49634-78-8Relevant academic research and scientific papers
Iron-catalyzed one-pot synthesis of quinoxalines: Transfer hydrogenative condensation of 2-nitroanilines with vicinal diols
Chun, Simin,Hong, Junhwa,Hong, Suckchang,Lee, Seok Beom,Oh, Dong-Chan,Putta, Ramachandra Reddy
, p. 18225 - 18230 (2021/06/03)
Here, we report iron-catalyzed one-pot synthesis of quinoxalines via transfer hydrogenative condensation of 2-nitroanilines with vicinal diols. The tricarbonyl (η4-cyclopentadienone) iron complex, which is well known as the Kn?lker complex, catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding carbonyl and 1,2-diaminobenzene intermediates were generated in situ. Trimethylamine N-oxide was used to activate the iron complex. Various unsymmetrical and symmetrical vicinal diols were applied for transfer hydrogenation, resulting in quinoxaline derivatives in 49-98% yields. A plausible mechanism was proposed based on a series of control experiments. The major advantages of this protocol are that no external redox reagents or additional base is needed and that water is liberated as the sole byproduct. This journal is
Synthesis, biological evaluation, and in silico studies of new acetylcholinesterase inhibitors based on quinoxaline scaffold
Khongkow, Pasarat,Lomlim, Luelak,Nualnoi, Teerapat,Saetang, Jirakrit,Suwanhom, Paptawan,Tipmanee, Varomyalin
, (2021/08/20)
A quinoxaline scaffold exhibits various bioactivities in pharmacotherapeutic interests. In this research, twelve quinoxaline derivatives were synthesized and evaluated as new acetyl-cholinesterase inhibitors. We found all compounds showed potent inhibitory activity against acetyl-cholinesterase (AChE) with IC50 values of 0.077 to 50.080 μM, along with promising predicted drug-likeness and blood–brain barrier (BBB) permeation. In addition, potent butyrylcholinesterase (BChE) inhibitory activity with IC50 values of 14.91 to 60.95 μM was observed in some compounds. Enzyme kinetic study revealed the most potent compound (6c) as a mixed-type AChE inhibitor. No cytotoxicity from the quinoxaline derivatives was noticed in the human neuroblastoma cell line (SHSY5Y). In silico study suggested the compounds preferred the peripheral anionic site (PAS) to the catalytic anionic site (CAS), which was different from AChE inhibitors (tacrine and galanthamine). We had proposed the molecular design guided for quinoxaline derivatives targeting the PAS site. Therefore, the quinoxaline derivatives could offer the lead for the newly developed candidate as potential acetylcholinesterase inhibitors.
Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of N-Heterocycles
Manna, Srimanta,Kong, Wei-Jun,B?ckvall, Jan-E.
supporting information, p. 13725 - 13729 (2021/09/08)
Herein, an iron(II)-catalyzed biomimetic oxidation of N-heterocycles under aerobic conditions is described. The dehydrogenation process, involving several electron-transfer steps, is inspired by oxidations occurring in the respiratory chain. An environmentally friendly and inexpensive iron catalyst together with a hydroquinone/cobalt Schiff base hybrid catalyst as electron-transfer mediator were used for the substrate-selective dehydrogenation reaction of various N-heterocycles. The method shows a broad substrate scope and delivers important heterocycles in good-to-excellent yields.
Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines fromortho-phenylenediamines and arylmethyl/ethyl amines
Sofi, Firdoos Ahmad,Sharma, Rohit,Rawat, Ravi,Chakraborti, Asit K.,Bharatam, Prasad V.
supporting information, p. 4569 - 4573 (2021/03/22)
Visible light promoted domino synthesis of 2-aryl benzimidazoles is reported through the reaction ofortho-phenylenediamines and arylmethyl amines under aerobic conditions. The methodology has wide substrate scope and tolerates a wide range of functional groups affording the products in high yields. The use of arylethyl amines instead of arylmethyl amines gives 2-aryl quinoxalines.
