Molybdenum oxide/bipyridine hybrid material {[MoO3(bipy)][MoO3(H2O)]}n as catalyst for the oxidation of secondary amines to nitrones

The inorganic–organic hybrid material {[MoO3(bipy)][MoO3(H2O)]}n (bipy = 2,2′-bipyridine) can be used as a water-tolerant catalyst for the oxidation of secondary amines under mild conditions using either urea hydrogen peroxide (UHP) or tert-butylhydroperoxide (TBHP) as the oxidant. Under optimized reaction conditions (2 mol % catalyst, 3–4 equiv TBHP, CH2Cl2 as the solvent, 40 °C), the corresponding nitrones were obtained with different efficiency depending on the nature of the cyclic or acyclic amine used.