Phosphonium chloride-catalyzed dehydrochlorinative coupling reactions of alkyl halides with hydridochlorosilanes

Abstract

The dehydrochlorinative Si-C coupling reactions of various primary and secondary alkyl chlorides with hydridochlorosilanes in the presence of tetrabutylphosphonium chloride as catalyst gave the coupling products with elimination of HCl as a gas. Coupling reactions of activated alkyl chlorides such as benzyl chlorides proceeded at 130degreesC, while unactivated organic chlorides such as silylalkyl chlorides and secondary alkyl chlorides required higher reaction temperatures of 150 or 170degreesC and longer reaction times. Primary alkyl chlorides reacted with trichlorosilane (1) to give coupling products in good to excellent yields, but secondary alkyl chlorides reacted at a slower rate and gave lower yields of products. Coupling reactions with methyldichlorosilane instead of 1 proceeded at slower rates and gave lower yields of products.