Study on 1,3,5-Triazine Chemistry in Dehydrocondensation:<i>Gauche</i>Effect on the Generation of Active Triazinylammonium Species
作者:Munetaka Kunishima、Takae Ujigawa、Yoshie Nagaoka、Chiho Kawachi、Kazuhito Hioki、Motoo Shiro
DOI:10.1002/chem.201202236
日期:2012.12.3
tertiary amines (tert‐amines), has been studied for the preparation of 2‐(4,6‐dimethoxy‐1,3,5‐triazinyl)trialkylammonium salts [DMT‐Am(s)]. DMT‐Ams derived from aliphatic tert‐amines exhibited activity for the dehydrocondensation between a carboxylic acid and an amine to form an amide in a model reaction. Based on a conformational analysis of DMT‐Ams and tert‐amines by NMR and X‐ray diffraction methods
2-氯-4,6-二甲氧基-1,3,5-三嗪(CDMT)与各种含氮化合物,特别是叔胺(反应叔-胺),已经研究了制备2-(4- ,6-二甲氧基-1,3,5-三嗪基)三烷基铵盐[DMT-Am(s)]。DMT-AMS衍生自脂族叔-胺为羧酸和胺之间的脱水缩合展示的活性,以形成在一个模型反应的酰胺。基于DMT-AMS和的构象分析叔通过NMR和X射线衍射法-胺,我们得出的结论是β-烷基中的保持笨拙与氮的孤对电子的关系叔胺会严重阻碍CDMT接近氮。因此,三甲胺和奎宁环没有这样的烷基基团容易地与反应CDMT而三乙胺,具有两个或三个这种笨拙的稳定构象β -烷基,根本不发生反应。这里提出的“ gaucheβ-烷基效应”理论为制备具有各种叔胺基团的DMT-Ams提供了有用的指导。的脱水缩合活性的调查叔-胺在CDMT /叔-胺在原位产生DMT-Am的都涉及系统,显示,笨拙的β烷基的效果变得相当显着; 酰胺的收率随着