A heterogeneous catalytic strategy for facile production of benzimidazoles and quinoxalines from primary amines using the Al-MCM-41 catalyst
Vasu, Amrutham,Naresh, Mameda,Krishna Sai, Gajula,Divya Rohini, Yennamaneni,Murali, Boosa,Ramulamma, Madasu,Ramunaidu, Addipilli,Narender, Nama
, p. 9439 - 9446 (2021/12/09)
This study reports a straightforward heterogeneous catalytic (Al-MCM-41) approach to synthesize nitrogen heterocycle moieties from primary amines under solvent-free conditions. The Al-MCM-41 catalyst was prepared using a hydrothermal method and characterized by various analytical techniques. The probability and limitations of the catalytic methodology were presented with various substrates. The catalytic method grants an attractive route to a wide variety of benzimidazole and quinoxaline moieties with good to excellent yields. The gram scale reaction and reusability (up to five cycles) of the Al-MCM-41 catalyst would greatly benefit industrial applications. This journal is
Nickel-Catalyzed Direct Synthesis of Quinoxalines from 2-Nitroanilines and Vicinal Diols: Identifying Nature of the Active Catalyst
Shee, Sujan,Panja, Dibyajyoti,Kundu, Sabuj
, p. 2775 - 2784 (2020/03/13)
The inexpensive and simple NiBr2/1,10-phenanthroline system-catalyzed synthesis of a series of quinoxalines from both 2-nitroanilines and 1,2-diamines is demonstrated. The reusability test for this system was performed up to the seventh cycle, which afforded good yields of the desired product without losing its reactivity significantly. Notably, during the catalytic reaction, the formation of the heterogeneous Ni-particle was observed, which was characterized by PXRD, XPS, and TEM techniques.
Homogeneous Nickel-Catalyzed Sustainable Synthesis of Quinoline and Quinoxaline under Aerobic Conditions
Bains, Amreen K.,Singh, Vikramjeet,Adhikari, Debashis
, p. 14971 - 14979 (2020/11/30)
Dehydrogenative coupling-based reactions have emerged as an efficient route toward the synthesis of a plethora of heterocyclic rings. Herein, we report an efficacious, nickel-catalyzed synthesis of two important heterocycles such as quinoline and quinoxaline. The catalyst is molecularly defined, is phosphine-free, and can operate at a mild reaction temperature of 80 °C. Both the heterocycles can be easily assembled via double dehydrogenative coupling, starting from 2-aminobenzyl alcohol/1-phenylethanol and diamine/diol, respectively, in a shorter span of reaction time. This environmentally benign synthetic protocol employing an inexpensive catalyst can rival many other transition-metal systems that have been developed for the fabrication of two putative heterocycles. Mechanistically, the dehydrogenation of secondary alcohol follows clean pseudo-first-order kinetics and exhibits a sizable kinetic isotope effect. Intriguingly, this catalyst provides an example of storing the trapped hydrogen in the ligand backbone, avoiding metal-hydride formation. Easy regeneration of the oxidized form of the catalyst under aerobic/O2 oxidation makes this protocol eco-friendly and easy to handle.
Iridium-Catalyzed Carbenoid Insertion of Sulfoxonium Ylides for Synthesis of Quinoxalines and β-Keto Thioethers in Water
Xu, Yingying,Huang, Xin,Lv, Guanghui,Lai, Ruizhi,Lv, Songyang,Li, Jianglian,Hai, Li,Wu, Yong
, p. 4635 - 4638 (2020/07/04)
Sulfoxonium ylides as safe carbene precursors are described for iridium-catalyzed carbene insertions and annulation, providing a facile and green approach to access a variety of quinoxaline derivatives in water. This water-mediated method also allows the preparation of β-keto thioethers under mild condition.
Cooperative iridium complex-catalyzed synthesis of quinoxalines, benzimidazoles and quinazolines in water
Chakrabarti, Kaushik,Maji, Milan,Kundu, Sabuj
supporting information, p. 1999 - 2004 (2019/04/27)
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 yields without using any external base. Finally, the preparative scale synthesis of various N-heterocycles and pharmaceutically active quinoxalines established the practicability of this protocol. For this iridium system, a metal-ligand cooperative mechanism was proposed based on kinetic and DFT studies.
Selective synthesis of (1: H-benzo [d] imidazol-2-yl)(phenyl)methanone and quinoxaline from aromatic aldehyde and o-phenylenediamine
Zhan, Zhenzhen,Ma, Haojie,Cui, Xinfeng,Jiang, Pengbo,Pu, Jinghong,Zhang, Yixin,Huang, Guosheng
supporting information, p. 5148 - 5152 (2019/06/03)
We have designed a general, inexpensive, and versatile method for the synthesis of (1H-benzo[d]imidazol-2-yl)(phenyl)methanone and the formation of C-N bonds via an aromatic aldehyde and o-phenylenediamine. In the presence of N,N-dimethylformamide/sulfur, (1H-benzo[d]imidazol-2-yl)(phenyl)methanone was obtained; however, in the absence of sulfur, quinoxaline was obtained in 1,4-dioxane. A wide range of quinoxalines and (1H-benzo[d]imidazol-2-yl)(phenyl)methanones was obtained under mild conditions.
