A magnetic metal organic framework material as a highly efficient and recyclable catalyst for synthesis of cyclohexenone derivatives

Cu immobilized on MgZnFe2O4 nanoparticles as a green catalyst in the synthesis of mono and bis-polyhydroquinolines

In this study, a green and environmentally friendly catalyst (MgZnFe2O4@ZSC-Cu) was synthesized using a simple and clean method. The catalyst was prepared by combining MgZnFe2O4 MNPs with Ziziphus spina-christi extract (ZSC) and immobilizing Cu ions on the resulting material. The catalyst was thoroughly characterized using various techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FE-SEM), Energy dispersive X-ray analyzer (EDS), Inductively coupled plasma-optical emission spectrometry (ICP-OES), Thermogravimetric (TGA), and Vibrating sample magnetometry (VSM) analyses. The catalytic activity of MgZnFe2O4@ZSC-Cu was evaluated in the Hantzsch reaction involving a four-component reaction with ethyl acetoacetate or dimedone/cyclohexane-1,3-dione, various aromatic aldehydes/di-aldehydes, and ammonium acetate. The structure of the newly formed bis compound and polyhydroquinolines was determined using FT-IR, 1H and 13C NMR spectroscopy. This catalyst provides numerous benefits, such as simple separation using a magnet, less reaction times, high product yield, solvent-free conditions, straightforward work-up, and the capability to reuse the catalyst for up to five cycles.

Fe3O4@SiO2@NTMPThio-Cu: a sustainable and eco-friendly approach for the synthesis of heterocycle derivatives using a novel dendrimer template nanocatalyst

In this research, Fe3O4@SiO2@NTMPThio-Cu was introduced as a novel and green heterogeneous nanocatalyst with a dendrimer template that is environmentally friendly and reusable based on Fe3O4@SiO2. In this way, magnetic silica nanoparticles were first modified with cyanuric chloride, followed by melamine and thiosemicarbazide, and ultimately, it's decorated with the cost-effective metal copper. The synthesized nanocatalyst was characterized by various analyses such as FT-IR, XRD, SEM, TGA, and EDX. The efficiency of Fe3O4@SiO2@NTMPThio-Cu was measured in one-pot synthesis of xanthene and spirooxindole-pyran derivatives under mild solvent-free conditions. High efficiency, excellent yield of products, mild reaction conditions, simple operation, no use of toxic organic solvents, and reusability of this catalyst increase the attractiveness of this technique for large-scale environmentally friendly operations.

Isoreticular Metal-Organic Framework-3 (IRMOF-3): From Experimental Preparation, Functionalized Modification to Practical Applications

Isoreticular metal-organic framework-3 (IRMOF-3), a porous coordination polymer, is an MOF material with the characteristics of a large specific surface area and adjustable pore size. Due to the existence of the active amino group (-NH2) on the organic ligand, IRMOF-3 has more extensive research and application potential. Herein, the main preparation methods of IRMOF-3 in existing research were compared and discussed first. Second, we classified and summarized the functionalization modification of IRMOF-3 based on different reaction mechanisms. In addition, the expanded research and progress of IRMOF-3 and their derivatives in catalysis, hydrogen storage, material adsorption and separation, carrier materials, and fluorescence detection were discussed from an application perspective. Moreover, the industrialization prospect of IRMOF-3 and the pressing problems in its practical application were analyzed and prospected. This review is expected to provide a reference for the design and application of more new nanomaterials based on IRMOF-3 to develop more advanced functional materials in industrial production and engineering applications.

Phosphomolybdic acid supported on magnetic poly calix[4]resorcinarene-EDTA-chitosan network as a recyclable catalyst for the synthesis of 5-aroyl-NH-1,3-oxazolidine-2-ones

In this work, a novel procedure for immobilization of phosphomolybdic acid (PMA) on Magnetic polycalix[4]resorcinarene grafted to chitosan by EDTA (calix-EDTA-Cs) was reported. The heterogeneous nanocomposite (CoFe2O4@calix-EDTA-Cs@PMA) was applied an acid nanocatalyst for the synthesis of 5-aroyl-NH-1,3-oxazolidine-2-ones through the reaction of α-epoxyketones with sodium cyanate (NaOCN) in polyethylene glycol (PEG) as a green solvent under ultrasonic irradiation conditions. Some features of this work include quick reaction time, high reaction yield, easy separation of the catalyst, thermal stability, and eco-friendly.

