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

Abstract

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 (1H, 51V) 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.