ELECTROPHILIC ADDITION TO STYRYLSILANES - SEQUENTIAL CARBON-CARBON BOND-FORMING REACTIONS

The replacement of the usual electron donating alkyl groups on silicon , with electronegative chloride ligands, changes the mechanism and out come of the reaction of (E)-beta-(dichlorobenzylsilyl)styrene with pro ton and carbon electrophiles. Electrophilic addition rather than the u sual substitution occurs, so that the silicon remains intact to mediat e further chemical reactions. The experimental results show that Fried el-Crafts reactions of the silylated alkene are subject to the same li mitations observed for non-silylated alkenes; the extent of polymeriza tion increases as the stability of the carbenium ion decreases.