Fabrication and characterization of inorganic-organic hybrid copper ferrite anchored on chitosan Schiff base as a reusable green catalyst for the synthesis of indeno[1,2-b]indolone derivatives.

This study presents a description of the catalytic synthesis of indeno[1,2-b]indolone derivatives. In this method, initially, a Schiff base compound was synthesized from the reaction of acetylacetone with 2-hydroxyaniline. Then, the prepared Schiff base was immobilized on chelated magnetic copper ferrite nanoparticles with a chitosan surface to design and prepare the CuFe2O4@CS-SB nanocomposite. Further, the one-pot multi-component cyclization reaction of aniline, dimedone and ninhydrin was conducted using the synthesized nanocomposite as a heterogeneous acid catalyst in water solvent under thermal conditions. In this reaction, the products were obtained in excellent yields and short reaction times, and the catalyst could be recycled and reused six times without any loss in product yields. By conducting FT-IR spectroscopy, 1H NMR spectroscopy, XRD, FE-SEM, TGA, elemental mapping scanning, EDX and BET analyses, the structure of the nanocatalyst was characterized. In addition, for the identification of organic compounds, FT-IR, 1H NMR, and 13C NMR spectroscopies and melting point analysis were used, which confirmed the synthesis of this class of derivatives.

Design, preparation and characterization of magnetic nanoparticles functionalized with chitosan/Schiff base and their use as a reusable nanocatalyst for the green synthesis of 1H-isochromenes under mild conditions.

In this study, a Schiff base complex magnetic nanocatalyst was designed and prepared. The structure of the Fe3O4@CS-SB-CaMgFe2O4 nanocatalyst was characterized using FT-IR spectroscopy, XRD, VSM, FE-SEM, EDX, elemental mapping, BET, and TGA techniques. The synthesis of 1H-isochromene compounds has attracted the attention of chemists due to their biological and medicinal properties. The 1H-isochromene derivatives were synthesized in the presence of the Fe3O4@CS-SB-CaMgFe2O4 nanocatalyst with excellent efficiency and short reaction time as well as according to the rules of green chemistry. This reaction was carried out using Fe3O4@CS-SB-CaMgFe2O4 as a catalyst to develop a simple method with low activation energy at room temperature under optimal conditions. This catalyst provides a promising route for the synthesis of 1H-isochromene multiple times through its recyclability without significant loss of catalytic activity. This nanocatalyst possesses several advantages, including cost-effectiveness, facile separation, environmental friendliness, and recyclability, for the efficient production of 1H-isochromenes. The obtained compounds were further analyzed using spectroscopic techniques, such as melting point, FT-IR, 1H NMR, and 13C NMR analyses, to confirm their structures. The spectra of the synthesized compounds were recorded and analyzed, and a plausible mechanism for their synthesis was proposed. The characterization results and structural elucidation provide valuable insights into the preparation of these compounds.

Design, fabrication and characterization of mesoporous yolk-shell nanocomposites as a sustainable heterogeneous nanocatalyst for synthesis of ortho-aminocarbonitrile tetrahydronaphthalenes.

A new structure of mesoporous spherical nanocomposites was designed and easily prepared from the reaction between NiCuFe2O4 nanoparticles and mesoporous silica in three steps. The prepared multi-yolk@shell NiCuFe2O4@mSiO2 mesoporous sphere was characterized by using FT-IR, XRD, VSM, EDX, BET, FE-SEM and HR-TEM techniques. This unique mesoporous nanocomposite sphere as a heterogeneous nanocatalyst has demonstrated highly catalytic activity for the green synthesis of tetrahydronaphthalene derivatives in 92-98% yields at reaction times of 60-75 min. This process was carried out through multi-component reaction of the cyclic ketone, malononitrile and aromatic aldehyde under solvent-free conditions. Furthermore, the procedure was optimized on the basis of catalyst loading amounts, various solvents and temperature conditions. This novel methodology exposes obvious benefits such as; catalyst reusability, easy reaction procedure, simplicity of work-up, excellent product yields and short reaction times.

Design, Fabrication and Characterization of Multi-Yolk@Shell NiCuFe2 O4 @mSiO2 Mesoporous Nanocomposite Spheres for the Synthesis of Pyrimido-Quinolines under Solvent-Free Conditions.

