Investigation of the hydrosilyation of chloroethylenes and their silyl-substituted derivatives by means of NMR spectroscopy

The authors made an attempt to study the reactivity of chlorinated ethylenes in their hydrosilylation and to trace its change as chlorine atoms accumulate and the latter are replaced by various silyl groups. They studied the reactions of 1,2-di-, tri-, and tetra-chloroethylenes and their silyl derivatives of formula Me/sub n/Cl/sub 3-n/SiR (n = 0-3; R = -CH=CHCl, -CH=CCl/sub 2/, -CCl=CCl/sub 2/) with the chlorosilanes Me/sub m/Cl/sub 3-m/SiH (m = 0-3) in the presence of Speier's catalyst under normal conditions. It was found that the hydrosilylation of 1,2-dichloroethylene leads mainly to the corresponding chlorosilanes, while the hydrosilylation products are formed in only small amounts. The replacement of a chlorine atom in 1,2-dichloroethylene by a silyl group considerably activates the molecule in reactions with hydride silanes. An analysis of the /sup 1/H and /sup 13/C NMR spectra showed that the hydrosilylation of (2-chlorovinyl)silanes leads to the formation of the same products as in the hydrosilylation of vinylsilanes and disilylethanes.