Large-Scale Synthesis of a Substituted <scp>d</scp>-Phenylalanine Using Asymmetric Hydrogenation
作者:Martin E. Fox、Mark Jackson、Graham Meek、Matthew Willets
DOI:10.1021/op200129m
日期:2011.9.16
seven-step route based on asymmetric hydrogenation of an N-acetyl dehydroamino-acid was developed. Starting with terephthalic dialdehyde, monoreduction of one aldehyde group, Erlenmeyer condensation, and ring-opening/O-deacetylation with methanol provided the 4-(hydroxymethyl)-substituted dehydrophenylalanine hydrogenation substrate. Asymmetric hydrogenation of this enamide using [((R,R)-Ethyl-DuPhos)Rh(COD)]BF4
需要合成路线以适合于快速放大至150 kg规模的N -BOC d-苯丙氨酸药物中间体。开发了一种基于N-乙酰基脱氢氨基酸不对称氢化的七步法。从对苯二甲酸二醛开始,一个醛基的单还原,Erlenmeyer缩合,以及用甲醇进行的开环/ O-脱乙酰化反应提供了4-(羟甲基)-取代的脱氢苯丙氨酸加氢底物。使用[((R,R)-乙基-DuPhos)Rh(COD)] BF 4的这种酰胺的不对称氢化反应以高对映体过量进行。随后,顺通过甲磺酰化/置换引入-2,6-哌啶基,引入BOC基团,并通过碱性水解除去乙酰基和甲酯基。该途径用于生产150kg的BOC氨基酸1。