Electrochemical Oxygen-Atom Transfer to Alkenes and Pyridines with a MnPorphyrin Catalyst Using Water as the Source of Oxygen

Oxygen-atom transfer (OAT) reactions, such as epoxidation, often use stoichiometric high-energy oxygen donors that present safety hazards, especially on large scale. Electrochemistry provides a means to replace these reagents with water as the O-atom donor. Here, we identify an electron-deficient Mn-porphyrin electrocatalyst that enables efficient OAT to alkenes and pyridines to access epoxides and N-oxides. The scope of the reaction includes terminal and electron-deficient alkenes that often prove challenging with other chemical and electrochemical methods. Direct comparisons with two chemical oxidation methods, (i) stoichiometric meta-chloroperoxybenzoic acid and (ii) the same Mn-porphyrin catalyst with PhI(OAc)2 as the oxidant, highlight the merits of the electrochemical reaction. Prospects for scalable application of the method is demonstrated through oxidation of pharmaceutically relevant alkenes in a stirred tank electrochemical reactor.