Neighbouring group participation by the vinyl group in reactions of sterically-hindered organosilicon compounds

Abstract

Anchimeric assistance by the γ-vinyl group makes (Me₃Si)₂C(SiMe₂CHCH₂)(SiMe₂I) much more reactive than (Me₃Si)₃CSiMe₂I towards CF₃CH₂OH, CF₃CH₂H, and silver salts, and treatment of (Me₃Si)₂C(SiMe₂CHCH₂)(SiEt₂I) with AgO₂CCF₃ or AgBF₄ gives mixtures of (Me₃Si)₂C(SiMe₂CHCH₂)(SiEt₂Y) and (Me₃Si)₂C(SiEt₂CHCH₂)(SiMe₂Y)(Y = O₂CCF₃ or F); these reactions appear to involve 1,3-vinyl-bridged silicocationic intermediates.