- NaOH-Mediated Direct Synthesis of Quinoxalines from o-Nitroanilines and Alcohols via a Hydrogen-Transfer Strategy
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A NaOH-mediated sustainable synthesis of functionalized quinoxalines is disclosed via redox condensation of o-nitroamines with diols and α-hydroxy ketones. Under optimized conditions, various o-nitroamines and alcohols are well tolerated to generate the desired products in 44-99% yields without transition metals and external redox additives.
- Wang, Yan-Bing,Shi, Linlin,Zhang, Xiaojie,Fu, Lian-Rong,Hu, Weinan,Zhang, Wenjing,Zhu, Xinju,Hao, Xin-Qi,Song, Mao-Ping
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p. 947 - 958
(2021/01/14)
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- Iron-catalyzed one-pot synthesis of quinoxalines: Transfer hydrogenative condensation of 2-nitroanilines with vicinal diols
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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
- Chun, Simin,Hong, Junhwa,Hong, Suckchang,Lee, Seok Beom,Oh, Dong-Chan,Putta, Ramachandra Reddy
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p. 18225 - 18230
(2021/06/03)
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- Hydrogen Auto-transfer Synthesis of Quinoxalines from o-Nitroanilines and Biomass-based Diols Catalyzed by MOF-derived N,P Co-doped Cobalt Catalysts
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A Co-based heterogeneous catalyst supported on N,P co-doped porous carbon (Co@NCP) is prepared via a facile in-situ doping-carbonization method. The Co@NCP composite features a large surface area, high pore volume, high-density and strong basic sites. Furthermore, doping of P atoms can regulate the electronic density of Co. Therefore, Co@NCP exhibits good performance for the synthesis of quinoxalines from o-nitroanilines and biomass-derived diols under alkali-free conditions.
- Sun, Kangkang,Li, Dandan,Lu, Guo-Ping,Cai, Chun
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p. 373 - 381
(2020/12/09)
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- Application of a reusable Co-based nanocatalyst in alcohol dehydrogenative coupling strategy: Synthesis of quinoxaline and imine scaffolds
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A nitrogen doped carbon supported cobalt catalyzed efficient synthesis of imines and quinoxaline motifs is reported. Co(OAc)2-Phen/Carbon-800 (Co-phen/C-800) showed the superior reactivity compared to other materials prepared at different temperature, in the synthesis of quinoxalines by the coupling between diamines and diols. Moreover, applying the transfer hydrogenation and acceptorless dehydrogenative coupling strategy, imines and quinoxaline derivatives were synthesized from the nitro compounds. The practical applicability of this protocol was demonstrated by the gram-scale synthesis and the reusability of the catalyst upto 8th cycle. Furthermore, several kinetic experiments were carried out to realize the probable mechanism.
- Panja, Dibyajyoti,Paul, Bhaskar,Balasubramaniam, Bhuvaneshwari,Gupta, Raju K.,Kundu, Sabuj
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- Nickel-Catalyzed Direct Synthesis of Quinoxalines from 2-Nitroanilines and Vicinal Diols: Identifying Nature of the Active Catalyst
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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.
- Shee, Sujan,Panja, Dibyajyoti,Kundu, Sabuj
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p. 2775 - 2784
(2020/03/13)
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- Cooperative iridium complex-catalyzed synthesis of quinoxalines, benzimidazoles and quinazolines in water
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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.
- Chakrabarti, Kaushik,Maji, Milan,Kundu, Sabuj
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supporting information
p. 1999 - 2004
(2019/04/27)
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- Cobalt complex catalyzed atom-economical synthesis of quinoxaline, quinoline and 2-alkylaminoquinoline derivatives
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A new phosphine-free Co(ii) complex-catalyzed synthesis of various quinoxalines via dehydrogenative coupling of vicinal diols with both o-phenylenediamines and 2-nitroanilines is reported. This complex was also effective for the synthesis of quinolines. The practical aspect of this catalytic system was revealed by the one-pot synthesis of 2-alkylaminoquinolines.
- Shee, Sujan,Ganguli, Kasturi,Jana, Kalipada,Kundu, Sabuj
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supporting information
p. 6883 - 6886
(2018/06/26)
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- Highly efficient synthesis of quinoxaline derivatives catalized by iridium complex
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A novel iridium complex was used to catalyze a mild reaction of phenylenediamine with propanediol that led to formation of quinoxaline derivatives with moderate to high yields. The reaction diemonstrated strong compatibility with substrates bearing various functional groups.
- Lv,Xie,Gu,Wu,Wan
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p. 2887 - 2890
(2017/03/22)
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- Efficient synthesis of quinoxalines from 2-nitroanilines and vicinal diols via a rutheniumcatalyzed hydrogen transfer strategy
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Via a ruthenium-catalyzed hydrogen transfer strategy, we have demonstrated a one-pot method for efficient synthesis of quinoxalines from 2-nitroanilines and biomass-derived vicinal diols for the first time. In such a synthetic protocol, the diols and the nitro group serve as the hydrogen suppliers and acceptors, respectively. Hence, there is no need for the use of external reducing agents. Moreover, it has the advantages of operational simplicity, broad substrate scope and the use of renewable reactants, offering an important basis for accessing various quinoxaline derivatives.
- Xie, Feng,Zhang, Min,Jiang, Huanfeng,Chen, Mengmeng,Lv, Wan,Zheng, Aibin,Jian, Xiujuan
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supporting information
p. 279 - 284
(2018/04/16)
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- One-pot synthesis of quinoxalines from reductive coupling of 2-nitroanilines and 1,2-diketones using indium
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The one-pot reduction-cyclization of 2-nitroanilines and 1,2-diketones to give quinoxalines was investigated. Using indium and an appropriate acid such as acetic acid or indium(III) chloride, various quinoxaline derivatives including 2,3-dialkylquinoxalines, 2,3-diphenylquinoxalines, 2,3-di-2-thiophenylquinoxalines, 2,3-di(pyridin-2-yl)quinoxalines, and dibenzo[a,c]phenazines were synthesized in moderate to excellent yield.
- Go, Ahra,Lee, Geunsoo,Kim, Jaeho,Bae, Seolhee,Lee, Byung Min,Kim, Byeong Hyo
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p. 1215 - 1226
(2015/03/04)
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