- An environmentally friendly, cost effective synthesis of quinoxalines: The influence of microwave reaction conditions
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A convenient, environmentally friendly and novel synthesis of quinoxalines using silica gel as the catalyst is described. The choice of microwave conditions has been shown to have a substantial impact on the reaction outcome with closed-vessel microwave irradiation resulting in the formation of quinoxalines in high yields and short reaction times. Preliminary mechanistic investigations have indicated that a slight build-up in pressure has a major impact on the reaction outcome.
- Jeena, Vineet,Robinson, Ross S.
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- One-pot aqueous-phase synthesis of quinoxalines through oxidative cyclization of deoxybenzoins with 1,2-phenylenediamines catalyzed by a zwtterionic Cu(II)/calix[4]arene complex
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A green protocol for the synthesis of quinoxalines has been developed from catalytic oxidative cyclization of deoxybenzoins with 1,2-phenylenediamines in water. The optimal conditions are involved in the use of a water-soluble mononuclear copper(II) complex of a zwitterionic calix[4]arene [Cu(II)L(H2O)]I2 (1, H4L?=?[5,11,17,23–tetrakis (trimethylammonium)–25,26,27,28–tetrahydroxycalix[4]arene]) as a catalyst in alkali solution after refluxing for 15?h in O2. The target quinoxaline and its derivatives were obtained in good yields (up to 88%). The procedure described in this paper is simple, practical and environmentally benign.
- Gao, Jun,Ren, Zhi-Gang,Lang, Jian-Ping
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- An environmentally benign attribute for the expeditious synthesis of quinoxaline and its derivatives
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A simple, efficient, and environmentally friendly ionic liquid mediated protocol for the synthesis of quinoxaline derivatives using carbonyl substrate and phenylenediamines has been described. A range of ionic liquids were synthesized, characterized via IR, 1H and 13C NMR and used as a solvent as well as catalyst for above protocol. The catalytic activities of ILs were evaluated and the relationship between the catalytic activity and acidity was discussed. It was also found that among the all ILs, [Bmim]CF3SO3 was the most effective, eco-friendly and less expensive solvent and catalyst for the above etiquette. This method is of significant value due to the eco-friendly nature of ionic liquid and non usage of separate catalyst to drive the reaction forward. The protocol proves to be efficient and environmentally benign in terms of good to excellent yields, low reaction times, simple work-up, ease of recovery, and reusability of ionic liquid for six times.
- Bhargava, Sangeeta,Soni,Rathore, Deepti
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- Copper-catalyzed synthesis of valuable heterocyclic compounds using a tandem oxidation process approach
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The synthesis of quinoxalines via a tandem oxidation process using a copper acetate monohydrate/2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) oxidative system has been described. Using this approach, a series of quinoxaline derivatives were formed in good yields within short reaction times under microwave irradiation. The oxidative system was also extended to the selective synthesis of dihydropyrazines and pyrazines.
- Jeena, Vineet,Sithebe, Siphamandla,Robinson, Ross S.
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- Ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br): A green and neutral reaction media for the efficient, catalyst-free synthesis of quinoxaline derivatives
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Quinoxaline derivatives were produced in excellent yields and short reaction times via the condensation of 1,2-diamines with 1,2-diketones in the neutral ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) under catalyst-free and microwave irradia
- Zare, Abdolkarim,Hasaninejad, Alireza,Parhami, Abolfath,Moosavi-Zare, Ahmad Reza,Khedri, Fatemeh,Parsaee, Zahra,Abdolalipoor-Saretoli, Maasoomeh,Khedri, Maasoomeh,Roshankar, Mehrnoosh,Deisi, Hanafieh
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Read Online
- PTSA-catalyzed one-pot synthesis of quinoxalines using DMSO as the oxidant
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An efficient p-toluene sulfonic acid–catalyzed, one-pot, two-step oxidative system for cyclization of o-diaminobenzene with 1,2-diaryl-2-hydroxyethanone to quinoxalines was described. A nontoxic, readily available oxidant, dimethylsulfoxide (DMSO), was applied in this process. A broad range of substrates was applied to this method, and target compounds were obtained with good yields.
