- p-TSA catalyzed synthesis of 2,4,5-triarylimidazoles from ammonium heptamolybdate tetrahydrate in TBAI
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A one-pot synthesis of 2,4,5-trisubstituted imidazoles from 1,2-diketone or α-hydroxy ketone, aldehyde and ammonium heptamolybdate tetrahydrate in an inexpensive and readily available ionic liquid, tetrabutylammonium iodide (TBAI) in molten state using catalytic amounts of p-TSA has been described.
- Khodaei, Mohammad Mehdi,Bahrami, Kiumars,Kavianinia, Iman
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- Imidazole-coumarin containing D – A type fluorescent probe: Synthesis photophysical properties and sensing behavior for F? and CN? anion
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A new class of D–A type intramolecular charge transfer (ICT) fluorescent probe, ICU has been designed and synthesized. The solvatochromic behavior, anion interaction and morphological features of the probe have been studied in detail. The molecular probe
- Ali, Rashid,Dwivedi, Sushil K.,Mishra, Hirdyesh,Misra, Arvind
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- On the fluorescent, steric and electronic factors affecting the detection of metallic ions using an imidazolyl-phenolic derived fluorescent probe
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The imidazolyl-phenolic probe used at the present study has its photophysic properties regulated by a tautomeric equilibrium. After the absorption of a photon, an excited state intramolecular proton transfer process generates a ketonic species, responsibl
- Orf?o, Ronaldo B.,De Carvalho, Fabrício,Homem-De-Mello, Paula,Bartoloni, Fernando H.
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- Multi-Mode White Light Emission in a ZnII Coordination Polymer from Excited-State Intramolecular Proton Transfer (ESIPT) Ligands
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Multi-mode photoluminescence, including enol-emission, keto-emission, and aggregate-related emission is achieved in a ZnIIcoordination polymer from excited-state intramolecular proton transfer (ESIPT) ligands. Single-phase white light emission
- Chen, Ling,Yan, Cheng,Pan, Mei,Wang, Hai-Ping,Fan, Ya-Nan,Su, Cheng-Yong
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- One-step synthesis of 2-aryl-4,5-diphenylimidazoles under microwave irradiation
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A series of 2-aryl-4,5-diphenylimidazoles were synthesized by a one-step condensation reaction of benzil, aromatic aldehyde, and ammonium acetate in acetic acid under microwave irradiation. The reactions were completed in 4-11 min with good yields and easy workup. Copyright Taylor & Francis, Inc.
- Zhou, Jian-Feng,Song, Yuan-Zhi,Yang, Yan-Ling,Zhu, Yu-Lan,Tu, Shu-Jiang
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- Mixed cobalt/nickel metal–organic framework, an efficient catalyst for one-pot synthesis of substituted imidazoles
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Abstract: In the present work, a three-dimensional bimetallic metal–organic framework, [CoNi(μ3-tp)2(μ2-pyz)2] (tp?=?terephthalic acid, pyz?=?pyrazine) was applied as a highly efficient and recoverable heterogeneous catalyst. The catalyzed reaction was the one-pot three-component condensation reaction between benzil or benzoin with various substituted aromatic aldehydes and ammonium acetate to synthesize the corresponding imidazoles in solvent-free conditions and high to quantitative yields. The catalyst can be recycled at least five times without significant loss in the catalytic activity. To the best of our knowledge, 2,4,5-trisubstituted 1H-imidazoles were not previously synthesized using MOFs as heterogeneous catalyst. The structure of previously reported cobalt/nickel MOF has been confirmed by various techniques, such as X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Brunauer–Emmett–Teller. Graphical abstract: [Figure not available: see fulltext.]
- Ramezanalizadeh, Hamed,Manteghi, Faranak
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- Design and development of a novel cellulose/γ-Fe2O3/Ag nanocomposite: A potential green catalyst and antibacterial agent
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A cellulose/γ-Fe2O3/Ag nanocomposite is synthesized and used as a catalyst for the synthesis of trisubstituted imidazoles and α-aminonitriles. This catalytic protocol is simple, the reaction yield is very high, and the reaction time is very short. The remarkable magnetic properties of the nanocomposite permit easy separation of the catalyst from the reaction mixture without considerable loss of catalytic activity. In addition, antibacterial properties of the nanocomposite are investigated. For this purpose, S. aureus as the representative of Gram-positive bacteria and E. coli as the representative of Gram-negative bacteria are evaluated. To study the morphology and characterization of the prepared nanocomposite, X-ray diffraction patterns (XRD), energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscopy (FE-SEM), vibrating sample magnetometry (VSM) and thermal gravimetric analysis/differential thermal analysis (TGA/DTA) are obtained.
- Maleki, Ali,Movahed, Hamed,Paydar, Reza
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- Triphenyl-imidazole based reversible coloro/fluorimetric sensing and electrochemical removal of Cu2+ ions using capacitive deionization and molecular logic gates
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A simple hydroxyl-substituted triphenyl-imidazole based receptor (HTPI) which selectively detects Cu2+ ion by colorimetric and fluorimetric methods was developed. HTPI detects the Cu2+ ions with the absorption enhancement and fluores
- David, C. Immanuel,Nandhakumar, R.,Prabakaran, G.,Prabhu, J.,Thamilselvan, A.,Velmurugan, K.,Vickram, R.
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- KSF supported 10-molybdo-2-vanadophosphoric acid as an efficient and reusable catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazole derivatives under solvent-free condition
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The one-pot three-component cyclocondensation has been developed involving the reaction of benzil with an aromatic aldehydes and ammonium acetate under thermal solvent-free conditions in the presence of a KSF supported 10-molybdo-2-vanadophosphoric acid catalyst. 10-Molybdo-2-vanadophosphoric acid was immobilized on KSF with a 20% loading, which showed the highest catalytic activity. The catalyst was fully characterized using FT-IR spectroscopy, thermal analysis, XRD and SEM analysis techniques. There are several distinct advantages to this protocol, including high yields, short reaction time, operational simplicity and a recyclable catalyst with a facile work-up procedure.
- Chavan, Laxmikant D.,Shankarwar, Sunil G.
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- Bronsted acid ionic liquid [Et3NH][HSO4] as an efficient and reusable catalyst for the synthesis of 2,4,5-triaryl-1H- imidazoles
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A simple and efficient procedure for synthesis of 2,4,5-triaryl-1H- imidazoles by one-pot three-component condensation of aromatic aldehydes, benzil and ammonium acetate under solvent-free conditions using ionic liquid [Et 3NH][HSO4] as catalyst is described. The remarkable features of this procedure are high yields, cleaner reaction profiles, use of non-toxic, easily available, cheap, recyclable catalyst, which also has an environmentally benign nature, and simple experimental and work-up procedures.