Multi-yolk@shell mesoporous silica spheres are becoming more and more attractive as high-performance catalysts because of their high surface areas, variable pore sizes, and low densities. In this work, a NiCuFe2 O4 magnetic core with a shell of mesoporous silica mesoporous has been prepared in an easy two-step procedure. The prepared multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres were characterized by using FT-IR, XRD, VSM, EDX, BET, FE-SEM and HR-TEM techniques. These unique multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres demonstrated high catalytic activity for the synthesis of pyrimidoquinolines. Also, this method exposes obvious benefits such as catalyst recyclability, easy reaction condition, simplicity of work up, high product yields and short reaction times.

Nickel ferrite nanoparticles doped on hollow carbon microspheres as a novel reusable catalyst for synthesis of N-substituted pyrrole derivatives.

Pyrroles are widely spread worldwide because of their critical applications, especially pharmacology. An expedition method for one-pot synthesis of N-substituted pyrrole derivatives has been presented by a reaction between 2,5-dimethoxytetrahydrofuran and various primary aromatic amines in the presence of NiFe2O4 anchored to modified carbon hollow microspheres (NiFe2O4@MCHMs) as a recoverable reactive catalyst. The Classon-Kass method has been used to synthesize the pyrroles in excellent yields and short reaction times in the same direction with green chemistry rules. This reaction was carried out by employing NiFe2O4@MCHMs as a catalyst to make a simple procedure with short activation energy in water as an accessible, non-toxic, and biodegradable solvent. This catalyst provides a promising pathway to synthesize N-substituted pyrroles several times in a row through the recyclability without remarkable loss of its catalytic activity. The NiFe2O4@MCHMs nanocatalyst was characterized by applying FT-IR, XRD, FE-SEM, TEM, EDS, BET, TGA, VSM, and elemental mapping techniques. Also, the synthesized N-substituted pyrrole derivatives were identified using melting point, FT-IR, and 1H NMR analyses.

Fabrication and characterization of mesoporous yolk-shell nanocomposites as an effective reusable heterogeneous base catalyst for the synthesis of ortho-aminocarbonitrile tetrahydronaphthalenes.

Mesoporous yolk-shell nanocomposites (MYSNs) were loaded with a mobile CaMg core inside the silica shell. CaMg@MYS nanocomposites have been effectively prepared inside the inner cavity of a novel structure that consists of hollow mesoporous silica spheres. Tetraethyl orthosilicate (TEOS) and an amount of cetyltrimethylammonium bromide (CTAB) are coated on the carbon spheres used as a hard template in the multi-step synthetic procedure. In this method, the target products were obtained in high to excellent yields between 87-96% and quick response times between 10-20 minutes under mild conditions. The CaMg@MYS catalyst shows promise as an efficient and reusable catalyst in multicomponent processes. The CaMg@MYS multi-yolk spheres compared to metal oxide nanostructures indicated both high catalytic performance and a significant factor as a novelty. To identify each product, FT-IR, 1H NMR, and melting point techniques were applied. Also, in order to characterize the prepared catalysts, FT-IR, XRD, FE-SEM, EDS, elemental mapping, and HR-TEM techniques were applied.

Flexible self-healing nanocomposite based gelatin/tannic acid/acrylic acid reinforced with zinc oxide nanoparticles and hollow silver nanoparticles based on porous silica for rapid wound healing.

In this research, gelatin (Ge), tannic acid (TA), acrylic acid (AA) as a matrix are used. Zinc oxide (ZnO) nanoparticles (10, 20, 30, 40 and 50 wt%) and hollow silver nanoparticles along with ascorbic acid (1, 3, and 5 wt%) are considered as reinforcement. In order to prove the functional groups of nanoparticles made from Fourier-transform infrared spectroscopy (FTIR), and determine the existing phases of the powders in the hydrogel, X-ray diffraction (XRD) is used, also to investigate the morphology, size, and porosity of the holes and in the scaffolds, scanning electron microscope analysis is used (FESEM). Then, mechanical tests such as tension and compression test are performed to determine the most optimal state of the composite. Also, the antibacterial test is performed for the manufactured powders and hydrogel, as well as the toxicity test for the fabricated hydrogel. The results show that the sample (30 wt% of zinc oxide and 5 wt% of hollow nanoparticles) is the most optimal hydrogel based on mechanical tests and biological properties.

Preparation and characterization of doped hollow carbon spherical nanostructures with nickel and cobalt metals and their catalysis for the green synthesis of pyridopyrimidines.

