Vanadium(IV) complexes bearing 3-hydroxypicolinic acid (H2hpic) as ligands, VO(Hhpic)2 (1) and the cyclic tetramer (VO)4(hpic)4 (2), have excellent catalytic ability for the oxidation of a variety of primary and secondary benzyl alcohols with molecular oxygen in acetonitrile or protic solvents such as ethanol and water, affording the corresponding aldehydes and ketones, respectively. Construction of multi-nuclear complexes by the selection of ligands attains higher turnover numbers and recycling of the catalyst.