- Deng, Xiaocui,Zhou, Zhongqiang,Zhang, Aiqing,Xie, Guangyong
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- Homoselective synthesis of 5-substituted 1H-tetrazoles and one-pot synthesis of 2,4,5-trisubstuted imidazole compounds using BNPs@SiO2-TPPTSA as a stable and new reusable nanocatalyst
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Considering the importance of tetrazole and imidazole derivatives in pharmacy, industry, and explosives, BNPs@SiO2-TPPTSA was easily prepared and used as an effective, stable, and renewable nanocatalyst for the homoselective synthesis of different 5-substituted 1H-tetrazoles and atom economic synthesis of 2,4,5-trisubstituted-1H-imidazoles in solventless conditions. BNPs@SiO2-TPPTSA was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), thermal gravimetric-differential thermal analysis (TGA-DTA), mapping, pH analysis, and Fourier transform infrared (FT-IR) techniques. Furthermore, the catalyst recycled for at least sequential five loads without a remarkable drop-in catalytic activity.
- Khodamorady, Minoo,Ghobadi, Nazanin,Bahrami, Kiumars
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- Zeolite HY and silica gel as new and efficient heterogenous catalysts for the synthesis of triarylimidazoles under microwave irradiation
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Zeolite HY and silica gel efficiently catalyzed the three component condensation of benzil, benzaldehyde derivatives, and ammonium acetate under solvent-free conditions and microwave irradiation.
- Balalaie, Saeed,Arabanian, Armin,Hashtroudi, Mehri S.
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- Organocatalyzed Solvent Free and Efficient Synthesis of 2,4,5-Trisubstituted Imidazoles as Potential Acetylcholinesterase Inhibitors for Alzheimer's Disease
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The catalytic potential of pyridine-2-carboxlic acid has been evaluated for efficient, green and solvent free synthesis of 2,4,5-trisubstituted imidazole derivatives 3a–3m. The compounds 3a–3m were synthesized by one pot condensation reaction of substituted aromatic aldehydes, benzil, and ammonium acetate in good to excellent yields (74–96 %). To explore the potential of these compounds against Alzheimer's disease, their inhibitory activities against acetylcholinesterase (AChE) were evaluated. In this series of compounds, compound 3m, bearing one ethoxy and a hydroxy group on the phenyl ring on 2,4,5-trisubstituted imidazoles, proved to be a potent AChE inhibitor (102.56±0.14). Structure–activity relationship (SAR) of these compounds was developed. Molecular dockings were carried out for the compounds 3m, 3e, 3k, 3c, 3a, 3d, 3j, and 3f in order to further investigate the binding mechanism. The inhibitor molecule was molecularly docked with acetylcholinesterase to further study its binding mechanism. The amino group of the compound 3m forms an H-bond with the oxygen atom of the residue (i. e., THR121) which has a bond length of 3.051 ?.
- Ashraf, Muhammad,Khan, Muhammad Asim,Liu, Xiao,Mutahir, Sadaf,Pervaiz, Sania,Tariq, Sidrah,Ullah, Islam,Zhou, Bao-Jing
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- Synthesis, characterization and theoretical investigations of the structure, electronic properties and third-order nonlinearity optics (NLO) of M(DPIP)2
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Three complexes of M(DPIP)2 (M = Cu, Co, Zn as 1, 2, 3) were synthesized and characterized by elemental analysis, IR, UV-Vis, thermogravimetry, and X-ray diffraction. Their nonlinear optical properties were measured by the Z-scan technique and
- Li, Kang,Tang, Guodong,Kou, ShanShan,Culnane, Lance F.,Zhang, Yu,Song, Yinglin,Li, Rongqing,Wei, Changmei
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- Synthesis and luminescence-structure relationship of 2,4,5-triarylimidazoles
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2,4,5-Triarylimidazoles were efficiently synthesized with excellent yields (90-96%) via the one-pot concentration of benzil, aromatic aldehyde and ammonium acetate in ionic liquid [BMIM][BF4] in the present of acetic acid. The luminescence-structure relationship of products was investigated.
- Yue, Shu-Ning,Wan, Yu,Ye, Ling,Zhang, Wen-Li,Cui, Hao,Zhang, Li-Zhuo,Zhou, Qiu-Ju,Zou, Huan,Liu, Zhen-Tao,Zhao, Ling-Ling,Zhou, Sheng-Liang,Wu, Hui
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- A practical and green approach toward synthesis of 2,4,5-trisubstituted imidazoles without adding catalyst
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A simple, efficient, and inexpensive procedure has been developed for the synthesis of 2,4,5-triaryl imidazoles by a three-component, one-pot condensation of benzil, aldehydes, and ammonium acetate in refluxing ethanol without adding catalyst. The catalyzed-by-itself approach shows a new direction in green synthesis of the title products. Copyright Taylor & Francis Group, LLC.
- Wang, Min,Gao, Jingjing,Song, Zhiguo
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- Aicd-base behavior, electrochemical properties and DFT study of redox non-innocent phenol-imidazole ligands and their Cu complexes
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Abstract Three Cu complexes (1, 2, 3) with N, O donor ligands having imidazole-phenol moieties 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol (L1H), 4-bromo 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol (L2H) and 1-(4,5-diphenyl-1H-imidazol-2-yl)
- Parween, Arfa,Mandal, Tarun Kanti,Guillot, Régis,Naskar, Subhendu
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- Ferric(III) nitrate supported on kieselguhr: A reusable and inexpensive catalyst for one-pot three-component synthesis of 2,4,5-trisubstituted imidazole derivatives under solvent-free conditions
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An efficient and green procedure for the synthesis of 2,4,5-trisubstituted-1H-imidazoles with various aldehydes, benzil, and ammonium acetate using a catalytic amount of ferric(III) nitrate supported on kieselguhr (Fe(NO3)3-Kie) as an active and low cost Lewis acid catalyst has been developed. The solid catalyst was easily separated from the reaction mixture and can be reused at least three times. This procedure has remarkable advantages compared to those reported in the previous literature, including high yields, cleaner reaction profiles, simple experimental and work-up procedures, and use of non-toxic or expensive catalyst. Moreover, this protocol is benign to the environment.
