Asymmetric Aerobic Oxidation of α-Hydroxy Acid Derivatives Catalyzed by Reusable, Polystyrene-Supported Chiral N-Salicylidene Oxidovanadium tert-Leucinates
作者:Santosh B. Salunke、N.Seshu Babu、Chien-Tien Chen
DOI:10.1002/adsc.201100062
日期:2011.5
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
通过点击化学方法研究了将两种不同的C-5-炔丙基醚改性的手性N-水杨基亚烷基钒(V)叔亮氨酸酯直接固定在4-叠氮基甲基取代的聚苯乙烯上的方法。在所研究的八种不同溶剂中,所得的聚苯乙烯负载催化剂促进了α-羟基(硫代)酯和酰胺的不对称,好氧氧化,其在氯仿中的对映选择性高达99%ee(选择性高达41)。这些聚苯乙烯负载的催化剂可以很容易地通过过滤回收,并至少连续四次重复使用,而不会损失反应性和对映选择性。