NHC‐Catalyzed Chemoselective Reactions of Enals and Aminobenzaldehydes for Access to Chiral Dihydroquinolines
作者:Shuquan Wu、Changyi Liu、Guoyong Luo、Zhichao Jin、Pengcheng Zheng、Yonggui Robin Chi
DOI:10.1002/anie.201909479
日期:2019.12.16
(NHC)-catalyzed reaction between α-bromoenals and 2-aminoaldehydes has been developed. Key steps include chemoselective reaction of the NHC catalyst with one of the aldehyde substrates (the bromoenal) to eventually generate an α,β-unsaturated acylazolium intermediate. Addition of the nitrogen atom of aminoaldehyde to the unsaturated azolium ester intermediate followed by intramolecular aldol reaction, β-lactone
已开发出一种N-杂环卡宾(NHC)催化的α-溴烯醛和2-氨基醛之间的反应。关键步骤包括NHC催化剂与醛底物之一(溴烯醛)的化学选择性反应,最终生成α,β-不饱和酰基la中间体。将氨基醛的氮原子添加至不饱和的偶氮酯中间体中,随后进行分子内羟醛反应,β-内酯形成和脱羧,从而得到具有高光学纯度的手性二氢喹啉。通过使用该方法快速制备的二氢喹啉产物可以容易地转化为多种功能分子,例如吡啶和手性哌啶。