Metal-free synthesis of sulfonamides via iodine-catalyzed oxidative coupling of sulfonyl hydrazides and amines

A novel, rapid, and environmentally-friendly protocol for the synthesis of sulfonamides using iodine as catalyst under solvent-free conditions is described. This method involves the oxidative coupling of sulfonyl hydrazides and amines in the presence of catalytic amount of iodine using TBHP as oxidant. This protocol does not require purification techniques such as column chromatography and recrystalization.