Kinetic Resolution Displaying Zeroth Order Dependence on Substrate Consumption: Copper-Catalyzed Asymmetric Alcoholysis of Azlactones
作者:Makoto Tokunaga、Junya Kiyosu、Yasushi Obora、Yasushi Tsuji
DOI:10.1021/ja058112j
日期:2006.4.5
Kinetic resolution of 4-alkyl-2-aryl-5-oxo-4,5-dihydrooxazole-4-carboxylic acid esters (azlactones 1) were achieved by copper-DTBM-SEGPHOS catalyzed alcoholysis reaction with good selectivity (12 examples). Variation of ee of unreacted substrates 1 and products 2 with conversion was found to follow the theoretical line of zeroth-order kinetic resolution, for which the selectivity profiles and graphical
4-烷基-2-芳基-5-氧代-4,5-二氢恶唑-4-羧酸酯(吖内酯1)的动力学拆分是通过铜-DTBM-SEGPHOS催化醇解反应实现的,具有良好的选择性(12个例子)。发现未反应的底物 1 和产物 2 的 ee 随转化率的变化遵循零级动力学分辨率的理论线,为此首次提供了选择性曲线和图形分析。零级反应的拆分效率高于一级反应。例如,与 1a 的反应以 57% 的转化率提供 (S)-1a (99% ee) 和 (R)-2a (74% ee),其中 k(rel) 值计算为 6.7 作为零阶动力学分辨率和 37 作为一级动力学分辨率。