Enantioselective Synthesis of α‐Aryl‐β
<sup>2</sup>
‐Amino‐Esters by Cooperative Isothiourea and Brønsted Acid Catalysis
作者:Feng Zhao、Chang Shu、Claire M. Young、Cameron Carpenter‐Warren、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.202016220
日期:2021.5.17
The synthesis of α‐aryl‐β2‐amino esters through enantioselective aminomethylation of an arylacetic acid ester in high yields and enantioselectivity via cooperative isothiourea and Brønsted acid catalysis is demonstrated. The scope and limitations of this process are explored (25 examples, up to 94 % yield and 96:4 er), with applications to the synthesis of (S)‐Venlafaxine⋅HCl and (S)‐Nakinadine B.
证明了通过异硫脲和布朗斯台德酸协同催化,对芳基乙酸酯进行对映选择性氨甲基化,以高收率和对映选择性合成α-芳基-β 2 -氨基酯。探索了该过程的范围和局限性(25 个示例,产率高达 94% 和 96:4 er),并应用于 ( S )-文拉法辛·HCl 和 ( S )-Nakinadine B的合成。机理研究是一致的遵循 C(1)-烯醇化铵途径,而不是替代的动态动力学解析过程。对照研究表明 (i) 观察到催化剂和产物 er 之间存在线性效应;(ii)酰基铵离子可以用作预催化剂;(iii)可逆的异硫脲加成到原位生成的亚胺离子上,产生可用作生产性预催化剂的非循环中间体。