Iodine-promoted cyclization of N-propynyl amides and N-allyl amides via sulfonylation and sulfenylation

Abstract

An iodine-promoted regioselective cyclization of N-propynyl/allyl amides with sulfonyl hydrazides has been developed for the synthesis of 5-methyl-arylsulfonyloxazoles and 5-methyl-arylthiooxazolines via sulfonylation and sulfenylation reactions. The notable features of this reaction are the formation of new C–S and C–O bonds, the broad functional group tolerance, and its applicability to alkyl sulfonyl hydrazides as well as internal alkynes.