Selective Formation of Alkoxychlorosilanes and Organotrialkoxysilane with Four Different Substituents by Intermolecular Exchange Reaction

Article abstract of DOI:10.1002/asia.201601120

Alkoxychlorosilanes are scientifically and industrially important toward preparing silicone and silica as well as preparation of siloxane-based nanomaterials by stepwise reactions of Si?OR (R=alkyl) and Si?Cl groups. Intermolecular exchange of alkoxy and chloro groups between alkoxysilanes and chlorosilanes (functional group exchange reaction) provides an efficient and environmentally benign route to alkoxychlorosilanes. BiCl₃ as a Lewis acid catalyst can promote the functional group exchange reactions more efficiently than conventional acid catalysts. Higher reactivity has been observed for chlorosilanes with smaller numbers of Si?CH₃ groups and for alkoxysilanes with larger numbers of Si?CH₃ groups. The reaction mechanism is proposed and selective syntheses of alkoxychlorosilanes are demonstrated. These findings also enable us to synthesize an organotrialkoxysilane with four different substituents.

Full text of DOI:10.1002/asia.201601120

CHEMISTRY
AN ASIAN JOURNAL
www.chemasianj.org
Accepted Article
Title: Selective Formation of Alkoxychlorosilanes and Four Different Substituted Or-
ganotrialkoxysilane by Intermolecular Exchange Reaction
Authors: Yuma Komata; Masashi Yoshikawa; Yasuhiro Tamura; Hiroaki Wada; At-
sushi Shimojima; Kazuyuki Kuroda
This manuscript has been accepted after peer review and the authors have elected
to post their Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by using the Digital
Object Identifier (DOI) given below. The VoR will be published online in Early View as
soon as possible and may be different to this Accepted Article as a result of editing.
Readers should obtain the VoR from the journal website shown below when it is pu-
blished to ensure accuracy of information. The authors are responsible for the content
of this Accepted Article.
To be cited as: Chem. Asian J. 10.1002/asia.201601120
Link to VoR: http://dx.doi.org/10.1002/asia.201601120
A Journal of
A sister journal of Angewandte Chemie
and Chemistry – A European Journal

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
Selective Formation of Alkoxychlorosilanes and Four Different
Substituted Organotrialkoxysilane by Intermolecular Exchange
Reaction
[
a],#
[a],#
[a]
[a]
[a]
Yuma Komata,
Masashi Yoshikawa,
Yasuhiro Tamura, Hiroaki Wada, Atsushi Shimojima,
[a, b]
and Kazuyuki Kuroda*
Abstract: Alkoxychlorosilanes are scientifically and industrially
important toward preparing silicone and silica as well as preparation
of siloxane-based nanomaterials by stepwise reactions of Si–OR (R
alkoxychlorosilane is partial alcoholysis of chlorosilanes (Eq.
[
13]
1);
however, the reaction often yields
a mixture of
[
14]
alkoxychlorosilanes with various numbers of OR groups,
and
=
alkyl) and Si–Cl groups. Intermolecular exchange of alkoxy and
selective synthesis of a single target compound can be achieved
with difficulty. Additionally, corrosive HCl gas generated as by-
product should be trapped or removed during the reaction. To
avoid the generation of HCl, alkali metal alkoxides can be used
chloro groups between alkoxysilanes and chlorosilanes (functional
group exchange reaction) provides an efficient and environmentally
3
benign route to alkoxychlorosilanes. BiCl as a Lewis acid catalyst
[
15]
can promote the functional group exchange reactions more
efficiently than conventional acid catalysts. Higher reactivity has
for the reaction instead of alcohols (Eq. 2).
Syntheses of
trialkoxychlorosilanes (SiCl(OR) ) without generating HCl have
3
been observed for chlorosilanes with smaller numbers of Si–CH
groups and for alkoxysilanes with larger numbers of Si–CH groups.
3
also been achieved by acid-catalyzed reactions between i) SiCl
4
[16]
3
and an unsymmetrical ether (tBuOMe) (Eq. 3),
ii) SiCl
4
and
(R =
[
17]
The reaction mechanism is proposed and selective syntheses of
alkoxychlorosilanes are demonstrated. These findings also enable
us to synthesize four different substituted organotrialkoxysilane.
triethyl orthoformate (HC(OEt)
Me, Et) and acetyl chloride (MeCOCl) (Eq. 5). Other reactions
3
) (Eq. 4)
and iii) Si(OR)
4
[
18]
[
19]
include chlorination of alkoxyhydrosilane with CCl
4
(Eq. 6) or
and partial
[
20]
trichloroisocyanuric acid (TCCA) (Eq. 7)
chlorination of Si(OEt)
[
21]
4
with thionyl chloride (Eq. 8).
These
reactions can produce specific alkoxychlorosilanes, governed by
those reactions, in relatively high yields; however, their
applicabilities for the synthesis of other alkoxychlorosilanes with
different numbers of OR and Cl groups have not been
mentioned.
Introduction
Alkoxysilanes and chlorosilanes are versatile compounds that
are used for protecting hydroxyl groups of organic compounds
[1]
forming silyl ethers, for surface modification of silica and metal
[
2]
oxides, and for producing siloxane-based materials by either
SiCl
SiCl
SiCl
SiCl
4
4
4
4
+ nROH → SiCl4-n(OR)
+ nROM → SiCl4-n(OR)
+ 3 tBuOR → SiCl(OR)
n
+ nHCl
+ nMCl (M: Na or K)
+ 3 tBuCl (R: Me or Et) (3)
(1)
(2)
[
3-5]
hydrolytic
or
non-hydrolytic
polycondensation.
n
Alkoxychlorosilanes, possessing both Si–OR (R = alkyl) and Si–
Cl groups, have recently attracted increasing attention because
the different reactivities of the two functional groups allow
stepwise reactions to form Si–C, Si–OH, or Si–O–Si bonds.
variety of siloxane-based nanomaterials have been synthesized
by silylation of silicate species with Si–Cl groups of
alkoxychlorosilanes,
polycondensation of Si–OR groups.
