- Modulated emission from dark triplet excitons in aza-acene compounds: fluorescence versus phosphorescence
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In the field of organic light-emitting diodes (OLEDs), research interests focus on making the optically dark triplet excitons shine in order to increase the electro-optic conversion efficiency of devices. In this work, two kinds of phenazine compounds, i.e. dibenzo[a,c]phenazine (DBP) and tribenzo[a,c,i]phenazine (TBP), were synthesized and used as model compounds to regulate the emission efficiency of the dark triplet excitons by chemical modification. Charge-transfer induced ultrafast intersystem crossing (CT-ISC) with a time constant of ～1 ps was observed for these two phenazine derivatives upon photoexcitation with a high triplet yield of 77.1% for DBP and 58.7% for TBP. The triplet excited states of DBP can produce ultra-long phosphorescence with lifetime as long as 318 ms at 77 K. The quantum yield for phosphorescence (ΦP) is determined to be 8.45%. In sharp contrast, the triplet-excited 3TBP* undergoes an efficient reverse intersystem crossing (RISC) process, resulting in bright delayed fluorescence emission with negligible phosphorescence. A controllable luminescence behavior from the triplet states between fluorescence and phosphorescence in phenazine derivatives is demonstrated. Theoretical calculations reveal that the structure-dependent triplet evolution is due to the charge-transfer induced energy level alignment within these compounds. Our results may have potential applications in the design of OLEDs and high triplet yield pure organic materials.
- Chen, Jianwei,Chen, Yi,Wu, Yishi,Wang, Xuedong,Yu, Zhenyi,Xiao, Lu,Liu, Yanping,Tian, He,Yao, Jiannian,Fu, Hongbing
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- Ternary Emission of Fluorescence and Dual Phosphorescence at Room Temperature: A Single-Molecule White Light Emitter Based on Pure Organic Aza-Aromatic Material
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Herein, a simple aza-aromatic compound dibenzo[a,c]phenazine (DPPZ), which exhibits single-molecule white light with a ternary emission, consisting of simultaneous fluorescence (S1→S0) and dual room-temperature phosphorescence (RTP, T2→S0 and T1→S0) is reported. The Commission Internationale de l' éclairage coordinates of DPPZ powder are (0.28, 0.33). To everyone's knowledge, this is the first case to achieve single-molecule white emission with ternary emission of fluorescence and dual RTP. This finding provides a prototype strategy to realize low-cost, stable pure organic single-molecule white light emission with three standard primary colors through further precise modulation of excited states.
- Zhou, Changjiang,Zhang, Shitong,Gao, Yu,Liu, Haichao,Shan, Tong,Liang, Xiaoming,Yang, Bing,Ma, Yuguang
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Read Online
- Use of co-grinding as a solvent-free solid state method to synthesize dibenzophenazines
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Many synthetic methods exist for dibenzoquinoxalines but only a few for dibenzophenazines and their aza derivatives and even less are 'green'. Some dibenzophenazines and dibenzopyridoquinoxaline have been efficiently obtained with good to excellent yield by a very simple method which does not require use of solvent or catalyst. Solid phase synthesis using co-grinding presents thus many advantages in developing greener synthetic organic pathways.
- Carlier, Leslie,Baron, Michel,Chamayou, Alain,Couarraze, Guy
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Read Online
- A general method for the synthesis of structurally diverse quinoxalines and pyrido-pyrazine derivatives using camphor sulfonic acid as an efficient organo-catalyst at room temperature
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A mild, convenient, eco-friendly, general and practical approach has been developed for the synthesis of a series of structurally diverse quinoxaline derivatives via the condensation reactions of various 1,2-diaminobenzene derivatives and 1,2-dicarbonyls
- Kaur, Gurpreet,Singh, Arvind,Kaur, Navdeep,Banerjee, Bubun
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- Electron-transfer reorganization energies of isolated organic molecules
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He I photoelectron spectra of phenanthrene (1), 1,10-phenanthroline (2), phenazine (3), dibenzo[a,c]anthracene (4), dibenzo[a,c]phenazine (5), and dipyrido[3,2-a;2′3′-c]phenazine (6) have been obtained. Assignment of the π ionization states was aided by electronic structure calculations: the first ionization state of 1, 2B1(π1), is observed at 7.888 ± 0.002 eV, 2B2(π1) of 2 is at 8.342 ± 0.002 eV, and 2B1g(π1) of 3 is at 8.314 ± 0.002 eV. Spectra of 4-6 are reported for the first time: 2A2(π1) of 4 is at 7.376 ± 0.002 eV, and both 5 (7.983 ± 0.002 eV) and 6 (8.289 ± 0.002 eV) exhibit quasi-degenerate first and second ionization states. Quantum-mechanical reorganization energies, λQM, were extracted from analyses of vibrational structure: values are 149 ± 5 (1), 167 ± 5 (2), 68 ± 2 (3), and 92 ± 4 (4) meV. Low-frequency modes were treated semiclassically: values of λSC are estimated to be 21 ± 1 (1), 13 ± 1 (2), 22 ± 1 (3), 66 ± 1 (4), 27 ± 9 (5), and 16 ± 1 (6) meV. Reorganization energies (λ = λQM + λSC) of isolated molecules are 170 ± 5 (1), 180 ± 5 (2), 90 ± 2 (3), and 158 ± 4 (4) meV. Density functional calculations (B3LYP/6-311G++(d,p)) give λ values that are on average 63 meV lower than experimentally derived energies.
