Easy Catalyst Research Articles

Palladium-Functionalized Polysiloxane Drop-Casted on Carbon Paper as a Heterogeneous Catalyst for the Suzuki-Miyaura Reaction.

In this work, a Pd(II)-C,N-cyclometalated complex was grafted to polysiloxanes via azide-alkyne cycloaddition. The obtained polymer-metal complex (Pd-PDMS) acts as a catalyst in the Suzuki-Miyaura reaction. Pd-PDMS was drop-casted onto a carbon fiber support, and the resulting membrane demonstrated catalytic activity in the cross-coupling reaction without yield loss after several catalytic cycles. The catalytic membrane allows for easy catalyst recycling and provides ultra-low palladium levels in Suzuki-Miyaura reaction products.

Mild one-pot production of glycerol carbonate from CO2 with separation from ionic liquid catalyst

Carbon capture and utilization stands as way forward in the minimization of CO2 emissions. It complements the search for clean and effective energy, as it is challenging to achieve zero to negative CO2 net emissions. The glycerol carbonate product opens a new strategy based on a double-residue approach (glycerol and CO2) to contribute, together with ionic liquids (ILs), drafting a new one-pot concept (intensified three phase reactor) at mild conditions and using homogeneous catalysts. In this work, the catalytic activity of [P666,14][Br] in the cycloaddition of CO2 to glycidol has been demonstrated to be highly effective under mild conditions of 45 °C and 5 bar. In addition, liquid–liquid extraction approach is found to be an efficient separation strategy for carbonate product and IL catalyst. 1-Decanol (DOH) is selected as efficient extracting solvent, due to its almost complete immiscibility with glycerol carbonate, as well as the high distribution ratio of the IL catalyst in DOH rich phase. It implies an easy product separation and, simultaneously, an easy catalyst recovery. A preliminary kinetic validation of the three-phase reactor performance has been properly described, enabling the intensified concept. Finally, combining COSMO/Aspen simulation and life cycle assessment (LCA) methodologies, low energy consumption (avoiding heating) and low GWP scenarios for the CO2 conversion process have been concluded. This work enables a new concept together with concluding the path to developing this CCU technology in the search of zero to negative CO2 emissions to sustainably capture and convert CO2 into value-added products.

Synthesis and application of merrifield resin based supported ionic liquids as organocatalyst for the greener synthesis of bio-active triazoles

A green and highly efficient catalysts based on merrifield resin supported acidic ionic liquids (MRBT-SILs) were synthesized using merrifield resin (non-toxic and chemically inert) and benzothiazole. The application of MRBT-SILs for the greener synthesis of 1,2,4-triazole-3-thiones or 1,2,4-triazole-3-oxones from condensation of ketones and thiosemicarbazide or semicarbazide respectively in 60% ethanol under ultra-sonication was studied. The protocol so developed has many additional benefits compared to those reported in previous articles such as smooth reaction, use of alcohol as solvent, good yield, ambient temperature, an easy workup procedure, catalyst recyclability, and high atom economy, making it highly efficient for synthesis as it obeys green chemistry principles. Further, catalyst could be reused up to eight cycles without any loss of its catalytic activity.

MPC@But-SO3H a mesoporous heterogeneous organocatalyst in one-pot tandem synthesis of dihydroindeno[1,2-b]pyrrole derivatives

