In this study, we have developed a new environmentally‐friendly magnetic nanocatalyst by treating CoFe₂O₄ magnetic nanoparticles with chlorosulfonic acid, tris (hydroxymethyl)aminomethane (THAM), 1,2‐dichloroethane, and phloroglucinol (PHG). They confirmed the synthesis of the catalyst using various techniques such as FT‐IR, SEM, MAP, EDS, XRD, TGA, DTA, and VSM. The researchers then evaluated the catalytic efficiency of the nanocatalyst in two reactions: the synthesis of 3,4‐dihydropyranochromenes from the reaction among aromatic aldehydes, 4‐hydroxycoumarin, and malononitrile, and the synthesis of chromeno[3,4‐ b ]quinoline‐6‐ones from the reaction among aniline, 4‐hydroxycoumarin, and aromatic aldehydes.

In this work, the surface of Fe 3 O 4 nanoparticles was functionalized with the glycine, furfural, and cobalt (II) nitrate hexahydrate to synthesize a novel support nanocatalyst (Fe 3 O 4 @gly@Furfural@Co(NO 3 ) 2 ). The characteristics of the nanocatalyst were confirmed by various techniques, such as energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectrometer, EDX mapping, scanning electron microscopy, X-ray diffraction, thermal gravimetric/derivative thermal gravimetric, vibrating sample magnetometer, and TEM. Finally, the performance of the nanocatalyst was investigated for the one-pot multicomponent synthesis of benzo[ b ]pyran and pyrano[2,3 -d ] pyrimidine derivatives. The good–excellent yield of the products was achieved in a green solvent under mild conditions at short reaction time. In addition, the green heterogeneous catalyst has features, such as environmental friendliness, easy separation from the reaction mixture by an external magnet, high catalytic activity, and reusability up to 6 stages without significant reduction of its catalytic activity.

Fe 3 O 4 @THAM-Mercaptopyrimidine nanoparticles, as eco-friendly and inexpensive compounds, catalyzed the synthesis of 1,8-dioxo-octahydroxanthenes efficiently through pseudo-three-component condensation of aromatic aldehydes and dimedone and the synthesis of polyhydroquinolines through via a four-component condensation of aromatic aldehydes, ethyl acetoacetate, dimedone, and ammonium acetate. The chemical structure of Fe 3 O 4 @THAM-Mercaptopyrimidine as a new nanocatalyst was completely confirmed with different techniques like FESEM, EDS, XRD, TGA, VSM, and FTIR analyses. This method has some benefits including low-temperature synthesis, good yields, short reaction time, easy work-up, and the use of a highly recyclable nanocatalyst.

In this article, a new and simple procedure was designed for the preparation of pyrazolopyranopyrimidine and dihydropyrano[2,3-c]pyrazole derivatives using the reaction between hydrazine hydrate, aryl aldehydes, malononitrile or barbituric acid, and ethyl acetoacetate using Fe3O4@THAM-piperazine as a solid nanocatalyst in a solution of water and ethanol at 60 degrees C. The present process offers advantages like easy workup, short reaction time, non-toxicity, and the use of green solvent. Moreover, recyclability studies were carried out that showed a high potential of reusing and recovering capability.

A green and efficient pathway for the synthesis of 2-amino-3-cyanopyridines and 2,4,6-triarylpyridines has been developed using Fe3O4@THAM-SO3H nanoparticles as a highly reusable nanocatalyst under mild reaction conditions. The use of environmentally friendly conditions, easy separation and reusability of the catalyst, low cost and simple methodology, good to excellent yields (70-90%), and short reaction times (15-40 min) are the advantages of this method.

Synthesis of organic compounds using some natural compounds as catalysts has gained more attention in recent decades. With respect to the importance of these procedures, the synthesis of 3,4-dihydropyrano[2,3-c]chromene and pyrano[2,3-d]pyrimidine derivatives using vitamin B-12 by a one-pot reaction of malononitrile, benzaldehydes and 4-hydroxycumarine or 1,3-dimethylbarbituric acid is reported.