- Amashukeli, Xenia,Winkler, Jay R.,Gray, Harry B.,Gruhn, Nadine E.,Lichtenberger, Dennis L.
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- Ring Closure of Heterocyclic Systems by Potassium-Graphite Intercalat - C8K
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Potassium-graphite intercalate C8K is the reagent of choice for the ring closure of the dianions of 2,3-diarylquinoxalines derivatives 1-3 to the dianions of dibenzophenazine derivatives 4-6 in high yields and high degree of purity.This process appears to occur via a thermal electrocyclic process of the dianions.
- Tamarkin, Dov,Cohen, Yoram,Rabinovitz, Mordecai
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Read Online
- Synthesis and photophysical properties of three ladder-type chromophores with large and rigid conjugation structures
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Three novel ladder-conjugated chromophores indicated as LT1–LT3 were synthesized and characterized. Further studies on linear, nonlinear optics and electrochemical properties demonstrated their photophysical features respectively. Compound LT1 shows good two-photon absorption cross-section (δ) up to?～1200?GM at 810?nm in tetrahydrofuran, which is attributed to intramolecular charge transfer effect, as supported by density functional theory theoretical calculations. Compound LT2 and LT3 show considerable molar extinction coefficients, which are more than 105, and higher quantum yields. Structure–function relationship is further discussed, suggesting a rational strategy to develop ladder-conjugated small molecules.
- Zhang, Kaichen,Dai, Yong,Zhang, Xinfu,Xiao, Yi
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Read Online
- Green Hydrothermal Synthesis of Fluorescent 2,3-Diarylquinoxalines and Large-Scale Computational Comparison to Existing Alternatives
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Here, the hydrothermal synthesis (HTS) of 2,3-diarylquinoxalines from 1,2-diketones and o-phenylendiamines (o-PDAs) was achieved. The synthesis is simple, fast, and generates high yields, without requiring any organic solvents, strong acids or toxic catalysts. Reaction times down to 90 % in all cases). Moreover, it was shown that HTS has high compatibility: (i) hydrochlorides, a standard commercial form of amines, could be used directly as combined amine source and acidic catalyst, and (ii) Boc-diprotected o-PDA could be directly employed as substrate that underwent HT deprotection. A systematic large-scale computational comparison of all reported syntheses of the presented quinoxalines from the same starting compounds showed that this method is more environmentally friendly and less toxic than all existing methods and revealed generic synthetic routes for improving reaction yields. Finally, the application of the synthesized compounds as fluorescent dyes for cell staining was explored.
- Amaya-García, Fabián,Caldera, Michael,Koren, Anna,Kubicek, Stefan,Menche, J?rg,Unterlass, Miriam M.
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p. 1853 - 1863
(2021/04/02)
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- In water organic synthesis: Introducing itaconic acid as a recyclable acidic promoter for efficient and scalable synthesis of quinoxaline derivatives at room temperature
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Substituted quinoxaline derivatives are traditionally synthesized by co-condensation of various starting materials. Herein, we describe a novel environmentally benign in water synthetic route for the synthesis of structurally and electronically diverse ninety quinoxalines with readily available substituted o-phenylenediamine and 1,2-diketones using cheap and biodegradable itaconic acid as a mild acid promotor in 1 hours. The reaction is performed at room temperature, which proceeds through cyclo-condensation reaction followed by obtaining the aforesaid nitrogen-containing heterocyclic adducts without performing the column chromatography up to 96% total yields. The simplicity, high efficiency, and reusable of the catalyst merits this reaction condition as “green synthesis” which enables it to be useful in synthetic transformations upto gram scale level.
