TfOH-catalyzed direct Michael addition and cascade cyclization reactions of unactivated ketones: A divergent route to functionalized benzofurans and benzofuro[3,2-b]pyridines
作者:Manman Sun、Jing Gui、Rong Zhong、Haijian Wu、Saimei Liu、Jinshan Li、Jianguo Yang、Zhiming Wang
DOI:10.1016/j.tet.2023.133394
日期:2023.5
TfOH-catalyzed direct Michael addition and cascade cyclization reactions of azadienes with unactivated ketones have been developed by controlling the amount of TfOH, which provide a divergent approach to 2,3-disubstituted benzofurans and benzofuro[3,2-b]pyridines. Due to their weak nucleophilicity, unactivated ketones are used for the first time to react with azadienes instead of preactivated carbonyl
通过控制 TfOH 的量,开发了 TfOH 催化的直接迈克尔加成和氮杂二烯与未活化酮的级联环化反应,这为 2,3-二取代苯并呋喃和苯并呋喃 [3,2- b ] 吡啶提供了不同的方法。由于其弱亲核性,首次使用未活化的酮代替预活化的羰基化合物与氮杂二烯反应,其中催化剂酸度是一个关键参数。这种在温和反应条件下使用商用酮的方法显示出合成和环境友好的优势,包括无金属催化剂、原子经济性和操作简单。