A palladium-catalyzed cross-electrophile coupling reaction involving sulfur dioxide for the direct synthesis of diversely functionalized sulfones

Abstract

A palladium catalyzed multicomponent cross-electrophile coupling involving sulfur dioxide under metal-reductant free conditions is presented here. Both aryl-alkyl and alkyl-alkyl sulfones could be successfully achieved. This protocol features mild reaction conditions, wide substrate scope, good functional group tolerance and excellent regioselectivity. Preliminary mechanistic studies reveal that two Pd catalytic cycles are involved and SO₂ exclusively couples with aryl iodides rather than allylic acetates, which are consistent with the DFT studies.