3
+ HC(OEt)
+ H CCOCl → SiCl(OEt)
SiH(OR) + CCl → R SiCl(OR) + CHCl
Si(OR) H + TCCA → 3 SiCl(OR)
Si(OEt) + SOCl → 2 SiCl(OEt)
+ =Si(OR) → 2 =SiCl(OR)
3
→ SiCl(OEt)
3
+ CHCl
3
(4)
(5)
(6)
(7)
(8)
(9)
Si(OEt)
4
3
3
+ H CCOOEt
3
[
6]
A
R
3
2
2
4
2
3
3
3
+ cyanuric acid
4
2
3 2
+ SO(OEt)
followed
by
hydrolysis
and
=SiCl
2
2
[
7, 8]
Furthermore, preferential
hydrolysis of Si–Cl groups of alkoxytrichlorosilanes leads to the
The functional group exchange reaction between
alkoxysilanes and chlorosilanes provides a more efficient and
formation of alkoxysilanetriols that can be assembled into
[
9, 10]
ordered siloxane structures.
Alkoxychlorosilanes are also
facile
route
to
alkoxychlorosilanes.
When
useful for synthesizing organoalkoxysilanes owing to the higher
alkoxysilanes/chlorosilanes having more than two OR/Cl groups
are employed as precursors, alkoxychlorosilanes can be formed
by partial exchange of the OR and Cl groups (Eq. 9). An early
[
11, 12]
reactivity of the Si–Cl groups with Grignard reagents.
One of the simplest methods to synthesize
report described the synthesis of SiCl
a mixture of Si(OMe) and SiCl at 120 °C.
reaction efficiently proceeds under mild conditions by employing
2 2
(OMe) (>65%) by heating
[
22]
4
4
The exchange
[
[
a]
b]
Y. Komata, M. Yoshikawa, Prof. H. Wada, Prof. A. Shimojima, Prof.
K. Kuroda
Department of Applied Chemistry, Faculty of Science and
Engineering, Waseda University
[11, 23-25]
catalysts.
have been obtained from
tetraalkoxysilane and tetrachlorosilane in the presence of HCl or
For example, trialkoxychlorosilanes (SiCl(OR)
3
)
a
3:1 (mol/mol) mixture of
3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
[
11, 25]
E-mail: kuroda@waseda.jp
Prof. K. Kuroda
Kagami Memorial Research Institute for Materials Science and
Technology, Waseda University
AlCl
3
.
The reaction with an AlCl
3
catalyst was also utilized
[
26]
to introduce
a
Si–Cl group into hexamethoxydisiloxane.
Although the formation of siloxane bonds with the generation of
[5]
RCl is competitive in the presence of Lewis acid catalysts, the
2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
#
These authors equally contributed to this work.
functional group exchange reaction precedes under controlled
conditions. One of the advantages of the functional group
exchange reaction is that by-products, such as HCl, are not
Supporting information for this article is given via a link at the end of
the document.
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
generated; however, relatively high yield syntheses have been
reported only for trialkoxychlorosilanes in those referred papers.
[
11, 23-25]
To the best of our knowledge, the potential of the
functional group exchange reaction to produce other
alkoxychlorosilanes has been largely unexplored.
In this paper, functional group exchange reactions between
alkoxysilanes and chlorosilanes have been investigated in detail
using bismuth (III) chloride (BiCl
3
) as a new catalyst. We have
recently reported that BiCl can act as a weak Lewis acid
3
catalyst for the controlled formation of siloxane (Si–O–Si) bonds
between tert-alkoxysilyl groups and chlorosilyl groups with
[
5, 27]
generating alkyl chloride.
This siloxane bond formation, that
is a side reaction from the viewpoint of the present study, is
avoided when alkoxysilanes possessing primary or secondary
alkoxy groups are employed as precursors. Accordingly,
ethoxysilanes are mainly used in this study.
In addition to typical reactions between tetrafunctional silanes
(
Si(OEt)
organosilanes with different numbers of organic substituents
Si–CH were also investigated (Eq. 10) to unveil the
4 4
and SiCl ) under varied conditions, the reactions of
(
3
)
mechanism of the exchange reaction toward the selective
syntheses of alkoxychlorosilanes. As an example to
demonstrate the usefulness of this exchange reaction,
organotrialkoxysilane having three different types of OR groups
was also synthesized.
2
9
Figure 1. Si NMR spectra of the mixtures (SiCl
the reaction in the presence of (a) no catalyst, (b) HCl catalyst, (c) AlCl
catalyst and (d) BiCl
4 4
/Si(OEt) = 1:3) after 24 h of
3
3
catalyst. Note that the signals of Si adjacent to Cl are
observed to be broad due to the quadrupolar relaxation.
(
10)
Results and Discussion
Effect of catalysts
The functional group exchange reactions between SiCl
Si(OEt) (molar ratio of SiCl :Si(OEt) = 1:3) were performed
under four different catalyst conditions (no catalyst, HCl, AlCl
and BiCl ) to obtain SiCl(OEt) as a target compound. For the
4
and
4
4
4
3
3
3
HCl catalyzed reaction, a small amount of water was added to
the mixture to form HCl (0.5 mol% relative to the total amount of
[
28]
Si)
BiCl
by partial hydrolysis of SiCl
4 3
. The amounts of AlCl and
3
were 0.25 mol% relative to the total amount of Si.
2
9
1
Figure 1 shows the Si NMR spectra of the mixtures after
4 h of the reaction at room temperature. In the absence of any
catalysts, only the signals of SiCl (−18.9 ppm) and Si(OEt)
−81.8 ppm) were observed, confirming that no reaction
proceeded. In the presence of acid catalysts (HCl, AlCl and
), new signals due to alkoxychlorosilanes, such as
(OEt) (−38.7 ppm), SiCl (OEt) (−56.1 ppm) and SiCl(OEt)
were observed. When BiCl
Figure 2. H NMR spectra of the mixtures (SiCl
4
/Si(OEt)
4
= 1:3) after 24 h of
the reaction in the presence of (a) no catalyst, (b) HCl catalyst, (c) AlCl
catalyst and (d) BiCl catalyst. The numbers (1–4) on the spectra correspond
to the numbers of OEt groups in the products.
3
2
3
4
4
(
3
BiCl
SiCl
3
3
NMR spectra (Figure 2). The chemical shifts of the ethoxy
groups, in particular, the −OCH − signals, are sensitive to the
2
2
2
3
[
29, 30]
(
−70.2 ppm),
3
was used as a
environment of the central Si atom, and are slightly shifted
downfield with increasing the number of Cl groups. The quartet
signals of −OCH
Si(OEt) , and were gradually shifted to ca. 3.91, 3.99 and 4.09
ppm for SiCl(OEt)
catalyst, the molar ratio of SiCl(OEt)
3 4
/Si(OEt) became the
highest. This result indicates that the exchange of OEt and Cl
2
− were centered at 3.85 ppm for unreacted
groups proceeded most efficiently using BiCl
present reaction conditions.
