Enantioselective sulfoxidation catalyzed by polymer-supported chiral Schiff base-VO(acac)2 complexes

The preparation of a series of polymer supported chiral Schiff bases derived from salicylic aldehydes and optically active amino alcohols is reported. These heterogeneous ligands have been complexed with VO(acac)(2) and employed to catalyze the enantioselective oxidation of sulfides to sulfoxides with hydrogen peroxide as an environmentally acceptable oxidant. The procedure affords the sulfoxides in good yield and selectivity and with ee values comparable to those obtained with the homogeneous counterparts. The catalyst can be used for at least four cycles without any significant decrease in both efficiency or enantioselectivity. (C) 2004 Elsevier Ltd. All rights reserved.