钌催化的吡啶并三唑与萘醌的脱氮环化提供了苯并[ f ]吡啶并[1,2- a ]吲哚衍生物的良好到优异的产率。而在 PivOH 和 oxone 存在下,吡啶并三唑与吲哚一起在无金属条件下产生吲哚并 [3,2- b ] 吲哚。醌环化通过钌-卡宾中间体进行,而吲哚环化可以通过重氮-吡啶鎓中间体进行。对照实验表明两种转化都遵循离子机制。
Iodine Mediated Base‐Controlled Regio‐Selective Annulation of 2‐(Pyridin‐2‐yl)acetate Derivatives with Acrylic Esters for the Synthesis of Indolizines
作者:Youlai Fang、Fei Li、Yuzhu Yang、Xiaolan Liu、Weidong Pan
DOI:10.1002/adsc.202000103
日期:2020.3.17
An iodine mediated base‐controlled reaction between 2‐(pyridin‐2‐yl)acetate derivatives and acrylicesters has been developed for the selective synthesis of 1,3‐disubstituted indolizines and 1,2‐disubstituted indolizines. A single‐pot reaction of 2‐(pyridin‐2‐yl)acetate derivatives and acrylicesters in the presence of CsOAc delivers 1,3‐disubstitued indolizines, while KHCO3 promotes the formation
A simple and efficient approach has been developed for the synthesis of imidazo[1,5-a]pyridines using the elemental sulfur mediated sequential dual oxidative Csp3–H amination of 2-pyridyl acetates and amines under metal- and peroxide-free conditions. Broad substrate scope, operational simplicity and gram-scale ability make this chemistry very practical.
已经开发了一种简单有效的方法,用于在无金属和无过氧化物的条件下,使用元素硫介导的乙酸2-吡啶酯和胺的连续双氧化Csp 3 -H胺化来合成咪唑并[1,5- a ]吡啶。广泛的底物范围,操作简便和克级能力使这种化学非常实用。
Iodine-Mediated Oxidative Cyclization of 2-(Pyridin-2-yl)acetate Derivatives with Alkynes: Condition-Controlled Selective Synthesis of Multisubstituted Indolizines
作者:Lisheng He、Yuzhu Yang、Xiaolan Liu、Guangyan Liang、Chunyan Li、Daoping Wang、Weidong Pan
DOI:10.1055/s-0039-1690229
日期:2020.2
An iodine-mediated oxidative cyclization reaction between 2-(pyridin-2-yl)acetate derivatives and different alkynes has been developed, which provides regioselective and chemoselective syntheses of multiply substituted indolizines under modified reaction conditions. Plausible mechanisms have been proposed to explain the selective syntheses of indolizines. This protocol can be also applied to the stepwise
Copper-Catalyzed Bisannulations of Malonate-Tethered <i>O</i>-Acyl Oximes with Pyridine, Pyrazine, Pyridazine, and Quinoline Derivatives for the Construction of Dihydroindolizine-Fused Pyrrolidinones and Analogues
作者:Chun-Bao Miao、Hong-Rong Guan、YiHan Tang、Kun Wang、Wen-Long Ren、Xinyu Lyu、ChangSheng Yao、Hai-Tao Yang
DOI:10.1021/acs.orglett.1c03078
日期:2021.11.19
A copper-catalyzed bisannulation reaction of malonate-tethered O-acyl oximes with pyridine, pyrazine, pyridazine, and quinoline derivatives has been developed for the concise synthesis of structurally novel dihydroindolizine-fused pyrrolidinones and their analogues. The present reaction shows excellent regioselectivity and stereoselectivity. Theoretical calculations reveal that the coordination effect
catalyzed synthesis of indolizine-1-carboxylates through oxidative CC and CN bondformations by the reaction of 2-pyridyl acetates with alkynes and alkenes without metal, oxidant, and base. This procedure is compatible with a broad range of functional groups in both alkynes and alkenes with good yields. The reaction proceeds through a tandem CC bondformation followed by an intramolecular cyclization