Access to Functionalized Cyclohex-2-enones from a Multicomponent Cascade Reaction of Readily Available Alkynes, Ketones, and Ethyl Acetoacetate

The synthesis of cyclohex-2-enone derivatives is a topic of current interest in organic chemistry. A novel three-component cascade reaction of alkynes with ketones and ethyl acetoacetate has been uncovered. This process provides di- and trisubstituted cyclohex-2-enones in good yields with excellent functional group tolerance. A variety of terminal alkynes and a wide range of aryl, alkyl, and cyclic ketones are viable in this transformation. Successful scale-up preparation and synthetic transformations have demonstrated the potential of this simple operating protocol.

Alkyl ammonium hydrogen sulfate immobilized on Fe3O4@SiO2 nanoparticles: a highly efficient catalyst for the multi-component preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives

In this, a three-component reaction for the preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives from N,N'-(sulfonylbis(1,4-phenylene))bis(3-oxobutanamide), aldehydes and 1H-tetrazol-5-amine is reported. The application of Fe3O4@SiO2-(PP)(HSO4)2 (A) as a catalyst afforded the desired products (a1-a18) in high yields in DMF as solvent as well as under solvent-free conditions.

ZnFe2O4@SiO2@L-lysine@SO3H: preparation, characterization, and its catalytic applications in the oxidation of sulfides and synthesis of Bis(pyrazolyl)methanes

Herein, we report the synthesis of ZnFe2O4@SiO2@L-lysine@SO3H as a green, novel magnetic nanocatalyst, containing the sulfuric acid catalytic sites on the surface of zinc ferrite as the catalytic support. The physical and chemical properties of raw and modified samples (ZnFe2O4@SiO2@L-lysine@SO3H) were characterized by TGA, EDX, PXRD, Map, and FTIR analyses. The prepared nanocatalyst has excellent catalytic activity in synthesizing the oxidation of sulfides to the sulfoxides and Synthesis of pyrazolyl (Bis(pyrazolyl)methane) derivatives under green conditions. This designed nanocatalyst offers several advantages including the use of inexpensive materials and high yield, simple procedure, and commercially available. The synthesized mesoporous nanocatalyst was recovered and reused in five continuous cycles without considerable change in its catalytic activity.

Captopril supported on magnetic graphene nitride, a sustainable and green catalyst for one-pot multicomponent synthesis of 2-amino-4H-chromene and 1,2,3,6-tetrahydropyrimidine

Captopril (CAP) is a safe, cost-effective, and environmentally organic compound that can be used as an effective organo-catalyst. Functional groups of captopril make it capable to attach to solid support and acting as promoters in organic transformations. In this work, captopril was attached to the surface of magnetic graphene nitride by employing a linker agent. The synthesized composite efficiently catalyzed two multicomponent reactions including the synthesis of 1,2,3,6-tetrahydropyrimidine and 2-amino-4H-chromene derivatives. A large library of functional targeted products was synthesized in mild reaction conditions. More importantly, this catalyst was stable and magnetically recycled and reused for at least five runs without losing catalytic activity.

