl)vinylsilane, and trichloro-
(vinyl)silane with chlorodimethylsilane and dichloro-
(ethyl)silane [reactions (4)–(7)] was carried out in the
presence of the Speier catalyst, and the products were
subjected to exhaustive alkylation with a Grignard
reagent.
We have studied in detail chlorodealkylation of 2-
(ethyldimethylsilyl)-1-(trimethylsilyl)ethane (IX). The
reaction was carried out at different temperatures, and
reagent ratio, using both sublimed and unsublimed
AlCl3. The reaction gave two main products: 1,2-bis-
Me3SiCH=CH2 + HSiEtCl2 → Me3SiCH2CH2SiEtCl2, (4)
V
(chlorodimethylsilyl)ethane (I)
and
1-(chloro-
MeCl2SiCH=CH2 + HSiEtCl2
dimethylsilyl)-2-[chloro(ethyl)methylsilyl]ethane (XII).
→ MeCl2SiCH2CH2SiEtCl2,
(5)
VI
The resulting experimental data are listed in Table 3.
As seen from these, the following exchange reactions
take place.
Cl3SiCH=CH2 + HSiEtCl2 → Cl3SiCH2CH2SiEtCl2, (6)
VII
Me3SiCH=CH2 + HSiMe2Cl → Me3SiCH2CH2SiMe2Cl. (7)
Table 1. Yields and properties of 1,2-bis(organochlorosilyl)
ethanes prepared by hydrosilylation of vinylsilanes (equi-
molar reagent ratio, Speier catalyst)
VIII
Reactions (4)-(6) are highly selective. The yields of
2-[dichloro(ethyl)silyl]-1-(trimethylsilyl)ethane (V), 2-
[dichloro(ethyl)silyl]-1-[dichloro(methyl)silyl]ethane
(VI), and 2-[dichloro(ethyl)silyl]-1-(trichlorosilyl)-
ethane (VII) reach 90-91% (Table 1). 2-(Chloro-
dimethylsilyl)-1-(trimethylsilyl)ethane (VIII) was
obtained in a slightly lower yield. The yields and
properties of compounds V–VIII are listed in Table 1.
bp, °C
Compound
Yield, %
n2D0
(1–2 mm Hg)
82.2
67.6
35.0
91.0
90.0
90.6
65.0
39–42a
100–102
30–32
–
I
1.5120
1.4660
1.4520
1.4170
1.4750
1.4325
II
III
V
39–40
75–76
VI
VII
VIII
81–82
Alkylation of compounds V–VIII with a Grignard
reagent in THF gave their hexaalkyl derivatives: 2-
(ethyldimethylsilyl)-1-(trimethylsilyl)ethane (IX), 1-
33–35
a mp 37°C .
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 9 2008

1670
LAKHTIN et al.
Therefore, further research into chlorodealkylation
of compounds X–XII was carried out just at such a
reagent ratio.
AlCl3
IX + 2 CH3–C(О)–Cl
ClMe2SiCH2CH2SiMe2Cl
I
+ CH3–C(О)–C2H5 + CH3–C(О)–CH3,
(12)
It is also seen from Table 3 that the reaction yields
with sublimed and unsublimed AlCl3 are virtually the
same. The optimal chlorodealkylation temperature is
30–40°C. As the reaction temperature is raised to 40–
50°C, elimination of the silyl groups, resulting in
formation of Me2SiCl2 (7.9%) and MeEtSiCl2 (5.6%)
takes place (Table 3, exp. no. 5). At 25–30°C instead
of 30–40°C, the yield of compound XIII decreases
from 30–35% (Table 3, exp. nos. 3, 4) to 19-20%
(Table 3, exp. nos. 6, 7).
AlCl3
IX + 2 CH3–C(О)–Cl
ClMe2SiCH2CH2SiMeEtCl
XIII
+ 2 CH3C(О)CH3.
(13)
Reaction (12) involves exchange of the ethyl and
methyl substituents on silyl groups with chlorines to
form compound I. Reaction (13) involves exclusively
methyl/chlorine exchange and gives rise to compound
XIII.
The established optimal temperature 30–40°C was
maintained in further chlorodealkylation studies on
compounds X–XII.
As follows from Table 3, the chlorodealkylation of
compound IX provides more product I than product
XIII. Hence, ethyl radicals are easier exchanged for
chlorines than methyls.
The chlorodealkylation of 1-[diethyl(methyl)silyl]-
2-(triethylsilyl)ethane (X), too, provides two main
It should be noted that further alkyl/chlorine
exchange in I, XIII, leading to trichloro-substituted
products like Cl2MeSiCH2CH2SiMe2Cl proceeds only
if the IX : AcCl : AlCl3 molar ratio are above 2.5.