- Tamuli, Kashyap J.,Nath, Shyamalendu,Bordoloi, Manobjyoti
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supporting information
p. 983 - 1002
(2021/02/27)
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- BSA-encapsulated cyclometalated iridium complexes as nano-photosensitizers for photodynamic therapy of tumor cells
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Photodynamic therapy is a promising treatment method. The development of suitable photosensitizers can improve therapeutic efficacy. Herein, we report three iridium complexes (Ir1, Ir2, and Ir3), and encapsulate them within bovine serum albumin (BSA) to f
- Xu, Yao,Wang, Xiang,Song, Kang,Du, Jun,Liu, Jinliang,Miao, Yuqing,Li, Yuhao
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p. 15323 - 15331
(2021/05/19)
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- Synthesis of quinoxaline, benzimidazole and pyrazole derivatives under the catalytic influence?of biosurfactant-stabilized iron nanoparticles in water
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Abstract: We have reported the synthesis, characterization, and catalytic applications of amorphous iron nanoparticles (FeNPs) using aqueous leaves extract of renewable natural resource Boswellia serrata plant. Synthesized FeNPs were stabilized in situ by the addition of aqueous pod extracts of Acacia concinna as a biosurfactant (pH 3.11). The structural investigation of biosynthesized nanoparticles was performed using UV–visible spectroscopy, X-ray diffraction analysis, selected area electron diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and BET analysis. The FeNPs were amorphous in nature with average particle size ~ 19?nm and successfully employed as heterogeneous catalyst for the synthesis of quinoxaline, benzimidazole, and pyrazole derivatives in aqueous medium at ambient conditions. The FeNPs could be recycled up to five times with modest change in the catalytic activity. Graphic abstract: [Figure not available: see fulltext.].
- Arde, Satyanarayan M.,Patil, Audumbar D.,Mane, Ananda H.,Salokhe, Prabha R.,Salunkhe, Rajashri S.
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p. 5069 - 5086
(2020/09/02)
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- [BBSA-DBN][HSO4]: a novel –SO3H functionalized Bronsted acidic ionic liquid for easy access of quinoxalines
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Abstract: A novel –SO3H difunctionalized Bronsted acidic ionic liquid (BAIL) 1, 5-bis (butanesulphonic acid)-diazobicyclo [4,3,0] non-5-enium hydrogen sulphate [BBSA-DBN][HSO4] is introduced for efficient synthesis of quinoxalines vi
- Patil, Megha U.,Shinde, Sachinkumar K.,Patil, Sandip P.,Patil, Suresh S.
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p. 4923 - 4938
(2020/08/24)
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- Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes
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An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.
- Kawauchi, Daichi,Noda, Kenta,Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 15793 - 15798
(2020/10/12)
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- Comprehensive experimental investigation of mechanically induced 1,4-diazines synthesis in solid state
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Compared mechanosynthesis of two condensed 1,4-diazines were investigated in ball milling conditions from o-phenylenediamine. 13C CP-MAS NMR revealed a hemiaminal intermediate for dibenzo[a,c]phenazine synthesis accumulated under mechanical act
- Oliveira, Paulo F.M.,Haruta, Naoki,Chamayou, Alain,Guidetti, Brigitte,Baltas, Michel,Tanaka, Kazuyoshi,Sato, Tohru,Baron, Michel
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p. 2305 - 2310
(2017/03/24)
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- Synthesis and characterization of phenanthrene derivatives with anticancer property against human colon and epithelial cancer cell lines
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A variety of polycyclic aromatic hydrocarbons have been synthesized and structurally characterized in our laboratory. Phenanthrene derivatives were efficiently prepared in excellent yields and high purity via a two-step sequence. Heck coupling yielded the corresponding diarylethenes, followed by classical oxidative photocyclization to achieve the expected phenanthrenes. First, we envisioned to synthesize a variety of substituted phenanthrenequinones. Second, we investigated the possibility of a dibenz[a,c]phenazine formation by addition of o-phenylenediamine after completion of the oxidation process. Moreover, because phenanthrenequinones are available so simply, it is likely that other uses will be found for these compounds. For example, 9,10-phenanthrenequinone can be sequentially reduced, alkylated, acetylated, and sulfonated. All the synthesized derivatives were evaluated for cytotoxic activity in vitro against the human epidermoid carcinoma epithelial cells Hep-2 and human colon carcinoma cells Caco-2 using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. From the structure–activity point of view, position and nature of the electron donating and electron withdrawing functional groups attached to the phenanthrene skeleton may contribute to the anticancer action. Interestingly, the analysis of the IC50 values suggests that most compounds exerted cytotoxic effects with selectivity against both cancer cells. Among them, methyl 8-methyl-9,10-phenanthrenequinone-3-carboxylate 11d showed the highest potency with IC50 values of 2.81 and 0.97 μg/mL.