Facile synthesis of FeCeOx nanoparticles encapsulated carbon nitride catalyst for highly efficient and recyclable synthesis of substituted imidazoles

Herein, we developed a novel composite called FeCeOx@g-C3N4 through a combination of sonication, sintering, and hydrothermal techniques to implement the principles of green chemistry by utilizing reusable nanocomposites in one-pot reactions. To gain a comprehensive understanding of the catalyst's structure, composition, and morphology, various characterization methods were employed. These included FT-IR analysis to examine chemical bonds, SEM and TEM imaging to visualize the catalyst's surface and internal structure, TGA to assess thermal stability, EDS for elemental composition analysis, and XRD to determine crystal structure. The FeCeOx@g-C3N4 nanocatalyst demonstrated remarkable efficacy in the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazole. Noteworthy features of this catalyst included high percentage yield, mild reaction conditions, short reaction time, and an efficient and straightforward procedure. Furthermore, the FeCeOx@g-C3N4 composite exhibited excellent recyclability and reusability. It could be recycled and reused up to four times without a significant decline in catalytic activity.

Synthesis of pyridone derivatives using 2D rod like bifunctional Fe based MOF and CuO nanocomposites as a novel heterogeneous catalyst

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 N‑amino-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.

Synthesis of Fe3O4@SiO2@Pr-NH2@DAP as a magnetic recyclable nano-catalyst for efficient synthesis of pyranothiazolopyrimidines and 4H-pyrans under solvent-free condition

In this research, we describe the synthesis of silica-coated nano-Fe3O4 particles, which were successfully modified by diaminopyrimidine, and their physicochemical properties were characterized using FT-IR, XRD, TEM, FE-SEM, EDX, EDX-mapping, and TGA. The catalytic activity of this novel nano-catalyst was evaluated by three-component reactions for the preparation of pyranothiazolopyrimidines and 4H-pyrans under solvent-free conditions. Recyclability of the catalyst up to six consecutive rounds, atom economy, high yield and purity of desired products, and easy work-up method are some of the exciting features of this system that make it more favorable from a green chemistry point of view.

SO3H-Functionalized Epoxy-Immobilized Fe3O4 Core-Shell Magnetic Nanoparticles as an Efficient, Reusable, and Eco-Friendly Catalyst for the Sustainable and Green Synthesis of Pyran and Pyrrolidinone Derivatives

A SO₃H-functionalized epoxy-immobilized Fe₃O₄ core-shell magnetic nanocatalyst was prepared through a simple three-step procedure, and it was identified by various analyses such as Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), differential thermal gravity (DTG), Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), vibration sample magnetometry (VSM), and powder X-ray diffraction (PXRD). BET analysis showed that the as-prepared nanocatalyst was synthesized with a mesoporous structure and high specific area (35.45 m² g^-1). The TEM image clearly showed that the particle size distribution was in the range of 47-65 nm. The designed magnetic nanocatalyst was used successfully in the synthesis of pyran derivatives via the reaction of dimedone, malononitrile, and various aromatic aldehydes and synthesis of pyrrolidinone derivatives via the reaction of various aromatic aldehydes, aniline, and diethyl acetylenedicarboxylate. The nanocatalyst was simply isolated from the reaction mixture utilizing an external magnet and reused several times according to the model reactions without significant loss in its efficiency.

Recent advances in synthesis of stilbene derivatives via cross-coupling reaction

The stilbenes are undoubtedly some of the most significant moieties in various bioactive natural and synthetic structures, and they are considered privileged structures. In recent years, the preparation of these structures via cross-coupling reactions has attracted much attention. In the current review, we present a summary of the recent developments in the construction of stilbene and stilbene derivatives by carbon-carbon coupling reactions of organic compounds in the presence of transition metal catalysts or under metal-free conditions. In this context, we outline the features of the important reactions, some product yields, and challenging reaction mechanisms.

Preparation and characterization of the h-BN/Fe3O4/APTES-AMF/CuII nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (h-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by h-BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable h-BN/Fe₃O₄/APTES-AMF/Cu^II catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of h-BN/Fe₃O₄/APTES-AMF/Cu^II nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles under ambient conditions. In addition, the use of green solvent, facile magnetic recoverability, and reusability of up to six successive runs made this protocol environmentally benign and economical. This work throws light on the development of covalently functionalized 2D-BN nanostructure-based copper catalysts and establishes its significance in furnishing industrially demanding products that would pave the way towards sustainable chemistry.