Fused heterocyclic systems containing the pyrimidine ring structure perform a significant role in numerous biological and pharmaceutical processes. Their properties include antibacterial, antifungal, anti-fever, anti-tumor, and antihistamine. As pyridopyrimidines are important in the essential fields of pharmaceutical chemistry, efficient methods for preparing these heterocycles are presented. In this study, a method for producing improved hollow carbon sphere nanostructures with cobalt and nickel (Co-Ni@HCSs) is presented. The nanocatalyst was prepared and identified by applying Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET), and elemental mapping techniques. The Co-Ni@HCSs nanocatalyst was proved to be highly efficient in synthesizing pyranopyrimidine derivatives. The sizeable active site, economic catalyst loading, easy workup, reusability, green reaction conditions, and excellent yields of all derivatives are some of the significant features of this process. Also, applying response surface methodology (RSM) and the Box-Behnken design (BBD) techniques allowed us to determine the influential factors of the laboratory variables and identify the optimum conditions for superior catalytic activity. Finally, synthesized organic compounds were identified by utilizing melting point, FT-IR, and hydrogen-1 nuclear magnetic resonance (1H NMR) analyses.

An efficient and eco-compatible multicomponent synthesis of 2,4,5-trisubstituted imidazole derivatives using modified-silica-coated cobalt ferrite nanoparticles with tungstic acid.

The aim of this study has been to offer a method for the synthesis of 2,4,5-trisubstituted imidazole derivatives based on green chemistry principles. Therefore, a one-pot multicomponent cyclocondensation reaction through aldehyde interaction with ammonium acetate and 1,2-diketone under solvent-free conditions was utilized as an eco-effective synthetic route using CoFe2O4@SiO2@(-CH2)3OWO3H NPs as the catalyst. The stabilized tungstic acid on 3-chloropropyl-anchored SiO2-coated CoFe2O4 magnetic nanoparticles was designed, prepared, and applied as a recyclable heterogeneous acid catalyst to attain high product yield in a short reaction time. The nanocatalyst structure was confirmed using FT-IR, Raman, XRD, FE-SEM, EDX, VSM, and TGA techniques, and the organic product structures were examined by melting point, FT-IR and 1H NMR analyses.

Preparation and Characterization of NiCoFe2O4 Nanoparticles as an Effective Catalyst for the Synthesis of Trisubstituted Imidazole Derivatives Under Solvent-free Conditions.

In this study, NiCoFe2O4 nanoparticles were prepared and used as a reactive catalyst for the synthesis of trisubstituted imidazoles. The multicomponent reactions of aromatic aldehydes, benzil and ammonium acetate were carried out under solvent-free and conventional heating conditions. In this reaction, some imidazole derivatives with high purity, short reaction times and high yields were obtained. The prepared nanocatalyst was characterized by FT-IR, XRD, EDX, VSM and SEM techniques. Moreover, the organic products were identified by melting point, FT-IR and 1H NMR analyzes.

Efficient One-Pot Synthesis of 1,4-Dihydropyridines Catalyzed by Magnetic MnFe2O4 Nanoparticles.

The efficient one-pot synthesis of some 1,4-dihydropyridines is described by a condensation reaction of some aldehyde derivatives, ethyl acetoacetate and ammonium acetate in the presence of superparamagnetic manganese ferrite nanoparticles at 80 °C. The advantages of this protocol include selectivity, high purity of the products, excellent yields, short reaction times, ease of processing, and environmentally friendly conditions for the synthesis of 1,4-dihydropyridines. In addition, the catalyst can be recovered and reused in multiple runs without significantly reducing the product yield.

Graphitic carbon nitride supported neodymium oxide as an efficient recyclable nanocatalyst for the one-pot synthesis of diazabenzo[a]anthraceneones.

In this research, a neodymium oxide@graphitic-carbon nitride nanocomposite was prepared and used as an efficient catalyst for the synthesis of some diazabenzo[a]anthraceneones under solvent-free conditions. The characterization of the Nd2O3@g-C3N4 nanocomposite was carried out by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM) and thermo-gravimetric analysis (TGA). The as-prepared compound was used as a catalyst for the one-pot three-component reaction of 2-naphthol, different substituted aromatic aldehydes, barbituric acid and its derivatives under solvent-free conditions. The catalyst is highly efficient, stable, separable, and recyclable and provides the corresponding diazabenzo[a]anthraceneones in good to high yields. This method provides several advantages such as mild reaction conditions, operational simplicity, low cost, safety, easy work up procedures and purification of products, low catalyst loading and reusability of the catalyst.

