Graphene oxide (GO) or reduced graphene oxide (rGO): efficient catalysts for one-pot metal-free synthesis of quinoxalines from 2-nitroaniline
摘要:
A straightforward one-pot preparation of library of quinoxalines from 2-nitroanilines under entirely metal-free conditions is described. Initial reduction of nitroaniline with hydrazine hydrate is efficiently catalyzed by graphene oxide (GO) or reduced graphene oxide (rGO), and further one-pot tandem reactions with 1,2-dicarbonyl compounds or with alpha-hydroxy ketones afford quinoxalines in excellent yields. The catalyst is recovered, characterized, and found to be recyclable for consecutive four runs examined with appreciable conversions. (C) 2015 Elsevier Ltd. All rights reserved.
NMR and 31PNMR). The molecular structure of the ligands (FL and BL) and complexes was established from single‐crystal X‐ray diffraction studies. Coppercomplexes have been shown to catalyse the one‐pot synthesis of imines and quinoxalines. Heterogenized catalyst (4) was prepared by reacting more active complex 3 with polystyrene supported triphenylphosphane, and characterized by elemental analyses
The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.
Synthesis of a polymer-capped palladium nanoparticles and its application as a reusable catalyst in oxidative coupling reaction of α-hydroxyketones and 1,2-diamines for preparation of pyrazines and quinoxalines
作者:Mohammad Ali Karimi Zarchi、Seyed Shahab Addin Darbandizadeh Mo Abadi
DOI:10.1007/s13738-018-1290-6
日期:2018.4
support. The catalyst displayed good catalytic activity when applied to the synthesis of quinoxalines via condensation of α-hydroxyketones with 1,2-diamines. A few pyrazine derivatives and various quinoxalines are prepared via coupling reaction of α-hydroxyketones and 1,2-diamines in high–excellent yields (81–99%) with short reaction times. The quinoxalines products were characterized by FT-IR, 1H and 13C
在交联的聚(4-乙烯基吡啶)-稳定的Pd(0)纳米粒子[P4-VP]-存在下,使用α-羟基酮和1,2-二胺开发了一种新型的吡嗪和喹喔啉合成方法PdNPs。该催化剂易于使用多种技术进行制备和表征,例如FT-IR和UV-Vis光谱,AAS,TEM,FESEM,EDX分析和XRD。结果证实了钯纳米颗粒在聚合物载体上的良好分散。当该催化剂通过α-羟基酮与1,2-二胺的缩合反应合成喹喔啉时,该催化剂表现出良好的催化活性。通过α-羟基酮与1,2-二胺的偶联反应,可以以短时间的高产率(81-99%)制备一些吡嗪衍生物和各种喹喔啉。FT-IR表征喹喔啉产品,将1 H和13 C NMR光谱和物理性质与已知化合物的文献值进行比较。本方法相对于常规经典方法的优点是快速且非常简单的后处理,并且该催化剂可重复使用多次而其活性没有明显损失。
FeCl<sub>3</sub> and Morpholine as Efficient Cocatalysts for the One-Step Synthesis of Quinoxalines from α-Hydroxyketones and 1,2-Diamines
作者:Weibin Song、Peng Liu、Min Lei、Hanyun You、Xubing Chen、Hu Chen、Lei Ma、Lihong Hu
DOI:10.1080/00397911.2010.523489
日期:2012.1.15
Abstract One-step conversion including intramolecular hydrogen bond decomposition, aerobic oxidation, and condensation from α-hydroxyketones and 1,2-diamines into quinoxalines is reported using FeCl3 and morpholine as cocatalysts. GRAPHICAL ABSTRACT
<scp>l</scp>-Proline mediated synthesis of quinoxalines; evaluation of cytotoxic and antimicrobial activity
作者:Ahmed Kamal、Korrapati Suresh Babu、Shaikh Faazil、S. M. Ali Hussaini、Anver Basha Shaik
DOI:10.1039/c4ra08615e
日期:——
A simple, greener and highly efficient method for the synthesis of functionalized quinoxalines has been developed employingl-proline as a catalyst in water. The newly synthesized quinoxaline–sulphonamide conjugates exhibited significant cytotoxic and antimicrobial activities.