Synthesis, characterization and catalytic activity in the oxidation of sulfides and styrene of vanadium(V) complexes with tridentate Schiff base ligands

A series of vanadium(V) complexes with chiral tridentate Schiff base ligands, obtained by a single condensation of R(-)-1-amino-2-propanol with salicylaldehyde and its derivatives, were prepared. The complexes were characterized by elemental analysis and by their IR, CD, UV-Vis, 1D (H-1, V-51) and 2D (COSY, gHSQC) NMR spectra. The vanadium(V) complexes have ability to catalyze the oxidation of sulfides [PhSR (R= Me, Bz)] in good yields and enantiomeric excesses, utilizing aqueous 30% H2O2 or cumene hydroperoxide (CHP) as oxidant. Catalytic activity of these complexes and also derived from R(-)-1,2-diaminopropane, resulted in ONO- and ONN-type of tridentate ligands, respectively, were tested in the oxidation of styrene, using aqueous 30% H2O2 or tert-butyl hydroperoxide (TBHP) as oxidant. (C) 2012 Elsevier B.V. All rights reserved.