<i>N</i>
,
<i>N</i>
‐Dialkylhydrazones as Versatile Umpolung Reagents in Enantioselective Anion‐Binding Catalysis
作者:Melania Gómez‐Martínez、María Carmen Pérez‐Aguilar、Dariusz G. Piekarski、Constantin G. Daniliuc、Olga García Mancheño
DOI:10.1002/anie.202013380
日期:2021.3
ion‐pair complex was envisioned. The formation of such a network was further supported by both experimental and computational studies, which showed the crucial role of the anion as a template unit. The asymmetric Reissert‐type reaction of quinolines as a model test reaction chemoselectively delivered highly enantiomerically enriched hydrazones (up 95:5 e.r.) that could be further derivatized to value‐added
提出了一种以多功能N , N-二烷基腙 (DAH) 作为极性反转 (umpolung) 亲核试剂的对映选择性阴离子结合有机催化方法。为了应用这一概念,我们设想了超分子手性离子对复合物中精心挑选的 CF 3取代的三唑基多齿 HB 供体催化剂、离子底物和腙之间的高度有序氢键 (HB) 网络。这种网络的形成得到了实验和计算研究的进一步支持,这表明阴离子作为模板单元的关键作用。喹啉的不对称 Reissert 型反应作为模型测试反应,化学选择性地产生高度对映体富集的腙(高达 95:5 er),可以进一步衍生为具有最多三个立体中心的增值化合物。