Palladium-Catalyzed Mono-Selective ortho CH Arylation of Aryl Sulfonamides in Water: A Concise Access to Biaryl Sulfoamide Derivatives

A green atom-economical method for the synthesis of biaryl sulfonamide derivatives via palladium(II)-catalyzed CH bond activation by employing an amino acid moiety as the bidentate directing group has been developed. The protocol proceeded efficiently in water; high yields and broad substrate scope were achieved. The reaction shows good functional group compatibility and proceeds in a highly selective manner at the ortho position of arenes connected to sulfonamide sulfur atoms. This auxiliary can be easily removed either by acidic hydrolysis, or converted into primary biaryl sulfomamides with a 30mol% amount of CuO as catalyst. Mechanistic studies show that the present bidentate directing group is essential for promoting ortho CH bond activation of arenes connected to sulfonamide sulfur atoms.