N-Heterocyclic Carbene-Promoted [4+2] Annulation of α-Chloro Hydrazones with α-Chloro Aliphatic Aldehydes to Access Enantioenriched Dihydropyridazinones
作者:Yipeng Zhou、Hongwei Zhou、Jianfeng Xu
DOI:10.1021/acs.joc.1c02581
日期:2022.3.4
α-chloro hydrazones and α-chloro aliphatic aldehydes via N-heterocyclic carbene (NHC) catalysis is outlined. These in situ-generated 1,2-diaza-1,3-dienes undergo asymmetric [4+2] annulation with NHC-bound enolates to afford the desired products bearing a stereogenic center at the C4 position. The notable features of this approach include good to excellent enantioselectivities, high functional group tolerance
概述了通过 N-杂环卡宾 (NHC) 催化从 α-氯腙和 α-氯脂肪醛中组装手性 4,5-二氢哒嗪-3(2 H )-ones 的快速方案。这些原位生成的 1,2-二氮杂-1,3-二烯与 NHC 结合的烯醇化物发生不对称 [4+2] 环化,从而提供在 C4 位置具有立体中心的所需产物。该方法的显着特点包括良好的对映选择性、高官能团耐受性、温和的反应条件、简单的操作程序以及与克级合成的相容性。