Enantioselective Sequential‐Flow Synthesis of Baclofen Precursor via Asymmetric 1,4‐Addition and Chemoselective Hydrogenation on Platinum/Carbon/Calcium Phosphate Composites
作者:Haruro Ishitani、Yuichi Furiya、Shu Kobayashi
DOI:10.1002/asia.202000065
日期:2020.6.2
Continuous‐flow synthesis of baclofen precursor (2 ) was achieved using achiral and chiral heterogeneous catalysts in high yield with high enantioselectivity. The key steps are chiral calcium‐catalyzed asymmetric 1,4‐addition of a malonate to a nitroalkene and chemoselective reduction of a nitro compound to the corresponding amino compound by using molecular hydrogen. A dimethylpolysilane (DMPS)‐modified
使用非手性和手性非均相催化剂以高收率和高对映选择性实现了巴氯芬前体(2)的连续流合成。关键步骤是手性钙催化的丙二酸酯向硝基烯烃的不对称1,4加成反应,以及通过使用分子氢将硝基化合物化学选择性还原成相应的氨基化合物。已经开发了一种以活性炭(AC)和磷酸钙(CP)为载体的二甲基聚硅烷(DMPS)改性的铂催化剂,该催化剂对硝基化合物的选择性加氢具有显着的活性。