3
catalyst under the
4
[30]
3
2 2 3
, SiCl (OEt) and SiCl (OEt), respectively.
1
More precise quantitative data were obtained from the H
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
1
The integrated ratios of these well-separated H NMR signals, in
combination with the proportion of residual SiCl evaluated by
Si NMR, enabled us to determine the mole percent of
SiCl(OEt) as listed in Table 1. The highest ratio (75%) was
achieved when the BiCl catalyst was used. This result is
important from the practical viewpoint. We confirmed that the
ratio of SiCl(OEt) decreased to 60 mol% and 45 mol% when the
amount of BiCl was further decreased to 0.05 mol% and 0.025
4
2
9
3
3
3
3
mol%, respectively, under otherwise identical conditions (NMR
data are shown in Figures S1 and S2 in Supporting Information
(
SI)).
Table 1. Proportions of SiCl(OEt)
3
under different catalyst conditions.
SiCl(OEt) (mol%)
Catalyst
none
3
2
HCl
16
57
75
AlCl
BiCl
3
3
29
Figure 3. Si NMR spectra of the mixtures after different reaction times
SiCl /Si(OEt) = 1:3, 0.1 mol% BiCl ).
The reason why BiCl
exchange reaction than AlCl
is consistent with the reactivity for siloxane bond formation on
3
has higher reactivity for the
is unclear; however, this tendency
(
4
4
3
3
[
31]
non-hydrolytic sol-gel process and alkoxylation of chlorosilane
Table 2. Time course of the proportions of the products formed by the reaction
between Si(OEt) and SiCl (SiCl /Si(OEt) = 1:3, 0.1 mol% BiCl ).
[16]
with unsymmetrical ethers.
These two reactions involve an
4
4
4
4
3
activation process of Si−Cl bond by Lewis acid catalyst,
therefore it is suggested that the functional group exchange
reaction has also such an activation process in its reaction
mechanism.
Reaction
time / h
SiCl
(mol%)
4
SiCl
(mol%)
3
(OEt)
SiCl
(mol%)
2
(OEt)
2
SiCl(OEt)
(mol%)
3
Si(OEt)
4
(mol%)
1
3
6
13
0
8
22
20
8
1
2
4
5
3
4
4
4
74
51
41
19
9
25
35
68
86
89
89
0
Effects of various parameters on functional group exchange
24
72
96
0
reaction catalyzed by BiCl
To understand the reaction process of the OR and Cl exchange
between Si(OEt) and SiCl , the mixtures after different reaction
3
0
2
0
1
6
4
4
120
0
1
6
2
9
times were analyzed by NMR. Figure 3 shows the Si NMR
spectra of the mixture after 1, 3, 6, 24, 72, 96 and 120 h of the
[5]
3
As we reported previously, BiCl can catalyze the siloxane
reaction in the presence of 0.1 mol% BiCl
two new signals assigned to SiCl (OEt) and SiCl(OEt)
observed along with that of residual Si(OEt) . The signal of SiCl
disappeared after 3 h, and an additional small signal due to
3
catalyst. After 1 h,
formation between Si–Cl groups and tert-alkoxy groups. To
investigate the effect of the types of alkoxy groups on the
exchange reaction with chloro groups, primary alkoxy group
3
3
were
4
4
(
(
OEt), secondary alkoxy group (OiPr) and tertiary alkoxy group
OtBu) were employed. To facilitate the analysis, 1:1 mixtures of
SiCl
SiCl
2
(OEt)
2
appeared. The time course of the proportions of
1
n
(OEt)4−n (n = 0–4) in the reaction mixture evaluated by
H
difunctional silanes, i.e., dichlorodimethylsilane Me
2
SiCl
2
and
NMR (Figure S3 in SI) is shown in Table 2. As the reaction
proceeded, SiCl (OEt) and Si(OEt) decreased while SiCl(OEt)
increased, which suggested that the functional group exchange
reaction between SiCl (OEt) and Si(OEt) (Eq. 11) occurred. No
significant change of the fraction of SiCl (OEt) during the
reaction also suggested that the reaction between SiCl (OEt)
and Si(OEt) proceeded concurrently (Eq. 12). Only a slight
change in the Si NMR spectra was observed between 96 h
and 120 h, suggesting that the reaction almost reached
equilibrium.
dialkoxydimethylsilanes Me Si(OR) (R = Et, iPr and tBu), were
2 2
3
4
3
reacted.
29
Figure 4 shows the Si NMR spectra of the mixtures after
4 h of the reaction. When the alkoxysilanes possessing OEt
3
4
2
2
2
and OiPr groups were used, the exchange reaction proceeded
exclusively to form Me SiCl(OR). On the other hand, in the case
of OtBu group, the signals that can be assigned to
2
2
2
4
2
9
octamethylcyclotetrasiloxane
decamethylcylopentasiloxane
(D
(D
4
,
−19.1
−21.5
ppm),
ppm),
5
,
dodecamethylcyclohexasiloxane (D
polydimethysiloxanes (−21.9 ppm) were observed.
formation of these cyclic species was also supported by
6
, −22.2 ppm) and higher
[
32]
The
SiCl
SiCl
3
2
(OEt) + Si(OEt)
(OEt) + Si(OEt)
4
→ SiCl
2
(OEt)
2
+ SiCl(OEt)
3
(11)
(12)
13
C
2
4
→ 2SiCl(OEt)
3
NMR (Figure S4 in SI). These results clearly show that siloxane
formation between the Si–OtBu and Si–Cl groups occurred.
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
2
9
29
Figure 5. Si NMR spectra of the reaction mixtures of SiCl
4
and Si(OEt)
4
with
Figure 4. Si NMR spectra of the reaction mixtures of Me
Me Si(OR) having different R groups (Me SiCl /Me Si(OR) = 1:1, 0.1 mol%
BiCl , after 24 h): (a) R = Et, (b) R = iPr and (c) R = tBu.
2 2
SiCl and
different molar ratios of (a) 1:3, (b) 1:1 and (c) 3:1 (0.1 mol% BiCl
96 h for 1:3 and 3:1 mixtures, after 72 h for 1:1 mixture).
3
cat., after
2
2
2
2
2
2
3
Note that cyclic oligosiloxanes with odd numbers of Si atom
such as D are never formed by siloxane formation alone. This
indicates that partial exchange of OtBu and Cl groups also
occurred.
Table 3. Proportions of the products formed by different molar ratios of SiCl4
and Si(OEt) (0.1 mol% BiCl , after 96 h for 1:3 and 3:1 mixture, after 72 h for
5
4
3
1:1 mixture).