Greener Syntheses of Coumarin Derivatives Using Magnetic Nanocatalysts: Recent Advances

Coumarins (2H-1-benzopyran-2-ones) are an important group of biological heterocyclic compounds present in various parts of many plant species, encompassing an array of biological and pharmaceutical activities. In view of the importance of coumarins in heterocyclic chemistry and biological sciences and recent advances in the design of magnetic nanocatalysts, we present herein recent developments pertaining to their synthesis exclusively using magnetic nanoparticles, which can be retrieved easily and thus conform to the tenets of greener synthesis. The preparation of various types of coumarins such as Pechmann-based coumarins, bis coumarins, pyranocoumarins, and coumarin derivatives bearing amine moiety, linked to nicotinonitriles, N-coumarin-2-furanone, and pyrrole-linked chromene derivatives using nanocatalysts with a Fe₃O₄ core are described. This review covers the synthetic developments in the recent years 2012-2021 and focuses entirely on the synthesis of coumarins in the presence of magnetic nanocatalysts using greener approaches such as solvent-free conditions or deploying alternative activation methods, namely microwave or ultrasound irradiation.

New ecofriendly heterogeneous nano-catalyst for the synthesis of 1-substituted and 5-substituted 1H-tetrazole derivatives

A novel ecofriendly heterogeneous catalyst containing Schiff base coordinated Cu(II) covalently attached to Fe₃O₄@SiO₂ nanoparticles through imidazolium linker [Fe₃O₄@SiO₂-Im(Br)-SB-Cu (II)] was synthesized and characterized by using various techniques. The catalytic efficiency of this nano-catalyst was tested in water in the synthesis of tetrazole derivatives using two one-pot multicomponent reaction (MCR) models: The synthesis of 1-aryl 1H-tetrazole derivatives from the reaction of aniline, triethyl orthoformate, and sodium azide and the synthesis of 5-aryl 1H-tetrazole derivatives from the reaction of benzaldehyde, hydroxy amine hydrochloride, and sodium azide. The investigation showed that (i) The catalyst is highly efficient in the synthesis of tetrazole derivatives with high yield (97%) in aqueous medium and mild temperatures; (ii) The catalytic effectiveness is due to the synergy between the metallic center and the imidazolium ion and (iii) The reuse advantage of the catalyst without contamination or significant loss (12% of loss range) in the catalytic activity.

Design, preparation and application of the semicarbazide-pyridoyl-sulfonic acid-based nanocatalyst for the synthesis of pyranopyrazoles

A novel, efficient, and recoverable nanomagnetic catalyst bearing the semicarbazide linkers, namely, Fe₃O₄@SiO₂@OSi(CH₂)₃-N(3-pyridoyl sulfonic acid)semicarbazide (FSiPSS) was designed, synthesized and characterized by the use of various techniques such as FT-IR, EDX, elemental mapping analysis, XRD, SEM, TEM, TGA/DTA, BET, and VSM. Then, the catalytic capability of the novel prepared nanomagnetic FSiPSS catalyst was successfully investigated in the synthesis of diverse pyranopyrazoles through a one-pot four-component condensation reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehydes, and malononitrile or ethyl cyano-acetate by the help of ultrasonication in very short reaction time, good to high yields and easy work-up (Fig. 1). Figure 1 Synthesis of diverse pyranopyrazoles by the FSiPSS nano-catalyst.

Catalytic synthesis of new pyrazolo [3,4-b] pyridine via a cooperative vinylogous anomeric-based oxidation

In this study, a novel nano-magnetic metal-organic frameworks based on Fe3O4 namely Fe3O4@MIL-101(Cr)-N(CH2PO3)2 was synthesized and fully characterized. The prepared sample was used as catalyst in the synthesis of pyrazolo [3,4-b] pyridines as convenient medicine by condensation reaction of aldehydes, 5-(1H-Indol-3-yl)- 2H-pyrazol-3-ylamine and 3-(cyanoacetyl)indole via a CVABO. The products were obtained with high yields at 100 °C and under solvent-free conditions.

