MULTIPLE REACTION PATHWAYS FOR THE OXIDATION OF 2,6-DIPHENYLPHENOLATES

Electrochemical oxidation of several 4-substituted-2,6-diphenylphenolates was studied in acetonitrile by different electrochemical methods. A variety of mechanisms are operative in this series of compounds: 2,6-diphenylphenolate (1(-)) is irreversibly oxidized to a dimer and then to diphenoquinone; 4-nitro-2,6-diphenylphenolate (2(-)) is reversibly oxidized to a dimer which gives rise to 2,6-diphenylbenzoquinone; a disproportionation of the 4-amino-2,6-diphenylphenoxyl radical (3') obtained upon oxidation of the corresponding phenolate 3(-) leads to the formation of the 2,6-diphenylquinoneimine; the 2,4,6-triphenylphenolate (4(-)) undergoes a reversible dimerization.