When the respective ratio is below 1:2:2, the
monosubstituted compounds Me3SiCH2CH2SiMe2Cl
and Me3SiCH2CH2SiMeEtCl are formed (2–3%).
products:
1-[chloro(ethyl)methylsilyl]-2-(chlorodi-
ethylsilyl)ethane
(XIV) (28%) and 1,2-bis
(chlorodiethylsilyl)ethane (21%), respectively.
2 MeEt2SiCH2CH2SiEt3 + 4 CH3C(О)Cl
AlCl3
ClMeEtSiCH2CH2SiEt2Cl
XIV
Hence, we found that the IX : AcCl : AlCl3 molar
ratio 1 : 2 (or 2.5) : 2 is optimal for the formation of
1,2-bis(diorganylchlorosilyl)ethanes.
+ ClEt2SiCH2CH2SiEt2Cl. (14)
XV
Table 3. Reaction conditions and yelds in the reaction of 2-
(ethyldimethylsilyl)-1-(trimethylsilyl)ethane (IX) with acetyl
chloride in the presence of AlCl3
Table 2. Yields and properties of 1,2-bis(trialkylsilyl)-
ethanes IX-XII and 1,2-bis(dialkylchlorosilyl)ethanes I,
XIII–XVI
Yields of reaction
Properties of reaction
Reaction conditions
productsа
Reaction
product
products
Starting Reaction
compound
typeа
bp, оСb
nD20
(yield, %)
Reaction
IX:AcCl:AlCl3
А
А
А
А
B
IX (93)
24
1.4320
1.4555
1.4590
1.4329
–
V
temperature,
I
XIII
molar ratio
X (74)
61–62
85–86
36–40
39–42
46–48
62–64
70–71
70–71
53
VI
°С
XI (60)
VII
VIII
IX
XII (79)
I (25–44)c
XIII (20–35)c
XIV (28)
XV (21)
XV (57)
XVI (14)
1
1:1:1
1:2:2
30–40
30–40
30–40
30–40
40–50
25–30
25–30
25.4
39.7
43.5
42.9
32.9
39.9
41.2
20.1
28.2
30.4
34.7
23.0
19.8
20.5
2b
1.4535
1.4598
1.4690
1.4690
–
B
X
3
1:2.5:2
1:2.5:2
1:2.5:2
1:2.5:2
1:2.5:2
4b
5
B
B
XI
XII
6
7b
(A) Grignard reaction and (B) chlorodealkylation. b 1–2 mm Hg.
c Data from Table 3.
a
a Per starting compound IX. b Sublimed AlCl3 was used.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 9 2008

SYNTHESIS OF UNSYMMETRICAL 1,2-BIS(DIORGANOCHLOROSILYL)ETHANES
1671
In this case, too, ethyl/chlorine exchange is
preferred over methyl/chlorine exchange.
First we explored the acetyl chloride–aluminum
chloride binary system. The calculated total energy
changes (ΔE, kcal mol–1) in this system revealed the
possibility of formation of an acetyl chloride–AlCl3
associate in which AlCl3 is coordinated by the oxygen
atom CH3C(Cl)O...AlCl3 (ΔE –22.8 kcal mol–1, ΔG
–7.26 kcal mol–1).
Unlike what is observed in the above reactions, the
chlorodealkylation of 1,2-bis(triethylsilyl)ethane (XI)
gives a single product, 1,2-bis(chlorodiethylsilyl)
ethane (XV) in 57% yield.
Et3SiCH2CH2SiEt3 + 2 CH3C(О)Cl
Then we took tetramethylsilane and the acetyl
chloride–AlCl3 associate were chosen as the starting
materials for the model chlorodealkylation reaction.
The process can be described by scheme (16).
AlCl3
ClEt2SiCH2CH2SiEt2Cl.
(15)
XV
Further increase of the length of the organic
substituent on silicon (transition from Si–Et to Si–Pr)
decreases the selectivity of this procedure. The
chlorodealkylation of 2-[dimethyl(propyl)silyl]-1-(tri-
methylsilyl)ethane results in formation of a complex
mixture of reaction products.
(CH3)4Si + CH3C(Cl)O···AlCl3
+
−
H
C
H
H
C
CH3
Cl
CH3
Si
CH3
AlCl3
XII + 2 CH3C(О)Cl
Me3SiCH2CH2SiMe2Cl
22%
CH3
O
AlCl3
+ ClMe2SiCH2CH2SiMe2Cl + ClMe2SiCH2CH2SiMeCl2
46% 15%
TS1
Cl
+ ClMe2SiCH2CH2SiMePrCl.
