- A Magnetic Heterogeneous Biocatalyst Composed of Immobilized Laccase and 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) for Green One-Pot Cascade Synthesis of 2-Substituted Benzimidazole and Benzoxazole Derivatives under Mild Reaction Conditions
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The design of reusable high-performance heterogeneous catalysts via the immobilization of chemical and biochemical species on magnetic nanoparticles increases the efficiency of catalytic systems by facilitating easy, fast, and clean separation processes. Laccase and 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl were separately immobilized on amine functionalized iron (II, III) oxide nanoparticles with covalent bonding using glutaraldehyde as a coupling reagent. The prepared catalyst was used to synthesize 12 benzoxazole and benzimidazole derivatives. The one-pot, two-step enzymatic aerobic oxidation reaction included the condensation of in situ-produced salicylaldehyde derivatives with aromatic amines, followed by an enzymatic dehydrogenation process. Optimal reaction conditions consisted of a citrate buffer (10 mM, pH 4.5) at 40 °C for an incubation time of 10 h and a heterogeneous catalyst containing immobilized laccase (80 mg, 100 U) and immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) (40 mg, 2 mol%). The catalyst retained more than 85% of its initial activity after 10 runs. In addition to the potential for reuse without significant losses in performance, eco-friendly attributes of this catalytic system include its high catalytic activity and the ease with which it can be recovered from the reaction mixture using an external magnet. (Figure presented.).
- Mogharabi-Manzari, Mehdi,Kiani, Mahshid,Aryanejad, Sima,Imanparast, Somaye,Amini, Mohsen,Faramarzi, Mohammad Ali
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- Near-infrared (NIR) luminescent hetero-tetranuclear Zn2Ln 2 (Ln = Nd, Yb or Er) complexes self-assembled from the benzimidazole-based HL and two rigid 4,4′-bipyridine ligands with different spacers
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(Chemical Equation Presented) Through the self-assembly of the benzimidazole-based ligand HL (HL = 2-(1H-benzo[d]imidazol-2-yl)-6- methoxyphenol) with Zn(OAc)2·2H2O, Ln(NO 3)3·6H2O (Ln = Nd, Yb, Er or
- Zhang, Zhao,Feng, Weixu,Su, Peiyang,Liu, Han,Zhang, Yao,Wang, Zheng,Miao, Tiezheng,Lue, Xingqiang,Fan, Daidi,Wong, Wai-Kwok,Jones, Richard A.
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- Exciplex formation between a pair of synthesized AIEgens leads to white light generation: A spectroscopic exploration
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Two compounds, namely 2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol (BIMP) and (E)-ethyl 2-cyano-3-(pyren-3-yl)acrylate (ECPA), were synthesized and characterized. BIMP portrayed an interesting feature of aggregation promoted enhancement of excited state intramolecular proton transfer (ESIPT) in water. On the other hand, ECPA shows AIE emission in solution. Steady state spectroscopic studies revealed that the BIMP-ECPA ensemble in solution behaves as a white light emitter, where BIMP acts as a donor and ECPA as an acceptor. The mechanism operative behind the observed white light generation was revealed to be exciplex formation between BIMP and ECPA. The current report is the first example of white light generation from two synthesized AIEgens through exciplex formation and hence holds its own merit for a smart choice of synthesized compounds resulting in white light generation. This journal is
- Bhattacharyya, Arghyadeep,Guchhait, Nikhil
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- 2-(3-Methoxy-2-hydroxyphenyl)benzimidazole
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Molecules of the title compound, 2-(1,3-benzimidazol-2-yl)-6-methoxyphenol, C14H12N2O2, are nearly planar, the greatest deviations from the molecular least-squares plane being -0.145 (3) A for C12 and -0.149 (3) A for C14. An intramolecular O - H...N hydrogen bond [O1...N1 2.577 (6) A] is observed.
