Silica sulfuric acid-coated Fe 3 O 4 nanoparticles as high reusable nanocatalyst for the oxidation of sulfides into sulfoxides, protection and deprotection of hydroxyl groups using HMDS and Ac 2 O

Preparation of a Ni-ascorbic acid MOF as a recyclable catalyst for the synthesis of sulfoxides and tetrazoles

This study introduces a novel, cost-effective, and environmentally friendly approach for synthesizing a heterogeneous Ni-ascorbic acid metal-organic framework (Ni-ascorbic acid MOF) catalyst via a hydrothermal method. The catalyst was prepared by combining nickel nitrate (Ni(NO3)2·6H2O) and ascorbic acid (C6H8O6) in DMF. Comprehensive characterization of the synthesized Ni-ascorbic acid MOF was performed using FT-IR, XRD, EDX, BET, SEM, TGA/DSC, and AAS techniques. These analyses revealed that the catalyst exhibits a spherical microsphere morphology with high crystallinity, a specific surface area of 16.62 m2 g-1, a pore diameter of 19.52 nm, and excellent thermal stability. The catalytic performance of Ni-ascorbic acid MOF was investigated in two distinct reactions, including the selective oxidation of sulfides to sulfoxides and the synthesis of 5-substituted 1H-tetrazoles. Under optimized reaction conditions, the catalyst demonstrated high efficiency with product yields ranging from moderate to excellent across various substrates. Furthermore, the catalyst exhibited remarkable recyclability, maintaining its activity over five consecutive cycles without significant leaching of nickel species, as confirmed by hot filtration tests. These findings underscore the potential of a Ni-ascorbic acid MOF as a sustainable and robust catalyst for diverse organic transformations.

Mesoporous magnetic supported Cu complex for one-pot synthesis of 5-substituted 1H-tetrazoles in green media and the oxidation of sulfides

We used the copper Phthalocyanine (Pc) on magnetic mesoporous silica nanoparticles. Therefore, several coordination sites became available which enhance chelating potency to load appropriate amounts of Gadolinium (Gd). This improves the catalytic activity in converting nitrile to tetrazole and selective oxidation of sulfides. Gadolinium (Gd) with incompletely occupied 4f and empty 5d orbitals can be used as the active component or as the promoter of the catalyst. Here, we outline the synthesis, characterization, and catalytic activity of a novel Gd(III) copper Phthalocyanine (Pc) coordination on the CoFe2O4/SBA-15 (CoFe2O4/SBA-15/CuPc@Gd). The prepared material was characterized using powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, elemental mapping, vibrating-sample magnetometer (VSM), Inductively coupled plasma atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption isotherm. The CoFe2O4/SBA-15/CuPc@Gd composite consists of a mesoporous structure with a surface area by BET and t-plot of 122.2 m2/g and 86.28 m2/g respectively, with a mean pore size of 5.37 nm, and pore volume of 0.164 cm3/g. The CoFe2O4/SBA-15/CuPc@Gd was successfully applied as a powerful catalyst for green synthesis of 5-substituted 1H-tetrazoles in water and selective oxidation of sulfides at room temperature. This catalyst was recovered and reused several times without a significant decrease in efficiency and stability. The catalyst could be fully recovered by an external magnetic field and showed good reusability.

A novel recyclable hydrolyzed nanomagnetic copolymer catalyst for green, and one-pot synthesis of tetrahydrobenzo[b]pyrans

Polymer-based catalysts have garnered significant interest for their efficiency, reusability, and compatibility with various synthesis processes. In catalytic applications, polymers offer the advantage of structural versatility, enabling functional groups to be tailored for specific catalytic activities. In this study, we developed a novel magnetic copolymer of methyl methacrylate and maleic anhydride (PMMAn), synthesized via in situ chemical polymerization of methyl methacrylate onto maleic anhydride, using benzoyl peroxide as a free-radical initiator. This polymerization process results in a robust copolymer matrix, which was subsequently hydrolyzed in an alkaline aqueous solution to introduce additional functional groups, yielding hydrolyzed PMMAn. These functional groups enhance the copolymer's ability to support the deposition of magnetic nanoparticles and participate in catalytic reactions. Following hydrolysis, we fabricated a unique magnetic composite, Fe3O4@Hydrol-PMMAn, by in situ coprecipitating Fe3O4 nanoparticles onto the hydrolyzed copolymer, creating a stable nanocatalyst. The structural and magnetic properties of Fe3O4@Hydrol-PMMAn were thoroughly analyzed using FTIR, XRD, SEM, EDX, VSM, and TGA. The Fe3O4@Hydrol-PMMAn nanocatalyst demonstrated remarkable catalytic performance in synthesizing tetrahydrobenzo[b]pyran derivatives through a three-component reaction, conducted without solvents to support green chemistry principles. A series of reaction parameters were optimized, including solvent choice, catalyst loading, and recyclability. The catalyst performed efficiently across a broad range of aldehydes, delivering high product yields (81-96%) with rapid reaction times (5-30 min) at a low catalyst loading of 0.015 g. A hot filtration test confirmed the heterogeneous nature of the nanocatalyst, which could be recycled up to four cycles with minimal loss in activity. The high yield, short reaction time, solvent-free conditions, and excellent reusability make Fe3O4@Hydrol-PMMAn a promising catalyst. These findings underscore its potential for converting waste products into valuable compounds, highlighting its utility in organic transformations and sustainable synthesis practices. Collectively, this work demonstrates that Fe3O4@Hydrol-PMMAn is highly effective for organic compound synthesis, advancing the development of versatile, sustainable nanocatalysts.

