Graphene oxide-THEIC-ECH-Chitosan network nanocomposite: a novel, efficient and recyclable catalyst for green synthesis of polyhydroquinoline derivatives (original) (raw)
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2020
Here, an efficient and biodegradable catalytic system prepared through a simple procedure is presented by using chitosan (Cs), epichlorohydrin (ECH) and trimesic acid (TMA). The obtained bio-based Cs/ECH-TMA was characterized by using different spectroscopic and analytical methods. The Cs-ECH-TMA biopolymeric materials were used, as a bifunctional heterogeneous and green catalyst, for efficient synthesis of biologically-active scaffolds including polyhydroquinolines (PHQs) and acridinediones through Hantzsch reaction in a one-pot reaction. Both PHQs and acridinediones were synthesized in the presence of heterogeneous Cs/ECH-TMA catalyst from their corresponding substrates in EtOH under reflux conditions in high to quantitative yields. The Cs/ECH-TMA catalyst is recyclable and can be reused at least five times.
2021
Trimesic acid-functionalized chitosan (Cs/ECH-TMA) material was prepared through a simple procedure by using chitosan (Cs), epichlorohydrin (ECH) and trimesic acid (TMA). The obtained bio-based Cs/ECH-TMA material was characterized using energy-dispersive X-ray (EDX) and Fourier-transform infrared spectroscopy (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. The Cs/ECH-TMA material was successfully used, as a multifunctional heterogeneous and sustainable catalyst, for efficient and expeditious synthesis of medicinally important polyhydroquinoline (PHQ) and polyhydroacridinedione (PHA) scaffolds through the Hantzsch condensation in a one-pot reaction. Indeed, the heterogeneous Cs/ECH-TMA material can be considered as a synergistic multifunctional organocatalyst due to the presence of a large number of acidic active sites in its structure as well as hydrophilicity. Both PHQs and PHAs were synthesized in the presence of biod...
2020
Here, an efficient and biodegradable catalytic system prepared through a simple procedure is presented by using chitosan (Cs), epichlorohydrin (ECH) and trimesic acid (TMA). The obtained bio-based Cs/ECH-TMA was characterized by using different spectroscopic and analytical methods. The Cs-ECH-TMA biopolymeric materials were used, as a bifunctional heterogeneous and green catalyst, for efficient synthesis of biologically-active scaffolds including polyhydroquinolines (PHQs) and acridinediones through Hantzsch reaction in a one-pot reaction. Both PHQs and acridinediones were synthesized in the presence of heterogeneous Cs/ECH-TMA catalyst from their corresponding substrates in EtOH under reflux conditions in high to quantitative yields. The Cs/ECH-TMA catalyst is recyclable and can be reused at least five times.
Journal of Heterocyclic Chemistry, 2019
Graphene-supported sulfonic acid (Gr@SO 3 H) has been prepared by covalent grafting of (3-mercaptopropyl)trimethoxysilane in the matrix of graphene followed by treatment with sulfuric acid and hydrogen peroxide. Gr@SO 3 H has been successfully characterized by Fourier transform infrared (FT-IR) spectroscopy, Fourier transform Raman (FT-Raman) spectroscopy, CP-MAS 13 C NMR spectroscopy, thermogravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, and X-ray diffractometer (XRD) analysis. Gr@SO 3 H served as a robust heterogeneous catalyst for the synthesis of bioactive 2,3-dihydroquinazolin-4(1H)-ones from anthranilamide and aryl aldehydes in ethanol. Recyclability experiments were executed successfully for six consecutive runs.
Preparation and catalytic application of graphene oxide-chitosan bionanocomposite
An efficient method for the synthesis of graphene oxide (GO)-chitosan bionanocomposite is demonstrated. Also, GO-chitosan is used as a green nanocatalyst in the synthesis of tetra-substituted imidazoles. This protocol has many advantages such as short reaction time, high yield, easy isolation of the catalyst and solvent-free conditions. We put upon Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analyzes for the confirmation of the nanocomposite production.
