Iodine-Promoted Radical Cyclization in Water: A Selective Reaction of 1,6-Enynes with Sulfonyl Hydrazides

An iodine-promoted one-pot radical cyclization reaction of 1,6-enynes with sulfonyl hydrazides to provide five-membered and hexatomic ring sulfonylated products under the same conditions is established. This reaction proceeded smoothly in water and gave the corresponding products by using I₂/TBHP instead of expensive and toxic catalysts with C–S and C–I bond formed in one step. This method also allowed easy access to significant functional sulfones for potential applications in medicinal and organic chemistry