- Xu, Xiaowen,Li, Yiqun
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- Electro-organic synthesis of 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol in Aqueous medium for organic monomer based Supercapacitor electrode
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An efficient cost-effective and eco-friendly electro-organic synthesis of 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol (DIP) in aqueous medium and its application as an electrode material for supercapacitor are reported here. The as-synthesized derivative was
- Elanthamilan,Sarala,Bella,Sathiyan,Sharmila Lydia,Sundar Manoharan,Princy Merlin
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- Sugar-Catalyzed Synthesis of Triarylimidazoles—An Exemplary Model of Sweet Chemistry
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Abstract: A fine, green, and efficient method has been proposed for the synthesis of2-aryl-4,5-diphenyl-1H-imidazoles usingvarious sugars such as glucose, fructose, sucrose, lactose, and maltose ascatalysts. The syntheses were carried out under very mild
- Babar, R.,Ijaz, F.,Khan, M. A.,Munawar, M. A.,Rizwan, M.,Shafqat, S. S.,Zafar, M. N.
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- Synthesis, Characterization, Modeling, and Antimicrobial Activity of FeIII, CoII, NiII, CuII, and ZnII Complexes Based on Tri-substituted Imidazole Ligand
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The reaction of the synthesized 2-(4,5-diphenyl-1H-imidazol-2-yl) phenol, (HL) ligand with FeIII, CoII, NiII, CuII, and ZnII ions at room temperature resulted in the formation of the five complexes; [Fe(L)2(H2O)(Cl)]·2H2O and [M(L)2)]·nH2O [M = Co, Zn (n = 2), Ni, Cu (n = 1)]. The ligand and its complexes were characterized based on elemental analyses, spectral, magnetic and molar conductance measurements. The molecular and electronic structure of the ligand and its complexes was optimized theoretically and the quantum chemical parameters were calculated. The results revealed an interesting geometrical variation; octahedral for FeL, seesaw for CoL, distorted square planar for NiL and CuL, as well a tetrahedral arrangement for ZnL. The HL ligand and its metal complexes were screened against the growth of pathogenic bacteria [Escherichia coli (G–) and Bacillus cereus (G+)] and fungi (Aspergillus fumigatus) in terms of the minimum inhibitory concentration (MIC). The metal complexes showed high enhancement as antimicrobial candidates with? lower MIC values compared with their parent ligand. Structure activity relationship formula was quantified by correlating the experimental MIC values with theoretical electronic chemical properties. Molecular docking of the complexes against CYP51B protein of A. fumigatus, the target enzyme for the antimicrobial reagents, was achieved to find the best orientation of the substrate, which would form a stable complex with overall minimum energy. The docking results enhanced the activity of the imidazole-based complexes as promising antimicrobial candidates.
- Ismael, Mohamed,Abdou, Aly,Abdel-Mawgoud
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- Graphene oxide-chitosan bionanocomposite: A highly efficient nanocatalyst for the one-pot three-component synthesis of trisubstituted imidazoles under solvent-free conditions
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In the present work, a green, rapid, convenient and eco-friendly method for the synthesis of 2,4,5-trisubstituted imidazoles is described. In this method, we used 1,2-diketone or α-hydroxy ketone, an aldehyde and ammonium acetate in the presence of graphene oxide-chitosan bionanocomposite, which acted as an efficient nanocatalyst. This protocol has many advantages such as short reaction time, high yield, easy separation of the catalyst and solvent-free condition. We used differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM) to confirm that the nanocomposite was formed, and FT-IR, 1H and 13C NMR analyses were performed for the confirmation of the synthesized products.
- Maleki, Ali,Paydar, Reza
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- Efficient elemental iodine catalyzed one-pot synthesis of 2,4,5-triarylimidazoles
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Elemental iodine is used as an efficient catalyst for the synthesis of 2,4,5-triarylimidazoles in excellent yields via condensation of benzoin, ammonium acetate, and aromatic aldehydes. This is a simple, one-pot, high yielding technique using cheap, non-toxic iodine in catalytic amounts.
- Kidwai, Mazaahir,Mothsra, Poonam,Bansal, Vikas,Goyal, Ritu
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- New phosphonium molybdate-promoted green, fast and selective catalytic procedure for the synthesis of trisubstituted imidazoles
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The compound 1,1′-(ethane,1,2-diyl)ditriphenylphosphonium hexamolybdate dimethylsulfoxide {C2H4[P(C6H5)3]2}{Mo6O19}·SO (CH3)2 (I) was prepared, and 1H-NMR, 13C-NMR, Fourier transform-infrared, differential scanning calorimetry and single crystal X-ray diffraction analysis were used to characterize the titled compound. Crystallographic data showed that compound I crystallized in the monoclinic crystal system in C2/c space group. The compound (I) was used for selective synthesis of 2,4,5-tri aryl imidazole derivatives under solvent-free conditions efficiently. Because of hindrance of the catalyst, the yields of products for aldehydes bearing para substituents are higher than the aldehydes bearing ortho substituents, and for aromatic aldehydes with meta substituents are very low.
- Salmasi, Reihaneh,Gholizadeh, Mostafa,Salimi, Alireza
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- One-pot synthesis of 2,4,5-trisubstituted imidazoles using [BPy]H 2PO4, an efficient and recyclable catalyst
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[BPy]H2PO4 was easily prepared and used as an efficient and recyclable catalyst for the one-pot synthesis of 2,4,5-trisubstituted imidazoles under solvent-free conditions in good to excellent yields. Solvent-free conditions, simple experimental and workup procedures, and the use of a nontoxic, recyclable catalyst of an environmentally benign nature are remarkable features of the procedure.
