Modulating alkene reactivity from oxygenation to halogenation via electrochemical O2 activation by Mn porphyrin

Abstract

Oxidation of organic substrates is achieved in nature under mild conditions thanks to metalloenzymes but remains a challenge for chemists. Herein we show by UV-Vis spectroelectrochemistry that when Mn^IIITPPCl is electrochemically reduced to Mn^II in CH₂Cl₂ under O₂, a Mn^IIO₂˙ species is generated. Benzoic anhydride reacts with the latter triggering a catalytic current in cyclic voltammetry. Electrolysis on the catalytic wave in the presence of cyclooctene leads to its oxygenation or halogenation depending on the axial ligand present as reported here for the first time.