Palladium-Catalyzed Intramolecular Oxidative Arylations for the Synthesis of Fused Biaryl Sulfones

This study unveils palladium-catalyzed intramolecular oxidative cyclizations in biaryl and heterobiaryl sulfones providing direct access to fused biaryl sulfones (dibenzothiophene-5,5-dioxides). Variously substituted diben-zothiophene-5,5-dioxides could be readily prepared in good to excellent yields under optimized conditions. In addition, bromination afforded dibromo derivative of dibenzothio-phene-5,5-dioxides, providing platform for late-stage diversification. The translational applications of this current protocol have successfully been demonstrated in the synthesis of 2,8-diamino derivative of dibenzothiophene-5,5-dioxides, a alpha(7)-nicotinic acetylcholine receptor agonist analogue, and novel single fluorene-tethered dibenzothiophene-5,5-dioxide, an organic emitter.