CH3
CH3
XVI 14%
C
Si
CH3
The yield of the target product, 1-(chloro-
dimethylsilyl)-2-[chloro(methyl)propylsilyl]ethane (XVI)
{mass spectrum, m/z (Irel, %): 227(2) [M – CH3]+, 207
(4) [M – Cl]+, 199(100) [M – Pr]+, 93(37) [SiMe2Cl]+},
is as low as 14%.
CH3
CH3
O
AlCl3
A
+
−
Hence, chlorodealkylation of 1,2-bis(trialkylsilyl)-
ethanes with acetyl chloride and AlCl3 can be used for
preparing 1,2-bis(diorganylchlorosilyl)ethanes with
various alkyl substituents (Me, Et, Pr) on the silicon
atom. However, sufficiently good yields are observed
with compounds containing Me and Et groups,
whereas the yields of propyl derivatives, like XVI, is
insignificant (Table 2).
CH3
CH3
CH3
Cl
C
Si
CH3
CH3
O
AlCl3
TS2
→ (CH3)3SiCl + (CH3)2CO···AlCl3.
(16)
To gain insight into the mechanism of the
chlorodealkylation reaction, we performed B3LYP/6-
31G** quantum-chemical calculations using the
Gaussian 98 program suite [17].
For reaction (16) we calculated the total energies of the
starting and final compounds, as well as possible
transition states TS1 and TS2, and intermediate A. The
relative energies of these species (Erel, kcal mol–1) are
listed in Table 4. The total energy of the isolated
starting molecules SiMe3, AcCl, and AlCl3 was taken
for a zero relative energy (Erel).
The tetramethylsilane–acetyl chloride–aluminum
chloride system was chosen as
a
model
chlorodealkylation reaction. At a stoichiometric
starting reagent ratio, the yield of chlorotrimethylsilane
is 97% [16].
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 9 2008

1672
LAKHTIN et al.
An important specific feature of reaction (16) is
that it has two transition states TS1 and TS.
Schematically, the spatial arrangement of these
Note that intermediate A has one and the same
structure for the motion along the reaction coordinate
from TS1 to A and from TS2 to A.
transition states and intermediate A with specified
interatomic distances (Å) and bond angles in the
intermediate (α 121.4°, β 120.1°, and γ 117.9°) is
shown below.
The activation barriers for the formation of TS1 and
TS2 are different. Hence, in going from the AcCl–
AlCl3 associate to TS1, i.e. from –22.8 to 26.6 kcal mol–1
(Table 4), the potential barrier is 49.4 kcal mol–1, and
in going from A to TS2, i.e. from –36.7 to –20.8 kcal mol–1
(Table 4), the potential barrier is much lower (15.9
kcal mol–1).
H
H
H
CH3
C
CH3
2.18
Si
CH3
CH3
Cl
1.91
C
2.66
Si
2.26
1.93
C
1.85
Cl
1.28
O
Hence, the potential barrier for the formation of
TS1 is several times higher than that for TS2. Con-
sequently, the formation of TS1, leading to alkyl
migration, is the key stage of the overall dechloro-
alkylation reaction. This conclusion is sufficiently
nicely consistent with the obtained experimental
evidence for the effect on this reaction of the alkyl
substituents on the silicon atom.
1.40
O
CH3
1.88
1.84
AlCl3
CH3
AlCl3
TS1
TS2
CH3
Cl
1.85
C
Si
1.85
α
1.48
CH3
O
β
γ
1.99
EXPERIMENTAL
AlCl3
A
The starting compounds and reaction products were
analyzed by GLC on an LKhM-80 chromatograph
equipped with a thermal conductivity detector; carrier
gas helium (30 ml min–1); 0.3 × 200 cm stainless-steel
columns, packed with 5% SE-30 on Chromaton N-
AW-DMCS (0.25–0.31 mm); temperature program
30–250°C (ramp rate 12°C/min).
The reaction begins with the formation of activated
complex TS1 for transfer of the methyl group from the
silicon atom in tetramethylsilane to the carbonyl
carbon atom in acetyl chloride. After that intermediate
A rearranges into activated complex TS2. In the latter
comples, chlorine transfer from carbon to silicon takes
place.
Identification was performed by GC-MS on a
Hewlett-Packard HP-5071 instrument, ionizing voltage
70 V. Separation was carried out on a DB-5 capillary
column (0.032 × 25000 cm, film thickness 25 μm);
temperature program 50–280°C (ramp rate 7°C/min),
carrier gas helium (0.8 ml/min). The molecular masses
are presented for the 28Si and 35Cl isotopes.
