Palladium-Catalyzed Thiocarbonylative Synthesis of α,β-Unsaturated Thioesters Using S-Aryl Thioformates as the Thioester Sources

A palladium-catalyzed thiocarbonylation reaction for the synthesis of α,β-unsaturated thioesters from vinyl triflates with S-aryl thioformates as the thioester sources has been developed. The reaction proceeded smoothly at low temperature, and a variety of α,β-unsaturated thioesters were produced in moderate to high yields with very good functional group tolerance. This protocol features mild reaction conditions, good substrate scope, and avoids the use of toxic CO gas or odorous thiols, which made it a worthy addition to α,β-unsaturated thioester synthesis via a thioester transfer process.