- Guédouar, Habiba,Aloui, Faouzi,Beltifa, Asma,Ben Mansour, Hedi,Ben Hassine, Béchir
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p. 841 - 849
(2017/06/20)
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- Synthesis of benzimidazole and quinoxaline derivatives using reusable sulfonated rice husk ash (RHA-SO3H) as a green and efficient solid acid catalyst
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In this work, a simple, rapid and efficient method for the preparation of benzimidazoles and quinoxalines from the condensation of o-phenylene diamines with aldehydes and/or 1,2-dicarbonyl compounds in the presence of sulfonated rice husk ash (RHA-SO3H) as an efficient green catalyst is reported. RHA-SO3H can be easily prepared using a readily available organic compound by simple modification of rice husk ash. All reactions are performed under mild reaction conditions with high to excellent yields. The method is applicable to aromatic, unsaturated and hetero aromatic aldehydes. The advantages of this method are short reaction times, milder conditions, easy work-up, solvent-free conditions and catalyst reusability.
- Shamsi-Sani, Mahnaz,Shirini, Farhad,Abedini, Masoumeh,Seddighi, Mohadeseh
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p. 1091 - 1099
(2016/04/26)
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- A zirconium Schiff base complex immobilized on starch-coated maghemite nanoparticles catalyzes heterogeneous condensation of 1,2-diamines with 1,2-dicarbonyl compounds
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A magnetically separable zirconium Schiff base nanocatalyst was synthesized under ultrasonic agitation. TEM images revealed a uniform spherical particle shape with average size of 10-14 nm for the as-prepared catalyst. The catalytic performance of ZrOL2@SMNP in the heterogeneous condensation of various 1,2-diamines and 1,2-dicarbonyls for the synthesis of heterocyclic compounds in ethanol has been explored.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
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p. 205 - 211
(2016/02/20)
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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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- An efficient synthesis of quinoxaline derivatives using zeolite y as a catalyst
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A convenient and simple procedure for the synthesis of some quinoxaline derivatives was developed via a reaction of oaryldiamines and 1,2-dicarbonyl compounds in the presence of Zeolite NaY as an efficient catalyst. The reactions were carried out at room
- Bodaghifard, Mohammad Ali,Mobinikhaledi, Akbar,Zendehdel, Mojgan,Ayalvar, Zeinab
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p. 345 - 348
(2015/09/07)
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- Propylsulfonic acid functionalized nanozeolite clinoptilolite as heterogeneous catalyst for the synthesis of quinoxaline derivatives
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In this work, the natural nanozeolite clinoptilolite (Nano CP) was successfully functionalized by propylsulfonic acid and applied as efficient heterogeneous catalyst for the synthesis of quinoxaline derivatives in aqueous media. The nanocatalyst was chara
- Baghbanian, Seyed Meysam
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p. 1113 - 1116
(2015/09/01)
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- Protic ionic liquids: A lucid, rational tool for synthesis of phthalazinediones, quinoxalines and benzopyrans
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Protic ionic liquids (PILs), which are easily produced through the combination of a Bronsted acid and Bronsted base, such as [Mim]Ac and 1,4-diazabicyclo[ 2.2.2]octane (DABCO):AcOH:H2O (1:1:3), were found to be lucid, tunable tool for synthesis
- Mulik,Chandam,Patil,Patil,Mulik,Salunkhe,Deshmukh
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p. 10085 - 10096
(2016/01/12)
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- A novel protocol for selective synthesis of monoclinic zirconia nanoparticles as a heterogeneous catalyst for condensation of 1,2-diamines with 1,2-dicarbonyl compounds
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ZrO2 nanocatalyst has been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies and transmission electron microscopy (TEM). Raman spectroscopies and XRD results indicated only formation of monoclinic zirconia. TEM images revealed spherical nanoparticles with 20-40 nm diameter range. The spectral and analysis data confirmed the effectiveness of the method for preparation of monoclinic zirconia by preventing grain growth or agglomeration of particles. The nanostructured ZrO2 exhibited high efficiency in catalyzing condensation of various 1,2-diamine and 1,2-dicarbonyl compounds for the synthesis of heterocyclic compounds. The recovery of the title heterogeneous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk one.