Transition states TS1 and TS2 are characterized by
imaginary vibration frequences 518 and 206 cm–1,
respectively, corresponding to first-order saddle points
on the total potential energy surface of the system.
Table 4. Relative energies of compounds and activated
complexes (Erel) participating in chlorodealkylation of
tetramethylsilane
The 1H NMR spectra were taken on a Bruker AM-
360 (360 MHz) Fourier spectrometer. Liquid
substances were analyzed as 15–30% solutions in
CDCl3 against internal TMS.
Compound
Erel, kcal mol–1
Starting reagents:
Reaction of chlorodimethyl(vinyl)silane (XVII)
with chloro(methyl)phenylsilane (XVIII). Com-
pound XVII, 24.1 g, was loaded in a three-necked
flask equipped with a reflux condenser and a dropping
funnel, and several drops of the Speier catalyst
(H2PtCl4 solution in propan-2-ol) were added to it.
Compound XVIII, 31.4 g, was then added dropwise. If
no reaction was observed, the mixture was heated to
(CH3)4Si, CH3C(Cl)O, AlCl3
MeC(Cl)O···AlCl3
0
–22.8
+26.6
–36.7
–20.8
Activated complex TS1
Intermediate A
Activated complex TS2
Final products:
Me3SiCl + Me2CO···AlCl3
–59.9
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 9 2008

SYNTHESIS OF UNSYMMETRICAL 1,2-BIS(DIORGANOCHLOROSILYL)ETHANES
1673
50–60°C. The addition rate depended on the intensity
REFERENCES
of condensation in the reflux condenser. The reaction
temperature was maintained in the range 60–110°C by
means of an oil bath. The reaction mixture was
analyzed periodically by GLC. The reaction product,
compound II was isolated by vacuum distillation.
Yield 37.5 g (67.6%), bp 100–102°C (1–2 mm Hg),
nD20 1.5129. 1H NMR spectrum, δ, ppm: 0.422 s [3H, Si
(CH3)2], 0.431 s [3H, Si(CH3)2], 0.695 s (3H, SiCH3),
~0.85 m (2H, CH2), ~1.1 m (2H, CH2), 7.4–7.7 m (5H,
C6H5).
1. Ushakov, N.V., Finkelshtein, E.Sh., and Babich, E.D.,
Vysokomol. Soedin., Ser. A, 1995, vol. 37, no. 3, p. 470.
2. Babich, E.D., Polymeric Materials Encyclopedia,
Salamone, C., Ed., Boca Raton: CRC, 1996, vol. 10,
p. 7621.
3. Interrante, L.V. and Shen, Q., Silicon-containing
Ppolymers: The Science and Technology of Their
Synthesis and Application, Johns, R.G., Ando, W., and
Chojnowsky, J., Eds., Dordrecht: Kluwer, 2000, p. 245.
4. Gusel’nikov, L.E. and Polyakov, Yu.P., Frontiers of
Organosilicon Chemistry, Bassindale, A.R. and Gas-
par, P.P., Eds., London: The Royal Society of
Chemistry, 1991, p. 50.
5. Gusel’nikov, L.E., Polyakov, Yu.P., Volnina, E.A., and
Nametkin, N.S., USSR Inventor’s Certificate no. 802313,
1980, Byull. Izobret., 1981, no. 5.
The other hydrosilylation reactions (1) and (3)–(7)
were carried out analogously. The yields and
properties of the synthesized compounds are listed in
Table 1.
Syntheses with Grignard reagents. Compounds
V–VIII were converted by means of Grignard reagents
(MeMgCl, EtMgCl, and PrMgBr) into compounds IX–
XII. The reactions were carried out as described in
[18]. The yields and properties of compounds IX–XII
are presented in Table 2.
6. Tverdokhlebova, I.I., Sutkevich, O.I., Ronova, I.A.,
Polyakov, Yu.P., Gusel’nikov, L.E., and Pavlova, S.A.,
Vysokomol. Soedin., Ser. A, 1988, vol. 30, p. 1070.
7. Polyakov, Yu.P., Gusel’nikov, L.E., Yadritseva, T.S.,
Bukalov, S.S., and Leites, L.A., Vysokomol. Soedin.,
Ser. A, 1995, vol. 37, p. 955.
8. Gusel’nikov, L.E., Volnina, E.A., Zaikin, V.G., Po-
lyakov, Yu.P., and Hametkin, N.S., Dokl. Akad. Nauk
SSSR, 1985, vol. 282, p. 901.
