Preparation of chiral oxovanadium (IV) Schiff base complex functionalized by ionic liquid for enantioselective oxidation of methyl aryl sulfides

Chiral oxovanadium (IV) Schiff base complex covalently grafted with ionic liquid (IL: 1-(3-aminopropyI)-3-methylimidazolium tetrafluoroborate) has been reported first time. The IL-functionalized complex was found to be an efficient catalyst in the enantioselective oxidation of methyl aryl sulfides to sulfoxides with hydrogen peroxide as an oxidant. Especially, the IL-functionalized complex could be recovered conveniently by simple precipitation with addition of hexane and reused at least six cycles without loss of activity and enantioselectivity. (C) 2011 Elsevier B.V. All rights reserved.