- Zhang, Zeyuan,Xie, Caixia,Feng, Lei,Ma, Chen
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- Silica sulfuric acid (SSA)/polyethylene glycol (PEG) as a recyclable system for the synthesis of quinoxalines and pyrazines
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An efficient and facile method has been developed for the condensation of 1,2-diamines with-hydroxyketones in polyethylene glycol (PEG) to quinoxalines and pyrazines with good yields in the presence of silica sulfuric acid (SSA). The important features of the methodology are simple operations, environmentally friendliness, and no requirement for metal catalysts. Additionally, the catalyst system (SSA/PEG) could be recovered easily and reused.
- Huang, Tieqiang,Jiang, Danna,Chen, Jiuxi,Gao, Wenxia,Ding, Jinchang,Wu, Huayue
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Read Online
- Ruthenium?p-cymene complexes with acylthiourea, and its heterogenized form on graphene oxide act as catalysts for the synthesis of quinoxaline derivatives
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Synthesis of a series of half-sandwich Ru(II) complexes (1-5) containing acylthiourea ligand is reported herein. All the Ru(II) complexes were well characterized by analytical and spectroscopic (UV-Vis, FT-IR, NMR and mass spectrometry) methods. Molecular structures of two (2 and 3) of the complexes were confirmed by single crystal X-ray diffraction, and the complexes adopted pseudo-octahedral geometry around Ru. Catalytic ability of the Ru complexes was evaluated in the synthesis of quinoxaline compounds from various 2-nitroaniline and hydroxy ketone derivatives via transfer hydrogenation approach. Active homogeneous catalyst was heterogenized by supporting it on graphene oxide, and the heterogeneous equivalent was characterized by Raman, XPS, TEM, SEM and ICP-OES techniques. Activity of the heterogeneous catalyst was tested, and it can be reused up to five cycles without any loss in activity.
- Bhuvanesh, Nattamai,Gopiraman, Mayakrishnan,Karvembu, Ramasamy,Sindhuja, Dharmalingam,Vasanthakumar, Punitharaj
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- 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 Hydrogen Transfer Reduction of Nitroarenes with Alcohols: Synthesis of Imines and Aza Heterocycles
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A straightforward and selective reduction of nitroarenes with various alcohols was efficiently developed using an iron catalyst via a hydrogen transfer methodology. This protocol led specifically to imines in 30-91% yields, with a good functional group tolerance. Noticeably, starting from o-nitroaniline derivatives, in the presence of alcohols, benzimidazoles can be obtained in 64-72% yields when the reaction was performed with an additional oxidant, DDQ, and quinoxalines were prepared from 1,2-diols in 28-96% yields. This methodology, unprecedented at iron for imines, also provides a sustainable alternative for the preparation of quinoxalines and benzimidazoles.
- Wu, Jiajun,Darcel, Christophe
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p. 1023 - 1036
(2021/01/09)
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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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- HBTU-catalyzed simple and mild protocol for the synthesis of quinoxaline derivatives
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HBTU-catalyzed, simple, mild, and effective protocol for the synthesis of quinoxalines has been established. The reaction between 1,2-diamines, benzil, and catalytic amount of HBTU in ethanol resulted into quinoxalines. Various aliphatic, aromatic and het
- Bhushan, B. Popatkar,Gangadhar, A. Meshram
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- AIE-ACTIVE CHEMO SENSORS FOR AMINE DETECTION AND RELATED FOOD-SAFETY MONITORING
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AIE-active chemosensors, according to the present teachings, exhibit UV-vis absorption change and become non-luminescent upon protonation. Upon deprotonation, the chemosensors revert to their original absorption and emission. This deprotonation process can be triggered in the presence of amines, and specifically, biogenic amines. The chemosensors can detect amine species, e.g., biogenic amines produced during food fermentation, quickly and with high sensitivity. Further, due to the AIE nature of the compounds, the chemosensors can be loaded onto a physical support and sealed inside a food package to monitor food spoilage.
