Visible-Light-Induced Carbonylative Synthesis of Aliphatic Thioesters

This study presents a visible-light-induced metal-free catalytic carbonylation method for the synthesis of alkyl thioesters. Utilizing Hantzsch esters as alkyl radical precursors, the method selectively captures aryl sulfonates from thiosulfonates via acyl radical intermediates in the presence of carbon monoxide, efficiently constructing alkyl thioesters. The reaction system is characterized by its mildness, which leads to the production of a range of thioester products in high yields with excellent functional group tolerance. Thiosulfonates, classified as bifunctional reagents, serve a dual role in this process. First, they function as a source of sulfur. Second, the arylsulfonyl radicals generate act as endogenous oxidants, thereby maintaining the reaction cycle.