Silica supported dodecatungstophosphoric acid (DTP/SiO<sub>2</sub>): An efficient and recyclable heterogeneous catalyst for rapid synthesis of quinoxalines
作者:Madhav J. Hebade、Tejshri R. Deshmukh、Sambhaji T. Dhumal
DOI:10.1080/00397911.2021.1939060
日期:2021.8.18
Abstract A facile synthesis of quinoxalines by the cyclocondensation of substituted phenacyl bromides with o-pheneylenediamines using silica-supported dodecatungstophosphoric acid (DTP/SiO2) as a recyclableheterogeneouscatalyst is unveiled in this research work. This method is practicable due to environmentally benign, easy workup, high yield, less reaction time, low cost, mild reaction condition
Direct synthesis of N-heterocycles via the acceptorless dehydrogenative coupling is very challenging and scarcely reported under 3d transition-metal catalysis. Here, we have developed an efficient Mn(I)-catalyzed sustainable synthesis of various quinoxalines from 1,2-diaminobenzenes and 1,2-diols via the acceptorless dehydrogenative coupling reaction. Further, this strategy was successfully applied
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
Cooperative iridium complex-catalyzed synthesis of quinoxalines, benzimidazoles and quinazolines in water
作者:Kaushik Chakrabarti、Milan Maji、Sabuj Kundu
DOI:10.1039/c8gc03744b
日期:——
Herein, an efficient methodology for the synthesis of a diverse class of N-heterocyclic moieties, such as quinoxalines, benzimidazoles and quinazolines, was developed in water using bio-renewable alcohols. The quinoxalines were successfully synthesized from a wide range of diamines and nitroamines with diols in air. Interestingly, benzimidazoles and quinazolines were synthesized with excellent isolated
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