A sustainable, metal-free, and highly efficient protocol for the synthesis of dihydroindeno[1,2-b]pyrrole derivatives via a tandem one-pot three-component reaction in aqueous medium at room temperature using an effective and reusable mesoporous heterogeneous organocatalyst, MPC@But-SO3H has been developed. MPC@But-SO3H was easily synthesized using a melamine-based covalent organic polymer and 1,4-butane sultone. The organocatalyst was well characterized by numerous spectroscopic techniques such as Fourier Transform Infrared (FTIR), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), Powder X-ray diffraction (PXRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), elemental mapping, and Thermal Gravimetric (TG) analyses. The catalyst displayed excellent catalytic potential, high thermochemical stability, and reusability for up to eight catalytic cycles. It offered the title compounds in excellent yields (˃90%) in a short reaction time (9-14 min). The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR), and the molecular structure of 2-(benzylamino)-3a,8b-dihydroxy-1-methyl-3-nitro-3a,8b-dihydroindeno[1,2-b]pyrrol-4(1H)-one (4a) was confirmed by the Single Crystal XRD (SC-XRD) analysis. The key features of the present protocol include the use of water as a green solvent, zero involvement of any metal, sustainable reaction conditions, easy catalyst recovery, and a simple work-up procedure. The calculations for green metrics parameters further supported the greenness and sustainability of the protocol.

Strategically engineered multifunctional graphene oxide hybrid nanomaterials for efficient catalytic degradation and emerging contaminants treatment

The use of functional textiles is growing in all fields of science and technology. Surface functionalization is mainly used to impart conventional textiles with new functionalities and improved performances. In the present study, a cobalt ferrite nanoparticle/graphene oxide (CoFe2O4/GO) coated polyethylene terephthalate (PET) fabric with excellent catalytic and antibacterial properties, has been successfully developed. The PET-coated CoFe2O4/GO samples, ranging from 1 % to 5 % wt. were obtained using a simple dip-coating method in CoFeO/GO solution (1 mg/mL), and were investigated through several physiochemical characterization techniques. CoFe2O4/GO and PET fabric have been shown to establish an interfacial connection by Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) results showed that CoFe2O4/GO coating did not affect the PET crystallinity and that CoFe2O4/GO hybrid was incorporated in the PET samples, which was proved as well by the morphological study through Scanning electron microscopy (SEM). Furthermore, thermogravimetric characterisation (TGA) verified that the coating does not change or impair the quality of the fibre and that the PET@CoFe2O4/GO as made is thermally stable. Tensile strength tests demonstrated that coated fabrics exhibited outstanding mechanical properties in comparison with pristine PET. Moreover, the coated PET@CoFe2O4/GO fabric was used as a model catalytic system for peroxymonosulfate (PMS) activation in the rhodamine B (RhB) degradation reaction. Total Organic Carbon (TOC) measurements showed that TOC removal reached 89.82 % in only 12 min reaction. The results confirmed that the coated fabrics exhibited high catalytic performances, good stability and reusability in consecutive degradation experiments with a degradation rate over 60 % even after 7 degradation cycles; Moreover, it is easily and simply separated from the mixture, by removing the textile sample from the aqueous solution. It is worth mentioning that the PET@CoFe2O4/GO fabrics showed outstanding antibacterial activity against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria with an inhibition diameter zone of up to 13 mm for PET@CoFe2O4/GO (5 %). Overall, these findings are of great importance as they permit the development of a novel multifunctional textile fabric, combining anti-bacterial activity, catalytic performance and mechanical properties. The study provides a textile-based catalyst with improved catalytic performance, re-usability in consecutive degradation reactions and easy catalyst separation compared to traditional supports. Thus, a huge potential application in several fields such as medicine, heterogeneous catalysis, and wastewater treatment.

A new strategy for immobilization of copper on the Fe3O4@EDTA nanocomposite and its efficient catalytic applications in reduction and one-pot reductive acetylation of nitroarenes and also N-acetylation of arylamines

A new and efficient Cu(II)-containing mesoporous nanocatalytic system was synthesized by direct immobilization of copper metal powder on the Fe3O4@EDTA nanocomposite. The as-prepared Fe3O4@EDTA@Cu(II) nanocomposite was then characterized by FT-IR, XRD, SEM, TEM, SEM-based EDX and elemental mapping, XPS, TGA, VSM, and also BET and BJH analyses. The resulting Fe3O4@EDTA@Cu(II) mesoporous nanocomposite exhibited satisfactory catalytic activity towards the reduction and one-pot reductive acetylation of nitroarenes and also N-acetylation of arylamines in water at 60 °C. Notably, the applied Cu(II)-containing nanocatalyst was efficiently recovered from the reaction mixture using an external magnetic field and could be reused successfully for five cycles. The protocol developed in this study offers several advantages in terms of mild reaction conditions, simple workflows, using water as a green solvent, and easy recovery and catalyst reuse, making it more ecologically and economically attractive.

