A facile stereoselective synthesis of (Z)-α-arylsulfonyl-α,β-unsaturated ketones

Palladium-catalyzed hydrostannylation of acetylenic sulfones 1 in benzene at room temperature gives highly regio- and stereoselectively (E)-α-stannylvinyl sulfones 2 in high yields. (E)-α-Stannylvinyl sulfones 2 are new difunctional group reagents which undergo Stille coupling reactions with acyl chlorides 3 to afford stereoselectively (Z)-α-arylsulfonyl-α,β-unsaturated ketones 4 in good yields. A one-pot stereoselective synthesis of (Z)-α-arylsulfonyl-α,β-unsaturated ketones 4 has also been achieved by tandem hydrostannylation-Stille coupling reaction of acetylenic sulfones 1 under mild conditions.