- Jafarpour, Maasoumeh,Rezapour, Elham,Ghahramaninezhad, Mahboobe,Rezaeifard, Abdolreza
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p. 676 - 682
(2014/02/14)
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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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- Poly(N,N ′-dibromo-N-ethyl-benzene-1,3-disulphonamide) and N,N,N ′,N ′-tetrabromobenzene-1,3- disulphonamide as novel catalysts for synthesis of quinoxaline derivatives
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Poly(N,N ′ -dibromo-N-ethyl-benzene-1,3-disulphonamide) [PBBS] and N,N,N ′,N ′ -tetrabromobenzene-1,3- disulphonamide [TBBDA] were used as efficient catalysts for the synthesis of quinoxaline derivatives in excellent yields from 1,2-diamines and 1,2-dicarbonyls under aqueous and solvent-free conditions. [Figure not available: see fulltext.]
- Ghorbani-Vaghei, Ramin,Hajinazari, Somaye
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p. 353 - 358
(2013/07/26)
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- Reusable α-MoO3 nanobelts catalyzes the green and heterogeneous condensation of 1,2-diamines with carbonyl compounds
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Crystalline nanobelts of α-MoO3 have been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies, high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the temperature programmed desorption (TPD) of ammonia. An orthorhombic lattice system for nano-MoO3 was established. The HRTEM images showed that the nanobelt morphology of α-MoO3 mostly ranged from 20-70 nm in width and 200-400 nm in length. The ammonia TPD profile demonstrated strong acidic sites. The spectral and analysis data confirmed the effectiveness of the method for the preparation of α-MoO3 nanobelts by prevention of grain growth or agglomeration of the particles. The nanostructured MoO3 exhibited a high efficiency in catalyzing the condensation reaction of various 1,2-diamine and carbonyl compounds for synthesis of heterocyclic compounds. The recovery of the title heterogenous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk material.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Ghahramaninezhad, Mahboube,Tabibi, Tooba
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p. 2087 - 2095
(2013/10/08)
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- A novel and simple synthesis of some new and known dibenzo phenazine and quinoxaline derivatives using lead dichloride
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A simple method for the synthesis of phenazine and quinoxaline derivatives have been developed via a reaction of o-phenylenediamines and 1,2-dicarbonyl compounds or aryl glyoxals in the presence of lead dichloride in ethanol at room temperature. This meth
- Karami, Bahador,Khodabakhshi, Saeed
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p. 1655 - 1658
(2013/09/24)
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- Graphite catalyzed green synthesis of quinoxalines
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A new simple approach using environmentally benign, cheap, and easily recyclable graphite as a heterogeneous catalyst for the synthesis of quinoxalines is described. A library of pharmacologically interesting diphenylquinoxalines is prepared by the double condensation of substituted benzils, phenanthrene-9,10-dione, and benzoin with aromatic diamines in 71-93% yields at room temperature in ethanol. Aliphatic diamines gave corresponding dihydropyrazines from substituted benzils in 72-92% yields.
- Kadam, Hari K.,Khan, Salman,Kunkalkar, Rupesh A.,Tilve, Santosh G.