MTP−IL] as Mesoporous Heterogeneous Organocatalyst for the One‐Pot Synthesis of Indeno [1,2‐b] Quinoxalin‐11‐Ylidenamine Derivatives: A Green, Sustainable, and Metal‐Free Protocol

AbstractHerein, we report a green, sustainable, and metal‐free, one‐pot three‐component protocol for the synthesis of indeno [1, 2‐b] quinoxalin‐11‐ylidenamine derivatives using a novel, effective, and recyclable mesoporous heterogeneous organocatalyst [MTP−IL]. [MTP−IL] was constructed by immobilizing an imidazolium‐cation‐based ionic liquid on a melamine−terephthalaldehyde covalent organic polymer and was thoroughly characterized using several analytical techniques. It displayed high thermochemical stability and catalytic efficacy, offering title compounds with 90–94 % yields in a short reaction time, and was recyclable for up to six cycles. The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR), and the molecular structure of N′‐(11H‐indeno[1,2‐b]quinoxalin‐11‐ylidene)benzohydrazide (7) was confirmed by the Single Crystal XRD (SCXRD) analysis. The key features of the present protocol are the use of ethanol as a green solvent, easy catalyst recovery, a simple work‐up procedure, and zero involvement of any metal.

Mesoporous MPC@TMG, a basic heterogeneous organocatalyst in C–C/C–N bond forming reactions: Tandem multicomponent synthesis of 5-amino-pyrazole-4-carbonitriles and 1H-pyrazolo [1,2-b] phthalazine-5, 10-dione derivatives under sustainable reaction conditions

A metal-free, effective, and sustainable protocol has been developed to carry out C–N and C–C bond-forming reactions leading to the formation of 5-amino-pyrazole-4-carbonitriles and 1H-pyrazolo [1,2-b] phthalazine-5, 10-dione derivatives via a tandem multicomponent reaction using mesoporous MPC@TMG as a basic heterogeneous organocatalyst. The reactions were performed in aqueous medium at room temperature. The synthesized organocatalyst MPC@TMG was characterized by numerous spectroscopic techniques such as Fourier Transform Infrared (FTIR), Powder X-ray diffraction (PXRD), Brunauer-Emmett-Teller (BET), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), elemental mapping, and Thermal Gravimetric (TG) analyses. MPC@TMG displayed excellent catalytic potential, high thermochemical stability, and reusability for up to eight catalytic runs and offered the title compounds in excellent yields (>90 %) in a short reaction time (6–15 min). The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The use of water as a green solvent, the generality of the method, easy catalyst recovery, a simple work-up procedure, and zero involvement of any metal are the key features of the present protocol making it green and sustainable for the synthesis of the desired heterocycles and is supported by the calculations for green metrics parameters.

Innovative Ex-Situ catalyst bed integration for LDPE plastic Pyrolysis: A thermodynamically closed system approach

The recycling of Low-Density Polyethylene (LDPE) poses a significant challenge due to its resistance to degradation and presence of impurities among the waste LDPE. This study introduces an innovative method for LDPE pyrolysis, aiming to enhance the efficiency of LDPE recycling and contribute to the circular economy of plastics. We utilized an HZSM-5 catalyst within a unique setup that incorporates a catalyst bed constructed from a quartz fibre membrane filter. This innovative hybrid method, a combination of in-situ and ex-situ modes, was designed to shield the catalyst from direct contact with undesired materials, thereby facilitating easy catalyst separation at the end of the process. Experiments were conducted in a high-pressure batch reactor, heated to 400 °C within a closed thermodynamic system. Parallel runs were performed for both pure and waste LDPE, with and without the catalyst. The catalytic pyrolysis resulted in an oil output of 40.3 % for waste LDPE and 43.5 % for pure LDPE, with a significant increase in aromatics when comparing thermal to catalytic pyrolysis. The calorific values of the pyrolysis liquids were found to be 46.2 for pure LDPE and 46.1 for waste LDPE, indicating their potential for sustainable hydrocarbon fuel synthesis. Following the catalytic pyrolysis, the spent catalyst underwent stepwise oxidation as a regeneration method, indicating a partial loss of activity but a similar influence on the degradation temperature as the fresh catalyst. This study not only presents a promising approach to LDPE recycling but also offers a comprehensive analysis of both the pyrolysis outputs and the spent catalyst. Such detailed analysis is crucial for refining the LDPE pyrolysis process and facilitating its scale-up for industrial applications.