Tetrazol-Cu(i) immobilized on nickel ferrite catalyzed green synthesis of indenopyridopyrimidine derivatives in aqueous media.

After the initial study of different protocols in the synthesis of indeno[2',1':5,6]pyrido[2,3-d]pyrimidines, herein, a new method is presented using cheaper and more accessible starting materials to produce high-efficiency products. In this protocol, the novel nanocatalyst is very effective in the progression of the reaction and increasing the efficiency. This green approach in aqueous media has several advantages as compared with other methods, such as easier work-up, very mild reaction conditions, reusability of the catalyst, and eco-friendliness. The products of this four-component condensation were evaluated using IR, 1H NMR, 13C NMR spectra, and C. H. N. analyses, and the catalyst structure was confirmed by FT-IR, XRD, SEM, EDX, TGA and VSM techniques.

Design, preparation, and characterization of CS/PVA/SA hydrogels modified with mesoporous Ag2O/SiO2 and curcumin nanoparticles for green, biocompatible, and antibacterial biopolymer film.

One of the most significant factors affecting the rapid and effective healing of wounds is the application of appropriate wound dressings. In the present study, novel antibacterial wound dressings are fabricated that consist of Chitosan (CS)/Polyvinyl alcohol (PVA)/Sodium Alginate (SA), which are all biocompatible, functionalized with mesoporous Ag2O/SiO2 and curcumin nanoparticles as reinforcements. In this research nanocomposites are fabricated (0 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% of Ag2O/SiO2). After the composition of nanocomposites using the cross-linked technique, Fourier Transform Infrared (FT-IR) spectroscopy is performed to confirm the functional groups that are added to the polymer at each step. X-ray diffraction (XRD) is done to show the crystallinity of Ag2O/SiO2. Field emission scanning electron microscopy (FE-SEM) studies are performed to demonstrate the morphology of the structure, Energy-dispersive X-ray spectroscopy (EDS) is done to examine the elements in the wound dressing and atomic force microscopy (AFM) study is performed to show surface roughness and pores. Then the nanocomposites with different weight percentages are cultured in three bacteria called Acinetobacter baumannii, Staphylococcus epidermidis, and Proteus mirabilis, all three of which cause skin infections. Finally, by performing the tensile test, the results related to the tensile strength of the wound dressings are examined. The results show that with the increase of Ag2O/SiO2, the mechanical properties, as well as the healing properties of the wound dressing, have increased significantly. Fabricating these nanocomposites helps a lot in treating skin infections.

A Brønsted acidic ionic liquid anchored to magnetite nanoparticles as a novel recoverable heterogeneous catalyst for the Biginelli reaction.

In this study, simple and effective methods were used for the preparation of an ionic liquid that immobilized magnetite nanoparticles. Fe3O4 nanoparticles were prepared via a chemical co-precipitation method. Then, a SiO2 shell was coated on the magnetic core via the Stober method. Finally, CPTES (chloropropyltriethoxysilane) and morpholine were coated on the SiO2 shell. Morpholine sulfate, an acidic ionic liquid, was successfully bound to magnetite nanoparticles (Mag@Morph-AIL) and this was used as an efficient catalyst for the preparation of 3,4-dihydropyrimidinones. Compared to previous works, the easy separation of the nanocatalyst using an external magnet and the recyclability, non-toxicity, versatility, and high stability of the catalyst, combined with low reaction times and excellent yields, make the present protocol very useful for the synthesis of the title products. The synthesized products and catalyst were confirmed via 1H-NMR, 13C-NMR, FT-IR, scanning electron microscope, X-ray diffraction, and elemental analysis.

Guanidine functionalized core-shell structured magnetic cobalt-ferrite: an efficient nanocatalyst for sonochemical synthesis of spirooxindoles in water.

Core/shell nanoparticles have a wide range of applications in the science of chemistry and biomedicine. The core-shell material can be different and modified by changing the ingredients or the ratio of core to the shell. In this research, a CoFe2O4@SiO2-guanidine nanocomposite was prepared and identified as an efficient catalyst for the one-pot synthesis of spirooxindole derivatives in water under ultrasonic irradiation conditions. The advantages of this method are in its simplicity, saving costs and energy, high yields, short reaction times, environmental friendliness, reusability and easy recovery of the catalyst using an external magnet. The catalyst was characterized by XRD, SEM, TEM, EDX, FT-IR, TGA and VSM techniques.

Synthesis of Novel bis-spirooxindoles Catalyzed by Magnetic Cobalt Ferrite Encapsulated MCM-41@MgO as a Solid Base.

