A Difluoromethylation Reagent: Access to Difluoromethyl Arenes through Palladium Catalysis.

A new radical difluoromethylation was developed by using inexpensive and readily available difluoroacetic anhydride and N -phenyl-4-methylbenzenesulfonamide for the first time. The reaction of arylboronic acids with the new difluoromethylation reagent, N -phenyl- N -tosyldifluoroacetamide, proceeded smoothly in the presence of palladium catalyst to provide difluoromethylarenes in satisfactory to excellent yields. The electronic property (electron-donating or electron-withdrawing) of the substituent linked to the aromatic ring did not considerably influence the reactivity of arylboronic acid. Various groups, including the synthetically useful functional groups Cl, CN, and NO 2 , were tolerated well under the current reaction conditions.