Thiourea Dioxide Catalyzed Sustainable Synthesis of Diverse Quinoxaline and Pyrazine Derivatives in Aqueous Medium at Ambient Temperature

AbstractAn eco‐conscious, metal‐free protocol has been developed to synthesize a diverse collection of biologically and pharmacologically active quinoxaline and pyrazine derivatives. The protocol involves a one‐pot condensation of various 1,2‐diamines with 1,2‐diones using thiourea dioxide as a catalyst and water as a solvent at ambient temperature. Notably, the catalyst can be reused up to five times without any significant loss of efficacy. The green aspects of this method involved milder reaction conditions, higher yields with shorter reaction times, simple work‐up, non‐chromatographic separations, good reusability, and easy catalyst recovery by simple filtration. Moreover, the reaction is successfully accelerated to a multigram scale, making it favourable for production at a larger scale.

Synthesis of 3, 3′- bis (indolyl) methanes using Bio-Waste metal free super acid as efficient with recyclable catalysts

A bio-waste metal free sulfonated carbonaceous super acid catalyst (BWC) is generated from sodium lignosulphonate, which is obtained from bio-waste sulphite pulping process of paper making industries. Here, we report a highly efficient catalytic a sulphonated carbon material catalyzed electrophilic substitution reactions of indoles with aromatic aldehydes to afford 3,3′-bisindolylmethane (BIM) derivatives. The synthesized BIM compounds were characterized by modern analytical techniques like NMR, MS, FT-IR, CHNS analysis. The BWC green catalyst was characterized by FT-IR, thermal gravimetric analysis (TGA) scanning electron microscopy (SEM), thermal electronic microscopy (TEM) with elemental analysis. The significant features of this catalysis are easy catalyst preparation, high product yields, environmental benignity, short reaction time, broad substrate scope, with use of non-toxic solvents. The catalysts could be recycled with reused three times without decrease in the catalytic activity significantly.

N-acetyl-PABA@Cu(II) supported on Fe3O4 as the new heterogeneous catalytic system to assist the MCR derived synthesis of 2,2-dimethyl-2H-[1,3]dioxino[4,5-b]pyrrol-4(7H)-ones heterocyclic scaffolds

The present work elicits the synthesis of 2,2-dimethyl-2H-[1,3]dioxino[4,5-b]pyrrole-4(7H)-ones derivatives catalyzed by heterogeneous Fe3O4 magnetic nanoparticles supported N-acetyl-PABA@Cu(II), which address the limitations of traditional organic synthesis approaches in terms of sustainable and efficient, resulting in improved yields, higher selectivity with no waste. The decorum embraces four-component reactions (4CRs) of amines, aldehydes, meldrum’s acid, and nitromethane facilitated by Fe3O4-N-acetyl-PABA-Cu(II) in the presence of ethanol (CH3CH2OH) as an ecologically benign solvent under ultrasonic irradiation at room temperature. Outstanding conversion rates and selectivity were attained by the heterogeneous catalyst through great catalytic performance. The simple work-up, easy catalyst recovery, and no base or additional activators were required. Characterization of the structures of synthesized compounds and catalysts was corroborated through different spectroanalytical techniques viz; FTIR, 1H &13C NMR, Mass elemental analyses, Energy-Dispersive X-ray Spectroscopy (EDX), Field-Emission Scanning Electron Microscope (FE-SEM), Powder X-ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Particle size analysis and Zeta potential.

