oxidative olefination of indole at C‐2, C‐3, C‐4 and C‐7 positions was well addressed. We report here a rhodium‐catalyzed NH‐indole‐directed ortho C−H bond olefination of 2‐arylindoles. This cross‐dehydrogenative‐coupling proved to be broad in substrate scope, tolerating a variety of functional groups. The synthesis of 6H‐isoindolo[2,1‐α]indoles via rhodium‐catalyzed ortho C−H olefination and subsequent
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
作者:Manar Ahmed Fouad、Francesco Ferretti、Dario Formenti、Fabio Milani、Fabio Ragaini
DOI:10.1002/ejoc.202100789
日期:2021.9.14
A very efficient, general and scalable protocol for the preparation of indoles and other N-heterocycles from suitably substituted nitroarenes using alkyl and phenyl formates as CO surrogates was described. Using phenyl formate, the products were isolated in yields often higher than those previously achieved by using gaseous CO. The mechanism of both the decarbonylation reaction of phenyl formate and
描述了使用烷基和苯基甲酸酯作为 CO 替代物从适当取代的硝基芳烃制备吲哚和其他N-杂环的非常有效、通用和可扩展的方案。使用甲酸苯酯,产物的分离产率通常高于以前使用气态 CO 实现的产率。通过动力学和机理研究阐明了甲酸苯酯的脱羰反应和环化反应的机理。
Pd‐Catalyzed Reductive Cyclization of Nitroarenes with CO
<sub>2</sub>
as the CO Source
作者:Xinyu Guan、Haoran Zhu、Yingwei Zhao、Tom G. Driver
DOI:10.1002/ejoc.201901629
日期:2020.1.9
A practical, broad‐scope reductive amination process that constructs N‐heterocycles from nitroarenes was developed that uses CO2 as the source of CO.
开发了一种实用的,广谱的还原胺化工艺,该工艺利用硝基芳烃构建N杂环,并使用CO 2作为CO的来源。
Carbon Atom Insertion into Pyrroles and Indoles Promoted by Chlorodiazirines
作者:Balu D. Dherange、Patrick Q. Kelly、Jordan P. Liles、Matthew S. Sigman、Mark D. Levin
DOI:10.1021/jacs.1c06287
日期:2021.8.4
calculations supporting a selectivity-determining cyclopropanation step. Computations surprisingly indicate that the stereochemistry of cyclopropanation is of little consequence to the subsequent electrocyclicringopening that forges the pyridine core, due to a compensatory homoaromatic stabilization that counterbalances orbital-controlled torquoselectivity effects. The utility of this skeletal transform is
Potassium
<i>tert</i>
‐Butoxide‐Promoted Acceptorless Dehydrogenation of N‐Heterocycles
作者:Tingting Liu、Kaikai Wu、Liandi Wang、Zhengkun Yu
DOI:10.1002/adsc.201900499
日期:2019.9.3
Potassium tert‐butoxide‐promoted acceptorlessdehydrogenation of N‐heterocycles was efficiently realized for the generation of N‐heteroarenes and hydrogen gas under transition‐metal‐free conditions. In the presence of KOtBu base, a variety of six‐ and five‐membered N‐heterocyclic compounds efficiently underwent acceptorlessdehydrogenation to afford the corresponding N‐heteroarenes and H2 gas in o‐xylene
钾叔N-杂环的丁醇促进的acceptorless脱氢高效地实现用于N-杂芳烃和氢气的过渡金属-自由条件下产生。在存在KO t Bu碱的情况下,各种六元和五元N-杂环化合物可以有效地进行无受体脱氢,从而在140°C的邻二甲苯中提供相应的N-杂芳烃和H 2气体。本协议提供了一条通往芳香族含氮化合物和H 2气体的便捷途径。