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Paragraph 0023-0025; 0116; 0117
(2020/03/09)
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- Phosphine free Mn-complex catalysed dehydrogenative C-C and C-heteroatom bond formation: A sustainable approach to synthesize quinoxaline, pyrazine, benzothiazole and quinoline derivatives
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Herein the first sustainable synthesis of quinoxalines, pyrazines and benzothiazoles catalysed by a phosphine free Mn(i) complex via acceptorless dehydrogenative coupling (ADC) is reported. This method is also applied successfully to synthesize quinolines via the dehydrogenation (removal of H2) and condensation (removal of H2O) reaction between 2-aminobenzyl alcohols and secondary alcohols.
- Das, Kalicharan,Mondal, Avijit,Srimani, Dipankar
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supporting information
p. 10582 - 10585
(2018/09/25)
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- The Direct Synthesis of Imines, Benzimidazoles and Quinoxalines from Nitroarenes and Carbonyl Compounds by Selective Nitroarene Hydrogenation Employing a Reusable Iron Catalyst
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The “replacement” of noble metals by earth abundant metals is a desirable aim in catalysis and a possible way of conserving rare elements. The “replacement” is especially attractive if novel selectivity patterns are observed permitting the development of novel coupling reactions. Herein, we report on a novel, robust and reusable iron catalyst, which permits the selective hydrogenation of nitroarenes in the presence of hydrogenation-sensitive functional groups. Based on the selectivity pattern observed, the direct iron-catalyzed synthesis of imines and benzimidazoles from nitroarenes and aldehydes becomes feasible. In addition, we introduce the direct synthesis of quinoxalines from nitroarenes and diketones applying our catalyst.
- B?umler, Christoph,Kempe, Rhett
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supporting information
p. 8989 - 8993
(2018/05/30)
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- Ligand-Tuneable, Red-Emitting Iridium(III) Complexes for Efficient Triplet–Triplet Annihilation Upconversion Performance
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A series of substituted 2-phenylquinoxaline ligands have been explored to finely tune the visible emission properties of a corresponding set of cationic, cyclometallated iridium(III) complexes. The electronic and redox properties of the complexes were investigated through experimental (including time-resolved luminescence and transient absorption spectroscopy) and theoretical methods. The complexes display absorption and phosphorescent emissions in the visible region that are attributed to metal to ligand charge-transfer transitions. The different substitution patterns of the ligands induce variations in these parameters. Time-dependent DFT studies support these assignments and show that there is likely to be a strong spin-forbidden contribution to the visible absorption bands at λ=500–600 nm. Calculations also reliably predict the magnitude and trends in triplet emitting wavelengths for the series of complexes. The complexes were assessed as potential sensitisers in triplet–triplet annihilation upconversion experiments by using 9,10-diphenylanthracene as the acceptor; the methylated variants performed especially well with impressive upconversion quantum yields of up to 39.3 %.
- Phillips, Kaitlin A.,Stonelake, Thomas M.,Chen, Kepeng,Hou, Yuqi,Zhao, Jianzhang,Coles, Simon J.,Horton, Peter N.,Keane, Shannon J.,Stokes, Emily C.,Fallis, Ian A.,Hallett, Andrew J.,O'Kell, Sean P.,Beames, Joseph M.,Pope, Simon J. A.
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p. 8577 - 8588
(2018/06/26)
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- A Highly Sensitive Bimodal Detection of Amine Vapours Based on Aggregation Induced Emission of 1,2-Dihydroquinoxaline Derivatives
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The detection of food spoilage is a major concern in food safety as large amounts of food are transported globally. Direct analysis of food samples is often time-consuming and requires expensive analytical instrumentation. A much simpler and more cost-eff
- Alam, Parvej,Leung, Nelson L. C.,Su, Huifang,Qiu, Zijie,Kwok, Ryan T. K.,Lam, Jacky W. Y.,Tang, Ben Zhong
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p. 14911 - 14917
(2017/10/07)
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- N-Bromosuccinimide-Mediated Synthesis of Substituted Quinoxalines
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An efficient and simple N-bromosuccinimide-mediated two-step synthesis of substituted quinoxalines from 1,2-diarylacetylenes and 1,2-diaminobenzenes in boiling AcOH, during a one-pot procedure has been developed. All the structures of the substituted quinoxalines were confirmed, some by single-crystal X-ray crystallography. Possible reaction pathways were discussed, and some data were matched with the previous work.