International Journal of NanoScience and Nanotechnology, 2016
In this work, an efficient and facile method has been developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from a condensation reaction of 2-aminobenzamide with various alkyl,aryl and alicyclic aldehydes or ketones using Fe3O4/chitosan as an environmentally benign, magneticallyrecoverable nanocomposite catalyst in ethanol at room temperature in high to excellent yields undermild reaction conditions. The Fe3O4/chitosan composite nanocatalyst was first prepared by a sol-gelmethod and characterized by using a variety of conventional techniques including Fourier transformsinfrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) andX-ray diffraction (XRD) analyses. The present work include several advantages such as avoiding the useof toxic solvents or expensive catalysts, generality, high yields, short reaction times, clean reactionprofile, ease of product isolation, simplicity, recyclability of the catalyst and finally agreement with t...
Journal of Nanostructure in Chemistry
In this work, a library of diverse chemically and medicinally important heterocyclic polyhydroquinoline derivatives was efficiently prepared via a one-pot multicomponent reaction starting from various raw materials including aromatic aldehydes, dimedone or 1,3-cyclohexandione, ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of Fe 3 O 4 /SiO 2-OSO 3 H as a sulfonated silica-based magnetic nanocatalyst in high yields. Main advantages of the present practical approach are ready availability of starting materials, non-toxicity, inexpensiveness, ease of workup procedure, diversity orientation synthesis and an eco-friendly nature of the reaction. The nanocatalyst was characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDX) spectra. The nanocatalyst was simply recovered using an external magnet and reused several times. Then, the pharmacological and biological activities of the products were theoretically examined by the prediction of activity spectra for substances (PASS) program.
Please cite this article as: Zohre Zarnegar, Javad Safari, Zahra Mansouri-Kafroudi, Environmentally benign synthesis of polyhydroquinolines by Co 3 O 4-CNT as an efficient heterogeneous catalyst, Catalysis Communications (2014), Abstract A novel and eco-friendly synthesis of polyhydroquinolines is efficiently catalyzed by Co 3 O 4-CNTs nanocomposites. This recyclable catalytic system provides a simple strategy to generate a variety of polyhydroquinolines under mild conditions. Utilization of easy reaction condition, recyclable nanocatalyst, reduced environmental impacts and simple work-up make this methodology as an interesting option for the eco-friendly synthesis of polyhydroquinolines.
Silicon, 2020
The development of new and robust sensors for real-time monitoring of environmental pollutants have received much attention. Therefore, in the present work, we have fabricated a simple and robust electrochemical sensor for the simultaneous electrochemical determination of dihydroxybenzene isomers using chitin (CHI) stabilized graphite (GR) hydrogel composite modified electrode. The GR-CHI hydrogel composite was prepared by a simple sonication of raw GR in CHI solution and the as-prepared materials were characterized by range of physicochemical methods. Compared with CHI and GR modified electrodes, the GR-CHI hydrogel composite modified electrode shows an excellent electron transfer ability and enhanced electrocatalytic activity towards hydroquinone (HQ), catechol (CC) and resorcinol (RC). Differential pulse voltammetry was used for the simultaneous determination of HQ, CC and RC. Under optimized conditions, the fabricated electrode detects the HQ, CC and RC in the linear response from 0.2 to 110.6 μM, 0.3 to 110.6 μM and 1.3 to 133.4 μM, respectively. The detection limit for HQ, CC and RC were 0.065 μM, 0.085 μM and 0.35 μM, respectively. The sensor shows its appropriate practicality towards the determination of HQ, CC and RC in different water samples.
In the present work, a green, rapid, convenient and eco-friendly method for the synthesis of 2,4,5-trisubstituted imidazoles is described. For achieving this purpose, we used 1,2-diketone or α-hydroxy ketone, an aldehyde and ammonium acetate in the presence of graphene oxide-chitosan bionanocomposite as an efficient nanocatalyst. This protocol has many advantages such as short reaction times, high yields, easy separation of the catalyst and solvent-free conditions. We put upon differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM) analyzes for the confirmation of nanocomposite producing and FT-IR, 1H and 13C NMR analyzes for the confirmation of the products synthesis.