Direct NMR assay of the enantiomeric purity of chiral β-hydroxy esters by using quinine as chiral solvating agent
摘要:
The use of quinine as a chiral solvating agent for NMR spectroscopy affords a general method for the enantiomeric purity determination of beta-hydroxyesters. The ester group represents the most suitable probe for the measurements, which can be optimized by varying the molar ratio ester/quinine, the total concentration or the temperature.
Asymmetric dehydration of β-hydroxy esters via kinetic resolution
作者:Yongtae Kim、Eui Ta Choi、Min Hee Lee、Yong Sun Park
DOI:10.1016/j.tetlet.2007.02.111
日期:2007.4
Catalytic asymmetricdehydration of β-hydroxyesters via kineticresolution has been investigated. The kineticresolution of rac-β-hydroxy esters in the presence of prolinol chiral ligand 2a and BrZnCH2CO2t-Bu can provide highly enantioenriched β-hydroxyesters 3 and 5–11 with selectivity factors ranging from 15 to 42.
已经研究了通过动力学拆分对β-羟基酯进行催化不对称脱水的方法。的动力学拆分外消旋-β-羟基酯在存在脯氨醇手性配体2A和BrZnCH 2 CO 2吨-Bu能够提供对映体富集的高度β羟基酯3和5 - 11有选择性因素,从15至42。
A cobalt-phosphine complex as mediator in the formation of carbon-carbon bonds
作者:Fulvia Orsini、Francesca Pelizzoni、Maurizio Pulici、Lidia M. Vallarino