ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 2, pp. 216 222.
Pleiades Publishing, Ltd., 2008.
Original Russian Text
pp. 236 243.
V.A. Kovyazin, V.V. Boev, V.M. Kopylov, I.B. Sokol’skaya, 2008, published in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 2,
Reaction of Organylalkoxysilanes with Ethanolamine
and Disproportionation of Transetherification Products
V. A. Kovyazin, V. V. Boev, V. M. Kopylov, and I. B. Sokol’skaya
State Research Institute of Chemistry and Technology of Organoelement Compounds,
sh. Entuziastov 38, Moscow, 111123 Russia
e-mail: vlkov@port.ru
Received March 21, 2007
Abstract Transetherification of organylalkoxysilanes with monoethanolamine was carried out. Dispropor-
tionation in mixtures containing organylalkoxysilanes with an amino group in the substituent was studied by
means of NMR spectroscopy. It was shown that the disproportionation rate decreases with increase size of
substituents on the silicon atom. The equilibrium composition of disproportionation products corresponds to
the normal statistical distribution, except for mixtures containing tris(1-methylpropylideneaminooxy)(vinyl)-
silane.
DOI: 10.1134/S1070363208020114
Various methods for preparing organylalkoxysilanes
containing an amino group in the alkoxy radical are
sufficiently well documented [1 6]. These compounds
attract special interest because of the presence of a
highly reactive amino group and a Si O bond in the
alkoxy radical. Voronkov et al. [1, 2] have described
the preparation of (2,2-diorganylaminoethoxy)alkoxy-
silanes. It is known that the reaction involves not only
alkoxy groups, but also Si H and Si Cl bonds. Hence
oligoethylene glycol ethers catalyze disproportionation
of triethoxysilane to tetraethoxysilane and monosilane
[7]. Disproportionation of organyltrichlorosilanes
RSiCl3 (R = Me, CH=CH2, Ph) and tetraethoxysilane,
catalyzed by DMF, has been described [8]. The equi-
librium compositions of disproportionation products
differed significantly from the normal statistical dis-
tribution, which has been explained by different Si Cl
and Si OEt bond energies.
silanes RnSi(OCH2CH2NR1R2)4
by etherification
n
of chlorosilanes with 2,2-diorganylaminoethanols.
Analogous products can be prepared by dehydrocon-
densation of amino alcohols with hydride-containing
alkoxysilanes [2, 3]. The transetherifications of tetra-
ethoxysilane, methyltriethoxysilane, and dimethyldi-
ethoxysilane under the action of amino alcohols, lead-
In the present work we studied the specific features
of transetherification of organylalkoxysilane with
ethanolamine without catalyst, associated with the
possible effect of the amino group, specifically, its
catalytic action on the transetherification process and
rearrangement of intermediate products.
ing to RnSi(OCH2CH2NR1R2)4
(R1 = R2
=
n
H, Me; n = 0, 1, 2; R1 = H, R2 = Me, R = Me [4], as
well as the reactions of triethoxy(vinyl)silane and tri-
ethoxy(phenyl)silane with monoethanolamine and
some other amino alcohols, catalyzed by metallic
sodium and giving R(Si(OCH2CH2NR1R2)3 (R = Vi,
Ph; R1 = R2 = H, Me; R1 = H, R2 = Me) [5], have
been reported. The transetherification of organylal-
koxysilanes under the action of monoethanolamine
and its N,N-dialkyl derivatives, proceeding without
To obtain both partial and complete transetherifica-
tion products, we reacted organylalkoxysilanes with
monoethanolamine at a varied reactant molar ratio.
Complete transetherification is described by the
following equation.
RnSi(OR1)4
+ nHOCH2CH2NH2
n
catalysts and forming R4 nSi(OCH2CH2NR1R2)n (R =
alkyl, aryl; R1 = H, Me, Et, R2 = Me, Et; n = 1 3) has
been described [1]. According to the patent [6], pro-
ducts of partial transetherification of Si(OCH2CH2
NH2)4 with nonanol undergo disproportionation.
I
IV
RnSi(OCH2CH2NH2)4
+ nR1OH,
(1)
n
VI X
R, R1 = Me, n = 1 (I, VI); R = CH = CH2, R1 = Me, n = 1
(II, VII); R1 = Et, n = 0 (III, VIII); R = (CH2)3NH2, R1 =
Et, n = 1 (IV, IX); R = (CH2)3NH(CH2)2NH2, R1 = Me,
n = 1 (V, X).
Disproportionation affects significantly the com-
position of products in the synthesis of organylalkoxy-
216