Reactions of heteroarylhydrosilanes with dichlorocarbene under phase-transfer conditions

Article abstract of DOI:10.1016/0022-328X(88)80230-4

The reactions of dimethyl(2-thienyl)-, methyl-, tri(2-thienyl)- and dimethyl(2-furyl)silanes (I-IV, respectively) with dichlorocarbene generated from sodium trichloroacetate under solid-liquid phase-transfer conditions afford the corresponding dichloromethylsilanes in 38-66percent yield.The reactivity of the thienylsilanes decreases with the number of electron-accepting thienyl substituents at the silicon atom.Using the competition reactions, the relative rate constants for the reaction of dichlorocarbene insertion into the Si-H bond of thienyl- and furyl-silanes (I and IV) were measured.The reactivity of these silanes was found to be greater than had been expected taking as a basis the Taft ?^* constants for the substituent at the silicon atom.This is apparently due to the existence of a p_?-d_? interaction between the heterocyclic ?-system and the d-orbitals of silicon.