Palladium-Catalyzed para-Selective Difluoromethylation of Arene Esters.

Highly efficient, palladium-catalyzed, para-selective difluoromethylation of arene esters has been developed using [1,1'-biphenyl]-2-dicyclohexylphosphine as the effective ligand. A wide variety of arene esters bearing various functional groups were all compatible with the reaction conditions, leading to para-difluoromethylated products in moderate to good yields. Moreover, benzoylamide and benzenesulfonamide were also well-tolerated, suggesting that this novel catalyst system has broad applications to a variety of substrates.