GO@dopamine-Cu as a Green Nanocatalyst for the Efficient Synthesis of Fully Substituted Dihydrofuran-2(5H)-ones

A new nanocatalyst graphene oxide@dopamine-Cu was synthesized, and its structure was characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDX), and thermogravimetric analysis – differential thermal analysis (TGA-DTA) techniques. The three-component one-pot reaction between an arylamine, aromatic aldehyde, and acetylenic carboxylate was achieved and formed methyl 5-oxo-2-aryl-4-(arylamino)-2,5-dihydrofuran-3-carboxylate derivatives (4) in the presence of the catalytic amount of graphene oxide@dopamine-Cu nanocatalyst in high yield. Molecular structures of products were characterized by FT-IR, 1H, 13C nuclear magnetic resonance (NMR), and Mass spectroscopy techniques. Representatively, the mass fragmentation of 4a was discussed, and the structure was confirmed. Easy reaction, high performance, and easy catalyst recyclability are the main advantages of this work. This nanocatalyst is recycled up to five successive runs.

Preparation of Core/Shell Fe3O4@SiO2 ⋅ DIL as a Magnetically Separable Catalyst for the Synthesis of 1, 8‐Dioxodecahydroacridine

AbstractIn this research, design and synthesis of the magnetic nanoparticle, coated by a silica shell and modified with dicationic ionic liquid are described. The characterization of Fe3O4@SiO2 ⋅ DIL was done by means of techniques such as XRD, FTIR, SEM, EDX, TEM, and TGA. The catalytic activity of Fe3O4@SiO2 ⋅ DIL as a new nanocatalyst was tested in the one‐pot tree‐component synthesis of 1,8‐dioxodecahydroacridines. To achieve higher yield of products, factors such as reaction temperature, reaction time, the amount of nanocatalyst and solvent were studied, and the optimized conditions were investigated. The results indicated that the reaction time for aromatic aldehydes bearing substituent at para position is shorter and higher yields of products were obtained with these substrates. Short reaction time, high yield of products, easy purification and easy recoverable catalyst without significantly loss of its activity are the main advantages of the process presented. The results clearly showed that the existing catalytic system could be eco‐friendly and economical to carry out this reaction.

Merging gold plasmonic nanoparticles and L-proline inside a MOF for plasmon-induced visible light chiral organocatalysis at low temperature.

Light-driven asymmetric photocatalysis represents a straightforward approach in modern organic chemistry. In comparison to the homogeneous one, heterogeneous asymmetric photocatalysis has the advantages of easy catalyst separation, recovery, and reuse, thus being cost- and time-effective. Here, we demonstrate how plasmon-active centers (gold nanoparticles - AuNPs) allow visible light triggering of chiral catalyst (proline) in model aldol reaction between acetone and benzaldehyde. The metal-organic framework UiO-66-NH2 was used as an advanced host platform for the loading of proline and AuNPs and their stabilization in spatial proximity. Aldol reactions were carried out at a low temperature (-20 °C) under light illumination which resulted in 91% ee with a closed-to-quantitative yield, 4.5 times higher than that without light (i.e. in the absence of plasmon triggering). A set of control experiments and quantum chemical modeling revealed that the plasmon assistance proceeds through hot electron excitation followed by an interaction with an enamine with the formation of anion radical species. We also demonstrated the high stability of the proposed system in multiple catalytic cycles without leaching metal ions, which makes our approach especially promising for heterogeneous asymmetric photocatalysis.