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p. 1003 - 1007
(2013/02/25)
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- Rice husk: A mild, efficient, green and recyclable catalyst for the synthesis of 12-Aryl-8, 9, 10, 12-tetrahydro [a] xanthene-11-ones and quinoxaline derivatives
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Rice husk, as a green and cheap reagent, can be used for the promotion of the synthesis of 12-aryl -8, 9,10,12-tetrahydrobenzo[α] xanthen-11-one derivatives (ATXOs) via three-component reaction of aldehydes, 2-naphthol and 5,5-dimethyl-1,3-cyclohexadione (dimedone) under solvent-free conditions. This catalyst can also be used for the preparation of quinoxaline derivatives in a mixture of H2O and CH3CN at 50 °C. The present methodology offers several advantages such as high yields, simple procedure, low cost, short reaction times, mild reaction conditions and use of a green, cheap and reusable catalyst.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali,Aliakbar, Ali-Reza
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p. 207 - 216
(2013/05/09)
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- Synthesis of novel aryl quinoxaline derivatives by new catalytic methods
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Quinoxalines are nitrogenous compounds that widely are used in various industries like paint, pharmaceutical and medicine. Quinoxaline ring is also part of antibiotics structure such as Actinomycin, Lomacin. By using of this synthesis method of these comp
- Soleymani, Reza,Niakan, Neda,Tayeb, Shohre,Hakimi, Shirin
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p. 687 - 701
(2012/10/30)
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- A Rapid Synthesis of Some 1,4-aryldiazines by the Use of Lithium Chloride as an Effective Catalyst
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The synthesis of some 1,4-aryldiazines (novel and known dibenzo[a,c]phenazines and quinoxalines) based on the condensation of 1,2-aryldiamines with aromatic 1,2-dicarbonyl compounds in the presence of lithium chloride as a heterogeneous catalyst is presen
- Karami, Bahador,Rooydel, Reza,Khodabakhshi, Saeed
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experimental part
p. 183 - 188
(2012/06/16)
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- Br?nsted acid hydrotrope combined catalyst for environmentally benign synthesis of quinoxalines and pyrido[2,3-b]pyrazines in aqueous medium
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A new Br?nsted acid hydrotrope combined catalyst (BAHC) has been developed and applied in acid catalyzed synthesis of pyrido[2,3-b]pyrazines and quinoxalines in an aqueous medium at ambient temperature with excellent yields. Interestingly, the catalyst ca
- Kumbhar, Arjun,Kamble, Santosh,Barge, Madhuri,Rashinkar, Gajanan,Salunkhe, Rajashri
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experimental part
p. 2756 - 2760
(2012/07/14)
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- A modified synthesis of some novel polycyclic aromatic phenazines and quinoxalines by using the tungstate sulfuric acid (TSA) as a reusable catalyst under solvent-free conditions
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Considering the synthesis of new compounds, we developed heterocyclic chemistry. We also helped to improve the classical synthetic route for the synthesis of quinoxalines and phenazines through implement in terms of solvent-free reaction. For the condensa
- Karami, Bahador,Khodabakhshi, Saeed,Nikrooz, Marzieh
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experimental part
p. 187 - 192
(2012/07/16)
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- Polyethylene glycol in water: A simple, efficient and green protocol for the synthesis of quinoxalines
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A variety of biologically important quinoxaline derivatives has been efficiently synthesized in excellent yields under extremely mild conditions using PEG-600 and water. This inexpensive, non-toxic, ecofriendly and readily available system efficiently condensed several aromatic as well as aliphatic 1,2-diketones with aromatic and aliphatic 1,2-diamines to afford the products in excellent yield. Polyethylene glycol (PEG) can be recovered and recycled. Indian Academy of Sciences.
- Chavan, Hemant V.,Adsul, Laxman K.,Bandgar, Babasaheb P.
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experimental part
p. 477 - 483
(2012/03/26)
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- Efficient protocol for the synthesis of quinoxaline, benzoxazole and benzimidazole derivatives using glycerol as green solvent
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A straightforward, efficient and more sustainable catalyst-free method has been developed for the synthesis of quinoxaline, benzoxazole, and benzimidazole ring system in glycerol to achieve yields that were comparable to or better than, those in conventional media. It is noteworthy that the reaction was exclusively carried out in glycerol-water system, rendering the methodology highly valuable from both environment and economic points of view.
- Bachhav, Harshal M.,Bhagat, Saket B.,Telvekar, Vikas N.
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experimental part
p. 5697 - 5701
(2011/11/04)
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- Synthesis of quinoxaline derivatives using TiO2 nanoparticles as an efficient and recyclable catalyst
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TiO2 nanoparticles were synthesized and characterized by SEM and XRD techniques. The TiO2 nanoparticles were employed as a recyclable, inexpensive and efficient catalyst for the synthesis of substituted quinoxalines in high to excellent yields and in relatively short duration.
