Optically Active Amines by Enzyme-Catalyzed Kinetic Resolution
作者:Klaus Ditrich
DOI:10.1055/s-2008-1078451
日期:2008.7
Chiral amines are resolved by an enzyme-catalyzed kineticresolution. Key steps are the selective acylation of one enantiomer with isopropyl methoxyacetate, separation of the resulting amide from the unreacted antipode, and finally amide hydrolysis. The process proceeds with excellent selectivity and is highly flexible with regard to substrates.
Fast DKR of Amines Using Isopropyl 2-Methoxyacetate as Acyl Donor
作者:Martijn A. J. Veld、Karl Hult、Anja R. A. Palmans、E. W. Meijer
DOI:10.1002/ejoc.200700568
日期:2007.11
The dynamic kinetic resolution (DKR) of various primary amine substrates was performed using a modified version of the Backvall system. A single equivalent of isopropyl2-methoxyacetate was used as acyldonor in combination with p-MeO Shvo complex as the racemization catalyst and Novozym 435 as the acylation catalyst. A reaction temperature of 100 °C was employed to ensure a high racemization rate
各种伯胺底物的动态动力学拆分 (DKR) 使用 Backvall 系统的改进版本进行。使用一当量的 2-甲氧基乙酸异丙酯作为酰基供体,结合 p-MeO Shvo 配合物作为外消旋化催化剂和 Novozym 435 作为酰化催化剂。采用 100 °C 的反应温度以确保高外消旋化速率。添加浓度为 0.5 M 的 2,4-二甲基-3-戊醇 (DMP) 作为氢供体成功地抑制了副产物的形成。在这些改进的 DKR 条件下,大多数底物在 26 小时内观察到完全转化,显示出高 ee 值和良好的化学选择性,而原始系统需要 72 小时的反应时间。