Chemoenzymatic enantioselective and stereo-convergent syntheses of lisofylline enantiomers via lipase-catalyzed kinetic resolution and optical inversion approach
作者:Paweł Borowiecki、Beata Zdun、Maciej Dranka
DOI:10.1016/j.mcat.2021.111451
日期:2021.3
were achieved when the preparative-scale EKR was carried out for 2 h at 60 °C. In addition, stereoinversion of the less biologically-relevant (S)-lisofylline into its (R)-enantiomer was successfully achieved via acetolysis of the respective optically pure (S)-mesylate by using 2 equiv of ceasium acetate and catalytic amount of 18-Crown-6 in dry toluene, followed by K2CO3-mediated methanolysis of (R)-acetate
首次提出外消旋赖索茶碱的高对映选择性酶促动力学拆分(EKR)。脂肪酶催化外消旋赖索茶碱酯交换反应关键参数的全面优化表明,最佳的生物催化系统由固定化的南极假丝酵母脂肪酶B组成。(Chirazyme L-2,C-3)悬浮在3当量的作为乙酰基供体的乙酸乙烯酯和作为溶剂的乙酸乙酯的混合物中。在最佳反应条件下,外消旋赖索茶碱的1 g规模(Chirazyme L-2,C-3)催化的动力学拆分为同手性形式(> 99%ee)的EKR产物提供了50%的转化率,以及尽可能高的对映选择性。当制备规模的EKR在60°C下进行2 h时,在反应产率(47-50%)和动力学拆分的光学活性产物的对映体纯度方面获得了最佳结果。此外,较少生物学相关(的stereoinversion小号)-lisofylline到其(- [R )-对映体已成功实现了通过通过在干燥的甲苯中使用2当量乙酸铯和催化量的18-Crown-6,然后通过K