- Chan, Chieh-Kai,Chang, Meng-Yang
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p. 3785 - 3793
(2016/10/30)
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- An efficient iodine-DMSO catalyzed synthesis of quinoxaline derivatives
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An efficient iodine-DMSO catalyzed system for the synthesis of quinoxaline derivatives was developed. The construction of this quinoxaline system went through a one-pot oxidation/cyclization process. The reaction afforded a variety of products in good to excellent yields. This methodology has potential applications in the synthesis of biologically and medicinally relevant compounds.
- Xie, Caixia,Zhang, Zeyuan,Yang, Bingchuan,Song, Gaolei,Gao, He,Wen, Leilin,Ma, Chen
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p. 1831 - 1837
(2015/03/04)
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- Nitrilotris(Methylenephosphonic Acid) as a New Highly Efficient and Recyclable Br?Nested Acid Catalyst for the Synthesis of Quinoxaline Derivatives under Mild and Green Conditions
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Nitrilotris(methylenephosphonic acid) has been introduced as a novel organocatalyst for the preparation of quinoxalines. It can efficiently catalyze the synthesis of quinoxaline derivatives from 1,2-diamines and 1,2-diketones under mild, efficient, and eco-friendly conditions. Excellent yields, very short reaction times, safety, and recyclability of the catalyst system are other features of the proposed method.
- Fathi, Safoura,Sardarian, Ali Reza
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p. 1471 - 1478
(2015/09/01)
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- A highly cis-selective and enantioselective metal-free hydrogenation of 2,3-disubstituted quinoxalines
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A wide range of 2,3-disubstituted quinoxalines have been successfully hydrogenated with H2 using borane catalysts to produce the desired tetrahydroquinoxalines in 80-99% yields with excellent cis selectivity. Significantly, the asymmetric reaction employing chiral borane catalysts generated by the in situ hydroboration of chiral dienes with HB(C6F5)2 under mild reaction conditions has also been achieved with up to 96% ee, and represents the first catalytic asymmetric system to furnish optically active cis-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines.
- Zhang, Zhenhua,Du, Haifeng
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supporting information
p. 623 - 626
(2015/03/04)
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- Visible-light-induced C=C bond cleavage of enaminones for the synthesis of 1,2-diketones and quinoxalines in sustainable medium
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The C=C double bond cleavage of enaminones has been realized under ambient conditions through visible-light catalysis in the presence of Rose Bengal, which leads to the synthesis of a class of 1,2-diketones without using any metal catalyst. In addition, the one-pot synthesis of quinoxalines has also been achieved under identical photocatalytic conditions by making use of the in situ generated 1,2-diketones as intermediates.
- Cao, Shuo,Zhong, Shanshan,Xin, Luoting,Wan, Jie-Ping,Wen, Chengping
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p. 1478 - 1482
(2015/06/24)
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- Eco-friendly synthesis of 2-aryl-1-arylmethyl-1H-benzimidazoles using alumina-sulfuric acid as a heterogeneous reusable catalyst
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A cost-effective and eco-friendly synthesis of 2-aryl-1-arylmethyl-1H- benzimidazoles has been developed through the condensation of different aldehydes with o-phenylenediamine using alumina-sulfuric acid as a recyclable heterogeneous solid acid catalyst.
