Synthesis, characterization and crystal structure of a dioxomolybdenum(VI) complex with a N,O type bidentate Schiff base ligand as a catalyst for homogeneous oxidation of olefins

The synthesis of a Mo(VI) Schiff base complex, cis-[MoO2{(4,6-bis(tert-butyl}-2-{(benzyl)iminomethyl}phenolate)(2)}], cis-[MoO2(L)(2)] where L = 4,6-bis(tert-butyl)-2-[(benzyl)iminomethyl)phenol, derived from benzylamine and 3,5-di-tert-butylsalyciialdehyde is reported. Full characterization of this complex was accomplished with elemental analyses, spectroscopic studies (NMR. IR and electronic) and X-ray structure analysis. This complex was tested as a catalyst for the homogeneous oxidation of olefins. The Mo(VI) complex is catalytically active for the epoxidation of aliphatic substrates at 80 degrees C, yielding the epoxide as the sole product in yields up to 100% and turnover numbers up to 5000. Under the optimized conditions styrene was oxidized in an 81% conversion to produce styrene oxide, benzaldehyde, and acetophenone. (C) 2009 Elsevier Ltd. All rights reserved.