- Elerman, Yalcin,Kabak, Mehmet
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- Synthesis and fungicidal activity of novel 6H-benzimidazo[1,2-c][1,3]benzoxazin-6-ones
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[Figure not available: see fulltext.] A series of 6H-benzimidazo[1,2-c][1,3]benzoxazin-6-one derivatives were synthesized in moderate to good yield by reaction of 2-(1H-benzimidazol-2-yl)phenols with triphosgene, and the structures of the target compounds
- Jiao, Yinchun,Ma, Caixia,Tan, Yuhuan,Tang, Zilong
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p. 581 - 587
(2021/06/16)
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- The ninhydrin core as carbonyl source to access 2-(2′-hydroxyaryl)benzimidazoles exploiting the ortho selectivity of ninhydrin-phenol adducts
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Although ninhydrin is an essential analytical tool in biochemical and forensic sciences, for the past several years, it has been employed as efficient building block for diverse organic scaffolds. In the present work, the ortho selectivity of ninhydrin-phenol adducts has been exploited to obtain 2-(2′-hydroxyaryl)benzimidazoles which are well known excited state intramolecular proton transfer (ESIPT) fluorophores. Under acidic condition, 3-(2-hydroxyaroyl)isoindolin-1-one intermediate generated in situ from ninhydrin-phenol adducts was treated with o-phenylenediamine resulting benzimidazole scaffolds via a two-step one pot strategy.
- Das, Suven,Maity, Suvendu,Ghosh, Prasanta,Dutta, Arpita
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p. 2862 - 2872
(2021/08/13)
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- A novel ternary GO@SiO2-HPW nanocomposite as an efficient heterogeneous catalyst for the synthesis of benzazoles in aqueous media
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A new solid acid catalyst, consisting of 12-phosphotungstic heteropoly acid (HPW) supported on graphene oxide/silica nanocomposite (GO@SiO2), has been developed via immobilizing HPW onto an amine-functionalized GO/SiO2 surface through coordination interaction (GO@SiO2-HPW). The GO@SiO2-HPW nanocomposite was characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The prepared nanocomposite could be dispersed homogeneously in water and further used as a heterogeneous, reusable, and efficient catalyst for the synthesis of benzimidazoles and benzothiazoles by the reaction of 1,2-phenelynediamine or 2-aminothiophenol with different aldehydes.
- Habibzadeh, Setareh,Firouzzadeh Pasha, Ghasem,Tajbakhsh, Mahmood,Amiri Andi, Nasim,Alaee, Ehsan
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p. 934 - 944
(2019/06/13)
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- Experimental and theoretical approving of anomeric based oxidation in the preparation of 2-sbstituted benz-(imida, oxa and othia)-zoles using [2,6-DMPy-NO2]C(NO2)3 as a novel nano molten salt catalyst
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The synthesis of 2-sbstituted benz-(imida, oxa and othia)-zole derivatives were occurred in the presence of 2,6-dimethyl-1-nitropyridin-1-ium trinitromethanide [2,6-DMPy-NO2]C(NO2)3via the condensation reaction between 1,2-phenylenediamine or 2-aminophenol or 2-aminothiophenol and corresponding aldehyde at room temperature under solvent-free conditions respectively. [2,6-DMPy-NO2]C(NO2)3 as a nano molten salt (NMS) catalyst was fully characterized by Fourier transform infrared (FT-IR), nuclear magnetic resonance (1H NMR and 13C NMR), mass, thermal gravimetric (TG), derivative thermal gravimetric (DTG), X-ray diffraction patterns (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. The described reactions are in close agreement with the green chemistry disciplines and their major advantages are good yields, short reaction time and ease of separation. Our recently new introduced concept entitled "anomeric based oxidation" was proposed for the final step of the described synthesis and it was also approved using theoretical studies.
- Zolfigol, Mohammad Ali,Khazaei, Ardeshir,Alaie, Saied,Baghery, Saeed,Maleki, Farahnaz,Bayat, Yadollah,Asgari, Asiye
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p. 58667 - 58679
(2016/07/06)
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- Benzimidazoles: A new class of carbonic anhydrase inhibitors
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Carbonic anhydrase inhibitory activity of benzimidazole derivatives 1-24 has been evaluated. Compounds 22 (IC50 = 7.47 ± 0.39 μM), 21 (IC50 = 10.31 ± 0.11 μM), 20 (IC50 = 23.1 ± 1.78 μM), 12 (IC50 = 12.16 ± 0.10
- Khan, Khalid Mohammed,Khan, Momin,Saleem, Muhammad,Taha, Muhammad,Perveen, Shahnaz,Choudhary, Mohammad Iqbal
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p. 901 - 904
(2013/07/26)
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- One-pot synthesis of benzimidazoles and benzothiazoles in the presence of Fe(HSO4)3 as a new and efficient oxidant
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A series of substituted benzimidazoles and benzothiazoles were prepared through the one-pot reaction of ophenylenediamine and o-aminothiophenol with various aldehydes in the presence of ferric hydrogensulfate both in EtOH and water as solvent. The reactions proceed smoothly in excellent yield, high chemoselectivity and with an easy work-up.
