Synthesis of Imidazo[1,2-<i>a</i>]pyridines via Near UV Light-Induced Cyclization of Azirinylpyridinium Salts
作者:Ilya P. Filippov、Anastasiya V. Agafonova、Gleb D. Titov、Ilia A. Smetanin、Nikolai V. Rostovskii、Alexander F. Khlebnikov、Mikhail S. Novikov
DOI:10.1021/acs.joc.2c00514
日期:2022.5.6
An efficient one-pot synthesis of imidazo[1,2-a]pyridines from 2-bromoazirines and pyridines has been developed. The construction of the bicyclic framework of imidazo[1,2-a]pyridines occurs in two steps through the formation of (2H-azirin-2-yl)pyridinium bromides followed by dehydrobrominative UV light-induced cyclization. The method can also be applied for the synthesis of imidazo[2,1-a]isoquinolines
已经开发了一种从 2-溴吖嗪和吡啶有效地一锅法合成咪唑并[1,2 - a ]吡啶的方法。咪唑并[1,2- a ]吡啶双环骨架的构建分两步进行,即形成(2 H -azirin-2-yl)溴化吡啶,然后进行脱氢溴化紫外光诱导环化。该方法还可用于合成咪唑并[2,1- a ]异喹啉。在溶液中不稳定,(2 H -azirin-2-yl)pyridinium/isoquinolinium bromides被定量转化为稳定的四氟硼酸盐,在溴离子存在下紫外照射下可环化为咪唑并[1,2- a ]吡啶。