The catalytic effect of calcium oxide and magnetite loading on magnetically supported calcium oxide-zeolite catalyst for biodiesel production from used cooking oil

This research focuses on developing a magnetically supported catalyst for efficient transesterification reaction of used cooking oil (UCO). The catalyst consists of calcium oxide (CaO) and ZSM-5 zeolite, which were synthesized using waste chicken eggshell and rice husk. Meanwhile, magnetite (Fe3O4) was used as a magnetic component. Various magnetic zeolite-supported CaO catalysts (CaZ/Fe) were prepared with different amounts of CaO (10, 30, 50, and 80 wt% of zeolite) and Fe3O4 (1:0.5, 1:1, 1:1.5 and 1:2 of CaO-zeolite:Fe3O4 ratio). The results identified the 50CaZ/0.5Fe catalyst as the most effective. The catalyst displayed a high surface area, strong basicity, and ideal morphology, thus contributing to a higher biodiesel yield of 91%. The recovery rate of the 50CaZ/0.5Fe catalyst was 88%, suggesting minimal loss and easy catalyst separation post-reaction using an external magnetic field. It also displayed superior stability, obtaining 85% biodiesel yield after 4 uses. The activation energy calculated in the kinetic study was 14.085 kJ/mol. Moreover, the properties of the synthesized biodiesel met the standards set by the ASTM D6751. Overall, the 50CaZ/0.5Fe catalyst with good magnetic behaviour and exhibits excellent catalytic activity suggested that this catalyst is promising for application in biodiesel production.

Mechanistic Insights into the Appel Reaction Mediated by a Poly-Phosphamide Material as a Heterogeneous Catalyst.

Due to notable thermochemical stability, polyphosphamides are often regarded as flame retardants, while molecular phosphamides can serve as versatile Lewis base to catalyze diverse organic transformations. Being chemically analogous to phosphine oxide, phosphamide can also be considered as a mediator for the phosphine-mediated reaction. Herein, an amorphous polymeric material consisting of phosphamide (-NH-P(O)) in the repeating unit (POP) has been prepared via condensation of tris(2-aminoethyl)amine (TREN) and phenyl phosphinic dichloride (PPDC). The POP is isolated as a metal-free and pure organic material which is made of a strong covalent bond and the phosphamide unit is deployed in the organic framework. The presence of phosphamide in the repeating unit of the isolated amorphous POP material can be confirmed by 31P CPMAS NMR, FTIR, and Raman studies. The core-level N 2p and P 2p X-ray photoelectron spectra are in accordance with the presence of tertiary amine nitrogen attached to carbon and secondary amine nitrogen attached to phosphorus. Elemental analyses have depicted approximately 19.7% of phosphorus content in the material, which is being utilized to study the catalytic Appel reaction with 76% conversion of alcohol to a corresponding halide and TON of 462. Quasi in situ Raman study has identified that amino phosphine formed via in situ reduction of the phosphamide unit of the POP catalyzes the halogenation of primary and secondary alcohols with wide substrate scope and functional group tolerance. Kinetic studies have established a first-order dependence with respect to alcohol, while deuterium labeling experiments emphasize that the deprotonation of alcohol is the rate-limiting step. High thermal stability of the material, scope of easy catalyst recyclability, and a cumulative TON of 1386 have led the POP as an emerging pure organic material to be explored further for other phosphine-mediated organocatalysis.

Tailoring Zn-based diacidic functionalization of Deep eutectic solvent Catalyst: Green and efficient synthesis of ε-Caprolactam under mild conditions

A novel Zn-based acidic functionalized deep eutectic solvent (DES) catalyst were prepared by a “tailoring” mixing procedure of Brønsted acidic hydrogen bond donors (HBD) and Lewis acidic hydrogen bond acceptor (HBA). It is found that the hydrogen bonded cluster with thermal stability and adjustable acidity has an excellent flexible hydrogen bond “assembly mode”, providing a suitable coordination microenvironment for Zn active center. The functionalized DESs were investigated to produce caprolactam from cyclohexanone oxime. The results showed that DES [ZnCl2][ChCl][TCA]2 had an excellent catalytic performance for the reaction with 100% cyclohexanone oxime conversion and ε-caprolactam 99.4% selectivity at 80 °C for 1.5 h, attributing to the strong complexing ability of Zn active center and the synergistic effect of BrØnsted and Lewis acid sites of DES, which also decreased the energy barriers of the intermediates and transition states, thus reducing the reaction energy (Ea = 29.22 kJ mol−1 and ΔG = –32.8 kJ mol−1). Otherwise, the recovered DES [ZnCl2][ChCl][TCA]2 was reused seven times with no significant decrease in its catalytic performance. The advantages of this method, such as high yield, short reaction time, and easy catalyst recovery, make the DES catalytic system a potential method for Beckmann rearrangement.