A naturally biodegradable, reusable, and eco-safe catalyst,i.e.,uric acid was developed and exploited for the green, facile and economical one-pot synthesis of pyran annulated heterocyclic systems from starting materials. This method gives an insight into the credibility of pathway followed by the aforementioned green and reusable catalyst in aiding the heterocyclic compounds formation. High atom economy, cleaner reaction profile, simple column-free work up condition, shorter reaction times, high to excellent yields, eco-safe and high catalytic activity make this present procedure an interesting alternative to the multistep approaches.

In this study, three eco‐friendly, efficient, and convenient protocols have been reported for one‐pot synthesis of 2,4,6‐triaryl pyridine, 2‐amino‐3‐cyanopyridine, and polyhydroquinoline derivatives using salicylic acid as a catalyst under solvent‐free condition. The reported protocols offer several significant advantages such as the application of a nontoxic, neutral, and cheap catalyst, environmentally friendly conditions, the easy isolation of products by filtering, short reaction times, simple methodology, and good yields.

As a segment of ongoing surveys and with the aim of expansion of environmentally benign processes, a series of biologically varied type of substituted 2-amino-3-cyano-4H-pyrans and pyran-annulated Scaffolds have been synthesized by tandem Knoevenagel-cyclocondensation of aldehydes, malononitrile, and C-H-activated acidic compounds in aqueous ethanol in the presence of Ag/TiO2 nano-thin films as an eco-friendly, recyclable, and, robust catalyst at 60 degrees C. The salient features of this protocol are mild reaction conditions, producing target compounds in high yields, short reaction times, high atom economy, eco-friendly catalyst, easy isolation of products and no column chromatographic separation. Also, it is observed that the catalyst is highly stable during the reaction and several reuse times without observable loss in catalytic performance.

The aim of this research is the synthesis of a novel acidic nanocatalyst using the layer-by-layer assembly technique. The CoFe2O4@TRIS@sulfated boric acid nanoparticles were easily synthesized and studied as a highly beneficial, recyclable, and magnetite nanocatalyst for the synthesis of 2-amino-3-cyanopyridine derivatives. The chemical structure of CoFe2O4@TRIS @sulfated boric acid nanocatalyst was completely confirmed with different techniques like FESEM, Map, EDS, XRD, TGA/DTG, VSM, and FT-IR analyses. Briefly, the newly synthesized nanocatalyst offers some advantages such as simplicity of work-up, highly stable, environmental friendliness, reusability, excellent yields, and short reaction time.

In this study, another approach for developing nanomaterials including Pd nanoparticles is reported. Fe3O4@THAM-Pd MNPs have been synthesized by a bottom-up strategy. Then, the structure of the nanocatalyst was completely confirmed by several techniques like BET, TEM, ICP-OES, FTIR, EDS, MAP, SEM, XRD, TGA/DTG, and VSM. Finally, the catalytic efficiency of the novel synthesized nanocatalyst was scrutinized in the synthesis of bis (pyrazolyl)methane derivatives. Furthermore, the recyclability and stability of Fe3O4@THAM-Pd MNPs were checked. The results showed that Fe3O4@THAM-Pd MNPs can use as a new and efficient heterogeneous catalyst. The stability of nanocatalyst can be due to the strong interaction of N-rich shells with Pd nanoparticles. (C) 2021 Elsevier B.V. All rights reserved.

In the present study, the synthesis and catalytic application of a novel thioglycolic acid doped on Fe3O4 nanomagnetic particles coated with tris(hydroxymethyl)aminomethane (THAM) and 1,2-dichloroethane are described. The morphology, structure, and physicochemical properties have elucidated by several analytical methods like FT-IR, TEM, VSM, XRD, TGA, and FE-SEM. This nanocatalyst has successfully applied as a heterogeneous acid catalyst in the synthesis of diversely substituted biologically important xanthene and 3-aminoisoxazole derivatives. This catalyst eliminates our need for long-time reaction and hard catalyst separation from product, and it can be easily recovered with an external magnet for eight consecutive times without a significant decrease in its catalytic properties.

