I<sub>2</sub> catalyzed tandem protocol for synthesis of quinoxalines via sp<sup>3</sup>, sp<sup>2</sup> and sp C–H functionalization
作者:Kamlesh S. Vadagaonkar、Hanuman P. Kalmode、Kaliyappan Murugan、Atul C. Chaskar
DOI:10.1039/c4ra08589b
日期:——
One-pot, atom-economic synthesis of quinoxalines has been achieved through generation of arylglyoxalfrom easily available ethylarenes, ethylenearenes and ethynearenes, and subsequent condensation with o-phenylenediamines. Catalytic I2 with TBHP as an oxidant in DMSO is the system of choice for this dominoreaction involving C–H functionalization/oxidative cyclization. This metal-free, mechanistically
One-Pot Protocol for the Synthesis of Imidazoles and Quinoxalines using<i>N</i>-Bromosuccinimide
作者:Sachin D. Pardeshi、Pratima A. Sathe、Kamlesh S. Vadagaonkar、Atul C. Chaskar
DOI:10.1002/adsc.201700900
日期:2017.12.11
N‐bromosuccinimide (NBS)‐mediated one‐pot, green, efficient and practical synthesis of substituted imidazoles and quinoxalines has been achieved by the reaction of styrenes with N‐arylbenzamidines and o‐phenylenediamines, respectively, in a water:1,4‐dioxane mixture. The reaction involves formation of an α‐bromo ketone as an intermediate in the presence of NBS and water, followed by condensation with
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
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.
Quinoxalines are a class of important heterocycles, so to explore a facile and practical new synthetic method is always demanded. We have developed a new catalyst-free domino synthesis of quinoxalines from phenacyl halides and 1,2-diaminoarenes. Phenacyl chlorides with lower activities are first used in synthesis of quinoxalines and afford up to 97 % yield with our protocol. Our process with sodium bicarbonate as deacid reagent is catalyst-free, simple, greener and practical.