A Ru catalyst 1 converts primary amines to nitriles using NaIO₄ in EtOAc/H₂O mixture, whereas imines are obtained under O₂ balloon pressure in toluene. These catalytic reactions illustrate a subtle dependency on the choice of oxidants and solvents in the oxidation of primary amines.

Abstract

The catalytic activity of a Ru complex 1, bearing a fused π-conjugated imidazo[1,2–a][1,8]naphthyridine-based mesoionic carbene (MIC) ligand, is examined for the oxidation of primary amines. Complex 1 affords nitrile or imine depending on the nature of the terminal oxidants and solvents used in the reactions. Primary amines are converted to nitriles using NaIO₄ in EtOAc/H₂O mixture, whereas imines are obtained under O₂ balloon pressure in toluene. A variety of nitriles and imines are accessed with high yields and selectivity. A set of control experiments, reaction profiles, and kinetic studies are undertaken to disclose the mechanistic details for nitrile and imine formation. The catalytic reactions illustrate a subtle dependency on the choice of oxidants and solvents in the oxidation of primary amines.