AbstractThe first example of benzylic C—H triflylation was accomplished with pyridine as a directing group. The reaction of various 2-benzylpyridines and (CF3SO2)2O in the presence of NEt3 in CH2Cl2 proceeded smoothly to afford the corresponding benzyl triflones in moderate to high yields.

A new approach toward the synthesis of aryl triflones was achieved by the formal insertion of arynes into C–SO2CF3 bonds. This reaction proceeds through addition of CF3SO2-containing nucleophiles to the in situ generated arynes and subsequent intramolecular rearrangement.

An unprecedent reaction of indoline-2,3-diones and (triphenylphosphonio)difluoroacetate (PDFA) afforded novel 3-fluoroalkenyl-3-trifluoromethyl-2-oxindoles in moderate to excellent yields. These products could be transformed into other trifluoromethylated oxindole derivatives.

A tunable chemoselective trifluoromethanesulfonylation and trifluoromethylation of arenediazonium tetrafluoroborates with Langlois’ reagent (NaSO2CF3) was developed. The Cu2O-catalyzed reaction in DMSO gave aryl trifluoromethanesulfones as the major products. On the other hand, the trifluoromethylated arenes were produced in the presence of oxidant tert-butyl hydroperoxide, CuBF4(MeCN)4, and 2,2′;6′,2″-terpyridine (tpy). Both of these transformations proceed under mild conditions and tolerate functional groups.

An unprecedent reaction of indoline-2,3-diones and (triphenylphosphonio)difluoroacetate (PDFA) afforded novel 3-fluoroalkenyl-3-trifluoromethyl-2-oxindoles in moderate to excellent yields. These products could be transformed into other trifluoromethylated oxindole derivatives.