Palladium(II) Acetate Mediated Dimerization/Cycloisomerization of 2-Sulfonyl-4-alkynones: Synthesis of trans-1,2-Difurylethylenes

Abstract

This paper describes a one-pot, atom-economic, easy-operation, open-atmosphere method for the synthesis of trans-1,2-difuryl­ethylenes by the straightforward Pd(OAc)2-mediated dimerization/cycloisomerization of 2-sulfonyl-4-alkynones in the presence of Na2CO3 and PPh3 under refluxing EtOH conditions, and proposes and discusses a plausible mechanism. This protocol provides a highly effective annulation via two carbon–oxygen (C–O) single-bond and one carbon–carbon (C=C) double-bond formations.