Redistribution reactions of alkoxy- and siloxysilanes, catalyzed by dimethyltitanocene

Abstract
Dimethyltitanocene is an excellent catalyst for the redistribution of alkoxy- and siloxyhydrosilanes. The redistribution reactions of triethoxysilane, diethoxymethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, pentamethyldisiloxane, and H—(SiMe2O)n—SiMe2H (n = 1 to 3) are described. The mechanism of these reactions is discussed in terms of TiH mediated displacements. The possibility of both Ti(III) and Ti(IV) mediated displacements are considered and a mechanism involving the former, which fits all of the experimental data, is proposed. Keywords: siloxanes, alkoxysilanes, redistribution, catalysis, dimethyltitanocene.