Synthesis of functionalized benzimidazoles and quinoxalines catalyzed by sodium hexafluorophosphate bound Amberlite resin in aqueous medium
作者:Pranab Ghosh、Amitava Mandal
DOI:10.1016/j.tetlet.2012.09.045
日期:2012.11
for the selective synthesis of 1,2-disubstitutedbenzimidazoles and quinoxalines in water–methanol (1:1) mixture with the aid of resin bound hexafluorophosphate ion as catalyst is reported. The method is also effective for the incorporation of quinoxaline nucleus at the A ring of pentacyclic triterpenoid, friedelin. A plausible mechanism for the formation of disubstituted benzimidazole has also been suggested
A copper-catalyzed oxidative couplingreaction of o-phenylenediamines with 2-aryl/heteroarylethylamines using molecular oxygen as an oxidant has been developed. This approach provides a practical and direct access to construct quinoxalines in excellent yields at roomtemperature. The reaction has a broad substrate scope and exhibits excellent functional-group tolerance. This method could be easily
Synthesis of libraries of quinoxalines through eco-friendly tandem oxidation–condensation or condensation reactions
作者:Susmita Paul、Basudeb Basu
DOI:10.1016/j.tetlet.2011.09.141
日期:2011.12
A facile and expeditious solid-phase synthesis of libraries of quinoxalines promoted on KF-alumina surface via tandem oxidation–condensation or condensation reactions is reported. The reaction protocol is operationally simple and mild. Moreover, solvent-free reaction condition makes the reaction procedure eco-friendly and economically viable.
One-potsynthesis: A sustainable and efficient protocol for the transition-metal-free one-potsynthesis of quinoxaline derivatives from lignin β-O-4 models and polymer in the presence of organic N-sources and KOH is presented. With this protocol, a wide range of functionalized quinoxalines are synthesized from lignin β-O-4 model compounds and β-O-4 polymer.
DMSO/tBuONa/O2-Mediated Efficient Syntheses of Diverse Quinoxalines through α-imino Radicals
作者:Chihong Zhang、Zhen Zhang、Deliang Wang、Wenkun Wang、Bo Jin、Tao Wen、Lihua Ye、Zhong-Ning Chen、Hu Cai
DOI:10.1039/d3cc00086a
日期:——
Herein, we described an efficient method involving the synthesis of diverse quinoxalines using DMSO/tBuONa/O2 system as single-electron oxidants to form α-imino radicals and nitrogen radicals for the direct construction of...