Oxidation by heterogeneous and homogeneous electron transfer of N-amidoimidates: mechanistic investigation

Anodic oxidation of N-amidoimidates 1 was investigated in acetonitrile at a platinum electrode by means of cyclic voltammetry at low and high scan rates. The electron transfer at the electrode or in solution by homogeneous redox catalysis using organic catalysts yielded the cation radical, which decays by deprotonation of the NH bond to give a radical. The rate of deprotonation kH and the standard oxidation potential of the N-amidoimidate cation radical/N-amidoimidate couple were derived from both techniques. The agreement of the predicted kinetics with the experiment data both under homogeneous and heterogeneous electron transfer conditions provides further support for the ECE mechanism.