Anodic Oxidation of Radicals

Radicals generated by oxidation of anions can be further oxidized to carbocations. The selectivity of the radical reaction compared with carbocation reaction is determined by the rate of the radical reaction and the rate of the radical oxidation, the latter being related to the oxidation potential of the radical [136]. 

Oxidation potentials for radicals have been determined by photomodulation voltammetry to be in the range of -1.03 V (vs see) for the A, A -dimethylamino-methylradical, —0.24 V for methoxymethyl, 0.09 V for fbutyl, 0.35 V for diphe-nylmethyl, 0.73 V for benzyl, 0.99 V for ethyl and 2.49 V for methyl [137]. In anodic addition of anions to double bonds it has been found that, depending on the oxidation potential of the adduct radical, either radical- or carbocation-derived products are obtained (Section 2.6.3.4). 

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