AIMS AND OBJECTIVE: Synthesis of novel bis-spirooxindoles was carried out from isatins, two equivalents of malononitrile, and various derivatives of cyclohexanones. BACKGROUND: A facile one-pot and four-component reaction was investigated for the synthesis of novel bisspirooxindoles from different derivatives of isatins, two equivalents of malononitrile and various derivatives of cyclohexanone in the presence of magnetic CoFe2O4@MCM-41@MgO NPS catalyst under mild conditions. MATERIALS AND METHODS: Firstly, the magnetic CoFe2O4@MCM-41@MgO was prepared in three steps. Afterwards, the CoFe2O4@MCM-41@MgO was used as a base catalyst for the one-pot synthesis of bisspirooxindoles. RESULTS AND DISCUSSION: The procedure exhibited several benefits, an excellent yield of products, short reaction times, reusability, and recyclability of the nanocatalyst. CONCLUSION: The structure of nanocatalyst was recognized by FT-IR, XRD, VSM, SEM, BET, and EDX techniques, and the structure of the organic products was determined by melting point, FT-IR, 1H NMR, 13C NMR, Mass spectra, and C.H.N analyses.

Chitosan-encapsulated manganese ferrite particles bearing sulfonic acid group catalyzed efficient synthesis of spiro indenoquinoxalines.

A simple, highly versatile and efficient synthesis of 5-phenyl-spiro[diindenopyridine-indenoquinoxaline]-diones is achieved through a four-component one pot reaction of ninhydrin, 1,2-diaminobenzene, 1,3-indandione and aniline. This reaction was catalyzed by MnFe2O4@CS-Bu-SO3H MNPs as a very efficient, recyclable heterogeneous catalyst in acetonitrile under reflux conditions. The catalyst can be recovered from the subsequent reaction mixture and reused for at least five cycles without any appreciable loss in its efficiency. The core-shell structure and composition of the produced magnetic nanocatalyst were analyzed using FT-IR, XRD, VSM, SEM, EDX and TGA techniques.

Magnetic bio-metal-organic framework nanocomposites decorated with folic acid conjugated chitosan as a promising biocompatible targeted theranostic system for cancer treatment.

In this work, a multifunctional magnetic Bio-Metal-Organic Framework (Fe3O4@Bio-MOF) coated with folic acid-chitosan conjugate (FC) was successfully prepared for tumor-targeted delivery of curcumin (CUR) and 5-fluorouracil (5-FU) simultaneously. Bio-MOF nanocomposite based on CUR as organic linker and zinc as metal ion was prepared by hydrothermal method in the presence of amine-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@NH2 MNPs). 5-FU was loaded in the magnetic Bio-MOF and the obtained nanocarrier was then coated with FC network. The prepared nanocomposite (NC) was fully characterized by high resolution-transmission electron microscope (HR-TEM), field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), nuclear magnetic resonance (NMR), and UV-vis analyses. In vitro release study showed controlled release of CUR and 5-FU in acidic pH confirming high selectivity and performance of the carrier in cancerous microenvironments. The selective uptake of 5-FU-loaded Fe3O4@Bio-MOF-FC by folate receptor-positive MDA-MB-231 cells was investigated and verified. The ultimate nanocarrier exhibited no significant toxicity, while drug loaded nanocarrier showed selective and higher toxicity against the cancerous cells than normal cells. SDS PAGE was also utilized to determine the protein pattern attached on the surface of the nanocarriers. In vitro and in vivo MRI studies showed negative signal enhancement in tumor confirming the ability of the nanocarrier to be applied as diagnostic agent. Owing to the selective anticancer release and cellular uptake, acceptable blood compatibility as well as suitable T2 MRI contrast performance, the target nanocarrier could be considered as favorable theranostic in breast cancer.

Multisulfonate hyperbranched polyglycerol functionalized graphene oxide as an efficient reusable catalyst for green synthesis of benzo[a]pyrano-[2,3-c]phenazines under solvent-free conditions.

A novel acid catalyst was prepared based on growing hyperbranched polyglycerol (HPG) on the surface of graphene oxide. Then, the hydroxyl groups of HPG on graphene oxide were functionalized by sulfonate groups to form an acid catalyst. The catalyst displayed a good loading level of acidic groups on the surface because of coating graphene oxide with HPG. This new catalyst is demonstrated to be highly effective in the preparation of benzo[a]pyrano[2,3-c]phenazine dyes.