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Salehian, Fatemeh,Biparva, Pourya
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experimental part
p. 3720 - 3725
(2012/01/11)
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- A facile synthesis of phenazine and quinoxaline derivatives using magnesium sulfate heptahydrate as a catalyst
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Convenient and simple procedures for the synthesis of phenazine and quinoxaline derivatives were developed via a reaction of o-phenylenediamines and 1,2-dicarbonyl compounds. In addition, the synthesis of two new 1,4-benzodiazine derivatives and the catal
- Karami, Bahador,Khodabakhshi, Saeed
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experimental part
p. 1191 - 1198
(2012/02/04)
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- Zirconium(IV)-modified silica gel: Preparation, characterization and catalytic activity in the synthesis of some biologically important molecules
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Zirconium modified silica gel was prepared by the grafting method and the resulting organic-inorganic hybrid material was found to be a highly effective catalyst for the range of organic transformations such as syntheses of coumarins, quinoxalines and 2,4
- Sharma,Sharma, Chetna
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scheme or table
p. 327 - 331
(2011/09/21)
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- A new class of phenazines with activity against a chloroquine resistant plasmodium falciparum strain and antimicrobial activity
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New phenazines were synthesized by oxygenation of 1- and 2-naphthol with transition metal peroxo complexes and in situ reaction with 1,2-diamines. The title compounds were evaluated for in vitro antimalarial activity against Plasmodium falciparum and chloroquine-resistant strains. Phenazines 12, 27, and 28 were most prominent in growth inhibition. In vivo protection against cerebral malaria was observed with the phenazines 11, 12, 20, and 27, whereas partial protection was provided by 19.
- Hussain, Hidayat,Specht, Sabine,Sarite, Salem R.,Saeftel, Michael,Hoerauf, Achim,Schulz, Barbara,Krohn, Karsten
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scheme or table
p. 4913 - 4917
(2011/09/15)
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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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experimental part
p. 1315 - 1324
(2011/08/06)
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- Reactions of 1,2,5-thiadiazole 1,1-dioxide derivatives with nitrogen nucleophiles. Part IV. Addition of α-diamines
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α-diamines, such as ethylendiamine and o-phenylendiamine, add to 3,4-aryl-disubstituted 1,2,5-thiadiazole 1,1-dioxides to give dihydropyrazines or quinoxalines, respectively and sulfamide. The new compound acenaphtho [5,6-b]-2,3-dihydropyrazine was synthesized and characterized. The addition of ethylendiamine to 3,4-diphenyl-1,2,5-thiadiazoline 1,1-dioxide gives 3,4-disubstituted thiadiazolidlne 1,1-dioxide, dihydropyrazines, or pyrazines, depending on the reaction condition used. The reactions were followed by cyclic voltammetry and NMR spectroscopy which, in some cases, allowed the detection of the thiadiazolidine intermediate. Copyright
- Mirifico, Maria Virginia,Caram, Jose Alberto,Vasini, Enrique Julio,Piro, Osear Enrique,Castellano, Eduardo E.
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experimental part
p. 163 - 169
(2010/04/30)
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- Metal hydrogen sulfates M(HSO4)n: As efficient catalysts for the synthesis of quinoxalines in EtOH at room temperature
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A convenient method for the synthesis of quinoxalines catalysed by metal hydrogen sulfates by the reaction of 1,2-diamino compounds and 1,2-dicarbonyl compounds in ethanol as solvent at room temperature is reported.
- Niknam, Khodabakhsh,Zolfigol, Mohammad Ali,Tavakoli, Ziba,Heydari, Zahra
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experimental part
p. 1373 - 1378
(2009/12/04)
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- PHENAZINE AND QUINOXALINE SUBSTITUTED AMINO ACIDS AND POLYPEPTIDES
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Disclosed herein are non-natural amino acids and polypeptides that include at least one non-natural amino acid, and methods for making such non-natural amino acids and polypeptides. The non-natural amino acids, by themselves or as a part of a polypeptide, can include a phenazine or quinoxaline substituent. Also disclosed herein are non-natural amino acid polypeptides that are further modified post-translationally, methods for effecting such modifications, and methods for purifying such polypeptides.
