Enantioselective Aerobic Oxidation of α-Hydroxy-Ketones Catalyzed by Oxidovanadium(V) Methoxides Bearing Chiral, <i>N</i>-Salicylidene-<i>tert</i>-butylglycinates
作者:Chien-Tien Chen、Jun-Qi Kao、Santosh B. Salunke、Ya-Hui Lin
DOI:10.1021/ol1024053
日期:2011.1.7
Chiral oxidovanadium(V) methoxides prepared from 3,5-disubstituted-N-salicylidene-l-tert-butylglycines and vanadyl sulfate in air-saturated MeOH serve as highly enantioselective catalysts for asymmetric aerobic oxidations and kinetic resolution of alkyl, aryl, and heteroaryl α-hydroxy-ketones with differed α-substituents at ambient temperature in toluene or TBME (tert-butyl methyl ether). The best
手性oxidovanadium(V)甲醇盐由3,5-二取代制备Ñ -salicylidene-升-叔-butylglycines和硫酸氧钒在空气饱和的MeOH中服务于非对称需氧氧化和烷基的动力学拆分为对映体选择性高的催化剂,芳基,和杂芳基在室温下在甲苯或TBME(叔丁基甲基醚)中具有不同α-取代基的α-羟基酮。最佳方案包括使用带有衍生自3,5-二苯基-或3-邻-联苯-5-硝基-水杨醛的tridendate模板的配合物。基于选择性因子(k rel),好氧氧化过程的动力学分辨率选择性在12至> 1000的范围内。)。