SiCl
4
/Si(OEt)
4
SiCl
(mol%)
4
SiCl
(mol%)
3
(OEt)
SiCl
(mol%)
2
(OEt)
2
SiCl(OEt)
(mol%)
3
Si(OEt)
4
(mol%)
molar ratio
:3
1:1
:1
It is reported that siloxane formation between Si–Cl and
Si–OR groups is dominated by the stability of carbocations
1
0
7
1
4
24
3
89
42
21
6
1
1
[
5]
25
16
formed during the reaction. The tertiary alkoxy group (OtBu)
can form carbocation with higher stability than those derived
from primary alkoxy group (OEt) and secondary alkoxy group
3
59
(
OiPr), thus leading to the formation of Si–O–Si bonds. To avoid
Table 4. Proportions of the products formed by different molar ratios of
MeSiCl and MeSi(OEt) (0.1 mol% BiCl , after 24 h).
this side reaction, alkoxysilanes having primary alkoxy groups
are the most suitable for the efficient synthesis of
alkoxychlorosilanes by the exchange reactions.
3
3
3
MeSiCl
MeSi(OEt)
molar ratio
3
MeSiCl
mol%)
3
MeSiCl
(mol%)
2
(OEt)
MeSiCl(OEt)
(mol%)
2
MeSi(OEt)
(mol%)
3
/
3
(
Factors affecting the proportion of the products by
functional group exchange reaction
1
:2
:1
0
6
85
25
9
0
2
25
50
As described above, SiCl(OEt)
from the 1:3 mixture of SiCl
3
was formed with high selectivity
and Si(OEt) . To examine the
4
4
possibility of the selective formation of other alkoxychlorosilanes
with different numbers of OR groups, the reactions between
various molar ratios of alkoxysilane and chlorosilanes were
are much higher than the statistical prediction (approximately
2%, 25%, and 5% when SiCl :Si(OEt) = 1:3, 1:1 and 3:1,
respectively), which suggests the high thermodynamic stability
of SiCl(OEt)
Similar results were also obtained when the precursors
having a methyl substituent, i.e., MeSiCl –MeSi(OEt) mixtures,
were used. Although alkoxychlorosilane having one chloro group,
MeSiCl(OEt) , was almost selectively formed from a 1:2 mixture
85%), the selectivity of alkoxysilane having two chloro groups,
4
4
4
performed. Toward the selective syntheses of SiCl
2
2
(OEt) and
SiCl
3
(OEt), the molar ratio of SiCl
4
to Si(OEt)
4
2
was adjusted to
3
.
9
1:1 and 3:1, respectively. Figure 5 shows the Si NMR spectra
of these mixtures, along with the spectrum for the 1:3 mixture,
after the reaction reached equilibrium with 0.1 mol% BiCl . In
contrast to the almost selective formation of SiCl(OEt) from the
:3 mixture, SiCl (OEt) and SiCl (OEt) were not obtained as
3
3
3
3
2
1
2
2
3
(
major products from the 1:1 and 3:1 mixtures, respectively.
2
MeSiCl (OEt), formed from a 2:1 mixture was relatively low
1
Quantitative data obtained by H NMR (Table 3, Figure S5 in SI)
(
50%) (Table 4, Figures S7 and S8 in SI).
The high selectivity of SiCl(OEt) from the 1:3 mixture of
and Si(OEt) was consistent with previous reports (HCl or
confirmed the relatively high proportion of SiCl(OEt)
3
in both
3
cases. Actually, the proportions of SiCl(OEt) shown in Table 3
3
SiCl
4
4
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
[
11, 25]
AlCl
Si(OEt)
however SiCl
SiCl
3
catalyst).
In the case of 1:1 mixture of SiCl
was also formed selectively in this study,
4
and
Methyl group is more electron-donating than Cl and OR
[
33]
4
, SiCl(OEt)
3
groups.
The above results mean that the functional group
2
(OMe)
2
was mainly formed from 1:1 mixture of
exchange reaction is more hindered as the electron density of Si
in chlorosilanes increases. On the other hand, the reaction is
more promoted as the electron density of O in alkoxysilanes
increases because of hyperconjugation from Si–C bond to
4
and Si(OMe) by heating as described in ref. 22.
4
Effects of organo-substituents on functional group
exchange reactions
[
34]
oxygen atom.
It is therefore reasonable to consider that the
The preferential formation of alkoxychlorosilane having one Cl
exchange reaction proceeds by a nucleophilic attack of the
oxygen of alkoxysilanes to the Si atom of chlorosilanes to form a
penta-coordinated intermediate. Because the reaction does not
group by the reaction between SiCl
4
and Si(OEt)
4
implies that
than
alkoxychlorosilanes have lower
reactivities
tetraalkoxysilane in terms of functional group exchange reaction.
We speculate that the reactivity of alkoxysilanes is dependent on
the electron densities on Si and/or O atoms. Similarly, the
electron density of the Si atom in chlorosilanes possibly affects
their reactivity.
3
occur in the absence of catalysts, BiCl should play a role in
activating the Si–Cl bonds of chlorosilanes. The activation of Si–
Cl bonds and the nucleophilic attack of alkoxysilanes were also
reported for non-hydrolytic condensation between alkoxysilanes
[
35]
and chlorosilanes to form Si-O-Si bonds.
A functional group
[
35]
First, we investigated the reactivities of chlorosilanes
exchange reaction competed with this Si-O-Si bond formation.
having different numbers of methyl substituents. SiCl
Me SiCl and Me SiCl were reacted with Si(OEt) at the molar
ratio of 1:1 in the presence of BiCl . The conversions of Si(OEt)
4
, MeSiCl
3
,
On the basis of these findings, the proposed reaction
mechanism is shown in Scheme 1.
2
2
3
4
3
4
To obtain iformation about the interaction between BiCl
3
2
9
29
after 24 h of reactions were evaluated by Si NMR (please note
and chlorosilanes/alkoxysilanes,
Si NMR spectra of the
were carefully
1
that H NMR data were not used because of the partial
mixtures of SiCl and TEOS with and without BiCl
4
3
overlapping of the signals) (Figures S9 and S10 in SI). As shown
in Table 5, as the number of methyl group on chlorosilane
compared (Figure 3 bottom); however, no intermediate species
as well as the changes of chemical shifts of the reactants were
observed (Figure S13). It is likely that the reaction rate is too
high and/or the concentration of the reaction intermidiates is too
low to be detected by NMR. Further research is underway to
obtain direct evidence to support the proposed reaction
mechanism.
increased, the conversion of Si(OEt)
4
decreased, which was
indicative of the decrease of the reactivity of chlorosilanes.
