Hydrosilylation of ortho- and para-substituted 2-phenylpropenes and ortho-, meta-, and para-alkoxysubstituted 3-phenylpropenes with chlorodimethylsilane in the presence of H2PtCI6 was effected. The resulting adducts were reacted with ethyntlmagnesium bromide to synthesize 2- and 3-arylpropyl(ethynyl)silanes.