Stereoselective Synthesis of Substituted (Z)-N-Allyl Sulfonamides via a Palladium-Catalyzed Three-Component Tandem Reaction

Abstract

This paper reports the efficient synthesis of substituted (Z)-N-allyl sulfonamides via a palladium-catalyzed threecomponent tandem reaction of N-buta-2,3-dienyl sulfonamides with iodides and sulfonyl hydrazide or sulfinic acid sodium salt as nucleophiles. Pd(PPh 3 ) 4 (2.5 mol %), K 2 CO 3 , and THF were used as the optimal catalyst, base, and solvent, respectively. The substituted (Z)-N-allyl sulfonamides were obtained in a 30−83% overall yield. Mechanistic investigations revealed that the formation of the single (Z)-isomer was controlled by the formation of a six-membered palladacycle intermediate.