Domino Approach for the Synthesis of Pyridinium Salts and 1,2,3,8<i>a</i>-Tetrahydroimidazo[1,2-<i>a</i>]pyridines from 2-Imidazolines and Propiolic Acid Esters
作者:Nikita E. Golantsov、Alexandra S. Golubenkova、Alexey A. Festa、Anton P. Novikov、Alexey V. Varlamov、Leonid G. Voskressensky
DOI:10.1021/acs.joc.3c00916
日期:2023.8.18
fragment, easily undergo a domino reaction to form pyridinium salts with β-(alkylammonio)ethyl group at the nitrogen atom in the presence of 2 equiv of a protic acid. Treatment of the above reaction mixture with a base gives 1,2,3,8a-tetrahydroimidazo[1,2-a]pyridines. Reaction of the latter compounds with acid chlorides affords pyridinium salts with β-(alkylamido)ethyl moiety at the nitrogen atom
1-烷基-2-咪唑啉和两分子丙炔酸烷基酯的加合物,具有N-炔丙基-β-烯胺酯片段,很容易发生多米诺骨牌反应,在氮原子上形成带有β-(烷基铵)乙基的吡啶鎓盐。存在 2 当量的质子酸。用碱处理上述反应混合物得到1,2,3,8α-四氢咪唑并[ 1,2- a ]吡啶。后一化合物与酰基氯反应,得到氮原子上带有β-(烷基酰氨基)乙基部分的吡啶鎓盐。