Catalytic Enantioselective Synthesis of α-Chiral Azaheteroaryl Ethylamines by Asymmetric Protonation
作者:Chao Xu、Calum W. Muir、Andrew G. Leach、Alan R. Kennedy、Allan J. B. Watson
DOI:10.1002/anie.201806956
日期:2018.8.27
The direct enantioselective synthesis of chiral azaheteroaryl ethylamines from vinyl‐substituted N‐heterocycles and anilines is reported. A chiral phosphoric acid (CPA) catalyst promotes dearomatizing aza‐Michael addition to give a prochiral exocyclic aryl enamine, which undergoes asymmetric protonation upon rearomatization. The reaction accommodates a broad range of N‐heterocycles, nucleophiles, and
报道了从乙烯基取代的N-杂环和苯胺直接合成手性氮杂杂芳基乙胺的对映体。手性磷酸(CPA)催化剂可促进脱氮使aza-Michael加成芳烃,从而产生前手性环外芳基烯胺,该胺在重新芳构化后会发生不对称质子化。该反应在前手性中心可容纳各种N-杂环,亲核试剂和取代基,从而产生高对映选择性的产物。DFT研究支持了基于催化剂诱导的LUMO降低的简便亲核加成,并从离子对前手性中间体进行了位点选择性,限速,分子内不对称质子转移。