Table 5. Conversions of Si(OEt)
4
by the reactions with different chlorosilanes
(1:1 ratio, 0.1 mol% BiCl
3
,after 24 h).
Chlorosilane
4
Conversion of Si(OEt) (%)
SiCl
MeSiCl
Me SiCl
Me SiCl
4
> 99
> 99
70
3
2
2
3
0
The reactivities of alkoxysilanes were then examined using
Si(OEt) , MeSi(OEt) , Me Si(OEt) and Me Si(OEt). When these
alkoxysilanes were reacted with SiCl at the molar ratio of 1:1,
4
3
2
2
3
4
the reactants were rapidly converted into alkoxychlorosilanes,
which made it difficult to compare the difference in the
reactivities of alkoxysilanes. The difference in the reactivities
was clearly observed when less reactive Me
2
SiCl
2
was used
SiCl
(
Figures S11 and S12 in SI). The conversions of Me
2
2
2
9
evaluated by Si NMR analysis are listed in Table 6. As the
number of methyl group in alkoxysilane increased, the
2 2
conversion of Me SiCl increased, that is, the reactivity of the
alkoxysilanes increased.
Scheme 1. Proposed mechanism of the functional group exchange reaction
3
catalyzed by BiCl .
2 2
Table 6. The conversions of Me SiCl by the reaction with different
alkoxysilanes (1:1 ratio, 0.1 mol% BiCl
3
, after 24 h).
Selective
synthesis
of
alkoxychlorosilanes
and
Alkoxysilane
2 2
Conversion of Me SiCl (%)
organotrialkoxysilanes
The validity of the results obtained in this study is exemplified by
the selective syntheses of alkoxychlorosilanes and
organotrialkoxysilane.
Si(OEt)
MeSi(OEt)
Me Si(OEt)
Me SiOEt
4
74
84
88
94
3
2
2
3
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
Selective syntheses of alkoxychlorosilanes
It is expected that the selective synthesis of certain
alkoxychlorosilanes can be achieved by the reaction between
Table 7. Selectivity of the products by the reaction between SiCl
Me SiOEt (0.1 mol% BiCl , after 24 h).
4
and
3
3
SiCl
4
Selectivity
(OEt) SiCl(OEt)
highly reactive chlorosilanes (SiCl
Me SiOEt), as suggested by Tables 5 and 6. Additionally, it is
expected that Me SiCl, which is a by-product formed by the
exchange reaction between Me SiOEt and SiCl , is not reacted
with the target products (SiCl (OEt) and SiCl (OEt) ) because of
its low reactivity, as described in Table 5. Using SiCl and
Me SiOEt, we were able to synthesize SiCl (OEt) and
SiCl (OEt) , both of which were not obtained as major products
when SiCl and Si(OEt) were used as precursors (see Table 3).
4
)
and alkoxysilanes
/
Me
3
SiOEt
SiCl
3
(OEt)
SiCl
2
2
3
Si(OEt)
(%)
4
(
3
molar ratio
(%)
(%)
(%)
3
1:1
1:2
1:3
98
2
< 1
0
0
7
3
4
21
0
61
11
18
82
3
2
2
4
3
3
To the best of our knowledge, the selective synthesis of three
types of alkoxychlorosilanes (SiCl (OR)4−n, n = 1–3) by the single
2
2
n
4
4
method has not been achieved by conventional studies of
functional group exchange reaction. Here, we have firstly
succeeded in selectively synthesizing all the three types of
29
Figure 6 shows the Si NMR spectra of the mixtures
obtained by the reactions between 1:1, 1:2 and 1:3 molar ratios
of SiCl
cases, Me
target compounds, SiCl
detected as major products. The quantitative analysis by
NMR (Figure S14 in SI and Table 7) confirmed that the
selectivities of SiCl (OEt) and SiCl (OEt) by the reactions with 1
and 2 equiv. of Me SiOEt were 98% and 61%, respectively.
These values are much higher than those achieved by the
reaction of SiCl and Si(OEt) (24% and 25% for SiCl (OEt) and
SiCl (OEt)
SiCl(OEt)
4
and Me
SiOEt was fully converted into Me
(OEt), SiCl (OEt)
3
SiOEt in the presence of BiCl
3
catalyst. In all
n
alkoxychlorosilanes (SiCl (OR)4−n, n = 1–3) by the exchange
3
3
SiCl, and the
reaction based on the investigation of the reaction
characteristics. This method can be worthwhile for syntheses of
various alkoxychlorosilanes and organoalkoxychlorosilanes.
3
2
2 3
and SiCl(OEt) , were
1
H
3
2
2
Synthesis of four different substituted organoalkoxysilanes
Organoalkoxysilanes having two or three different alkoxy groups
are potentially useful for producing new siloxane-based
materials because of the different reactivities among alkoxy
groups. For example, long-chain alkoxy groups and sterically
hindered tertiary alkoxy groups are more stable against
hydrolysis than short-chain and lower alkoxy groups, which
allows the formation of nanostructured materials by self-
3
4
4
3
2
2
,
respectively; see Table 3). The selectivity of
was also high (82%), which is identical to that
3
resulted from a 1:3 mixture of SiCl
selectivity of the target alkoxychlorosilanes can be effectively
enhanced by using Me SiOEt as an alkoxysilane precursor,
which is attributable not only to the high reactivity of Me SiOEt,
SiCl (see Table 5)
4
and Si(OEt)4. Thus, the
3
assembly of oligosiloxanes having both Si–OR and Si–OH
3
[10, 36]
groups.
The reactivity of alkoxysilanes for siloxane bond
but also to the low reactivity of Me
suppressing the reverse reaction.
3
formation with Lewis acid catalyst also depends on the type of
[27]
alkoxy groups. As we reported previously, alkoxy groups that
can release
a stable carbocation preferentially react with
chlorosilanes to form siloxane bonds. Despite these attractive
features, there have been only a few reports on the synthesis of
alkoxysilanes with two or three different alkoxy groups. Three
different alkoxy groups have been successfully introduced by
stepwise alkoxylations of MeSiCl
carbohydrate derivatives.
3
(Eq. 13) with bulky alcohols of
We presume that simple alkyl
alcohols such as methanol and ethanol may be unsuitable for
this reaction because multisubstituted alkoxysilanes
MeSiCl3−n(OR ) , n = 1–3) are likely formed at the first step of
alkoxylation due to lower steric repulsion.
