Asymmetric dihydroxylation using heterogenized cinchona alkaloid ligands on mesoporous silica
作者:Hong Myung Lee、Sang-Wook Kim、Taeghwan Hyeon、B.Moon Kim
DOI:10.1016/s0957-4166(01)00284-1
日期:2001.7
Cinchona alkaloids have been successfully grafted on mesoporous silica. Asymmetric dihydroxylation using the heterogenized chiral ligands proceeded with varying degrees of enantioselection depending upon the nature of the chiral ligands. High asymmetric induction (up to >99.5% enantiomeric excess) almost equal to that obtained from the homogeneous catalyst system could be achieved using a dimeric alkaloid
金鸡纳生物碱已成功嫁接到中孔二氧化硅上。根据手性配体的性质,使用杂化的手性配体的不对称二羟基化以不同程度的对映体选择性进行。高不对称诱导(高达> 99.5%对映体过量)几乎等于从均相催化剂系统获得的可利用与配位体和所述支撑体(之间的六碳链接的二聚体生物碱配体来实现L3),而较差的结果是当使用单体生物碱配体系统时获得。重复回收固定的配体系统后,对映选择性降低。