RESUMEN

A straightforward, expeditious, robust, and efficient synthesis of NiO@Bentonite nanocatalyst was done using a simple microwave method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), thermal behavior analysis, and vibrating sample magnetometer (VSM) techniques were used to characterize the physicochemical properties of the NiO@Bentonite nanocomposites. The outcomes demonstrated that the NiO nanoparticles are evenly distributed throughout the Bentonite surface and that the NiO@Bentonite nanocomposites have a high specific surface area and rich pore structure. The following report details the investigation of this catalyst for the preparation of 1, 8-dioxodecahydroacridine heterocycles in a one-pot, three-component reaction of aromatic aldehydes, dimedone, and aniline. After the conditions were optimized, the results demonstrated that this reaction could be carried out in an aqueous medium with a good yield.

RESUMEN

In this research, a suitable and efficient CoFe2O4@ZnO@Bentonite nano-catalyst was designed and synthesized by using zinc oxide (ZnO) and cobalt ferrite (CoFe2O4) nanoparticles and bentonite by microwave irradiation. Characteristics of the synthesized nanocomposite were investigated by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray (EDX), transmission electron microscope (TEM), X-ray diffraction (XRD), Bruner- Emmett-Teller (BET) and vibrating sample magnetometer (VSM) techniques. The produced catalyst was effectively employed as a supported solid acid catalyst in mildly agitated three-component reactions involving aromatic aldehydes, 4-hydroxycoumarin, and 1,3-dimethyl-barbituric acid in a single pot to produce benzylbarbiturocoumarins. Starting materials were condensed via three C-C bond formation by CoFe2O4@ZnO@Bentonite as an efficient, recyclable, and environmentally safe nanocatalyst to obtain target products. The advantages of this method include using a natural substrate, small amounts of catalyst, aqueous media, performing reactions at ambient temperature, simple separation and purification of products, and good yields with short reaction times.

RESUMEN

In this study, a Co-MOF was synthesized via a co-precipitation procedure and then used as support for stabilizing Ag ions and producing Co-MOF@Ag2O nanocomposite by microwave irradiation. The characterization of synthesized Co-MOF@Ag2O nanocomposite was performed by using different techniques such as field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analyses, X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) and Fourier-transform infrared (FT-IR). The prepared Co-MOF@Ag2O nanocomposite was applied as a heterogeneous nano-catalyst in the synthesis of pyrazolopyranopyrimidines in water at 50 °C via the one-pot multicomponent reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehydes and barbituric acid derivatives. Through this straightforward and effective protocol, different tricyclic fused pyrazolopyranopyrimidines were synthesized at high yields, and short reaction times, through an uncomplicated work-up process with no by-product. The Co-MOF@Ag2O nanocomposite has been effectively recycled for four consecutive cycles without appreciable loss in its activity. Cost-effectiveness, no need for column chromatography, mild conditions, catalyst recyclability, and eco-friendly nature make it a promising candidate compared to other methods.

RESUMEN

In this study, a new and efficient Rod-like bifunctional Fe-based MOF@CuO nanocomposites (RL BF Fe-based MOF@CuO NC) were synthesized as new and efficient heterogeneous catalyst through a simple method from easily available 1,3,5-benzenetricarbocylic acid linker, nitrate ferric as a source of iron and copper oxide (CuO) nanoparticles under microwave irradiation. The synthesized nanocatalysts were characterized with different techniques such as Brunauer-Emmett-Teller (BET), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), mapping, transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The RL BF Fe-based MOF@CuO NC had relatively high specific surface area (203 m2 g-1) while exhibiting superparamagnetic properties. The catalytic activity of RL BF Fe-based MOF@CuO NC was explored in a facile and green methodology to prepare diverse N­amino-2-pyridones by one-pot four component reactions comprising aromatic aldehyde, malononitrile, methyl cyanoacetate and hydrazine hydrate within mild and solvent-free conditions. This protocol enjoys features like providing the final products during low reaction times in excellent yields under solvent-free conditions. The use of easily available and inexpensive reactants for the synthesis of the catalyst, environmental compatibility, low catalyst loading, fast and clean work-up and reusability of catalyst for several cycles with consistent activity are counted as the outstanding features of this procedure.

RESUMEN

Various pyrano[2,3-d]pyrimidines were synthesized by the multicomponent reaction of aldehydes, malononitrile, and acidic C-H compounds such as barbituric acid through the tandem Knoevenagel-Michael cyclocondensation pathway in an environmentally friendly reactive medium in the presence of a recoverable nanocomposite. This nanocomposite includes Fe3O4 nanoparticles placed on an organometallic framework. The synthesized Fe3O4@iron-based metal-organic framework nanocomposite was characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, a vibrating sample magnetometer, and thermogravimetric analysis.