[
37]
7
(
n
7
7
MeSiCl
MeSiCl
3
2
+ R OH → MeSiCl
2
(OR ) +HCl
7
8
7
8
(OR ) + R OH → MeSiCl(OR )(OR ) +HCl
7
8
9
7
8
9
MeSiCl(OR )(OR ) + R OH → MeSi(OR )(OR )(OR ) + HCl (13)
We demonstrate here that the functional group exchange
reaction is useful for the synthesis of a four different substituted
organoalkoxysilanes.
As
described
above,
alkoxymonochlorosilane can be formed almost selectively by
adjusting the molar ratio of alkoxysilane and chlorosilane;
1
0
3
therefore, the reaction among organotrichlorosilane (R SiCl )
1
0
7
and two kinds of organotrialkoxysilanes (R Si(OR ) and
R Si(OR )
3
1
0
8
3
) would produce three organochloroalkoxysilanes
29
Figure 6. Si NMR spectra of the reaction mixtures of SiCl
4 3
and Me SiOEt
(
Eq. 14). Organoalkoxysilanes with two or three different alkoxy
with molar ratios of (a)1:1, (b) 1:2 and (c) 1:3 (0.1 mol% BiCl , after 24 h).
3
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
groups are then formed by the reaction between this mixture and
9
an alcohol (R OH) (Eq. 15).
1
0
10
7
10
8
3 3 3
R SiCl + R Si(OR ) + R Si(OR )
1
0
7
10
7
8
10
8
→
2 2
R SiCl(OR ) + R SiCl(OR )(OR ) + R SiCl(OR ) (14)
1
0
7
10
7
8
10
8
9
R SiCl(OR )
2
+ R SiCl(OR )(OR ) + R SiCl(OR )
2
+ 3 R OH
1
0
7
9
10
7
8
9
→
2
R Si(OR ) (OR ) + R Si(OR )(OR )(OR )
1
0
8
9
+
2
R Si(OR ) (OR )
(15)
1
0
7
8
9
To separate the target compound R Si(OR )(OR )(OR )
from R Si(OR )
1
0
7
9
10
8
9
2 2
(OR ) and R Si(OR ) (OR ) by distillation, it is
effective to enlarge the difference of the molecular weights
7
8
between R and R . Methyl group and n-octyl group were
7
8
chosen as R and R , respectively. Iso-propyl group was chosen
9
for R because of its stability against hydrolysis. Vinyl group was
1
0
chosen as R because of its utility for chemical modification
such as hydrosilylation, thiol-ene reaction and olefin metathesis.
2
9
Figure 7. Si NMR spectra of (a) the reaction mixture of CH
2 3
=CHSiCl ,
CH =CHSi(OMe) and CH =CHSi(OC (1 mol% BiCl , after 24 h), (b) after
2
3
2
8
H
)
17 3
3
Trichlorovinylsilane,
octoxyvinylsilane were reacted in the presence of BiCl
Figure 7(a) shows the Si NMR spectrum of the crude sample
after 24 h of the reaction. Three signals were observed at −39.9
ppm, −41.5 ppm and −43.2 ppm, and these can be ascribed to
trimethoxyvinylsilane
and
tri-n-
(1 mol%).
subsequent alkoxylation with 2-propanol, and (c) final product obtained by
distillation.
3
2
9
alkoxysilanes. It should be noted that the method is not so
efficient in terms of yield (ca. 50%) because a half of product
should be by-products. In addition, the product would be a
mixture of two enentiomers. When optical resolution is
accomplished in our future work, the obtained chiral compound
will be useful as a precursor of new siloxane-based materials.
Racemization may occur during substitution reactions such as
hydrolysis in a liquid-phase because of the formation of a penta-
coordinated intermediate; however, it is expected that the
chirality is reflected in the structure and/or morphology of the
products by employing solid-phase reactions. Even though there
are such limitations, the preparation of various unique
alkoxysilanes described in this section will be further developed
if the difference of the reactivities among primary different alkoxy
groups in functional group exchange reaction is clarified in more
detail.
CH
CH
2
=CHSiCl(OMe)
2
,
CH
, respectively. The starting compounds,
trimethoxyvinylsilane and tri-n-
2
=CHSiCl(OMe)(OC
8
H
17
)
and
2
=CHSiCl(OC H )
8
17 2
trichlorovinylsilane,
octoxyvinylsilane (−3.1 ppm, −55.2 ppm and −58.5 ppm,
respectively) were not detected. After the addition of pyridine
and 2-propanol, three signals appear at higher magnetic field
than those before the addition (Figure 7(b); −57.4 ppm, −58.5
ppm and −59.7 ppm). These should correspond to
CH
CH
2
=CHSi(OMe)
=CHSi(OiPr)(OC
2
(OiPr), CH
2 8 17
=CHSi(OMe)(OiPr)(OC H ) and
2
9
2
8
17 2
H )
, respectively. The Si NMR spectrum
(
Figure 7(c)) of the product isolated by vacuum distillation shows
1
three signals at −56.2 ppm, −58.5 ppm and −60.8 ppm. The H
NMR spectrum (Figure S15 in SI) confirmed that this product
contained equal amounts of −CH=CH
OC 17 groups. Furthermore, CH =CHSi(OMe)(OiPr)(OC
was observed by HRMS (found: m/z = 297.1856 for [M+Na] ,
8 17
calcd: 297.1856), indicating that CH =CHSi(OMe)(OiPr)(OC H )
2
, −OMe, −OiPr and
−
8
H
2
8 17
H )
+
2
2
9
was successfully synthesized. It is reasonable that the main Si Conclusions
signal at −58.5 ppm (Figure 7(c)) is assigned to
CH
2
=CHSi(OMe)(OiPr)(OC
8
H
17). Because the functional group
The functional group exchange reactions between alkoxysilanes
and chlorosilanes to form alkoxychlorosilanes have been studied
exchange reaction would not exhibit enentioselectivity, the
product is a mixture of two enentiomers. The other small signals
using various precursors under different conditions. BiCl acts as
3
(
−56.2 ppm and −60.8 ppm) may be formed through
transesterification between CH =CHSi(OMe)(OiPr)(OC
heating during distillation (Eq. 16 shows an example for
an efficient Lewis acid catalyst for this reaction. The reaction is
2
8
H17) by
strongly governed by the types of chlorosilanes and
alkoxysilanes used as the precursors. The higher reactivities are
found for chlorosilanes having smaller numbers of electron-
1
0
7
8
9
transesterification of R Si(OR )(OR )(OR ).
3
donating substituents (i.e., Si–CH ) and for alkoxysilanes having
larger numbers of electron-donating substituents (i.e., Si–CH3).
