An efficient metal-free synthesis of 2-(pyrazin-2-yl)benzimidazoles from quinoxalinones and diaminomaleonitrile via a novel rearrangement
摘要:
A simple and highly efficient metal-free method for the synthesis of 2-(pyrazin-2-yl)benzimidazoles has been developed on the basis of the novel ring contraction of 3-aroyl- and 3-alkanoyiquinoxalin-2-ones with diaminomaleonitrile. (C) 2011 Elsevier Ltd. All rights reserved.
A facile TBHP-mediated direct oxidative coupling of quinoxalin-2(1H)-ones with arylaldehydes has been developed under metal-free conditions. This method provided a convenient and efficient approach to various 3-acylated quinoxalin-2(1H)-ones from readily available starting materials with excellent regioselectivity. This reaction proceeded efficiently under mild conditions over a broad range of substrates
selective C3-H acylation of quinoxalin-2(1H)-ones has been developed in a green and sustainable manner. In contrast to the conventional anionic eosin Y-based photoredox process, neutral eosin Y acts as the actual catalyst, which was responsible for the hydrogen-atom transfer (HAT) process to generate the acyl radical with readily available aldehydes as the radicalprecursor.
Direct C3–H acylation of quinoxalin-2(1H)-ones with α-oxocarboxylic acids under thermo conditions promoted by PIDA has been achieved in a moderate to good yield in a very fast manner.
Reaction for the Synthesis of Benzimidazol-2-ones, Imidazo[5,4-<i>b</i>]-, and Imidazo[4,5-<i>c</i>]pyridin-2-ones via the Rearrangement of Quinoxalin-2-ones and Their Aza Analogues When Exposed to Enamines
作者:Vakhid A. Mamedov、Nataliya A. Zhukova、Anastasiya I. Zamaletdinova、Tat’yana N. Beschastnova、Milyausha S. Kadyrova、Il’dar Kh. Rizvanov、Victor V. Syakaev、Shamil K. Latypov
DOI:10.1021/jo501526a
日期:2014.10.3
A synthetically useful protocol has been developed for the preparation of highly functionalized N-pyrrolylbenzimidazol-2-ones. The reaction of variously substituted 3-aroyl- and 3-alkanoylquinoxalin-2(1H)-ones with commercially available enamines in acetic acid results in a rapid rearrangement and formation of N-pyrrolylbenzimidazol-2-ones in modest to excellent yields. The key step of the rearrangement
Acid-Catalyzed Multicomponent Rearrangements <i>via</i> 2-((Quinoxalin-3(4<i>H</i>)-on-2-yl)(aryl)methylene)malononitriles, Generated <i>In Situ</i>, for Divergent Synthesis of Pyrroles with Different Substitution Patterns
作者:Vakhid A. Mamedov、Elena A. Khafizova、Nataliya E. Algaeva、Shamil K. Latypov、Oleg G. Sinyashin
DOI:10.1021/acs.joc.0c01180
日期:2020.8.7
divergent approaches to multifunctionalized pyrroles with different substitution patterns, have been established (47 examples). In this work, a new rearrangement of quinoxalinones with the participation of the in situ-generated 2-en-1-imine moiety of the substituent at C3 makes it possible to construct two new heterocyclic systems, namely, a benzimidazolone and a pyrrole, simultaneously under one-pot reaction