Efficient synthesis of 1,3-naphtoxazine derivatives using reusable magnetic catalyst (GO-Fe3O4-Ti(IV)): anticonvulsant evaluation and computational studies

A series of 2-aryl/alkyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines (S₁-S₁₁) were synthesized with an eco-friendly and recoverable nanocatalyst (GO-Fe₃O₄-Ti^(IV)) as an efficient magnetic composite. The new nanocatalyst was characterized by FT-IR, XRD and, EDS analysis. A conformable procedure, easy to work up and having a short reaction time with high yields are some advantages of this method. The new catalyst is also thermal-stable, reusable and, environment-friendly. The chemical structures of the synthesized 1,3-oxazine compounds were confirmed by comparing their melting points with those reported in literature. Then, the anticonvulsant activity of these compounds was assessed by the intraperitoneal pentylenetetrazole test (ipPTZ). Compounds S₁₀ and S₁₁ displayed considerable activity against chemically-induced seizure tests. The molecular simulation was also done to achieve their binding affinities as γ-aminobutyric acid A (GABA-A) receptor agonists as an assumptive mechanism of their anticonvulsant action. The result of molecular studies represented strongly matched with biological activity. Molecular docking simulation of the potent compound (S₁₀) and diazepam as the positive control was performed and some critical residues like Thr262, Asn265, Met286, Phe289, and Val290 were identified. Based on the anticonvulsant results and also in silico ADME predictions, S₁₁ can be to become a potential drug candidate as an anticonvulsant agent.

Magnetic chitosan stabilized Cu(II)-tetrazole complex: an effective nanocatalyst for the synthesis of 3-imino-2-phenylisoindolin-1-one derivatives under ultrasound irradiation

In the present research, a recyclable catalyst has been prepared via a simple approach using chitosan as a linear polysaccharide. This paper reports the synthesis of novel copper(II) complex of 5-phenyl-1H-tetrazole immobilized on magnetic chitosan (MCS@PhTet@Cu(II)) as an effective catalyst. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and inductively coupled plasma mass spectrometry (ICP-MS) techniques were applied for the characterization of the catalyst. The catalytic activity of MCS@PhTet@Cu(II) was evaluated in the ultrasound-assisted synthesis of 3-imino-2-phenylisoindolin-1-one derivatives via the reaction between benzoyl chloride and arylcyanamides in ethanol at ambient temperature. Utilizing a wide variety of arylcyanamides under mild conditions, no use of toxic organic solvents, moderate reaction time, high yields along with catalyst excellent reusability and easy separation of the products without any tedious separation techniques, made this method a novel and simple process. The resulting heterogeneous catalyst showed valuable advantages such as easier work-up, better stability, and greater separation ability using an external magnet. The catalyst showed high efficacy and recyclability even after five cycles with no significant loss of its efficacy. The present methodology provides a path for the preparation of structurally diverse heterocyclic compounds, which may exhibit important biological activity.

Functionalized hybrid magnetic catalytic systems on micro- and nanoscale utilized in organic synthesis and degradation of dyes

Herein, a concise review of the latest developments in catalytic processes involving organic reactions is presented, focusing on magnetic catalytic systems (MCSs). In recent years, various micro- and nanoscale magnetic catalysts have been prepared through different methods based on optimized reaction conditions and utilized in complex organic synthesis or degradation reactions of pharmaceutical compounds. These biodegradable, biocompatible and eco-benign MCSs have achieved the principles of green chemistry, and thus their usage is highly advocated. In addition, MCSs can shorten the reaction time, effectively accelerate reactions, and significantly upgrade both pharmaceutical synthesis and degradation mechanisms by preventing unwanted side reactions. Moreover, the other significant benefits of MCSs include their convenient magnetic separation, high stability and reusability, inexpensive raw materials, facile preparation routes, and surface functionalization. In this review, our aim is to present at the recent improvements in the structure of versatile MCSs and their characteristics, i.e., magnetization, recyclability, structural stability, turnover number (TON), and turnover frequency (TOF). Concisely, different hybrid and multifunctional MCSs are discussed. Additionally, the applications of MCSs for the synthesis of different pharmaceutical ingredients and degradation of organic wastewater contaminants such as toxic dyes and drugs are demonstrated.