By choosing suitable precursors in terms of reactivity, the
1
0
7
8
9
2
R Si(OR )(OR )(OR )
10
7
8
10
8
9
→
R Si(OR )
2
(OR ) + R Si(OR )(OR )
2
(16)
compositions of alkoxysilanes, including
a four different
We succeeded in synthesizing a four different substituted
organoalkoxysilanes by using functional group exchange
substituted organotrialkoxysilane, formed by functional group
exchange reactions are successfully controlled. The synthetic
methodology of four different substituted organotrialkoxysilanes
has a potential for controlled preparation of siloxane-based
nanomaterials by stepwise reaction of different alkoxy groups.
[
37]
reaction. Compared with a previous method,
simple alkyl
alkoxy groups can be used in the method reported here;
therefore it is more advantageous for the synthesis of
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
The synthetic methodology reported here should expands the
synthetic fields of not only the organosilicon compounds but also
extended siloxane-based nanomaterials.
numbers of alkoxy groups were calculated from the relative intensity
1
29
ratios of H NMR signals of the alkoxy groups. Si NMR was also
1
employed for the quantitative analysis when the H NMR signals are
4
overlapped and for the compounds having no alkoxy group (e.g., SiCl ).
The conversion of each reaction was calculated from the proportion of
residual alkoxysilane/chlorosilane precursors. The selectivity was
calculated from the proportion of the target product formed by the
reaction. HRMS analysis (Electrospray ionization) was conducted by
using a JEOL JMS-T100 CS instrument. Sample was dissolved in
methanol.
Experimental Section
Materials
Bismuth (III) chloride (BiCl
Chemical Co. Inc. Aluminum chloride (AlCl
3
>
98.0%) was purchased from Kanto
98.0%), pyridine
99.5%), 2-propanol (super dehydrated,
CHOH > 99.7%), toluene (dehydrated, C CH > 99.5%), were
3
>
(
(
dehydrated,
C)
5 5
C H N
>
Acknowledgements
H
3
2
6
H
5
3
purchased from Wako Pure Chemical Industries, Ltd. and used as
received. The authentic samples of octamethylcyclotetrasiloxane
The authors are grateful to Dr. Fujio Yagihashi (Interdisciplinary
Research Center for Catalytic Chemistry, AIST) for providing
(
(Me
provided from Shin-Etsu Chemical Co., Ltd. Tetrachlorosilane (SiCl
8.0%), tetraethoxysilane (Si(OEt) 96.0%), trichloro(methyl)silane
MeSiCl 98.0%), triethoxymethylsilane (MeSi(OEt) 98.0%,
dichlorodimethylsilane (Me SiCl 98.0%), diethoxydimethylsilane
Me Si(OEt) 98.0%), chlorotrimethylsilane (Me
trimethylethoxysilane (Me SiOEt
dodecamethylcyclohexasiloxane ((Me SiO)
tert-butoxide (KOC(CH > 97.0%), trichlorovinylsilane (CH
8.0%), and trimethoxyvinylsilane (CH =CHSi(OMe) > 98.0%) were
purchased from Tokyo Chemical Industry Co., Ltd. and used as received.
Di-iso-propoxydimethylsilane (Me Si(OiPr) ), di-tert-butoxydimethylsilane
Me Si(OtBu) ) and tri-n-octoxyvinylsilane (CH =CHSi(OC were
synthesized as described in SI.
2 4 2 5
SiO)4, D ) and decamethylcyclopentasiloxane ((Me SiO)5, D ) were
4
>
4 5
authentic samples of cyclic oligosiloxanes (D and D ). They are
9
4
>
also grateful to Dr. Ryutaro Wakabayashi (Waseda Univ.) for
helpful discussion. This work was supported by the
(
3
>
3
>
2
2
>
"
Development of Innovative Catalytic Processes for
(
2
2
>
3
SiCl
>
98.0%),
98.0%),
Organosilicon Functional Materials" project (PL: K. Sato) from
the New Energy and Industrial Technology Development
Organization (NEDO).
3
>
2
6
, D
6
, > 98.0%), potassium
3
=CHSiCl >
3
)
3
2
9
2
3
Keywords: alkoxysilane • chlorosilane • Lewis acid • exchange
reaction • selective synthesis
2
2
(
2
2
2
8 17 3
H ) )
[
[
[
1]
2]
3]
P. G. M. Wuts, T. W. Greene, Greene's Protective Groups in Organic
Synthesis, Wiley, 2006, pp. 406-410.
Functional group exchange reactions of alkoxysilanes and
chlorosilanes
E. F. Vansant, P. Voort, K. C. Vrancken, Characterization and Chemical
Modification of the Silica Surface, Elsevier, 1995, pp. 149-298.
C. J. Brinker, G. W. Scherer, Sol-gel Science: The Physics and
Chemistry of Sol-gel Processing, Academic Press, 1990, pp. 108-216.
P. H. Mutin, A. Vioux, Chem. Mater. 2009, 21, 582-596.
All reactions were performed in
atmosphere without using any solvents. AlCl
reduced pressure at room temperature before the reaction. The mixtures
of chlorosilanes, alkoxysilanes and catalyst (mainly BiCl ) were stirred at
a
Schlenk flask under nitrogen
3
and BiCl were dried under
3
[
[
[
4]
5]
6]
R. Wakabayashi, K. Kuroda, ChemPlusChem 2013, 78, 764-774.
K. Kuroda, A. Shimojima, K. Kawahara, R. Wakabayashi, Y. Tamura, Y.
Asakura, M. Kitahara, Chem. Mater. 2014, 26, 211-220.
3
1
29
room temperature and were analyzed by H and Si NMR after a certain
periods of time.
[
[
[
7]
8]
9]
D. Mochizuki, A. Shimojima, T. Imagawa, K. Kuroda, J. Am. Chem. Soc.
2
005, 127, 7183-7191.
Y. Hagiwara, A. Shimojima, K. Kuroda, Chem. Mater. 2008, 20, 1147-
153.
Synthesis of four different substituted organotrialkoxysilane using
organoalkoxychlorosilane as an intermediate
1
Y. Fujimoto, A. Shimojima, K. Kuroda, Chem. Mater. 2003, 15, 4768-
BiCl
Schlenk
CH =CHSi(O(CH
3
was dried under reduced pressure at room temperature in a
flask, and CH =CHSiCl CH =CHSi(OMe) and
CH were added to the flask. After stirring the
4774.