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Page/Page column 174
(2008/12/07)
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- Spectroscopic and electrochemical properties of dichlorodiimine complexes of Au(III) and Pt(II) with 1,4-diazine derivatives of o-phenanthroline
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A series of dichlorodiimine complexes [M(N∧N)Cl2] z of Au(III) and Pt(II) with 1,4-derivatives of o-phenanthroline [(N∧N) = o-phenanthroline (phen), dipyrido[f,h]quinoxaline (dpq), dipyrido[a,c]phenazine (dppz), 6,7-dicyanodipyrido[f,h]quinoxaline (dicnq)] were prepared and characterized by 1H NMR, electronic absorption, and emission spectroscopy and by cyclic voltammetry. In all the complexes, the 3(π-π*)-type transition is the spin-forbidden transition of the lowest energy, responsible for the luminescence. The longest wave bands in the absorption spectra of the Au(III) and Pd(II) complexes were assigned in accordance with the results of the electrochemical studies to the 1(d*)-and 1(d*)-type transitions, respectively. Pleiades Publishing, Inc., 2006.
- Ivanov,Puzyk,Balashev
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p. 843 - 848
(2008/02/02)
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- Are multicomponent strecker reactions of diketones with diamines under high pressure amenable to heterocyclic synthesis?
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Employing double Strecker strategy, two new heterocyclic compounds, 5,6,11,12-tetrahydro-6,11-dimethyldibenzo[b,f][1,4]diazocine-6,11-dicarbonitrile and 1,2,3,4,5,10-hexahydrophenazine-4a, 10a-dicarbonitrile, were prepared in one step albeit in low yields. The reaction has proven to be very limited, but such a sterically hindered amine as N-methylaniline underwent Strecker reaction with benzaldehyde and TMSCN to give the corresponding α-amino nitriles.
- Kumamoto, Koji,Iida, Hirokazu,Hamana, Hiroshi,Kotsuki, Hiyoshizo,Matsumoto, Kiyoshi
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p. 675 - 681
(2007/10/03)
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- Quantitative cascade condensations between o-phenylenediamines and 1,2-dicarbonyl compounds without production of wastes
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o-Phenylenediamines 1 underwent a series of cascade condensations with 1,2-dicarbonyl compounds to afford quantitative yields (eight cases) of heterocycles in solid-state syntheses that avoided waste formation. The products were produced in pure form and did not require purifying workup. The components were ball-milled in stoichiometric ratio, or in exceptional cases they were melted together and heated in the absence of solvents (some of them giving quantitative yields). Benzils and 2-hydroxy-1,4-naphthoquinone afforded quinoxaline derivatives 3 and 5, 2-oxoglutaric acid gave a 3-oxodihydroquinoxaline 7, and oxalic acid afforded the dihydroquinoxaline-2,3-dione 9. This last condensed with la in the melt, to afford a mixture of bis(benzimidazolyl) 10 and fluoflavin 11. Alloxane hydrate provided a 100% yield of the 3-oxodihydroquinoxaline-2-carbonylureas 15/16 at room temperature. Parabanic acid required a melt reaction providing a 78% yield of 3-oxodihydroquinoxalinyl-2-urea 22 and side products. Despite numerous reaction steps, most of these uncatalyzed stoichiometric reactions proceeded quantitatively in the solid state to give only one product (plus water), with unsurpassed atom economy. If catalysis with HCl was tried, the results were inferior. If melt reactions were required it appeared to be advantageous to have the products crystallize directly at the reaction temperature. The synthetic results have been interpreted mechanistically and compared to some similar solution reactions that do not exhibit the benefits of the solid-state techniques. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
- Kaupp, Gerd,Naimi-Jamal, M. Reza
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p. 1368 - 1373
(2007/10/03)
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- Synthesis and characterization of 9,10-bis(arylimino)-9,10-dihydrophenanthrenes, the structure of (Z,Z)-9,10-bis(phenylimino)-9,10-dihydrophenanthrene and PdCl2-[(E,E)-9,10-bis(phenylimino)-9,10-dihydrophenanthrene] in the solid state and in so
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The synthesis and characterization of substituted phenanthrene-9,10-quinone diimines of the type 9,10-bis(arylimino)-9,10-dihydrophenanthrene (aryl-BIP) is described. These rigid bisnitrogen ligands have been synthesized by a metal-mediated cyclodehydroge
- Van Belzen, Ruud,Klein, Rene A.,Smeets, Wilberth J.J.,Spek, Anthony L.,Benedix, Roland,Elsevier, Cornelis J.
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p. 275 - 285
(2007/10/03)
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- Synthesis of quinoxalines under focussed microwave irradiation
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Quinoxalines were obtained by the condensation of α-diones with o-diaminobenzenes without solvent under focussed microwave irradiation.
- Villemin,Martin
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p. 2319 - 2326
(2007/10/02)
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