2818-82-8Relevant academic research and scientific papers
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
Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Archana, Govindhasamy,Alves, Luis G.,Martins, Ana M.,Shanmuga Bharathi, Kuppannan
, (2020/11/16)
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.
Propyl–SO3H functionalized SBA-15: Microwave-mediated green synthesis of biologically active multi-substituted imidazole scaffolds
Gabla, Jenifer J.,Lathiya, Dharmesh R.,Revawala, Akash A.,Maheria, Kalpana C.
, p. 1863 - 1881 (2019/01/04)
Abstract: Propylsulfonic acid functionalized Santa Barbara Amorphous-15 (SBA-15–Pr–SO3H) catalyst has been synthesized using a surface modification of mesoporous SBA-15 via the one-pot co-condensation method. The synthesized SBA-15–Pr–SO3H has been characterized by peculiar characterization techniques such as small- and wide-angle XRD, SEM–EDX, TEM, TG–DTA, acidity, FT-IR, Py-FT-IR and BET surface area analysis. The catalytic activity of synthesized catalyst has been studied towards solvent-free MW irradiation for the green and rapid synthesis of multi-substituted imidazoles, [2,4,5-triphenyl-1(H)-imidazole (tri-imidazole) and 1-benzyl-2,4,5-triphenyl-1H-imidazole (tetra-imidazole)]. The SBA-15–Pr–SO3H catalyst was found to be an efficient and recyclable solid acid catalyst and this solvent-free MW protocol afforded products in good to excellent yields of both, tri and tetra imidazoles (> 95%) within shorter reaction time (3?min) at 600?W as compared to the SBA-15 and other existing protocols. The applicability of this protocol was further explored by conducting the experiments in the presence of varied solvents and substituted aldehydes to generate a library of both, tri- and tetra-imidazole scaffolds. The catalyst was found to be reusable up to several runs without loss of its catalytic activity. This report allows the rapid and scalable access to a variety of multi-substituted imidazoles using SBA-15–Pr–SO3H, as heterogeneous catalyst. Graphical abstract: SBA-15–Pr–SO3H catalyzed solvent-free MW assisted green synthesis of multi-substituted imidazoles via MCRs.[Figure not available: see fulltext.].
An eco-compatible pathway to the synthesis of mono and bis-multisubstituted imidazoles over novel reusable ionic liquids: An efficient and green sonochemical process
Ahmed Arafa, Wael Abdelgayed
, p. 16392 - 16399 (2018/05/22)
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.
Shape-dependent catalytic activity of Fe3O4 nanostructures under the influence of an external magnetic field for multicomponent reactions in aqueous media
Rafiee,Joshaghani,Ghaderi-Shekhi Abadi
, p. 74091 - 74101 (2015/09/15)
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.
Organocatalyzed solvent free an efficient novel synthesis of 2,4,5-trisubstituted imidazoles for α-glucosidase inhibition to treat diabetes
Yar, Muhammad,Bajda, Marek,Shahzad, Sohail,Ullah, Nisar,Gilani, Mazhar Amjad,Ashraf, Muhammad,Rauf, Abdul,Shaukat, Ayesha
, p. 65 - 71 (2015/02/19)
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.
Tributylhexadecylphosphonium bromide: An efficient reagent system for the one-pot synthesis of 2,4,5-trisubstituted imidazoles
Heidari, Mohammad,Rezaei, Mohsen,Badri, Rashid
, p. 73 - 76 (2015/04/27)
The reaction of benzil, an aromatic aldehyde, and ammonium acetate in ethanol at reflux in the presence of tributylhexadecylphosphonium bromide as catalyst affords a 2,4,5-trisubstituted imidazole. The present methodology offers several advantages over the literature methods, including excellent yields, shorter reaction times, environmentally benign milder reaction conditions, cost-effectiveness of catalyst, easy workup, and purification of products by nonchromatographic methods.
Highly efficient and eco-friendly synthesis of 2-alkyl and 2-aryl-4,5-diphenyl-1H-imidazoles under mild conditions
Magee, David I.,Bahramnejad,Dabiri, Minoo
, p. 2591 - 2594 (2013/06/05)
Highly efficient one-pot reactions of benzil or benzoin, ammonium acetate, and aliphatic or aromatic aldehydes were carried out in water in the presence of 1-methylimidazolium trifluoroacetate ([Hmim]TFA) under mild and green conditions. This approach can be useful for the three-component synthesis of 2-alkyl- and 2-aryl-4,5-diphenyl-1H-imidazoles in high yields. By conducting the reactions in aqueous media, the solid products were precipitated and could be isolated simply by filtration.
Room temperature synthesis of tri-, tetrasubstituted imidazoles and bis-analogues by mercaptopropylsilica (MPS) in aqueous methanol: application to the synthesis of the drug trifenagrel
Mukhopadhyay, Chhanda,Tapaswi, Pradip Kumar,Drew, Michael G.B.
supporting information; experimental part, p. 3944 - 3950 (2010/08/07)
The heterogeneous solid catalyst, mercaptopropylsilica (MPS), has been prepared by a modified procedure in water and its structure confirmed by solid state carbon-13 CP-MAS NMR spectrum. This catalyst has been efficiently utilized for the synthesis of a w
l-Proline: an efficient catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles
Samai, Subhasis,Nandi, Ganesh Chandra,Singh, Pallavi,Singh
experimental part, p. 10155 - 10161 (2010/02/27)
A simple highly versatile and efficient synthesis of 2,4,5-trisubstituted imidazoles is achieved by three-component cyclocondensation of 1,2-dicarbonyl compound, aldehyde and ammonium acetate using l-proline as a catalyst in methanol at moderate temperature. To explore the utility of this method 1,2,4,5-tetrasubstituted imidazoles were also synthesized. The key advantages of this process are high yields, cost effectiveness of catalyst, easy work-up and purification of products by non-chromatographic methods.
An efficient and one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by InCl3·3H2O
Das Sharma, Saikat,Hazarika, Parasa,Konwar, Dilip
, p. 2216 - 2220 (2008/09/18)
InCl3·3H2O was found to be a mild and effective catalyst for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted imidazoles at room temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields.
