d-Phg-l-Pro Dipeptide-derived prolinol ligands for highly enantioselective Reformatsky reactions
作者:Eun-kyoung Shin、Hyun Jung Kim、Yongtai Kim、Yangmee Kim、Yong Sun Park
DOI:10.1016/j.tetlet.2006.01.070
日期:2006.3
prepared from the dynamic kineticresolution of N-(α-bromo-α-phenylacetyl) proline ester 1 in asymmetric nucleophilic substitution and subsequent reduction. The peptide-derived prolinols are tested as chiral ligands in the asymmetric addition of Reformatsky reagent to aromatic aldehydes. Chiral ligand 3c has been shown to be effective to produce enantioenriched β-hydroxyesters 5a–j with up to 98% ee
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。
(R)-(+)-N-Methylbenzoguanidine ((R)-NMBG) catalyzed acylative kinetic resolution of racemic 3-hydroxy-3-aryl-propanoates
作者:Akira Yamada、Kenya Nakata
DOI:10.1016/j.tetlet.2016.09.014
日期:2016.10
cyclohexane carboxylic anhydride under mild reaction conditions. A tert-butyl ester moiety is necessary to achieve a high selectivity. The effects of the substituents on the aromatic rings of the substrates were systematically investigated, and diverse substrates participated in the reaction with good s-values (>20) irrespective of the type of substituents and their patterns, except for o-methoxy group