Catalytic asymmetric transfer hydrogenation/dynamic kinetic resolution: an efficient synthesis of florfenicol
作者:Xinlong Wang、Lingjun Xu、Lingjie Yan、Haifeng Wang、Sheng Han、Yan Wu、Fener Chen
DOI:10.1016/j.tet.2016.02.045
日期:2016.4
A robust and practical method has been developed for the synthesis of florfenicol (1) starting from commercial available 4-(methylsulfonyl) benzoic acid. The key step in this synthesis was the Ru-chloramphenicol base catalyzed asymmetric transfer hydrogenation of N-Boc α-amino-β-ketoester 5 through a dynamic kinetic resolution, which afforded the key chiral building block, anti-(2S,3S)-α-Boc-amino-β-hydroxyl
从市售的4-(甲基磺酰基)苯甲酸开始,已经开发了一种强大且实用的方法来合成氟苯尼考(1)。该合成的关键步骤是Ru-氯霉素碱通过动态动力学拆分催化N -Bocα-氨基-β-酮酸酯5的不对称转移加氢反应,提供了关键的手性结构单元,抗-(2 S,3 S)-α-Boc-氨基-β-羟基酯4,具有高非对映选择性(92%de)和对映选择性(78%ee)。一系列新型氯霉素基础配体L1-L10的合成也包括在内。该方案还可用于氟苯尼考的完全合成类似物的不对称合成。