Decarboxylative (Thio)esterification of α-Keto Acids via Carbonyl-Photoredox/Copper Dual Catalysis

An efficient visible-light-induced copper-catalyzed decarboxylative (thio)esterification of α-keto acids with (thio)phenols has been developed using 2-chloro-thioxanthen-9-one as the photocatalyst and dimethyl sulfoxide (DMSO) as the terminal oxidant and solvent, enabling the efficient synthesis of aryl (thio)benzoates in moderate to excellent yields (66 examples). This operationally simple protocol exhibits excellent tolerance toward various functional groups, has been applied to the synthesis of pharmaceutical/natural product derivatives, and proceeds efficiently on a gram scale.