- Zhang, Yuliang,Zhou, Zhongqiang
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- Acidic ionic liquid [(CH2)4SO3HMIM] [HSO4]: A green media for the simple and straightforward synthesis of 2,4,5-trisubstituted imidazoles
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2,4,5-Trisubstituted imidazoles have been synthesized in excellent yields (85-95%) in the presence of 5mol% of [(CH2)4SO3HMIM] [HSO4] as a Brnsted acidic ionic liquid. Copyright
- Heravi, Majid M.,Zakeri, Masoumeh,Karimi, Narges,Saeedi, Mina,Oskooie, Hossien A.,Tavakoli-Hosieni, Niloofar
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- Magnetic horsetail plant ash (Fe3O4@HA): a novel, natural and highly efficient heterogeneous nanocatalyst for the green synthesis of 2,4,5-trisubstituted imidazoles
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Horsetail plant ash (HA), as a natural source of mesoporous silica, has been prepared from the exposure of horsetail plant (Equisetum Arvense) to high temperature. In the present study, a new magnetically separable and also recoverable Fe3O4 nanoparticles were synthesized in the presence of natural horsetail plant ash (HA) as a support to result in Fe3O4@HA. FT-IR, XRD, TEM, SEM–EDX and VSM analysis were combined to characterize the morphology and structure of this novel synthesized nanocatalyst. This magnetically solid acid nanocatalyst showed an excellent catalytic activity for the synthesis of 2,4,5-trisubstituted imidazoles at room temperature in aqueous media. The procedure led to corresponding products in high to excellent yields and appropriate times. Additionally, this nanocatalyst can be easily recovered by a magnetic field and reused for six other consecutive reaction runs without noticeable loss of its catalytic efficiency. Based on this study, Fe3O4@HA is found to be an efficient, magnetically separable, recyclable, and green catalyst with natural source. Graphic abstract: In this work, horsetail plant ash was used as a natural source of mesoporous silica for the synthesis of Fe3O4@HA as a highly powerful magnetically solid acid nanocatalyst, which was fully characterized using various techniques. The activity of the newly synthesized nanocatalyst was tested for the synthesis of 2,4,5-trisubstituted imidazole derivatives.[Figure not available: see fulltext.]
- Hosseini Mohtasham, Nina,Gholizadeh, Mostafa
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p. 2507 - 2525
(2021/03/24)
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- Catalytic conversion of 2,4,5-trisubstituted imidazole and 5-substituted 1H-tetrazole derivatives using a new series of half-sandwich (η6-p-cymene)Ruthenium(II) complexes with thiophene-2-carboxylic acid hydrazone ligands
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A new series of half-sandwich (η6-p-cymene) ruthenium(II) complexes with thiophene-2-carboxylic acid hydrazide derivatives [Ru(η6-p-cymene)(Cl)(L)] [L = N'-(naphthalen-1-ylmethylene)thiophene-2-carbohydrazide (L1), N'-(anthracen-9-ylmethylene)thiophene-2-carbohydrazide (L2) and N'-(pyren-1-ylmethylene)thiophene-2-carbohydrazide (L3)] were synthesized. The ligand precursors and their Ru(II) complexes (1–3) were structurally characterized by spectral (IR, UV–Vis, NMR and mass spectrometry) and elemental analysis. The molecular structures of the ruthenium(II) complexes 1–3 were determined by single-crystal X-ray diffraction. All complexes were used as catalysts for the one-pot three-component syntheses of 2,4,5-trisubstitued imidazole and 5-substituted 1H-tetrazole derivatives. The catalytic studies optimized parameters as solvent, temperature and catalyst. The catalysts revealed very active for a broad range of aromatic aldehydes presenting either electron attractor or electron donor substituents and, although less active, moderate to high activities were observed for alkyl aldehydes.
- Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Archana, Govindhasamy,Alves, Luis G.,Martins, Ana M.,Shanmuga Bharathi, Kuppannan
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- Magnetic nanoparticle-supported sulfonic acid as a green catalyst for the one-pot synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions
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In this work, magnetic nanoparticle-supported sulfonic acid (γ-Fe2O3-SO3H) is used as an efficient catalyst in the synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles in a short time (40-70 min for trisubstituted imidazoles and 30-40 min for tetrasubstituted imidazoles) and high-purity products were obtained (92-98% for trisubstituted imidazoles and 94-98% for tetrasubstituted imidazoles) in simple multicomponent reactions. The structure of these products was confirmed via FT-IR and NMR. Green and recyclable catalysts, eco-friendly and solvent-free conditions, high catalytic activity, shorter reaction time, easy recovery by an external magnet, high purity, and excellent yields are some features of these reactions.
- Amoozadeh, Ali,Kolvari, Eskandar,Sakhdari, Mahnaz
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- Ultrasound-assisted synthesis of NiO nanoparticles and their catalytic application for the synthesis of trisubstituted imidazoles under solvent free conditions
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The present protocol reports the ultrasound assisted synthesis of NiO nanoparticles(NPs) using benzylamine as a base and different types of cyclodextrins (CDs) as capping agents. The use of α-CD, β-CD or γ-CD leads to different morphologies of NiO NPs. In particular, NiO nanosheets obtained using β-CD as the capping agent. The synthesized NPs were characterized by FEG-SEM, TEM, XRD and EDS analysis. They showed high catalytic activity towards synthesis of different trisubstituted imidazoles under solvent free conditions. In addition, NiO NPs could be recycled and reused consecutively up to four recycle runs without much loss of their catalytic activity.
- Bhanage, Bhalchandra M.,Chaurasia, Shivkumar,Gajengi, Aravind L.,Monflier, Eric,Ponchel, Anne,Ternel, Jeremy
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- Visible light-induced aerobic oxidation of diarylalkynes to α-diketones catalyzed by copper-superoxo at room temperature
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We have developed the visible light induced simple copper(ii) chloride catalyzed oxidation of diarylacetylenes to α-diketones by molecular oxygen at room temperature. The in situ generated copper(ii)-superoxo complex is a light-absorbing species that oxidizes inert diarylacetylenes to α-diketones. In contrast to reported photochemical processes, the current oxidation protocol does not require any exogenous photocatalyst or radical initiator. The green chemistry metrics evaluation signifies that the E-factor for the current oxidation process is ~2.3 times better than that of reported photochemical processes. The current reaction scores 63 on the EcoScale of 0-100, indicating an adequate synthesis process. Thus, the overall oxidation process is simple, environmentally benign, and economically feasible. This journal is
- Charpe, Vaibhav Pramod,Hwang, Kuo Chu,Sagadevan, Arunachalam
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supporting information
p. 4426 - 4432
(2020/08/10)
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- Catalytic activity of Co(II) Salen&at;KCC-1 on the synthesis of 2,4,5-triphenyl-1H-imidazoles and benzimidazoles
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The synthesis, reactions and biological properties of imidazoles and benzimidazole make up the bulk of the ring chemistry. In this study, the reaction between different types of aromatic aldehydes and ammonium acetate with diphenylethanedione, in ethanol solvent, using the Co(II) Salen complex&at;KCC-1 catalyst which is produced from Co (II) complex which is supported onto the KCC-1 was studied. The results showed that the products were synthesized in good to excellent yields. The products were identified with IR and NMR spectroscopy. Also, the catalyst was identified by FT-IR, TGA, TEM, and XRD. Finally, the catalyst was reused several times without lack of catalytic activity.