A novel composite of ionic liquid-containing polymer and metal-organic framework as an efficient catalyst for ultrasonic-assisted Knoevenagel condensation

1-Butyl-3-vinylimidazolium chloride was synthesized and polymerized with acrylamide to furnish an ionic liquid-containing polymer, which was then used for the formation of a composite with iron-based metal-organic framework. The resultant composite was characterized with XRD, TGA, FE-SEM, FTIR, EDS and elemental mapping analyses and its catalytic activity was appraised for ultrasonic-assisted Knoevenagel condensation. The results confirmed that the prepared composite could promote the reaction efficiently to furnish the corresponding products in high yields in very short reaction times. Moreover, the composite exhibited high recyclability up to six runs. It was also established that the activity of the composite was higher compared to pristine metal-organic framework or polymer.

Formamidation of a wide range of substituted and functionalized amines with CO and a base

We have developed a base mediated formamidation of amines with CO under mild conditions, which allows for the synthesis of a wide range of aromatic and aliphatic formamides in high yields and gram amounts in the absence of a transition metal.

A novel domino protocol for three-component synthesis of new dibenzo[e,g]indoles: flexible intramolecular charge transfers

New and electronically interesting 2-aryl-3-nitrodibenzo[e,g]indoles were synthesized effectively via a hitherto unreported three-component domino reaction under catalysis of a superparamagnetic nano-composite.

Catalyst-free Synthesis of Aminomethylphenol Derivatives in Cyclopentyl Methyl Ether via Petasis Borono-Mannich Reaction

OBJECTIVE

Aminomethylphenol molecules have wider applications in pharmaceuticals, agrochemicals, plant protection and promising functional materials. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of view.

MATERIALS AND METHODS

In order to establish an effective synthetic method for preparing aminomethylphenol derivatives, the Petasis borono-Mannich reaction of salicylaldehyde, phenylboronic acid and 1,2,3,4- tetrahydroisoquinoline was selected as a model reaction. A variety of reaction conditions are investigated, including solvent and temperature. The generality and limitation of the established method were also evaluated.

RESULTS AND DISCUSSION

It was found that model reaction can be carried out in cyclopentyl methyl ether at 80 oC under catalyst-free conditions. This protocol, with broad substrate applicability, the reaction of various arylboronic acid, secondary amine and salicylaldehyde proceeded smoothly under optimal reaction conditions to afford various aminomethylphenol derivatives in high yields. A practical, scalable, and high-yielding synthesis of aminomethylphenol derivatives was successfully accomplished.

CONCLUSION

A catalyst-free practical method for the synthesis of minomethylphenol derivatives based on Petasis borono-Mannich (PBM) reaction of various arylboronic acid, secondary amine and salicylaldehyde in cyclopentyl methyl ether has been developed. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of cyclopentyl methyl ether as the reaction medium, clean reaction profiles, easy operation, and high to excellent yield.

Zr@IL-Fe3O4 MNPs as an efficient and green heterogeneous magnetic nanocatalyst for the one-pot three-component synthesis of highly substituted pyran derivatives under solvent-free conditions

The present study was conducted to synthesize Zr@IL-Fe3O4 MNPs as a new magnetically recoverable heterogeneous catalyst, which was then characterized by Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), vibrating sample magnetometry (VSM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The catalytic behavior of the Zr@IL-Fe3O4 MNPs was efficiently used for the synthesis of highly substituted pyran derivatives via a one-pot three-component condensation of 4-hydroxycoumarin/dimedone, malononitrile, and arylaldehydes under solvent-free conditions. This new methodology demonstrated some important features, including short reaction times, excellent yields, lower loading of the catalyst, easy work-up, and recyclability of the catalyst for a minimum of six times without any noticeable decrease in catalytic activity.

