Energy-transfer-enabled visible-light photocatalytic sulfamidation of aryl halides

This paper discloses the visible-light-driven C-N cross-coupling between aryl halides and sulfonamides to give N-(hetero)aryl sulfonamides employing a novel dual catalytic system of nickel ion and arylketone. Inexpensive energy-transfer photocatalyst thioxanthen-9-one dramatically accelerated this reaction, providing a diverse range of products in good yields under mild conditions. This reaction demonstrated excellent functional group tolerance, was applicable to the synthesis of drug-like molecules, and could be performed on a gram scale. The mechanism involves the oxidative addition of an aryl halide to Ni(0) catalyst, transmetallation of the resulting aryl-Ni(II) halide complex, energy transfer from photoexcited thioxanthen-9-one to an aryl-Ni(II)-amido intermediate, and subsequent reductive elimination to afford N-(hetero)aryl sulfonamides.