Palladium-catalyzed furylation and thienylation of activated alkenes with 2-furoyl chloride and 2-thenoyl chloride

2-Furoyl or 2-thenoyl chlorides readily react with activated alkenes in the presence of a tertiary amine and a catalytic amount of palladium(II) acetate to give 2-furylated or 2-thienylated alkenes. Under similar conditions, 2-benzofuroyl chloride undergoes facile alkenylation to produce 2-alkenylated benzofurans. The reaction involves a highly efficient decarbonylation of furoyl or thenoyl-palladium species.