Аннотация:Silicon hydride dehydrocondensation reaction is widely used in fine organic and organosilicon synthesis, for example, to obtain symmetric hexaorganodisiloxanes, highly thermal-, frost-, radiation-, and chemically resistant linear or branched oligo- and polymeric siloxane fluids, polyorganosiloxane resins of a ladder or cubic structure. Moreover, this reaction is of great theoretical importance for the chemistry of organosilicon compounds in general, and also constitutes the basis for understanding the mechanism of nucleophilic substitution at silicon.
The catalytic activity of various platinum complexes in dehydrocondensation reactions of R’3SiH (where R’-ethyl, R’–methyl, phenyl) with alcohols was previously noticed.
We prepared triorganoalkoxysilanes of general formula R1nR2(3-n)SiOR3, where R1–CH3, R2–C6H5, R3–CH3, C2H5, C3H7, C4H9, n=0÷2 with the yield of 97%, as a minimum, through dehydrocondensation of individual triorganosilanes in the form of R1nR2(3-n)SiH. The reaction was carried out with a stoichiometric amount of a monohydroxy alcohol in the presence of a Spier catalyst (solution of H2PtCl6•6H2O in isopropyl alcohol).
The degree of the reaction completion and the composition of the dehydrocondensation products were monitored by 1H and 29Si NMR spectroscopy, and GLC.