A Highly Regioselective Reaction of Allylic Acetates with Silylated Carbon Nucleophiles Directed by a Sulfenyl Group. Scope, Limitation, and Mechanistic Aspects

Abstract α-(Sulfenylmethyl)allyl acetates reacted with silylated carbon nucleophiles in the presence of a catalytic amount of TMSOTf to give products substituted at the α-position of the sulfenylmethyl group in moderate to good yields with high regioselectivity. The theoretical calculation on an intermediate cationic species indicated that an episulfonium ion was a stable form; the observed regioselectivity was rationalized qualitatively on the basis of the coefficients of LUMO of the cation. Some transformations of the products were also demonstrated.