Aromatic and Benzylic C—H Bond Functionalization upon Reaction Between Nitriles and Perfluoroalkyl Sulfoxides.

We studied the thermal behavior of some intermediates formed by reaction of nitriles with perfluoroalkyl sulfoxides upon trifluoromethanesulfonic anhydride activation. Bistriflate ketal 3, precursor of sulfilimine 1, may undergo a rearrangement to sulfanyl nitrile 5 after triflic acid elimination under thermal conditions. With p-tolyl trifluoromethyl sulfoxide, remote triflic acid elimination from intermediate 4 leads to benzamide 8 formation. These reactions involve, respectively, selective functionalization of the aromatic ortho C–H bond or the benzylic C–H bond para to the sulfoxide group. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)