Stabilization of Au-nanoparticle-decorated postsynthesis-modified Cu(BDC-NH2) MOF as a reusable heterogeneous catalyst in an intermolecular hydroamination of allenamides with arylamines

Here, we prepared an efficient and reusable catalyst by stepwise post-synthetic modification of surface nitrogen-enriched Cu(BDCNH2) metal-organic frameworks (MOFs) and used it as a catalyst for the preparation of [Cu(BDCNH2) -AuNTf2]. Catalytic performance results of the [Cu(BDCNH2)-AuNTf2] catalyst showed high efficiency in modulating the microenvironment of AuNTf2 Nanoparticles. Successful preparation of [Cu(BDCNH2)-AuNTf2] catalyst has been proven by various techniques, including FT-IR, XRD, SEM, BET, EDS, ICP, and TGA. The synthesis of allylamino E-enamides with good yield and high stereoselectivity was carried out under mild conditions in the presence of AuNTf2 Nanoparticle catalysis. Clean method, easy catalyst manufacturing, high efficiency, and recyclability are the most important advantages of this procedure.

MgO-MgAl2O4: An Efficient Catalyst for Multicomponent Synthesis of Substituted 4H-pyran

Background: The 4H-pyran compounds are an important class of heterocyclic compounds due to their diverse biological and pharmaceutical properties. Moreover, 4H-pyran is a crucial structural component commonly encountered in the pharmaceutical industry. Thus, it has recently gained significant attention from industry researchers and academic organizations. Herein, we report an efficient and eco-friendly one-pot strategy to synthesize bioactive compounds containing 4H-pyran motifs via a multicomponent reaction. This reaction occurs by reacting equimolar amounts of ethyl acetoacetate, malononitrile, and substituted aldehyde under mild conditions in the presence of a solid catalyst, MgO-MgAl2O4. This latter, was obtained by heat treatment, at 800°C, of a layered double hydroxide with the metal cation ratio of Mg2+/Al3+ = 3:1, and it was characterized by some techniques including XRD, TG-DTA, FT-IR and N2 adsorption-desorption. Therefore, bioactive compounds containing the pyran unit may possess intriguing biological properties. The synthetic protocol offers advantages such as a simple procedure, good to excellent yields, and easy catalyst separation from the reaction mixture. Methods: Substituted 4H-pyran derivatives were prepared by the condensation reaction of substituted aldehydes, ethyl acetoacetate and malononitrile using MgO-MgAl2O4 catalyst under mild conditions. This study aims to develop an efficient methodology for synthesizing 4H-pyran heterocyclic compounds that have potential applications in biological sciences. The study utilizes MgO-MgAl2O4 as a highly effective heterogeneous catalyst. Results: The present research details the synthesis of 4H-pyran bioactive compounds using sustainable reaction conditions, which resulted in high yields and facilitated the easy separation of the catalyst from the reaction mixture. Conclusion: In summary, the MgO-MgAl2O4 spinel nanostructure has been successfully prepared and fully characterized by using different physicochemical techniques such as XRD, TG-DTA, FT-IR and N2 adsorption-desorption. Afterwards, its catalytic activity was investigated through the one-pot condensation of aryl aldehyde, malononitrile and ethyl acetoacetate. Moreover, it exhibits good catalytic activity for the synthesis of 4H-pyran derivatives under green conditions. These latter have many benefits, such as simple procedure, good to excellent yields and easy separation of the catalyst from the reaction mixture.