Alcohol Oxidation Assisted by Molybdenum Hydrazonato Catalysts Employing Hydroperoxide Oxidants

Molybdenum(VI) catalysts were obtained from methanol or acetonitrile by the reaction of [MoO2(C5H7O2)(2)] and isonicotinoyl- or nicotinoyl-based aroylhydrazones. Reactions in methanol resulted in the formation of the mononuclear complexes [MoO2(L1-4)(MeOH)] (1a-4a), while the ones in acetonitrile provided polynuclear complexes [MoO2(L1-4)](n) (1-4)(.) Crystals of polynuclear compound, [MoO2(L-3)](n)center dot H2O (3 center dot H2O), suitable for X-ray diffraction analysis were obtained by the solvothermal procedure at 110 degrees C. Complexes were characterized by infrared spectroscopy (IR-ATR), nuclear magnetic resonance (NMR), elemental analysis (EA), and thermogravimetric analysis (TGA). The prepared catalysts were tested in alcohol oxidation reactions. Carveol, cyclohexanol, and butan-2-ol were investigated substrates. Because the alcohol oxidations are very challenging due to various possible pathways, the idea was to test different oxidants, H2O2, TBHP in water and decane, to optimize the researched catalytic system.

Automated summary

Molybdenum(VI) catalysts were prepared through reactions in methanol or acetonitrile, resulting in different structures of complexes. The polynuclear compound was characterized by X-ray diffraction analysis, and the catalytic performance in alcohol oxidation reactions was evaluated for carveol, cyclohexanol, and butan-2-ol.