Stereoselective Synthesis of (R)-glycidyl Butyrate from Racemic Glycidyl Butyrate or Epichlorohydrin Via Hydrolytic Kinetic Resolution
作者:Chengjun Jiang、Jianbo Yan
DOI:10.2174/157017811795371412
日期:2011.5.1
The differences of (R)-glycidyl butyrate synthesis via hydrolytic kinetic resolution of glycidyl butyrate directly or regioselective opening epichlorohydrin as key steps by using Jacobsens hydrotic kinetic resolution are compared. In the view of separation problem, it is hard to get the pure (R)-glycidyl butyrate by kinetic resolution of glycidyl butyrate directly. Via kinetic resolution of epichlorohydrin, treatment with butyric acid in the presence of CrCl3 and then epoxidation with NaOH, the total yield of 38.5% and optical purity of 99% are obtained.
A new dinuclear chiral salen complexes for asymmetric ring opening and closing reactions: Synthesis of valuable chiral intermediates
作者:Santosh Singh Thakur、Shu-Wei Chen、Wenji Li、Chang-Kyo Shin、Seong-Jin Kim、Yoon-Mo Koo、Geon-Joong Kim
DOI:10.1016/j.jorganchem.2005.12.044
日期:2006.4
A new dinuclear chiral Co(salen) complexes bearing group 13 metals have been synthesized and characterized. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity for the asymmetric ring opening of epoxides with H2O, chloride ions and carboxylic acids and consequently provide enantiomerically enriched terminalepoxides (>99% ee). It also catalyzes the asymmetric
Hydrolytic Kinetic Resolution of Terminal Epoxides catalyzed by Novel Bimetallic Chiral Co (Salen) Complexes
作者:Rahul B. Kawthekar、Geon‐Joong Kim
DOI:10.1080/00397910701872658
日期:2008.3.28
complexes bearing transition-metal salts have been synthesized. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity in hydrolytic kinetic resolution (HKR) of racemicterminalepoxides and consequently provided enantiomericallyenrichedepoxides (up to 99% ee).
已经合成了带有过渡金属盐的新型双金属手性 Co (salen) 配合物。容易制备的配合物在外消旋末端环氧化物的水解动力学拆分 (HKR) 中表现出非常高的催化反应性和对映选择性,因此提供了对映异构体富集的环氧化物(高达 99% ee)。
Synthesis of Optically Pure Terminal Epoxide and 1,2‐Diol via Hydrolytic Kinetic Resolution Catalyzed by New Heterometallic Salen Complexes
作者:Santosh Singh Thakur、Shu‐Wei Chen、Wenji Li、Chang‐Kyo Shin、Yoon‐Mo Koo、Geon‐Joong Kim
DOI:10.1080/00397910600640354
日期:2006.8
The inactive chiral (salen)Cocomplex is easily activated by InCl3 and TlCl3 Lewis acids by forming heterometallic salencomplexes. These complexes show very high catalytic activity for the synthesis of enantiomerically enriched terminal epoxides (>99% ee) and 1,2‐diols simultaneously via hydrolytickineticresolution. Strong synergistic effects of different Lewis acids, Co‐In and Co‐Tl, were exhibited
Quantitative analysis and determination of the enantiomeric purity of glycerides by13C NMR spectroscopy. Application to the lipase-catalysed transesterification of triacylglycerides
作者:Claude Rabiller、Françoise Maze
DOI:10.1002/mrc.1260270611
日期:1989.6
13C NMR spectroscopy can be used for the quantitative analysis of mixtures of glycerides and the enantiomeric purity can be determined by using Eu(hfbe)3-d reagent. This technique was applied to the study of the reaction mixture obtained from the transesterification of tributyrin catalysed by My-lipase (Candida cylindracea). A ‘preference’ of this lipase for the pro-R ester function of tributyrin is demonstrated.
13C NMR 光谱法可用于甘油酯混合物的定量分析,并可通过使用 Eu(hfbe)3-d 试剂确定对映体的纯度。该技术被用于研究由 My-脂肪酶(圆柱形念珠菌)催化的三丁炔酯化反应混合物。结果表明,这种脂肪酶 "偏爱 "三丁炔醇的前 R 酯功能。