Copper-catalyzed aerobic oxidative coupling of o-phenylenediamines with 2-aryl/heteroarylethylamines: direct access to construct quinoxalines

Abstract

A copper-catalyzed oxidative coupling reaction 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 room temperature. The reaction has a broad substrate scope and exhibits excellent functional-group tolerance. This method could be easily scaled up and applied to the synthesis of biologically active molecules bearing a quinoxaline structural scaffold.

Copper catalyzed photoredox synthesis of α-keto esters, quinoxaline, and naphthoquinone: controlled oxidation of terminal alkynes to glyoxals

“…Synthesis of quinoxaline via double condensation of 1,2-phenylenediamines with phenylglyoxals in the presence of a catalyst is a well-established concept in organic synthesis. 14 a Hashmi et al reported gold and silver bi-metal co-catalyzed synthesis of quinoxaline derivatives from terminal alkynes which involved the oxidation of phenyl acetylene to phenylglyoxals using external oxidant pyridine N-oxide (4 equiv.) 14 b (Scheme S6, ESI † ).…”

Preparation of Ferricyanic Acid Doped Aryl Amine Copolymer and Its Electrochemical Properties

“…近年来，在材料科学领域中，新型有机/无机杂化材 料正引起人们的广泛关注。该类材料由于有机和无机组分 的协同效应，使其具有突出的性能，在光、电、磁等领域 具有广泛的应用前景 [1][2][3]。 有机共轭聚合物(COPs)是一类非常特殊的聚合物功 能材料，由于其独特的共轭结构，导电性，电化学活性， 使它们成为功能聚合物功能材料研究的热点 [4][5][6][7][8][9]。比如， 芳胺聚合物中的聚苯胺在常温下经过化学和电化学掺杂 过程使其具有优异的导电性能，并且由于其易于合成、原 料易得、结构多样化、掺杂原理独特、导电性和稳定性好 等优势，是目前最具应用前景的导电聚合物。而聚苯二胺 作为一种重要的芳香二胺类聚合物，因为其大分子结构中 含有比聚苯胺较多的活性自由氨基和亚胺基，并且还拥有 多功能性，近年来已被广泛关注 [10][11][12][13][14][15]。 普鲁士蓝(prussian blue， PB)及其衍生物是一种混合价 态的化合物。 其具有优良的电化学可逆性， 高度的稳定性， 容易制备等优点， 因此在化学修饰电极、 电显示、 电催化、 二次储能电池等方面有很大的应用前景 [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]…”

Recent Advances in the Synthesis of Benzimidazole Derivatives from the Oxidative Coupling of Primary Amines

“…18 Nevertheless, at a slightly more elevated temperature of 130 °C for 24 hours, CuI was also able to catalyze the oxidation of 2-phenylethylamine, which, in the presence of o-phenylenediamine, was converted into a sixmembered 2-phenylquinoxaline product through a reaction mechanism recently reported by Gopalaiah and coworkers for their similar CuBr-catalyzed protocol (Scheme 7, dashed arrows). 20 In the presence of o-phenylenediamine (A), copper-catalyzed aerobic oxidation of 2-phenylethylamine produces the cross-coupled imine B which, after copper-catalyzed benzylic oxidation, leads to the formation of the keto-imine E via benzyl radical intermediate C and hydroperoxide D.…”