- Ali Nasseri, Mohammad,Allahresani, Ali,Naghdi, Elaheh
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- Design and synthesis of three Fe(III) mixed-ligand complexes: Exploration of their biological and phenoxazinone synthase-like activities
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New Fe(III) complexes with mixed ligands based on 1-{(E)-[(4-methylphenyl)imino]methyl}-2-naphthol (HN) as primary ligand and secondary co-ligand of O-hydroxy quinolone (HQ), 2-(1H-benzimidazol-2-yl)phenol (HB) and 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol
- Ismael, Mohamed,Abdel-Mawgoud, Abdel-Mawgoud M.,Rabia, Mostafa K.,Abdou, Aly
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supporting information
(2020/02/05)
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- An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent
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A mild and highly efficient reaction for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetically supported Lewis acidic deep eutectic solvent on magnetic nanoparticles (LADES?MNP) has been developed via one-pot multicomponent processes under solvent-free sonication. These reactions have good to excellent yields, mild conditions, and work-up simplicity. This method represents a new method for the preparation of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles. More importantly, LADES?MNP can be easily recovered by magnetic separation and reused five times without significant loss of catalytic activity.
- Nguyen, Thanh Thi,Thi Le, Ngoc-Phuong,Nguyen, The Thai,Tran, Phuong Hoang
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p. 38148 - 38153
(2019/12/03)
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- Sulfonated-polyvinyl amine coated on Fe3O4 nanoparticles: a high-loaded and magnetically separable acid catalyst for multicomponent reactions
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Abstract: In this study, a PVAm-bearing SO3H groups/Fe3O4 nanocomposite was prepared via a simple and in situ polymerization of acrylamide onto the surface of magnetic nanoparticles without using organosilane precursors. In order to obtain amine-functionalized magnetic, Hofmann degradation was carried out. In the following, sulfonated-polyvinyl amine coated on Fe3O4 nanoparticles was prepared by covalent grafting of chlorosulfonic acid on amine groups. The introduction of polymer to the surface of magnetic nanoparticles increases the loading content with functional groups extremely. The resulting hybrid material was effectively employed as an unprecedented acid magnetic catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions. High yields, mild reaction conditions, short reaction times, operational simplicity with reusability are the notable features of the catalyst. The structure of the newly developed catalyst was characterized using TGA, FT-IR, SEM, TEM, VSM, EDX, CHNS, and XRD analysis. Magnetic separation and recycling of the catalyst for at least 8 runs is possible without any significant deterioration in catalytic activity. This work is the first report of employing PVAm as a linker for immobilizing liquid acid on a support.
- Arghan, Maryam,Koukabi, Nadiya,Kolvari, Eskandar
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p. 2333 - 2350
(2019/06/17)
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- A 2, 4, 5 - tri-substituted imidazole of preparation method (by machine translation)
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The invention relates to a 2, 4, 5 - tri-substituted imidazole of preparation method, the method is to be sequentially [...] or benzoins, aldehyde compounds, ammonium acetate and catalyst organic acid added in the reactor, in the 85 - 125 °C oil bath under the heating condition the reaction, after the reaction is complete to obtain a reaction mixture; the reaction mixture by washing, filtration, recrystallization after separation, to get the pure product 2, 4, 5 - tri-substituted imidazole. The present invention is simple, the production cost is low, and the yield is high, and has a good industrial application prospect. (by machine translation)
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Paragraph 0036; 0037; 0038
(2019/04/10)
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- An eco-compatible pathway to the synthesis of mono and bis-multisubstituted imidazoles over novel reusable ionic liquids: An efficient and green sonochemical process
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Novel and environmentally benign ionic liquids (ILs) comprised of DABCO were successfully synthesized. These ILs were used as robust catalysts for the sonochemical one pot multi-component synthetic route for the functionalized annulated imidazoles in water with excellent yields. The present protocol scored well in terms of yield economy as compared with the conventional procedures. The merits of the current green method include simplicity, applicability, broad functional groups tolerance, clean reaction profiles, and no tedious work-up and they give high-to-quantitative yields. From the environmental viewpoint, these eco-friendly green catalysts can be effortlessly retrieved and reused at least seven successive times without substantial loss in catalytic activity.
- Ahmed Arafa, Wael Abdelgayed
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p. 16392 - 16399
(2018/05/22)
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- Cu(II) immobilized on guanidinated epibromohydrin-functionalized γ-Fe2O3@TiO2 (γ-Fe2O3@TiO2-EG-Cu(II)): A highly efficient magnetically separable heterogeneous nanocatalyst for one-pot synthesis of highly substituted imidazoles
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A simple, efficient and eco-friendly procedure has been developed using Cu(II) immobilized on guanidinated epibromohydrin-functionalized γ-Fe2O3@TiO2 (γ-Fe2O3@TiO2-EG-Cu(II)) for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles, via the condensation reactions of various aldehydes with benzil and ammonium acetate or ammonium acetate and amines, under solvent-free conditions. High-resolution transmission electron microscopy analysis of this catalyst clearly affirmed the formation of a γ-Fe2O3 core and a TiO2 shell, with mean sizes of about 10–20 and 5–10?nm, respectively. These data were in very good agreement with X-ray crystallographic measurements (13 and 7?nm). Moreover, magnetization measurements revealed that both γ-Fe2O3@TiO2 and γ-Fe2O3@TiO2-EG-Cu(II) had superparamagnetic behaviour with saturation magnetization of 23.79 and 22.12?emu g?1, respectively. γ-Fe2O3@TiO2-EG-Cu(II) was found to be a green and highly efficient nanocatalyst, which could be easily handled, recovered and reused several times without significant loss of its activity. The scope of the presented methodology is quite broad; a variety of aldehydes as well as amines have been shown to be viable substrates. A mechanism for the cyclocondensation reaction has also been proposed.
