N-Heterocyclic Carbene-Catalyzed Formal [3+3] Annulation of Alkynyl Acylazoliums for the Synthesis of Benzofuro[3,2-<i>b</i>]pyridin-2-ones
作者:Xiaoxue Wang、Yuebo Shao、Simiao Zhang、Tao Lu、Ding Du
DOI:10.1021/acs.joc.1c01230
日期:2021.9.3
acid esters with N-heterocyclic carbene catalysis, a formal [3+3] annulation of alkynyl acylazoliums with indolin-3-ones has been developed for the rapid construction of structurally interesting benzofuro[3,2-b]pyridin-2-ones with potential bioactivities. This protocol provides a highly efficient and simple method for the synthesis of the target molecules under mild reaction conditions with a wide substrate
Copper-Catalyzed Alkynylation/Cyclization/Isomerization Cascade for Synthesis of 1,2-Dihydrobenzofuro[3,2-<i>b</i>]pyridines and Benzofuro[3,2-<i>b</i>]pyridines
作者:Huan-Ping Xie、Lei Sun、Bo Wu、Yong-Gui Zhou
DOI:10.1021/acs.joc.9b02512
日期:2019.12.6
An efficient copper-catalyzed cascade alkynylation/cyclization/isomerization reaction of aurone-derived azadienes with terminal alkynes has been developed, giving a series of 1,2-dihydrobenzofuro[3,2-b]pyridines with excellent yields. The obtained 1,2-dihydrobenzofuro[3,2-b]pyridines can be conveniently transformed into the corresponding benzofuro[3,2-b]pyridines under basic conditions. Additionally
已经开发出了一种高效的铜催化的黄酮衍生氮杂二烯与末端炔烃的级联炔化/环化/异构化反应,得到了一系列具有优异收率的1,2-二氢苯并呋喃[3,2- b ]吡啶。所获得的1,2-二氢苯并呋喃[3,2- b ]吡啶可在碱性条件下方便地转化为相应的苯并呋喃[3,2- b ]吡啶。另外,苯并呋喃[3,2- b ]吡啶也可以通过一锅反应由氮杂二烯和末端炔烃制备。合成的效用通过高产率地抑制强效拓扑异构酶的三种生物活性分子的合成得到了证明。该策略为1,2-二氢苯并呋喃[3,2- b]吡啶和苯并呋喃[3,2- b ]吡啶。
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。