- Eshghi, Hossein,Rahimizadeh, Mohammad,Shiri, Ali,Sedaghat, Parisa
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experimental part
p. 515 - 518
(2012/04/23)
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- Synthesis and β-glucuronidase inhibitory potential of benzimidazole derivatives
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Benzimidazole derivatives 1-24 have been synthesized and their in vitro β-glucuronidase inhibitory activitiy was evaluated. Compounds 15 (IC 50 = 6.33 ± 0.40 μM), 7 (IC50 = 22.0 ± 0.33 μM), 2 (IC50 = 23.1 ± 1.78 μM), 17 (I
- Khan, Khalid Mohammed,Khan, Momin,Ambreen, Nida,Rahim, Fazal,Naureen, Shagufta,Perveen, Shahnaz,Choudhary, M. Iqbal,Voelterc, Wolfgang
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body text
p. 421 - 427
(2012/09/05)
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- Hetero-binuclear near-infrared (NIR) luminescent Zn-Nd complexes self-assembled from the benzimidazole-based ligands
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With the compound [Zn(HL1)2(Py)] (H2L 1 = 2-(1H-benzo[d]imidazol-2-yl)-6-methoxyophenol), Py = pyridine) or [Zn(HL2)2(Py)] (H2L2 = 2-(1H-benzo[d]imidazol-2-yl)-4-bromo
- Zou, Dan,Feng, Weixu,Shi, Guoxiang,Lü, Xingqiang,Zhang, Zhao,Zhang, Yao,Liu, Han,Fan, Daidi,Wong, Wai-Kwok,Jones, Richard A.
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p. 359 - 366
(2013/01/13)
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- Hetero-binuclear near-infrared (NIR) luminescent ZnLn (Ln = Nd, Yb or Er) complexes self-assembled from the benzimidazole-based ligand
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With the [Zn(HL)2(Py)] compound from the benzimidazole-based ligand H2L (H2L: 2-(1H-benzo[d]imidazol-2-yl)-6- methoxyohenol) as the precursor, the series of four hetero-binuclear ZnLn arrayed complexes [ZnLn(HL)2/sub
- Shi, Guo-Xiang,Feng, Wei-Xu,Zou, Dan,Lü, Xing-Qiang,Zhang, Zhao,Zhang, Yao,Fan, Dai-Di,Zhao, Shun-Sheng,Wong, Wai-Kwok,Jones, Richard A.
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scheme or table
p. 126 - 130
(2012/08/08)
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- Construction of four 3d-4d/4d complexes based on salen-type schiff base ligands
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Through a two-step synthetic strategy, four d10 Schiff-base complexes CdZn(DMF)(La)(NO3)2 (1), Cd[Zn(L a)Cl]2·H2O (2) and [Cd(DMF)L bS]2·2H2O (S
- Gong, Xue,Ge, Ying-Ying,Fang, Mao,Gu, Zhi-Gang,Zheng, Sheng-Run,Li, Wei-Shan,Hu, She-Jun,Li, Shu-Bin,Cai, Yue-Peng
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scheme or table
p. 6911 - 6915
(2012/05/20)
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- Mononuclear Cu and dinuclear Cu-Ln complexes of benzimidazole based ligands including N and O donors: Syntheses, characterization, X-ray molecular structures and magnetic properties
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The synthesis of two mononuclear precursor copper complexes, [(HL 2)2Cu], 1, and [(HL3)2Cu] ·H2O,2, and three dinuclear Cu-Ln complexes, [(HL 1)2Cu(CH3CN)2G
- Fellah, Fatima Zohra Chiboub,Costes, Jean-Pierre,Duhayon, Carine,Daran, Jean-Claude,Tuchagues, Jean-Pierre
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experimental part
p. 2111 - 2119
(2010/08/21)
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- Polyethylene glycol: A recyclable solvent system for the synthesis of benzimidazole derivatives using CAN as catalyst
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Ceric ammonium nitrate (CAN) efficiently catalysed the synthesis of benzimidazole derivatives from o-phenylenediamine and aldehydes in PEG. This method provides a novel route for the synthesis of benzimidazoles in good yields with little catalyst loading.