2
3
,
2
3
[10] J. Suzuki, A. Shimojima, Y. Fujimoto, K. Kuroda, Chem. Eur. J. 2008,
2
2
)
7
3
)
3
14, 973-980.
mixture for 24 h at room temperature, dehydrated toluene, an excess of
dehydrated pyridine and 2-propanol were added, and the mixture was
stirred for 1 h at room temperature. Pyridine hydrochloride was removed
by vacuum filtration, and residual pyridine, 2-propanol and
[11] R. J. P. Corriu, J. J. E. Moreau, P. Thepot, M. W. C. Man, Chem. Mater.
1992, 4, 1217-1224.
[12] K. J. Shea, D. A. Loy, O. Webster, J. Am. Chem. Soc. 1992, 114, 6700-
6710.
CH
2
=CHSi(OMe)
2
(OiPr) were evaporated. Then, colorless clear liquid
[13] D. F. Peppard, W. G. Brown, W. C. Johnson, J. Am. Chem. Soc. 1946,
68, 70-72.
was obtained by vacuum distillation.
[
[
14] M. Kumada, K. Tarama, J. Soc. Chem. Ind. Japan 1951, 54, 213-215.
15] J. Beckmann, D. Dakternieks, A. Duthie, M. L. Larchin, E. R. T. Tiekink,
Appl. Organomet. Chem. 2003, 17, 52-62.
Characterization
1
13
29
[16] R. Wakabayashi, Y. Sugiura, T. Shibue, K. Kuroda, Angew. Chem. Int.
Ed. 2011, 50, 10708-10711.
Liquid-state H, C and Si NMR spectra were recorded on a Bruker
Avance 500 spectrometer with resonance frequencies of 500.13, 125.76,
[
17] T. F. M. Yoshikiyo, H. Sato, T. Machida, H. Ikeuchi, T. Yano, Y. Tanaka,
Japan Patent 2006-83187, 2006.
3
and 99.36 MHz, respectively. The samples, CDCl and tetramethylsilane
were put into 5mmφ glass tubes. For Si NMR measurements, a small
29
[
18] R. G. Mirskov, V. I. Rakhlin, S. N. Adamovich, M. G. Voronkov, Dokl.
Chem. 2008, 421, 194-196.
amount of chromium (III) acetylacetonate was also added to promote the
2
9
relaxation of Si nuclei, and 64 scans were accumulated with a recycle
delay of 10 s. The proportions of alkoxychlorosilanes with different
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
[
19] J. Ohshita, R. Taketsugu, Y. Nakahara, A. Kunai, J. Organomet. Chem.
004, 689, 3258-3264.
between 1 equiv. H
2
O and excess of SiCl
4 2 4 3
. (H O + SiCl → SiCl (OH) +
2
HCl, SiCl (OH) + SiCl
3
4
→ Cl SiOSiCl + HCl)
3
3
[
[
20] S. Varaprath, D. H. Stutts, J. Organomet. Chem. 2007, 692, 1892-1897.
21] V. V. Kazakova, O. B. Gorbatsevich, S. A. Skvortsova, N. V.
Demchenko, A. M. Muzafarov, Russ. Chem. Bull. 2005, 54, 1350-1351.
22] J. R. Van Wazer, S. Norval, Inorg. Chem. 1965, 4, 1294-1297.
23] V. M. Kopylov, I. S. Shragin, T. I. Rybkina, A. I. Chernyshev, M. I.
Shkolnik, E. N. Ukhina, Zh. Obshch. Khim. 1984, 54, 359-366.
[29] L. Z. Miller, J. L. Steinbacher, T. I. Houjeiry, A. R. Longstreet, K. L.
Woodberry, B. F. Gupton, B. Chen, R. Clark, D. T. McQuade, J. Flow
Chem. 2012, 2, 92-102.
[
[
[30] E. Liepiņš, I. Zicmane, E. Lukevics, J. Organomet. Chem. 1986, 306,
167-182.
[31] L. Bourget, P. H. Mutin, A. Vioux, J. M. Frances, J. Polym. Sci., Part A:
Polym. Chem. 1998, 36, 2415-2425.
[
24] E. A. Chernyshev, E. N. Lebedev, S. I. Kleshchevnikova, N. G.
Komalenkova, V. G. Bykovchenko, A. A. Tagachenkov, Zh. Obshch.
Khim. 1995, 65, 1142-1144.
[32] D. J. Burton, R. K. Harris, K. Dodgson, C. J. Pellow, J. A. Semlyen,
Polym. Commun. 1983, 24, 278-281.
[
[
25] Y. Miyashita, A. Tsukamoto, S. Asai, Japan Patent, 5-310751, 1993.
26] S. Sakamoto, A. Shimojima, K. Miyasaka, J. Ruan, O. Terasaki, K.
Kuroda, J. Am. Chem. Soc. 2009, 131, 9634-9635.
[33] N. Inamoto, S. Masuda, Chem. Lett. 1982, 11, 1003-1006.
[34] A. Decken, J. Passmore, X. Wang, Angew. Chem. Int. Ed. 2006, 45,
2773-2777.
[
[
27] R. Wakabayashi, K. Kawahara, K. Kuroda, Angew. Chem. Int. Ed. 2010,
[35] R. J. P. Corriu, D. Leclercq, P. H. Mutin, H. Samson, A. Vioux, J.
Organomet. Chem. 1994, 466, 43-50.
4
9, 5273-5277.
28] HCl (0.5 mol%) was generated by the reaction between SiCl
mol% of H O because 2 equiv. HCl is generated by the reaction
4
and 0.25
[36] K. Iyoki, A. Sugawara-Narutaki, A. Shimojima, T. Okubo, J. Mater.
Chem. A 2013, 1, 671-676.
2
[37] R. P. Clausen, M. Bols, J. Org. Chem. 1997, 62, 4457-4464.
This article is protected by copyright. All rights reserved

Chemistry - An Asian Journal
10.1002/asia.201601120
FULL PAPER
Entry for the Table of Contents
Layout 1:
FULL PAPER
Selective synthesis of
Yuma Komata, Masashi Yoshikawa,
alkoxychlorosilanes: A series of
Yasuhiro Tamura, Hiroaki Wada, Atsushi
Shimojima and Kazuyuki Kuroda*
alkoxychlorosilanes, SiCl
n
(OEt)4-n (n:
1-3), were selectively synthesized by
functional group exchange reaction.
Additionally, a four different
substituted organotrialkoxysilane was
successfully synthesized.
Page No. – Page No.
Selective Formation of
Alkoxychlorosilanes and Four
Different Substituted
Organotrialkoxysilane by
Intermolecular Exchange Reaction
This article is protected by copyright. All rights reserved