RESUMEN

Background: Organophosphate pesticides are one of the most extensively applied insecticides in agriculture. These insecticides persist in the environs and thereby cause severe pollution problems. Iron oxide polymer nanocomposites are wastewater remediation agents synthesized by various methods. When compared to chemical processes, green synthesis using plant extract is thought to be more cost- and environmentally-friendly. Objectives: This study aimed to evaluate the green synthesis of Fe3O4@ß-Cyclodextrin (Fe3O4@ß-CD) nanoparticles using Ferulago angulata (F. angulata) methanol extract. These nanoparticles are loaded on polylactic acid (PLA) nanofibrous nanocomposite along with Ferulago angulata extract (2, 4, and, 6wt %) to produce PLA/Fe3O4@ß-CD/F. angulata extract nanofibrous nanocomposite as a new nano biosorbent. Furthermore, the antibacterial properties of this compound and its activity in diazinon removal have been evaluated. Materials and Methods: Fe3O4@ß-CD nanoparticles synthesis was performed via co-precipitation method using FeCl3.6H2O and FeCl2.4H2O and ß-cyclodextrin, and Ferulago angulata extract. Then polylactic acid/ Fe3O4@ß-CD / F. angulate.extract nanofibrous nanocomposite was prepared by the electrospinning method. Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the structure of the nanocomposite. The antibacterial activity of this nanocomposite against several fish and human bacterial pathogens, as well as its effectiveness in diazinon elimination, have been evaluated in the sections that follow. Results: The nanocomposite structure demonstrated that Fe3O4 nanoparticles were produced and put into the polylactic acid matrix with an average particle size of 40 nm. Furthermore, the results showed that this nanocomposite exhibited removal efficiency of diazinon over 80% after 120 minutes under pH=7 and 2.5 gr.L-1 nanocomposite concentration. Also, this structure showed above 70% antibacterial ability against Bacillus cereus, Staphylococcus epidermidis and 60% antibacterial ability against Streptococcus iniae and Yersinia ruckeri. Conclusion: Fe3O4 nanocomposite synthesis may be accomplished in a delicate and efficient manner by using Ferulago angulata to produce Fe3O4@-CD nanoparticles. The stability of the nanoparticles was enhanced by combining Ferulago angulata extract with polylactic acid nanofibers to create an antibacterial homocomposition nanocomposite. This device may be used to remove and disinfect diazinon from aqueous media in an environmentally friendly manner.

RESUMEN

In this study, controllable and optimal microwave irradiation has been used to synthesize the novel nanostructures of Bi2O3 under environmental conditions. The final products had a thermal stability of 210°C, an average particle size distribution of 85 nm, and a surface area of 783 m2/g. The high thermodynamic stability of Bi2O3 nanostructures was confirmed by TG and differential scanning calorimetry (DSC) analyses. The nanostructure nature of compounds, and most importantly, the use of an effective, cost-effective, and rapid synthesis route of microwave have created significant physiochemical properties in the Bi2O3 products. These unexpected properties have made the possibility of potential application of these products in various fields, especially in nano-catalyst applications. It is well-documented that, as Lewis acid, bismuth nano-catalyst exhibits a great catalytic activity for the green synthesis of some bio-active barbituric acid derivatives using precursors with electron-donating or electron-withdrawing nature in high yields (80%-98%). After incorporating this catalyst into the aqueous media, all the reactions were completed within 2-3 min at room temperature. The main advantages of this method are practical facility, the availability of starting materials, and low costs besides the catalyst reusability. Additionally, the catalyst synthesis process may be carried out in the aqueous media for a short period with medium to high yields. The obtained results have opened a new window for the development of a novel nano-catalyst with practical application.

RESUMEN

Reactivity characteristics of Tranylcypramine and adopting on C60 (ih) in gas and water phases have been focused in the present work, using DFT B3LYP/6-311+G (d, p). Calculation of chemical structure (dipole momentum), thermodynamic features (gibbs free energy, enthalpy, entropy, as well as thermal capacity) and electronic parameters (σ, µ, ω, χ and η) were carried out. Based on the calculations of HOMO and LUMO energy, Tranylcypramine indicated the properties of stability and reactivity. There are two active sites for Tranylcypramine, which both show thermodynamic stability.

Asunto(s)

Fulerenos , Teoría Cuántica , Espectrometría Raman , Electrónica , Fulerenos/química , Modelos Moleculares , Conformación Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica

RESUMEN

In this study, the recyclable heterogeneous cluster bud Fe-MOF@Fe3O4 'nanoflower' composite (CB Fe-MOF@Fe3O4 NFC) was successfully synthesized using Fe(NO3)3·9H2O, 8-hydroxyquinoline sulfate monohydrate, and Fe3O4 nanoparticles by microwave irradiation. The as-prepared CB Fe-MOF@Fe3O4 NFC was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), vibrational sampling magnetometry (VSM), and Fourier transform infrared spectroscopy (FTIR). The CB Fe-MOF@Fe3O4 NFC samples proved to have excellent catalytic activity. The activity of the CB Fe-MOF@Fe3O4 NFC nanocatalyst was explored in the synthesis of dihydropyrano[3, 2-c]chromene derivatives via a three-component reaction of 4-hydroxycoumarin, malononitrile, and a wide range of aromatic aldehyde compounds. Optimized reaction conditions had several advantages, including the use of water as a green solvent, environmental compatibility, simple work-up, reusability of the catalyst, low catalyst loading, faster reaction time, and higher yields.

