Bonded- and discreted-Lindqvist hexatungstate-based copper hybrids as heterogeneous catalysts for the one-pot synthesis of 2-phenylquinoxalines <i>via</i> 2-haloanilines with vinyl azides or 3-phenyl-2<i>H</i>-azirines
hexatungstate-based copper hybrids (Cu-POMs) ([Cu2(O)OH(phen)2]2[W6O19]·6H2O (1) and [Cu2(phen)4Cl] [HW6O19]·2H2O (2) (phen = 1,10-phenanthroline)) were controllably synthesized and routinely characterized. Cu-POMs 1–2 consisted of identical [W6O19] unit and similar copper–phen complexes, the two units are bonded via four Cu–O chemical bonds in compound 1; however, compound 2 is discreted and stabilized by intermolecular
An efficient one-pot synthesis of 2-substituted quinoxalines from 1,2-diamines and phenacyl bromides is developed using K10-montmorillonite (K10 clay) as a catalyst at 50 degrees C in acetonitrile medium. This method offers an easy route for the synthesis of substituted quinoxalines in high yields. A plausible mechanism is proposed in which quinoxalines are formed via dehydration-dehydrohalogenationcyclization sequence. Further, the K10 clay catalyst is recovered by simple filtration and reused six times without any loss in its catalytic activity. (C) 2014 Elsevier Ltd. All rights reserved.
Accessing Quinoxalines by Ring-Opening/Cyclization/Detosylation/Aromatization of Activated Aziridines with 2-Bromoanilines: Synthesis of Tyrphostin AG 1296
作者:Chandan Kumar Shahi、Sajan Pradhan、Aditya Bhattacharyya、Raushan Kumar、Manas K. Ghorai
DOI:10.1002/ejoc.201700506
日期:2017.6.30
Synthesis of substituted 2-arylquinoxalines via an unprecedented Cu(I) catalyzed ring-opening-cyclization followed by detosylation-aromatization of activated aziridines with 2-bromoanilines has been accomplished. The transformation efficiently accommodates a wide range of aziridines and 2-bromoanilines to afford the desired quinoxaline frameworks in excellent yields (up to 86%) as a single regioisomer