Nitroxide chemistry. Part V. Reactions between bistrifluoromethyl nitroxide and alkylbenzenes; mechanism of formation of carbonyl compounds

The reaction sequence ArCH3 [graphics omitted] XH + ArCH2X [graphics omitted] XH, ArCHX2, (CF3)2NX, ArCOX[Ar = Ph, p-ClC6H4, C6F5; X =(CF3)2N·O] has been established, and evidence adduced for the formation of aldehydes, ArCHO, as precursors of the carbonyl compounds ArCOX. The compounds PhCH2X, PhCHX2, and PhCX3 have been synthesised by treatment of benzyl bromide, benzylidene dichloride, and benzylidyne trichloride, respectively, with the mercurial HgX2[X =(CF3)2N·O]; the first of these undergoes C–O bond cleavage when heated with hydrobromic or hydriodic acid, with liberation of the hydroxylamine (CF3)2N·OH; the last decomposes thermally into PhCO2N-(CF3)2 and two compounds believed to be isomers of (CF3)2N·C6H4·CO2·N(CF3)2.