- Pramanik, Amit,Roy, Rimi,Khan, Sagar,Ghatak, Avishek,Bhar, Sanjay
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p. 1771 - 1777
(2014/03/21)
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- A highly efficient procedure for the synthesis of quinoxaline derivatives using polyvinylpolypyrrolidone supported triflic acid catalyst (PVPP·OTf)
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A polyvinylpolypyrrolidone supported triflic acid was shown to be useful as a recyclable heterogeneous catalyst for the rapid and efficient synthesis of quinoxaline derivatives in good-to-excellent yields. The catalyst is easily prepared, air-stable, reus
- Khaksar, Samad,Tajbakhsh, Mahmoud,Gholami, Milad,Rostamnezhad, Fariba
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p. 1287 - 1290
(2014/10/15)
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- Pentafluorophenylammonium triflate: A highly efficient catalyst for the synthesis of quinoxaline derivatives in water
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A simple, inexpensive, environmentally friendly and efficient route for the rapid and efficient synthesis of quinoxaline derivatives using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. Various quinoxaline derivatives were synthesi
- Khaksar, Samad,Radpeyma, Hanieh
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p. 1023 - 1027
(2014/12/10)
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- Sodium bromate/sodium hydrogen sulfite: A new catalyst for the synthesis of quinoxaline derivatives
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Treatment of 1,2-phenylenediamine with benzil analogs in the presence of a mixture of sodium bromate/sodium hydrogen sulfite in water gave the corresponding quinoxalines in high yields. The method is eco-friendly due to use of water instead of other hazar
- Khan, Khalid M.,Hussain, Shafqat,Perveen, Shahanaz,Rahim, Fazal,Yousuf, Sammer,Hussain, Ejaz
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p. 426 - 431
(2014/05/20)
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- A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
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A highly efficient and versatile method for the synthesis of quinoxaline derivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange, conformational, and/or tautomeric exchanges between several forms for most of the bis-benzimidazolylquinoxalines signals of bridged and neighboring carbon atoms and the hydrogen atoms of the neighboring carbon atoms of benzimidazole fragments in the NMR spectra are broadened. The conjugation between the benzimidazole fragments and the quinoxaline core of the molecules is increased from the quinoxaline derivative (10c) to its thiadiazol[f]- (17) and pyrrolo[a]-(19) annulated derivatives, resulting in a greater planarity of the molecule as a whole.
- Mamedov, Vakhid A.,Zhukova, Nataliya A.,Syakaev, Victor V.,Gubaidullin, Aidar T.,Beschastnova, Tat'Yana N.,Adgamova, Dil'Bar I.,Samigullina, Aida I.,Latypov, Shamil K.
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supporting information
p. 1403 - 1416
(2013/02/23)
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- Surfactant micelles as microreactors for the synthesis of quinoxalines in water: Scope and limitations of surfactant catalysis
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The scope and limitations of surfactants as catalysts for the synthesis of quinoxalines using microreactors made of the surfactants in water has been assessed. The catalytic potential followed the order: non-ionic surfactants > anionic surfactants > Bronsted acid surfactants > cationic surfactants. The non-ionic surfactant, Tween 40, is the most effective catalyst affording excellent yields within a short reaction time at room temperature and is compatible with different variations of the 1,2-diketones and 1,2-diamines. The reaction medium (spent water) containing the catalyst, as well as the catalyst itself (recovered Tween 40) can be reused for five consecutive reactions. The better catalytic efficiency of the surfactant (Tween 40) compared to the various Lewis/Bronsted acids, as well as the surfactant combined Lewis acid, suggests that surfactants, which generate microreactor assemblies at the interface, are better suited as catalytic aids to promote organic reactions in water. The inferior results obtained in organic solvents, which provide a homogeneous reaction mixture compared to those obtained in water, indicate the specific role of water. This has been depicted as a synergistic dual activation through the hydrogen bond mediated formation of supramolecular assemblies involving a water dimer and the reactants. The catalytic assistance of the surfactant could be ascribed to the ability of the surfactant molecule to undergo hydrophobic and hydrogen bond forming interactions with water and the reactants in orienting the reactants at the water interface and encapsulating inside the microreactors to facilitate the cyclocondensation. The Royal Society of Chemistry 2013.
- Kumar, Dinesh,Seth, Kapileswar,Kommi, Damodara N.,Bhagat, Srikant,Chakraborti, Asit K.
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p. 15157 - 15168
(2013/09/02)
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- A green and efficient protocol for the synthesis of quinoxaline, benzoxazole and benzimidazole derivatives using heteropolyanion-based ionic liquids: As a recyclable solid catalyst
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In this paper, we introduce two nonconventional ionic liquid compounds which are composed of propane sulfonate functionalized organic cations and heteropolyanions as green solid acid catalysts for the highly efficient and green synthesis of 2,3-disubstitutedquinoxaline derivatives. These ionic liquids are in the solid state at room temperature and the synthesis is carried out via the one-pot condensation reaction of various o-phenylenediamine with 1,2-diketone derivatives. Benzoxazole and benzimidazole derivatives were also synthesized by these novel catalysts via the one-pot condensation from reaction orthoester with o-aminophenol (synthesis of benzoxazole derivatives) and ophenylenediamine (synthesis of benzimidazole derivatives). All experiments successfully resulted in the desired products. The described novel synthesis method has several advantages of safety, mild condition, high yields, short reaction times, simplicity and easy workup compared to the traditional method of synthesis.
