Oxidative deamination of benzylamine by electrogenerated quinonoid systemsas mimics of amine oxidoreductases cofactors

The reactions of a new type of quinonoid system with benzylamine have been investigated in methanol in order to mimic the reactions occurring in the c ourse of the enzymatic oxidation of amines by quinone cofactors. Under stri ctly anaerobic conditions, unstable quinonoid species 1(ox)-4(ox) have been selectively electrogenerated using anodic-controlled potential electrolysi s. Thus, we have demonstrated that 3,4-quinone 1(ox) is incapable of deamin ating benzylamine, while 3,4-iminoquinone species 3(ox) and 4(ox) act as ef ficient catalysts for the autorecycling oxidation of benzylamine: the react ion efficiency reached 64 turnovers. Additional mechanistic investigations reveal that the oxidation of benzylamine by our quinonoid model cofactors p roceeds unambiguously via a transamination mechanism, as suggested for many enzymatic systems.