- Nejatianfar, Mahdi,Akhlaghinia, Batool,Jahanshahi, Roya
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- Benzethonium Chloride Catalyzed One Pot Synthesis of 2,4,5-trisubstituted Imidazoles and 1,2,4,5-tetrasubstituted Imidazoles in Aqueous Ethanol as a Green Solvent
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A simple, efficient procedure has been developed using N-cationic surfactant namely Benzethonium chloride (BzthCl, 10 mol%) as novel catalyst for the synthesis of 2,4,5-trisubstituted imidazoles by condensation of aldehyde, ammonium acetate and benzil usi
- Parthiban,Joel Karunakaran
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p. 3004 - 3015
(2019/01/05)
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- In silico studies, synthesis and pharmacological evaluation to explore multi-targeted approach for imidazole analogues as potential cholinesterase inhibitors with neuroprotective role for Alzheimer's disease
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Alzheimer's disease (AD) is a progressive neurodegenerative disorder with multiple factors associated with its pathogenesis. Our strategy against AD involves design of multi-targeted 2-substituted-4,5-diphenyl-1H-imidazole analogues which can interact and inhibit AChE, thereby, increasing the synaptic availability of ACh, inhibit BuChE, relieve induced oxidative stress and confer a neuroprotective role. Molecular docking was employed to study interactions within the AChE active site. In silico ADME study was performed to estimate pharmacokinetic parameters. Based on computational studies, some analogues were synthesized and subjected to pharmacological evaluation involving antioxidant activity, toxicity and memory model studies in animals followed by detailed mechanistic in vitro cholinesterase inhibition study. Amongst the series, analogue 13 and 20 are the most promising multi-targeted candidates which can potentially increase memory, decrease free radical levels and protect neurons against cognitive deficit.
- Gurjar, Archana S.,Darekar, Mrunali N.,Yeong, Keng Yoon,Ooi, Luyi
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p. 1511 - 1522
(2018/02/13)
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- Appel reagent as novel promoter for the synthesis of polysubstituted imidazoles
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We present an efficient method for the synthesis of polysubstituted imidazoles in the presence of Appel reagent (Ph3P/CCl4). Tri-substituted imidazoles is synthesized via condensation of aldehydes, benzil and ammonium acetate, and tetra-substituted imidazole is prepared via condensation of aldehydes, benzil, ammonium acetate and primary amines. These protocols allow the simple preparation of the desired products using readily available reagent instead of complex, expensive and toxic reagents under mild reaction conditions in excellent yields.
- Khoshneviszadeh, Mehdi,Mahdavi, Mohammad
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p. 343 - 352
(2018/05/07)
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- Simple, Efficient, and Convenient One-Pot Synthesis of Imidazole Derivatives in the Presence of Nanosilica-supported Imidazolium Ionic Liquid as a Catalyst
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An efficient and simple synthesis of 2,4,5-trisubstituted imidazoles is achieved by three-component cyclocondensation of benzil, aldehyde, and ammonium acetate by using nanosilica-supported imidazolium ionic liquid as a catalyst under solvent-free conditions. The key advantages of this process are high to excellent yields, short reaction time, easy work-up, and the reusability of the catalyst.
- Alinezhad, Heshmatollah,Alinezhad, Vajiheh,Mohseni Tavakkoli, Sahar
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p. 385 - 389
(2017/04/24)
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- One-pot synthesis of 2,4,5-trisubstituted imidazole derivatives catalyzed by BTPPC under solvent-free conditions
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A simple and efficient method for one-pot synthesis of lophine derivatives (2,4,5-trisubstituted imidazoles) by using the benzyltriphenylphosphonium chloride (BTPPC), as a catalyst, under solvent-free conditions is described. BTPPC is an available and inexpensive catalyst; also, it can be easily supplied. This procedure led to the corresponding 2,4,5-trisubstituted imidazoles products in high yields.
- Alikarami, Mohammad,Amozad, Mozhgan
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p. 177 - 184
(2017/07/24)
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- One-pot synthesis of multisubstituted imidazoles catalyzed by Dendrimer-PWAn nanoparticles under solvent-free conditions and ultrasonic irradiation
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An efficient, green and eco-friendly protocol has been developed for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles via one-pot condensation reaction using Dendrimer-PWAn as catalyst under solvent-free conditions or ultrasonic irradiation in excellent yields. The reactions under conventional heating conditions were compared with the ultrasonic-assisted reactions. The operational simplicity, practicability and applicability of this protocol to various substrates make it an interesting alternative to previous procedures. The present methodology offers several advantages such as excellent yields, short reaction times, a cleaner reaction, and the absence of any tedious work-up or purification. The catalyst is easily separated from the products by filtration and also exhibits remarkable reusable activity. SEM, BET and DLS of the catalyst were also investigated after each reaction cycle.
- Esmaeilpour, Mohsen,Javidi, Jaber,Dehghani, Farzaneh,Zahmatkesh, Saeed
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p. 163 - 185
(2017/01/14)
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- Doping of copper (I) oxide onto a solid support as a recyclable catalyst for acetylation of amines/alcohols/phenols and synthesis of trisubstituted imidazole
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A study of copper-mediated C-heteroatom especially C-N and C-O bond formations using simpler methodologies has been carried out. In the present work, acetylation of various substrates such as amines, phenols and alcohols; synthesis of 2,4,5-trisubstituted imidazole is done using simple and easily available starting materials. Copper (I) oxide was synthesized in situ by the reduction of Fehling's solution with glucose followed by its anchoring onto different supports like silica, HAP, basic alumina and cellulose. Comparison and contrasts between the reactivity of copper (I) oxide supported onto different supports for these reactions are made. The reactivity of copper (I) oxide seems to be largely dependent on the nature of support and the most active catalyst for a particular reaction was further characterized by different spectroscopic techniques such as FTIR, XRD, TGA, XPS, SEM, TEM and AAS. The catalysts were found to be stable, easily recyclable without any significant loss in activity. Graphical abstract: Applications of solid supported copper (I) oxides (where solid support is silica, HAP, cellulose and basic alumina) are studied for various organic transformations with special emphasis on C-N and C-O bond formation reactions.[Figure not available: see fulltext.]
- Gupta, Manjulla,Gupta, Monika
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p. 231 - 241
(2016/01/09)
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- A waste to wealth approach through utilization of nano-ceramic tile waste as an accessible and inexpensive solid support to produce a heterogeneous solid acid nanocatalyst: To kill three birds with one stone
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Regarding the subject of waste products/materials, recycling or reusing has had a pivotal role on account of environmental and economic reasons. As a consequence, the essential task, nowadays, can be invention of new and practical pathways to reuse or even recycle them. In this framework, until now, recycling of some waste products such as tile wastes has not been taken into consideration; so, we were prompted by the possibility of recycling tile wastes in the catalytic direction. To this end, we use them as cost-effective, available, and nontoxic support materials for the heterogenization of sulfuric acid, in order to prepare the novel nano-ceramic tile waste supported sulfonic acid catalyst (nano-ceramic tile waste-SO3H or n-CTW-SA). This solid acid catalyst was well characterized through FT-IR, XRD, FE-SEM, EDX, TEM, TGA, BET, BJH, pH analysis and Hammett acidity function. The as-prepared nano-ceramic tile waste supported sulfonic acid catalyst proved to be an active heterogeneous catalyst in multicomponent reactions (MRCs) for the rapid and efficient one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles in high yields and selectivity. In comparison with some other homogeneous and heterogeneous catalysts, nano-ceramic tile waste supported sulfonic acid displayed a greater activity. Moreover, being highly stable, inexpensive, accessible, retrievable, reusable, and having low toxicity are some other beneficial points of this catalyst.
