Reaction of Aldehydes/Ketones with Electron-Deficient 1,3,5-Triazines Leading to Functionalized Pyrimidines as Diels–Alder/Retro-Diels–Alder Reaction Products: Reaction Development and Mechanistic Studies
作者:Kai Yang、Qun Dang、Pei-Jun Cai、Yang Gao、Zhi-Xiang Yu、Xu Bai
DOI:10.1021/acs.joc.6b02570
日期:2017.3.3
(IEDDA) reactions of heterocyclic aza-dienes are rarely reported since highly reactive and electron-rich dienophiles are often found not compatible with strong acids such as Lewis acids. Herein, we disclose that TFA-catalyzed reactions of electron-deficient 1,3,5-triazines and electron-deficient aldehydes/ketones can take place. These reactions led to highly functionalized pyrimidines as products in fair
杂环氮杂二烯的催化逆电子需量Diels-Alder(IEDDA)反应很少见,因为经常发现高反应性和富电子的亲二烯体与强酸(例如路易斯酸)不相容。在此,我们公开了缺电子的1,3,5-三嗪和缺电子的醛/酮的TFA催化反应。这些反应导致高度官能化的嘧啶作为产物以公平至良好的产率。通过实验和计算研究相结合,仔细研究了反应机理。这些反应包括逐步反电子需求异狄尔斯-阿尔德(ih DA)反应的级联,然后是逆狄尔斯-阿尔德(r DA)反应和除水。两者都需要酸在DA和r DA反应中。通过比较当前反应体系中醛/酮及其对应的乙烯基醚的相对反应性,进一步验证了该机理。