- Vahdat, Seyed Mohammad,Baghery, Saeed
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p. 618 - 627
(2013/09/12)
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- Logic design and synthesis of quinoxalines via the integration of iodination/oxidation/cyclization sequences from ketones and 1,2-diamines
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A novel protocol for the synthesis of quinoxalines has been developed from simple ketones and 1,2-diamines. This process underwent a logic approach to bis-substituted quinoxalines via a consecutive iodination/Kornblum oxidation/cyclization in the presence of I2/CuO/DMSO and to mono-substituted quinoxalines via an iodination/cyclization/aromatization in the presence of I2/CuO/K3PO4·3H 2O.
- Lian, Mi,Li, Qi,Zhu, Yanping,Yin, Guodong,Wu, Anxin
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p. 9598 - 9605
(2012/11/07)
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- A novel one-pot synthesis of quinoxaline derivatives in fluorinated alcohols
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Hexafluoroisopropanol (HFIP) is explored as an effective medium for the synthesis of quinoxaline derivatives in high yields at room temperature. The solvent (HFIP) can be readily separated from reaction products and recovered in excellent purity for direc
- Khaksar, Samad,Rostamnezhad, Fariba
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p. 2581 - 2584
(2012/10/29)
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- Glycerin and CeCl3 7H2O: A new and efficient recyclable reaction medium for the synthesis of quinoxalines
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An efficient and environmentally benign process for the synthesis of quinoxalines has been developed using glycerine-cerium chloride as a reaction medium. This method is applicable to a variety of diketones and 1,2-phenylenediamines to afford the corresponding quinoxaline derivatives in excellent yields. The reaction medium was recovered and reused for further reactions without any problem. Taylor & Francis Group, LLC.
- Venkat Narsaiah,Kranthi Kumar
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experimental part
p. 883 - 892
(2012/03/11)
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- DABCO-catalyzed oxidation of deoxybenzoins to benzils with air and one-pot synthesis of quinoxalines
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Aerobic oxidation of deoxybenzoins could be efficiently catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) with air as the sole oxidant to give the corresponding benzils in excellent yields. The effects of reaction conditions, such as different bases, temperature, time and solvent, on the yield of the product were investigated. Moreover, the process has been successfully extended to a one-pot synthesis of quinoxalines from benzyl ketones and aromatic 1,2-diamines. Georg Thieme Verlag Stuttgart New York.
- Qi, Chaorong,Jiang, Huanfeng,Huang, Liangbin,Chen, Zhengwang,Chen, Huoji
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experimental part
p. 387 - 396
(2011/04/15)
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- Eco-friendly synthesis of quinoxaline derivatives by grinding under solvent-free conditions
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An efficient and facile synthesis of quinoxaline derivatives in excellent isolated yields by the condensation of 1,2-diamines and 1,2-diketones on grinding under solvent-free conditions at ambient temperature has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup, and environmentally benign.
- Li, Jun,Jiang, Dan-Na,Chen, Jiu-Xi,Liu, Miao-Chang,Ding, Jin-Chang,Wu, Hua-Yue
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experimental part
p. 403 - 406
(2011/05/14)
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- Niobium pentachloride as a highly efficient catalyst for the synthesis of quinoxaline derivatives
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Niobium pentachloride is found to be an efficient catalyst for the synthesis of quinoxaline derivatives via the condensation of aromatic 1,2-dicarbonyl compounds (or unsymmetrical 1,2-diketones or α-hydroxy ketones) with 1,2-diamines. All the reactions were performed at room temperature while using acetonitrile as solvent. The present methodology offers several advantages such as excellent yields, short reaction time and environmentally benign milder reaction conditions.
- Kidwai, Mazaahir,Mishra, Neeraj Kumar,Bhatnagar, Divya,Jahan, Anwar
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experimental part
p. 5051 - 5054
(2012/07/03)
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- Samarium triflate catalyzed efficient synthesis of quinoxalines
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A highly efficient method for the synthesis of quinoxalines derivatives has been developed using samarium triflate as catalyst. The method is applicable to a variety of 1,2-diketones and 1,2-diamines to afford the corresponding quinoxalines derivatives in high yields. All the reactions were carried out at acetonitrile reflux.