9. Gusel’nikov, L.E., Volkova, V.V., Volpina, E.A., Glad-
kova, N.K., Negrebetsky, Vad.V., and Blazso, M.,
Inorg. Organomet. Polymers, 1998, vol. 8, p. 89.
Reaction of 1-(trimethylsilyl)-2-(ethyldime-
thylsilyl)ethane (IX) with acetyl chloride in the
presence of AlCl3. Compound IX, 37.6 g, and 53.4 g
of AlCl3 were loaded under argon into a four-necked
flask equipped with a stirrer, a refux condenser, and a
dropping funnel. The mixture was stirred until
homogeneous, and 39.5 g of freshly distilled acetyl
chloride was added dropwise. The reaction involved
heatrelease, and the temperature of the process was
maintained in the range 30–40°C by varying the rate of
addition of acetyl chloride. After the addition was
complete, the mixture was stirred for 4 h more and left
under argon for 10 h. The reaction products were
isolated by vacuum distillation. Compound I, 18.6 g
[mp 37°C from hexane, bp 92–93°C (1–2 mm Hg), 1H
NMR spectrum, δ, ppm: 0.415 s (12H, SiCH3), 0.818 s
(4H, CH2)], and compound XIII, 13.8 g {bp 46–48°C
10. Gusel’nikov, L.E., Polyakov, Yu.P., and Nametkin, N.S.,
Dokl. Akad. Nauk SSSR, 1980, vol. 353, p. 1133.
11. Gusel’nikov, L.E., Polyakov, Yu.P., Volnina, E.A., and
Nametkin, N.S., USSR Inventor’s Certificate no. 810701,
1981, Byull. Izobret., 1981, no. 9.
12. Gusel’nikov, L.E., Polyakov, Yu.P., Volnina, E.A., and
Nametkin, N.S., J. Organomet. Chem., 1985, vol. 292,
no. 2, p. 189.
13. Lukevics, E.Ya. and Voronkov, M.G., Gidrosilili-
rovanie, gidrogermilirovanie, gidrostanillirovanie
(Hydrosilylation, Hydrogermylation, Hydrostannyla-
tion), Riga: Akad. Nauk Latv. SSR, 1964.
14. Andrianov, K.A., Souchek, I., and Khananashvili, L.M.,
1
(1 mm Hg), nD20 1.4535; H NMR spectrum, δ, ppm:
Usp. Khim., 1979, vol. 48, no. 7, p. 1233.
15. Polyakov, Yu.P., Cand. Sci. (Chem.) Dissertation, Mos-
cow, 1986.
16. Sakurai, H., Tominaga, K., Watanabe, T., and Kumada, M.,
Tetrahedron Lett., 1966, no. 45, p. 5493.
17. Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E.,
Robb, M.A., Cheeseman, J.R., Zakrzewski, V.G.,
Montgomery, J.A., Stratmann, R.E., Buran, J.C., Dap-
prich, S., Millam, J.M., Daniels, A.D., Kudin, K.N.,
Strain, M.C., Farkas, O., Tomasi, J., Barone, V., Cossi, M.,
0.37 s (3H, H3CSiEt), 0.41 s [6H, Si(CH3)2], 0.80–0.85
m (6H, CH2CH2, CH2CH3), 1.02 t (3H, CH3CH2)}
were obtained. The experiments at other temperatures
and reagent ratios were carried out analogously. The
resulting data are listed in Table 3.
Chlorodealkylation of compounds X–XII was
carried out analogously. The yields and properties of
the reaction products are listed in Table 2.
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Cammi, R., Menucci, B., Pomelli, C., Adamo, C.,
Johnson, B., Chen, W., Wong, M.W., Andres, J.L.,
Gonsalez, C., Head-Gordon, M., Replogle, E.S., Pople, J.A.,
Gaussian 98, Revision A.7, Pittsburgh, PA: Gaussian,
1998.
Clifford, S., Ochterski, J., Petersson, G.A., Ayala, P.Y.,
Cui, Q., Morokuma, K., Malick, D.K., Rabuck, A.D.,
Raghavachari, K., Foresman, J.B., Cioslowski, J., Or-
tiz, J.V., Baboul, A.G., Stefanov, B.B., Liu, G.,
Liashenko, A., Piskorz, P., Komaromi, I., Gomperts, R.,
Martin, R.L., Fox, D.J., Keith, T., Al-Laham, M.A.,
Peng, C.Y., Nanayakkara, A., Challacombe, M., Gill, P.M.W.,
18. Preparativnaya organicheskaya khimiya (Preparative
Organic Chemistry), Moscow: Khimiya, 2nd ed., 1964,
p. 653.
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