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-aminopropyl)-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.
Graphical abstractChiral oxovanadium (IV) Schiff base complex covalently grafted with ionic liquid has been found to be an efficient and reusable catalyst for the asymmetric oxidation of methyl aryl sulfide to sulfoxide using hydrogen peroxide as an oxidant.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► An amphiphilic IL-functionalized chiral Schiff base complex was first prepared. ► The complex could overcome the mass transfer disadvantage in biphasic reaction. ► The IL moiety had the positive effects on the catalytic activity. ► The complex presented tunable solubility as ILs, resulting in facile reuse.
Journal: Catalysis Communications - Volume 12, Issue 15, 15 September 2011, Pages 1488–1491