Palladium‐Catalyzed Cyclization/Thiocarbonylation for the Synthesis of Thioester‐Substituted Benzofurans with S‐Aryl Thioformates as the Thioester Sources

A palladium‐catalyzed cyclization and thiocarbonylation reaction is disclosed for the synthesis of thioester‐containing benzofurans. By using S‐aryl thioformates as efficient and convenient thioester surrogates, a variety of thioester‐functionalized benzofurans were formed in moderate to excellent yields with very good functional group tolerance. This protocol features mild reaction conditions, broad substrate scope, and no manipulation of toxic CO gas and odorous thiols.