Enantioconvergent Synthesis of Functionalized γ-Butyrolactones via (3 + 2)-Annulation
作者:C. Guy Goodman、Morgan M. Walker、Jeffrey S. Johnson
DOI:10.1021/ja511701j
日期:2015.1.14
A dynamic kinetic resolution of β-halo α-keto esters in an asymmetric homoenolate reaction is described. A chiral N-hetereocyclic carbene catalyzes the a3 → d3-umpolung addition of α,β-enals to racemic α-keto esters, forming γ-butyrolactones with three contiguous stereocenters. The addition occurs with high regio-, diastereo-, and enantiocontrol. This methodology constitutes an intermolecular DKR process
描述了在不对称均烯醇化物反应中β-卤代α-酮酯的动态动力学拆分。手性 N-杂环卡宾催化 α,β-烯醛与外消旋 α-酮酯的 a3 → d3-umpolung 加成,形成具有三个连续立体中心的 γ-丁内酯。添加发生在高区域控制、非对映控制和对映控制下。这种方法构成了一个分子间 DKR 过程,以在关键键形成事件期间设置三个立体中心。