- Raghuveerachary,Devanna
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experimental part
p. 1628 - 1630
(2012/01/05)
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- Synthesis of quinoxalines in presence of zinc triflate
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A simple and efficient method for the synthesis of quinoxaline derivatives has been developed. The reactions were carried out in presence of zinc triflate in acetonitrile reflux. The method is applicable to a variety of diketones and 1,2-phenylenediamines to afford the corresponding derivatives in excellent yields.
- Subrahmanyam, C. Siva,Narayanan
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experimental part
p. 1331 - 1333
(2011/12/21)
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- Citric acid: An efficient and green catalyst for rapid one pot synthesis of quinoxaline derivatives at room temperature
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The condensation of o-phenylenediamines with 1,2-dicarbonyl compounds in the presence of citric acid afforded the corresponding quinoxaline derivatives in higher yields at room temperature in ethanol, and most of the reactions were completed in less than 1 min.
- Mahesh, Radhakrishnan,Dhar, Arghya Kusum,Sasank T.v.n.v., Tara,Thirunavukkarasu, Sappanimuthu,Devadoss, Thangaraj
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experimental part
p. 389 - 392
(2012/01/05)
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- Efficient, ecofriendly, and practical process for the synthesis of quinoxalines catalyzed by amberlyst-15 in aqueous media
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Amberlyst-15/H2O has been used as an efficient and environmentally friendly catalytic system for the synthesis of quinoxalines. The present methodology offers several advantages, such as excellent yields, short reaction time, and simple workup. Copyright Taylor & Francis Group, LLC.
- Liu, Ju-Yan,Liu, Jing,Wang, Jia-Di,Jiao, De-Quan,Liu, Hai-Wang
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experimental part
p. 2047 - 2056
(2010/08/13)
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- Niobium (V) chloride: An efficient catalyst for the synthesis of quinoxalines
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A simple and efficient method for the synthesis of quinoxalines derivatives has been developed. All the reactions were carried out in presence of niobium (V) chloride at acetonitrile reflux conditions. The method is applicable to a variety of diketones and 1, 2-phenylenediamines to afford the corresponding derivatives in excellent yields.
- Venkateswarlu,Leelavathi
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experimental part
p. 208 - 211
(2011/07/08)
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- Magnetic Fe3O4 nanoparticles as new, efficient, and reusable catalysts for the synthesis of quinoxalines in water
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A novel, environmentally friendly procedure has been developed for the synthesis of quinoxaline derivatives in the presence of magnetic Fe 3O4 nanoparticles. The reaction between 1,2-diamines and 1,2-dicarbonyl compounds was carried out in water to afford quinoxaline derivatives in high yield. The catalyst can be recovered by the use of an external magnet and reused for five cycles with almost consistent activity. CSIRO 2010.
- Lue, Hong-Yan,Yang, Shu-Hong,Deng, Jia,Zhang, Zhan-Hui
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experimental part
p. 1290 - 1296
(2011/04/15)
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- Application of metalloporphyrins as new catalysts for the efficient, mild and regioselective synthesis of quinoxaline derivatives
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A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1,2-diamines with α-diketones in the presence of catalytic amounts of metalloporphyrins at room temperature is described. Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields and short reaction times. In this report, the effects of central metal in porphyrin core and substituents on tetraphenylporphyrin skeleton have been studied.
- Mohammadi, Khosro,Hasaninejad, Alireza,Niad, Mahmud,Najmi, Mojtaba
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experimental part
p. 1052 - 1058
(2011/11/14)
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- Efficient and inexpensive synthesis of benzimidazoles and quinoxalines
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o-Phenylenediamines were reacted with carbonyl compounds, β-ketoesters, and 1,2-diketones in presence of ammonium salts to give benzimidazoles and quinoxalines in very good yields. Ammonium salts are commercial and environmentally benign catalysts. Copyright Taylor & Francis Group, LLC.