- Kolvari, Eskandar,Zolfagharinia, Somayeh
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p. 93963 - 93974
(2016/10/21)
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- Ionophore silica-coated magnetite nanoparticles as a recyclable heterogeneous catalyst for one-pot green synthesis of 2,4,5-trisubstituted imidazoles
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Novel multi-SO3H functionalized strong Br?nsted acidic ionic liquid coated magnetite nanoparticles have been prepared and applied as catalyst for the synthesis of 2,4,5-trisubstituted imidazoles. The results showed that a novel catalyst was very efficient for the reaction and could be magnetically separated and reused at least 6 times with less reduction in its catalytic activity. Operational simplicity, low cost of the catalyst used, high yields, environmental friendliness, wide applicability, reusability and easy recovery of the catalyst using an external magnet are the most important features of this methodology. The catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), dynamic laser scattering (DLS) and vibrating sample magnetometry (VSM).
- Naeimi, Hossein,Aghaseyedkarimi, Dorsa
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p. 1243 - 1253
(2016/01/15)
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- A mechanistic study of carbonyl activation under solvent-free conditions: Evidence drawn from the synthesis of imidazoles
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Syntheses of various imidazoles and their derivatives, imidazole N-oxides and 1-hydroxyimidazole 3-oxides, from sterically different dicarbonyl moieties provided insights into the self-catalytic effect of the condensed phase reactions of carbonyl compounds. The self-catalytic activity in solvent-free multi-component syntheses was investigated using a combination of methods viz., reactivity, spectroscopy and theory. While IR spectroscopic studies revealed that reacting molecules were polarised in bulk, quantum mechanical calculations of associated HCHO monomers suggest an increase in the average dipole moment of each monomer and provide evidence for the presence of cooperative effects. A comparative study of the kinetics of un-catalysed and catalysed reactions with the help of HPLC provided insights into the mechanism.
- Pradhan, Kiran,Tiwary, Bipransh Kumar,Hossain, Mossaraf,Chakraborty, Ranadhir,Nanda, Ashis Kumar
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p. 10743 - 10749
(2016/02/05)
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- Isocyanurate-based periodic mesoporous organosilica (PMO-ICS): A highly efficient and recoverable nanocatalyst for the one-pot synthesis of substituted imidazoles and benzimidazoles
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Isocyanurate bridging periodic mesoporous organosilica (PMO-ICS) was shown to be a highly active and efficient recyclable catalyst for the three-component synthesis of imidazole derivatives from benzoin, different aldehydes and ammonium acetate under mild reaction conditions in short reaction times and good to excellent yields in EtOH. Also, benzimidazole derivatives were efficiently prepared from o-phenylenediamine and different aldehydes in the presence of PMO-ICS. Moreover, the catalyst was also recovered and reused at least four times without a significant decrease in its activity. The PMO-ICS catalyst was characterized by Fourier transformer infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA), powder X-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm (NADI) techniques as well as field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, avoiding the use of toxic transition metals or reactive reagents for modification of the catalytic activity, short reaction times, high to excellent yields, easy separation and purification of the products, and reusability of the catalyst.
- Dekamin, Mohammad G.,Arefi, Elham,Yaghoubi, Amene
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p. 86982 - 86988
(2016/10/19)
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- Shape-dependent catalytic activity of Fe3O4 nanostructures under the influence of an external magnetic field for multicomponent reactions in aqueous media
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High-quality and high-active one-dimensional (1-D) Fe3O4 nanostructures were synthesized via an external magnetic field (EMF) at the intensity range 0-526 μT in aqueous solution, without using any surfactant and organic solvent at room temperature. Characterization of the products was carried out using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectrophotometry (FT-IR), a laser particle size analyzer, surface area (Brunauer-Emmett-Teller, BET), and vibrating sample magnetometer (VSM). The results show that EMF at a critical adjusted intensity has a great influence on the structural features such as the morphology, particle size, surface pore size distribution, and magnetic properties of the Fe3O4 nanostructure. The morphology changed from peg-like network structures to needle-like cage structures by an exposure synthesis treatment with EMF at an intensity of 362 μT. The catalytic activity of two nanostructures prepared in the presence and absence of EMF were compared in a tricomponents reaction (TCR) for the synthesis of trisubstituted imidazoles under electromagnetic irradiation. The best results were obtained for the catalyst produced in the presence of EMF while the tricomponent reaction was carried out in the absence of EMF. This EMF condition was used for the preparation of a series of alkyl-, aryl-, and heteroaryl-substituted imidazoles from the corresponding benzoin and benzil in aqueous solution as green reaction conditions. It was found that the catalyst can be efficiently recycled and reused for several repeating cycles without significant loss of catalytic activity.
- Rafiee,Joshaghani,Ghaderi-Shekhi Abadi
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p. 74091 - 74101
(2015/09/15)
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- Increased SBA-15-SO3H catalytic activity through hydrophilic/hydrophobic fluoroalkyl-chained alcohols (RFOH/SBA-15-Pr-SO3H)
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A superior catalytic activity for the SBA-15-functionalized sulfonic acid containing fluoroalkyl chain alcohols (RFOH/SBA-15-Pr-SO3H adduct) is presented for the synthesis of highly substituted imidazoles. The advantages of this method include low catalyst loading, simple procedure, excellent yields, recyclability of catalyst, and short reaction times.
- Rostamnia, Sadegh,Doustkhah, Esmail
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p. 1345 - 1347
(2015/06/16)
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- Perlite: An inexpensive natural support for heterogenization of HBF4
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Nano-perlite-fluoroboric acid (n-PeFBA) has been synthesized by immobilization of HBF4 on perlite to produce an efficient green heterogeneous reusable solid acid catalyst. The catalyst was characterized by (FE-SEM, EDX, BET and BJH). This catalyst was employed to prepare biologically important 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles with high yields and selectivities. Advantages of solid acid include: low cost, facile handling, simple preparation, high stability, reusability and low toxicity. The catalyst could be recovered and reused for several runs without deterioration in catalytic activity.
