Reductive cleavage of an SiCl3 group by amine hydrochlorides and base

A new procedure has been developed for removing the SiCl₃ group from α-trichlorosilyl-substituted amines. In this procedure the trichlorosilyl substrate is treated first with amine hydrochloride in CH₃CN, followed by hydrolysis with aqueous hydroxide. Using this sequence, amines corresponding to replacement of the trichlorosilyl group with hydrogen can be conveniently isolated in good yields for all tested cases. Evidence suggests the intermediacy of an unstable chlorosilane species formed by probable nucleophilic attack of chloride. In conjunction with the addition reaction fo HSiCl₃ to enamines to form the α-trichlorisilyl amines, the cleavage completes a new method for the transformation of enamines to amines which could be a useful alternative to either catalytic hydrogenation or metal hydride reduction.