2-(2-吡啶基)氮丙啶-2-羧酸酯和硫酯中的三元环可以在铜(II)催化下选择性裂解N-C2键或在HCl作用下选择性裂解C-C键,分别提供吡唑并[1,5- a ]吡啶或咪唑并[1,5- a ]吡啶系列的异构氮丙啶扩环产物。形成吡唑并吡啶的温和催化反应条件使得可以通过一锅、三阶段程序直接从4-溴异恶唑获得它们,而无需分离中间体2-溴氮丙啶和2-(2-吡啶基)氮丙啶。
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。
Mild Metal-Free Sequential Dual Oxidative Amination of C(sp<sup>3</sup>)–H bonds: Efficient Synthesis of Imidazo[1,5-<i>a</i>]pyridines
作者:Yizhe Yan、Yonghui Zhang、Zhenggen Zha、Zhiyong Wang
DOI:10.1021/ol4008487
日期:2013.5.3
A metal-free sequential dual oxidative amination of C(sp3)–H bonds under ambient conditions was the first developed, affording imidazo[1,5-a]pyridines in good to excellent yields. The reaction was involved in two oxidative C–N couplings and one oxidative dehydrogenation process with six hydrogen atoms removed.
首次开发了在环境条件下无金属的C(sp 3)-H键的顺序双氧化胺化反应,可提供咪唑并[1,5- a ]吡啶,并具有良好或优异的收率。该反应涉及两个氧化C–N偶联和一个氧化脱氢过程,其中去除了六个氢原子。
Diiodine-Mediated Oxidative Reaction for the Construction of Imidazo[1,5-a]pyridines under Metal-Free Conditions
An efficient and general protocol has been developed for preparing imidazo[1,5-a]pyridines in moderate to excellent yields by an I2-mediated sequential dual oxidative C(sp3)–H amination of ethyl pyridin-2-ylacetates with benzylamines. The metal- and peroxide-free reaction involves oxidative dehydrogenation and two C–N couplings.
Divergent Synthesis of Pyrazolo[1,5-<i>a</i>]pyridines and Imidazo[1,5-<i>a</i>]pyridines via Reagent-Controlled Cleavage of the C–N or C–C Azirine Bond in 2-Pyridylazirines
作者:Anastasiya V. Agafonova、Artem A. Golubev、Ilia A. Smetanin、Alexander F. Khlebnikov、Dar’ya V. Spiridonova、Mikhail S. Novikov
DOI:10.1021/acs.orglett.3c02696
日期:2023.10.6
The three-memberedring in 2-(2-pyridyl)azirine-2-carboxylic esters and thioesters can undergo selective cleavage of either the N–C2 bond under copper(II) catalysis or the C–C bond under the action of HCl to provide isomeric azirine ring expansion products of pyrazolo[1,5-a]pyridine or imidazo[1,5-a]pyridine series, respectively. Mild catalytic reaction conditions for the formation of pyrazolopyridines
2-(2-吡啶基)氮丙啶-2-羧酸酯和硫酯中的三元环可以在铜(II)催化下选择性裂解N-C2键或在HCl作用下选择性裂解C-C键,分别提供吡唑并[1,5- a ]吡啶或咪唑并[1,5- a ]吡啶系列的异构氮丙啶扩环产物。形成吡唑并吡啶的温和催化反应条件使得可以通过一锅、三阶段程序直接从4-溴异恶唑获得它们,而无需分离中间体2-溴氮丙啶和2-(2-吡啶基)氮丙啶。