- Kidwai, Mazaahir,Jahan, Anwar,Bhatnagar, Divya
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experimental part
p. 607 - 612
(2010/12/25)
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- An efficient and eco-friendly tungstate promoted zirconia (WO x /ZrO2) solid acid catalyst for the synthesis of 2-aryl benzimidazoles
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An eco-friendly catalytic amount (0.3 g) of tungstate-promoted zirconia (WO x /ZrO2) solid acid catalyst has been explored in the synthesis of 2-aryl benzimidazoles using aryl aldehydes and o-phenylenediamine. This is one of the fundamental aspects in green chemistry for simple experimental and product isolation protocol combined with easy recovery and reusability of the catalyst. It is expected to contribute in the development of clean and environment friendly strategy for synthetic protocols. The incorporated promoter showed strong influence on the surface and bulk properties of zirconia. The catalytic activity results suggest that the methodology adopted offers significant improvements for the synthesis of benzimidazole derivatives with respect to yields, simplicity and green aspects by avoiding toxic conventional catalysts and solvents. Henceforth, a good substrate conversion and excellent product selectivity were obtained over tungstate promoted zirconia solid acid catalyst.
- Shingalapur, Ramya V.,Hosamani, Kallappa M.
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scheme or table
p. 63 - 68
(2010/09/05)
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- Synthesis of benzimidazoles and benzoxazoles using palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate) as a novel catalyst
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Structurally well-defined palladium bis(2,2,6,6-tetramethyl-3,5- heptanedionate) complex is reported to be an efficient catalyst for the synthesis of benzimidazole and benzoxazole derivatives in good yields. A novel approach for one-pot synthesis of benzimidazoles via direct reductive amination and N-arylation followed by hydrogenation-cyclization methodology is also described. Copyright
- Bhor, Malhari D.,Bhanage, Bhalchandra M.
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experimental part
p. 1743 - 1749
(2010/07/04)
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- Synthesis and fluorescent properties of 2-(1H-benzimidazol-2-yl)-phenol derivatives
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A high yield one pot synthesis of 2-(2-hydroxyaryl)-1H-benzimidazole derivatives by 2-hydroxy aromatic aldehydes with aromatic 1,2-diamines in the presence of manganese(III) acetate at room temperature was developed. Nine fluorescencers 2-(2-hydroxyaryl)-1H-benzimidazoles with substituent(s) X (X = H, CH3, CH3O, Cl) and two fluorescencers 2-(2-hydroxyaryl)-1H-naphth[2,3-d]imidazoles with substituent of H or Cl were prepared in 38-87% yield and the ultraviolet absorption and fluorescent spectra of the eleven compounds synthesized were measured in methanol. The fluorescent characteristics of the 2-(2-hydroxyaryl)benzimidazole derivatives prepared were investigated on the basis of excited-state intramolecular proton transfer mechanism, Stokes' shift, quantum yield, and the relationship between fluorescent intensity and the substituents were derived.
- Ouyang, Jie,Ouyang, Chenguang,Fujii, Yuki,Nakano, Yoshiharu,Shoda, Takuji,Nagano, Tetsuo
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p. 359 - 365
(2007/10/03)
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- Carbonyl and thiocarbonyl compounds XX. Reaction of hydroxybenzaldehydes with o-phenylenediamine; newer aspects in benzimidazole synthesis
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The nature of the products of the uncatalysed reaction of the o-hydroxybenzaldehydes 1a-d with o-phenylenediamine in boiling ethanol is mainly dependent on the molar ratio of the reactants and the nature of the substituents at the phenyl ring of the aldeh
- Latif, N.,Mishriky, N.,Assad, F. M.
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- Reaction of Biologically Active &β-Nitrostyrenes with o-Phenylenediamine: A New Route to the Synthesis of 2-Substituted Benzimidazoles
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β-Nitrostyrenes (1) react with o-phenylenediamine in ethanol to give exclusively 2-substituted benzimidazoles (2) regardless of the nature and position of substituents in the phenyl ring.The correspondnig 2,3-dihydroperimidines (4) are readily obtained by reacting 1,8-diaminonaphthalene with benzaldehydes.Possible routes for the formation of 2 have been discussed.The nitrostyrenes (1) have been found to be toxic to fresh water snails and phytopathogenic fungi in high dilutions.
- Latif, N.,Mishriky, N.,Assad, F. M.,Meguid, S. Abdel
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p. 872 - 874
(2007/10/02)
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