- Raju, B. China,Theja, N. Dharma,Kumar, J. Ashok
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experimental part
p. 175 - 188
(2009/04/07)
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- Bismuth(III)-catalyzed rapid synthesis of 2,3-disubstituted quinoxalines in water
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A variety of 2,3-disubstituted quinoxalines are readily prepared in high yields under extremely mild conditions by cyclocondensation of arene-1,2-diamines with 1,2-dicarbonyls using a catalytic amount of bismuth(III) triflate. The reactions of 2,3-diamino
- Yadav, Jhillu S.,Subba Reddy, Basi V.,Premalatha, Kokku,Shankar, Kattela Shiva
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experimental part
p. 3787 - 3792
(2009/06/17)
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- Efficient synthesis of quinoxaline derivatives catalyzed by p-toluenesulfonic acid under solvent-free conditions
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A series of quinoxaline derivatives were efficiently synthesized in excellent yields by the reaction of 1,2-diamines and 1,2-diketones with grinding catalyzed by p-toluenesulfonic acid under solvent-free conditions at room temperature. Compared with the classical synthetic method, this new method has the advantages of convenient manipulation and environmental friendliness. Copyright Taylor & Francis Group, LLC.
- Shi, Da-Qing,Dou, Guo-Lan
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p. 3329 - 3337
(2008/12/22)
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- Ketones as a new synthon for quinoxaline synthesis
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o-Phenylenediamines react with an array of ketones in PEG-400 at 60 °C under an atmosphere of air in the presence of KOH to afford the corresponding quinoxalines in good yields.
- Cho, Chan Sik,Ren, Wen Xiu,Shim, Sang Chul
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p. 4665 - 4667
(2008/03/12)
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- Synthesis of quinoxalines by cyclization of α-arylimino oximes of α-dicarbonyl compounds
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Heating the title compounds 1 at reflux in acetic anhydride yields quinoxalines 3 and 4 via a presumed aryliminoiminyl radical 5, resulting from homolytic cleavage of the N-O bond in the intermediate ester 2. The observed regioselectivity of the reaction is also rationalized by implicating such a radical. (C) 2000 Elsevier Science Ltd.
- Xekoukoulotakis,Hadjiantoniou-Maroulis,Maroulis
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p. 10299 - 10302
(2007/10/03)
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- The syntheses of pyrazino-containing sultines and their application in Diels-Alder reactions with electron-poor olefins and [60]fullerene
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The Diels-Alder reactions of heterocyclic o-quinodimethanes, generated in situ from 6,7-disubstituted quinoxalino[2,3-d]-[1,2λ4]oxathiine 2-oxides (6a-c), 2,3-disubstituted-8,9-dihydro-6H-8λ 4-[1,2]oxathiino[4,5-g]quinoxalin-8-one (7a-c) (sultines), and pyrazinosultine (22), with electron-poor olefins and [60]fullerene are described. The heterocyclic-fused sultines 7a-c and 22 are readily prepared from the corresponding dibromides 9a-c and 24 with the commercially available Rongalite (sodium formaldehyde sulfoxylate). When heated in the presence of electron-poor dienophiles and [60]fullerene, all of the sultines underwent extrusion of SO2, and the resulting heterocyclic o-quinodimethanes (3a-d, 4a-c, and 25) were intercepted as the 1:1 adducts in good to excellent yields. The temperature-dependent 1H NMR spectra of fullerene derivatives 31-38 show a dynamic process for the methylene protons. The activation free energies (ΔGc?) determined for the boat-to-boat inversion of these pyrazino-containing C60 compounds (31-34 and 38) are found to be in the range of 14.1-14.8 kcal/mol, but they are in the range of 15.2 to >17.1 kcal/mol for adducts 35-37. The activation free energies (ΔGC?) are significantly affected by (1) the orientations and (2) the substituents of the quinoxaline rings and (3) the extended benzannulation in the arenes of C60 adducts (see Table 2), which implies that both electronic interactions and steric effects between the aromatic addends and C60 are important. Tautomerization of methylquinoxaline to its enamine is invoked as a rationalization for the lowering of ΔGC? in some of the fulleroadducts.
- Liu, Jing-Horng,Wu, An-Tai,Huang, Ming-Hwei,Wu, Chein-Wei,Chung, Wen-Sheng
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p. 3395 - 3403
(2007/10/03)
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