Asymmetric Aerobic Oxidation of α-Hydroxy Acid Derivatives Catalyzed by Reusable, Polystyrene-Supported Chiral N-Salicylidene Oxidovanadium tert-Leucinates

✍ Scribed by Santosh B. Salunke; N.Seshu Babu; Chien-Tien Chen

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 276 KB
• Volume: 353
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.201100062

✦ Synopsis

Abstract

The direct immobilization of two different C‐5‐propargyl ether‐modified, chiral N‐salicylidene vanadyl(V) tert‐leucinates onto 4‐azidomethyl‐substituted polystyrene by click chemistry was examined. Among the eight different solvents investigated, the resulting polystyrene‐supported catalysts promote the asymmetric, aerobic oxidation of α‐hydroxy (thio)esters and amides with enantioselectivities of up to 99% ee (selectivity factor up to 41) in chloroform. These polystyrene‐supported catalysts can be readily recovered by filtration and reused for at least four consecutive runs without discernible loss of reactivity and enantioselectivity.