Reactivity of bio-inspired Cu(II) (N2/Py2) complexes with peroxide at room temperature

Developing coordination complexes of earth abundant metals that can perform substrate oxidations under benign conditions is an ongoing challenge. Herein, the reactivity of two mononuclear Cu-complexes toward the oxidant H₂O₂ is reported. Both complexes displayed ligand oxidation upon reaction with the oxidant. Analysis of spectroscopic data established that the respective product complexes contained mononuclear Cu(II) centers. Moreover, treatment of these Cu-complexes with oxidant in the presence of substrate resulted in the interception of ligand oxidation with preferential oxidation of the substrate. Computational studies identified plausible mechanistic pathways, suggesting a copper-oxyl intermediate as the likely reactive intermediate responsible for substrate and ligand oxidation. To our knowledge, this is the first Cu-mediated system that showed ligand oxidation, oxo-transfer capability, and external hydrocarbon oxidation under stoichiometric conditions.