In situ decorated pd NPs on Triazin-encapsulated Fe3O4/SiO2-NH2 as magnetic catalyst for the synthesis of diaryl ethers and oxidation of sulfides

This article is devoted to the synthesis of a new magnetic palladium catalyst that has been immobilized on A-TT-Pd coated-magnetic Fe3O4 nanoparticles. Such surface functionalization of magnetic particles is a promising method to bridge the gap between heterogeneous and homogeneous catalysis approaches. The structure, morphology, and physicochemical properties of the particles were characterized through different analytical techniques, including TEM, FT-IR, XRD, SEM, EDS, TGA-DTG, ICP, and VSM techniques. The obtained Fe3O4@SiO2@A-TT-Pd performance can show excellent catalytic activity for the synthesis of diaryl ethers and oxidation of sulfides, and the corresponding products were obtained with high yields. The advantages of this catalyst include a simple test method, green reaction conditions, no use of dangerous solvents, short reaction time, low catalyst loading, and reusability. Also, the nanocatalyst was easily separated from the reaction mixture with the help of a bar magnet and recovered and reused several times without loss of stability and activity.

Efficient synthesis of some [1,3]-oxazine derivatives in the presence of solid acid nano catalyst based on ferrierite and study on their activity against breast cancer through molecular docking calculation

In this research, the magnetic solid acid nanocatalyst based on ferrierite has been prepared and used as catalyst for the green synthesis of some [1,3]-oxazine derivatives in water at room temperature. The synthesized compounds were obtained in high to excellent yields after short reaction times and the structure of synthesized products were investigated by spectroscopic methods such as: FT-IR, 1H NMR and 13C NMR. The prepared magnetic solid acid catalyst was characterized using XRD, FT-IR, FE-SEM, EDX, elemental mapping, TGA and VSM analysis methods. Magnetic catalyst has easy separation ability, which leads to better and easier recycling. The preparation and synthesis of [1,3]-oxazine derivatives were carried out at room temperature in the presence of M-FER/TEPA/SO3H. Easy workup, green solvent (water) and also short reaction times with high to excellent yield of products, are some of advantageous of presented method. Docking calculations on the structure of the synthesized compounds proved their medicinal properties against breast cancer cells.

3-(Sulfamic acid)-propyltriethoxysilane on biochar nanoparticles as a practical, biocompatible, recyclable and chemoselective nanocatalyst in organic reactions

Recyclable and inexpensive catalysts, waste regeneration, use of available and safe solvents are important principles of green chemistry. Therefore, in this project, biochar nanoparticles (BNPs) were synthesized by the pyrolysis method from chicken manure. Then, 3-(sulfamic acid)-propyltriethoxysilane (SAPES) was immobilized on the surface of BNPs (SAPES@BNPs). The prepared catalyst (SAPES@BNPs) was used as a commercial, practical, biocompatible and reusable catalyst in the selective oxidation of sulfides to sulfoxides. Further, the catalytic application of SAPES@BNPs was explored in the multicomponent synthesis of tetrahydrobenzo[b]pyrans under mild and green conditions. BNPs were characterized using SEM, TGA and XRD techniques. SAPES@BNPs were characterized using SEM, FT-IR spectroscopy, WDX, EDS, TGA, and XRD techniques. Particle size distribution was obtained by histogram graph. SAPES@BNPs can be recovered and reused several times. The purity of the products was studied using NMR spectroscopy.

Fe3O4@BNPs@SiO2–SO3H as a highly chemoselective heterogeneous magnetic nanocatalyst for the oxidation of sulfides to sulfoxides or sulfones

To achieve green chemistry goals and also to reduce the cost of catalysts as well as to avoid producing toxic wastes and show the importance of separation and recycling of catalysts from the reaction medium, in this work, we describe the preparation and characterization of magnetic acidic boehmite nanoparticles as a heterogeneous catalyst, which is called Fe₃O₄@BNPs@SiO₂–SO₃H. This catalyst works efficiently in the selective oxidation of sulfides to sulfoxides or sulfones in the presence of H₂O₂ as a green oxidant. It can easily be separated from the reaction medium by using an external magnet and it was recycled 6 times without loss of magnetic catalytic properties.

To achieve the green chemistry goals and importance of separation and recycling of catalyst from the reaction medium, Fe₃O₄@BNPs@SiO₂–SO₃H is introduced as a novel heterogeneous nanocatalyst for the oxidation of sulfides to sulfoxides or sulfones.

Highly efficient, green, rapid, and chemoselective oxidation of sulfur-containing compounds in the presence of an MCM-41@creatinine@M (M = La and Pr) mesostructured catalyst under neat conditions

MCM-41@creatinnine@M (M = La and Pr) as a highly efficient and reusable heterogeneous catalyst prepared by a simple procedure for the oxidation of sulfur-containing compounds.

Biogenic CuFe2O4 magnetic nanoparticles as a green, reusable and excellent nanocatalyst for acetylation reactions under solvent-free conditions

A convenient green method has been developed for the synthesis of biogenic CuFe₂O₄ magnetic nanoparticles using tea extracts within a very short reaction time.

Magnetic Fe3O4@silica sulfuric acid nanoparticles promoted regioselective protection/deprotection of alcohols with dihydropyran under solvent-free conditions

Protection (and deprotection) of hydroxyl groups via tetrahydropyranylation was carried out effectively using a catalytic amount of Fe3O4 supported silica sulphuric acid nanoparticles (Fe3O4@SiO2@SO3H) under solvent-free conditions.