An efficient, solvent-free and one-pot procedure for the synthesis of pyrido[2,3-d]pyrimidine derivatives by condensation of aromatic aldehydes, malononitrile and 6-amino-1,3-dimethyl uracil at 90 degrees C catalyzed by lactic acid as an inexpensive, biological and eco-friendly compound is described. The remarkable benefits of this procedure are green and environmentally friendly reaction conditions, high yields, short reaction time, simple methodology and easy workup.

In this research, Fe3O4-MCM-41-SO3H was synthesized as a magnetically reusable Lewis acid catalyst and used in the cyclization reaction of 3-acylcoumarins or 3-chromonecarboxylic acid with arylhydrazine derivatives for the synthesis of pyrazoles in high yields under solvent-free conditions and with a simple work-up process. Fe3O4-MCM-41-SO3H was characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analyses.

In this study, a robust DABCO‐catalyzed method has been reported for the reaction of readily available material, including various aromatic/aliphatic aldehydes and acetoacetanilide affording N , N ′‐diaryl‐2‐aryl‐6‐hydroxy‐6‐methyl‐4‐oxocyclohexane‐1,3‐dicarboxamides. The reaction proceeds at 50 °C under solvent‐free conditions via a one‐pot pseudo ‐three‐component reaction to yield functionalized cyclohexanones containing four quaternary stereogenic centers. Simple reaction conditions, moderate‐to‐high yields of product, no need of column chromatographic purification, eco‐friendliness, shorter reaction time, and simple work‐up has transformed this method an interesting route to the available procedures. The stereoselectivity of compounds was envisaged with crystallography and NMR spectroscopy.

New derivatives of chromeno[4,3-b]quinolin-6-one were synthesized using novel SO3H-tryptamine supported on Fe3O4@SiO2@CPS which could be recycled as an effective magnetic nanocatalyst. SEM, EDX, XRD, FT-IR, TGA, VSM and BET analyses were utilized to confirm the magnetic nanocatalyst structure. Evaluation of Antimicrobial (antibacterial and antifungal) function of magnetic nanocatalyst as well as derivatives undergone synthesis was carried out according to MIC, MBC and MFC values. Moreover, evaluation of the derivatives subject to synthesis was performed according to DPPH free radical besides the biological features, in order to obtain justifiable biological features.

DABCO (1,4-diaza-bicyclo[2,2,2]octane) was applied as an efficient catalyst for the one-pot three-component synthesis of highly functionalized cyclohexenones: 2-oxo-N,4,6-triarylcyclohex-3-enecarboxamides via the condensation between acetophenone/4-methylacetophenone, aromatic aldehydes, and acetoacetanilide in ethanol at ambient condition. This methodology has a number of advantages such as high yields, short reaction times, clean work-up (just simple filtration), and mild reaction conditions.

In this article, a one-pot three-component synthesis of 3-aminoisoxazolmethylnaphthol derivatives has been developed using Fe3O4–NHPhSO3H as a recyclable heterogeneous nanocatalyst using available 3-aminoisoazoles, aldehyde derivatives and 2-naphthol under solvent-free conditions. This environmentally friendly methodology with excellent green chemistry credentials, such as using the low loading of reusable, nontoxic, easy- to-handle catalyst, shorter reaction time without any byproduct, avoidance of hazardous organic solvents and easy workup (the catalyst can be easily separated from the reaction mixture by an external magnet), can be used in a wide range of applications. A one-pot three-component synthesis of 3-aminoisoxazolmethylnaphthol derivatives has been developed via Fe3O4–NHPhSO3H as a recyclable heterogeneous nanocatalyst by available 3-aminoisoazoles, aldehyde derivatives and 2-naphthol in solvent-free conditions. This green process with main aspects such as operational simplicity, good-to-excellent yields, low cost, easy handling, being eco-friendly and reusability of the catalyst, absence of any tedious workup or purification and avoidance of hazardous or toxic reagents/catalysts/solvents opens an effective and convenient way to naphthalen-2-ol-functionalized isoxazole systems, which are promising compounds for different biomedical applications.