- Kolvari, Eskandar,Koukabi, Nadiya,Hosseini, Maliheh M.,Khandani, Zeinab
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p. 36828 - 36836
(2015/05/05)
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- Multi-component synthesis of highly substituted imidazoles catalyzed by nanorod vanadatesulfuric acid
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Nanorod vanadatesulfuric acid (VSA NRs), as a recyclable and eco-benign catalyst, was used for one-pot synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles using aldehydes, benzil, benzoin or 9,10-phenanthrenequinone and ammonium acetate or aniline under solvent-free conditions providing high to excellent yields. VSA is easily prepared by a simple reaction of chlorosulfonic acid and sodium metavanadate in high purity. As compared with the conventional procedures, the present protocol offers several advantages such as simplicity of procedure, short reaction time, high yields, easy workup, recoverability and reusability of the catalyst and simple purification of the products.
- Nasr-Esfahani, Masoud,Montazerozohori, Morteza,Abdizadeh, Tooba
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p. 1491 - 1499
(2015/09/15)
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- Fe3O4@SiO2·HM·SO3H as a recyclable heterogeneous nanocatalyst for the microwave-promoted synthesis of 2,4,5-trisubstituted imidazoles under solvent free conditions
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A simple, highly versatile and efficient synthesis of 2,4,5-trisubstituted imidazoles is achieved through a three component one pot reaction of benzil, benzaldehyde and NH4OAc. This reaction has been catalyzed by Fe3O4@SiO2·HM·SO3H, a very efficient, novel recyclable heterogeneous catalyst, under microwave irradiation and solvent free conditions. The catalyst can be recovered for the subsequent reactions and reused for at least five rounds, without any appreciable loss of its efficiency.
- Naeimi, Hossein,Aghaseyedkarimi, Dorsa
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p. 9415 - 9421
(2015/12/01)
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- One-pot synthesis of multisubstituted imidazoles under solvent-free conditions and microwave irradiation using Fe3O4@SiO2-imid-PMAn magnetic porous nanospheres as a recyclable catalyst
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An efficient, green and ecofriendly procedure has been developed using Fe3O4@SiO2-imid-PMAn as a magnetic catalyst for a rapid and improved synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions and microwave irradiation in excellent yields. The reactions under conventional heating conditions were compared with the microwave-assisted reactions. The operational simplicity, practicability and applicability of this protocol to various substrates make it an interesting alternative to previous procedures. The present approach offers several advantages such as short reaction times, high yields, simplicity of operation, easy work-up, a cleaner reaction and ease of recovery and reusability of the catalyst using a magnetic field. Also, the nanocatalyst can be easily recovered by the application of a magnetic field and reused for the next reactions at least 5 times without distinct deterioration in catalytic activity. SEM, BET, DLS and leaching of the catalyst after each reaction cycle were investigated.
- Esmaeilpour, Mohsen,Javidi, Jaber,Zandi, Maryam
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p. 3388 - 3398
(2015/05/20)
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- (Carboxy-3-oxopropylamino)-3-propylsilylcellulose as a novel organocatalyst for the synthesis of substituted imidazoles under solvent-free conditions
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(Carboxy-3-oxopropylamino)-3-propylsilylcellulose (COPAPSC), a novel organocatalyst, has been prepared by a synthesis grafting of -COOH functionalized organosilanes on a cellulose using surface hydroxyl groups as anchor points. The -CO2H group-functionalized cellulose was synthesized via the consecutive surface functionalization with 3-aminopropyltriethoxysilane (3-APTES) followed by the condensation of the surface -NH2 groups with succinic anhydride. COPAPSC is used as a catalyst for the synthesis of tri- and tetra-substituted imidazoles from the reaction of benzil, aromatic aldehydes, ammonium acetate, and amines under solvent-free conditions. The key advantages of this process are high yields, easy work-up, purification of products by non-chromatographic methods and the reusability of the catalyst.
- Salimi, Mehri,Nasseri, Mohammad Ali,Chapesshloo, Tayyebeh Daliran,Zakerinasab, Batol
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p. 33974 - 33980
(2015/04/27)
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- Metal complexes bearing 2-(imidazol-2-yl)phenol ligands: synthesis, characterization and catalytic performance in the fixation of carbon dioxide with epoxides
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A series of metal complexes bearing 2-(imidazol-2-yl)phenol ligands (Zn, Cu, Ni, Co, Pb) were synthesized and their structures were characterized by IR, NMR, elemental analysis and X-ray. The catalytic activities of all complexes for the coupling reaction of CO2 and epoxide were then detected. The activity influence factors, such as temperature, time, pressure, substituents of ligands and metal centre, were systematically investigated. All these complexes were efficient to catalyze the coupling of CO2 and epoxide to generate cyclic carbonate in perfect yields (>90%) and selectivities (>99%) under optimized conditions of (2 MPa, 5 h, 110 °C) without any organic solvents. A 99.7% yield and >99% selectivity for propylene carbonate (PC) were obtained with C7/n-Bu4NI as catalyst system under the optimized conditions. The catalysts were also proved to be applicable to other terminal epoxides. It is worthy noted that the Pb(ii) complex was firstly used to catalyze the coupling reaction of epoxides with carbon dioxide. Moreover, these metal catalysts were recyclable with only minor losses in catalytic activity after simple separation. Finally, a plausible mechanism was given.
- Peng, Jing,Yang, Hai-Jian,Wei, Zidong,Guo, Cun-Yue
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p. 53063 - 53072
(2015/06/25)
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- Organocatalyzed solvent free an efficient novel synthesis of 2,4,5-trisubstituted imidazoles for α-glucosidase inhibition to treat diabetes
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A new and efficient solvent free synthesis of 2,4,5-trisubstituted imidazoles (3a-3j) was achieved by N-acetyl glycine (NAG) catalyzed three components condensation of aldehydes, benzil and ammonium acetate. Our synthetic methodology accommodated a range of various substituted alkyl and aryl aldehydes. Evaluation of α-glucosidase inhibitory activity of these imidazole derivatives revealed that most of them presented good α-glucosidase inhibition at low micro-molar concentrations. Among the synthesized compounds, compound 3c, bearing the ortho-hydroxy phenyl substituent at position 2 displayed the highest inhibitory activity with an IC50 value 74.32 ± 0.59 μM. In silico molecular docking for all compounds and computational studies of the most active compound 3c were also performed.
- Yar, Muhammad,Bajda, Marek,Shahzad, Sohail,Ullah, Nisar,Gilani, Mazhar Amjad,Ashraf, Muhammad,Rauf, Abdul,Shaukat, Ayesha
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