Visible-Light-Mediated Oxidative Amidation of Aldehydes by Using Magnetic CdS Quantum Dots as a Photocatalyst

A magnetic CdS quantum dot (Fe₃ O₄ /polydopamine (PDA)/CdS) was synthesized through a facile and convenient method from inexpensive starting materials. Characterization of the prepared catalyst was performed by means of FTIR spectroscopy, XRD, SEM, TEM, energy-dispersive X-ray spectroscopy, and vibrating-sample magnetometer techniques. Fe₃ O₄ /PDA/CdS was found to be a highly active photocatalyst for the amidation of aromatic aldehydes by using air as a clean oxidant under mild conditions. The photocatalyst can be recovered by magnetic separation and successfully reused for five cycles without considerable loss of its catalytic activity.

Application of novel nanomagnetic metal-organic frameworks as a catalyst for the synthesis of new pyridines and 1,4-dihydropyridines via a cooperative vinylogous anomeric based oxidation

Herein, a new magnetic metal-organic frameworks based on Fe3O4 (NMMOFs) with porous and high surface area materials were synthesized. Then, NMMOFs were characterized by FT-IR, XRD, SEM, elemental mapping, energy dispersive X-ray (EDS), TG, DTG, VSM, and N2 adsorption-desorption isotherms (BET). Fe3O4@Co(BDC)-NH2 as a magnetic porous catalyst was applied for synthesis of novel fused pyridines and 1,4-dihydropyridines with pyrazole and pyrimidine moieties as suitable drug candidates under ultrasonic irradiation. The significant advantages of the presented methodology are mild, facile workup, high yields, short reaction times, high thermal stability, and reusability of the described NMMOFs catalyst.

Choline Chloride/Glycerol Promoted Synthesis of 3,3-Disubstituted Indol-2-ones

Objective:

3,3-Disubstituted indol-2-one derivatives have wider applications in pharmaceuticals and they are key intermediates for the synthesis of many kinds of drug candidates. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of views.

Methods:

In order to establish an effective synthetic method for preparing 3,3-disubstituted indol-2-one derivatives, the bis-condensation reaction of isatin and 1H-indene-1,3(2H)-dione was selected as a model reaction. A variety of natural deep eutectic solvent (NADES) were prepared and used for this reaction. The generality and limitation of the established method were also investigated.

Results:

It was found that model reaction can be carried out in natural deep eutectic solvent (NADES) based on choline chloride (ChCl) at 80 oC under microwave irradiation. This protocol with a broad substrate applicability afforded various 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione) derivatives in high yields.

Conclusion:

simple and efficient procedure has been developed for synthesis of 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione), spiro[indoline-3,7'-pyrano[5,6-c:5,6-c']dichromene]-2,6',8'-trione, and spiro[indoline-3,9'-xan-thene] trione via bis-condensation between isatin with 1,3-indandione, 4-hydroxycoumarin or 1,3-cyclohexanedione in nat-ural deep eutectic solvent (NADES) based on choline chloride (ChCl) and glycerol (Gl) under microwave irradiation. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvent, clean reaction profiles, non-chromatographic purification procedure, and high to excellent yield. Furthermore, the use of NADES as green reaction medium reduces burden on environment and makes the present method environmentally sustainable.

Design and synthesis of a new magnetic metal organic framework as a versatile platform for immobilization of acidic catalysts and CO2 fixation reaction

The first report of the use of an acidic magnetic metal organic framework for the chemical fixation of CO2 as an environmentally friendly reaction.

Magnetic nanocatalysts utilized in the synthesis of aromatic pharmaceutical ingredients

This review covers recent developments in nanoscale magnetic catalytic systems and their applications in facilitating organic synthetic reactions of aromatic pharmaceutical ingredients.

A core–shell superparamagnetic metal–organic framework: a recyclable and green catalyst for the synthesis of propargylamines

This is the first report on the use of a magnetic metal–organic framework for the green synthesis of propargylamine derivatives.