Palladium-Catalyzed\nTrifluoroacetylation of Arylboronic\nAcids Using a Trifluoroacetylation Reagent

A new trifluoroacetylation reagent was developed by using\ninexpensive\nand readily available trifluoroacetic anhydride and <i>N</i>-phenyl-4-methylbenzenesulfonamide for the first time. The reaction\nof (het)aryl boronic acids with the new trifluoroacetylation reagent, <i>N</i>-phenyl-<i>N</i>-tosyltrifluoroacetamide, proceeded\nsmoothly in the presence of a palladium catalyst to provide trifluoromethyl\nketones in satisfactory to excellent yields. Various groups, including\nthe synthetically useful functional groups Cl, TMS, and PhCO, were\ntolerated well under the current reaction conditions. This new trifluoroacetylation\nreagent can be used in the large-scale synthesis of trifluoromethyl\nketones, even at a low palladium catalyst loading.