RESUMEN

INTRODUCTION: We developed a simple, fast and new method for the Fries rearrangement of aryl esters. MATERIALS AND METHODS: 4-Hydroxy pyridinium triflate functionalized silica is a very efficient, reusable and economically available catalyst for the Fries rearrangement in solvent-free condition and under microwave irradiation. RESULTS AND DISCUSSION: Also, a notable selectivity was observed in the presence of 4-hydroxy pyridinium triflate functionalized silica. CONCLUSION: Selectivity, shorter reaction time, high yield, and easy work-up are advantages of this synthetic method.

RESUMEN

New spiro[indoline-3,4'-[1,3]dithiine]@Cu(NO3)2 supported on Fe3O4@gly@CE magnetic nanoparticle were synthesized and used as efficient and recyclable catalyst in the synthesis of 2-oxospiro[indoline-3,4'-[1,3]dithiine]-5'-carbonitrile derivatives. The structure of magnetic nanoparticles were confirmed using energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), infrared spectroscopy (FT-IR) and inductively coupled plasma optical emission spectroscopy (ICP-OES). Subsequently, antibacterial and antifungal activities in terms of inhibition zone diameter, minimum inhibitory concentration, minimum bactericidal concentration and antioxidant activity against the DPPH free radical of the derivatives were investigated. The results revealed acceptable biological effects of the synthetic derivatives and a significant relationship between their structure and biological activity were observed.

Asunto(s)

Antibacterianos/farmacología , Antifúngicos/farmacología , Antioxidantes/farmacología , Indoles/síntesis química , Nitrilos/síntesis química , Compuestos de Espiro/síntesis química , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Antioxidantes/síntesis química , Antioxidantes/química , Compuestos de Bifenilo/antagonistas & inhibidores , Catálisis , Cobre/química , Cobre/farmacología , Relación Dosis-Respuesta a Droga , Hongos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Indoles/química , Nanopartículas de Magnetita/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Nitratos/química , Nitratos/farmacología , Nitrilos/química , Tamaño de la Partícula , Picratos/antagonistas & inhibidores , Compuestos de Espiro/química , Relación Estructura-Actividad , Propiedades de Superficie

RESUMEN

l,3-Dithiin with two sulfurs in its structure is a six-membered, sulfur-containing heterocyclic compound. New derivatives of 6'-amino-2'-(arylidene)spiro[indeno[1,2-b]quinoxaline[1,3]dithiine]-5'-carbonitrile were prepared by the multi-component reaction of active methylene compounds, carbon disulfide, malononitrile and multi-ring compounds containing a carbonyl group in the presence of piperidine as a catalyst at room temperature with high efficiency. The antimicrobial effects including antibacterial and antifungal effects based on inhibition zone diameter (IZD), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were studied.

Asunto(s)

Antibacterianos/farmacología , Antifúngicos/farmacología , Indenos/farmacología , Quinoxalinas/farmacología , Compuestos de Espiro/farmacología , Antibacterianos/síntesis química , Antifúngicos/síntesis química , Bacterias/efectos de los fármacos , Hongos/efectos de los fármacos , Indenos/síntesis química , Pruebas de Sensibilidad Microbiana , Quinoxalinas/síntesis química , Compuestos de Espiro/síntesis química

RESUMEN

A new biological active hexapeptide of C-terminal of nocistatin, contains Glu-Gln-Lys-Gln-Leu-Gln sequence was synthesized according to solid phase peptide synthesis on the surface of 2-chloro tritylchloride resin and using fmoc-protected amino acids in the presence of TBTU (O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyl uranium tetrafluoroborate) as a coupling reagent. Then, amidation of the C-terminus of peptides was carried out using NH4Cl and alkyl ammonium chloride (RNH3Cl) in the presence of TBTU and a tertiary amine (DIPEA) as the base at room temperature in good to high yields. Cleavage of the desired peptides from the surface of the resin after the addition of TFA (1%) provided the protected peptides. All of the products were purified using preparative HPLC and structures were assigned according to MALDI-mass spectrometry data.

RESUMEN

The reaction of cyclo-hexyl isocyanide and alkyl-idene Meldrum's acid (systematic name 2,2-dimethyl-1,3-dioxane-4,6-dione) in the presence of cyclo-hexyl ketoxime and dichloro-methane as solvent resulted in the title compound, 2C(28)H(43)N(3)O(5)·H(2)O. One methyl-ene group of the cyclo-pentane ring was found to be disordered and was refined with occupancies 0.75:0.25. Intra-molecular N-H⋯O hydrogen bonds occur. The crystal structure is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.