A nickel nanoparticle engineered CoFe2O4@GO-Kryptofix 22 composite: a green and retrievable catalytic system for the synthesis of 1,4-benzodiazepines in water

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.

Preparation of nanodiamond anchored on copper tannic acid as a heterogenous catalyst for synthesis of 1,4-benzodiazepines derivatives

In this research, a new and eco-friendly heterogeneous catalyst (ND@Tannicacid-Cu) was synthesized based on nanodiamond and copper tannic acid via esterification process. The as-prepared catalyst was characterized by Fourier transforms infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The catalytic efficacy of the intended catalyst was examined by one-step three-component reaction of 1,4-benzodiazepine derivatives from a mixture of ortho-phenylenediamine, aromatic aldehydes, and dimedone under mild conditions. In all instances, corresponding 2,4-benzodiazepines derivatives were synthesized with high efficiency, short reaction time, straightforward work up procedure, no requirement for column-chromatography, and cost-effective catalyst. The heterogeneous catalyst was easily recycled using fillers, and it can be reused for eight cycles without significantly diminishing its performance.

Immobilized nickel boride nanoparticles on magnetic functionalized multi-walled carbon nanotubes: a new nanocomposite for the efficient one-pot synthesis of 1,4-benzodiazepines

In this study, a new magnetic nanocomposite consisting of Ni2B nanoparticles anchored on magnetic functionalized multi-walled carbon nanotubes (Fe3O4/f-MWCNT/Ni2B) was synthesized and characterized using various techniques such as FT-IR, XRD, FESEM, SEM-based EDX, SEM-based elemental mapping, HRTEM, DLS, SAED, XPS, BET, TGA, and VSM. The as-prepared magnetic nanocomposite was successfully employed for the preparation of bioactive 1,4-benzodiazepines from the three-component reaction of o-phenylenediamine (1), dimedone (2), and different aldehydes (3), in polyethylene glycol 400 (PEG-400) as a solvent at 60 °C. The obtained results demonstrated that the current one-pot three-component protocol offers many advantages, such as good-to-excellent yields within acceptable reaction times, favorable TONs and TOFs, eco-friendliness of the procedure, easy preparation of the nanocomposite, mild reaction conditions, a broad range of products, excellent catalytic activity, green solvent, and reusability of the nanocomposite.

Synthetic aspects of 1,4- and 1,5-benzodiazepines using o-phenylenediamine: a study of past quinquennial

Benzodiazepines, seven-membered heterocyclic compounds having two nitrogen atoms at different positions, are ruling scaffolds in the area of pharmaceutical industry. They act as cardinal moieties in organic synthesis as well as in medicinal chemistry. Among the different benzodiazepines, 1,4- and 1,5-benzodiazepines play a far-reaching role in the field of biological activities such as anticonvulsion, anti-anxiety, sedation, and hypnotics. In the past few decades, researchers have conducted a lot of work on these moieties and developed broad, valuable, and significant approaches for their synthesis. In this review article, we recapitulate the systematic synthetic strategies of 1,4- and 1,5-benzodiazepines using o-phenylenediamine as a precursor over the past five years (2018-2022). This article will be helpful for scientists and researchers to examine and explore novel and efficient methods for the synthesis of these biologically active moieties.

Synthesis of a novel ternary ZIF-8/GO/MgFe2O4 nanocomposite and its application in drug delivery

In recent year, metal-organic frameworks (MOFs) have been displayed to be a category of promising drug delivery systems because of their crystalline structure, the potential of further functionality, and high porosity. In this research, graphene oxide was synthesized from pure graphite via hummer method and then MgFe2O4 nanoparticles was incorporated into the synthesized ZIF-8 metal-organic frameworks which followed with loading on the surfaces of graphene oxide. In continue, tetracycline as an antibiotic drug was loaded on the surfaces and the cavities of the prepared nanocomposite. The outcomes of this research revealed that 90% of the tetracycline was loaded on the synthesized ZIF-8/GO/MgFe2O4 nanostructure. Next, drug release was done at pH: 5 and pH: 7.4 within 3 days, resulting about 88% and 92% release of the tetracycline, respectively. With using different spectroscopic methods like X-ray crystallography (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX/Mapping), Fourier transform infrared (FTIR), thermalgravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET), the structure of synthesized materials was confirmed. Furthermore, the antibiotic activity of tetracycline trapped into the ZIF-8/GO/MgFe2O4 was evaluated by agar-well diffusion method on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, which showed good antibacterial results.

A novel strategy for stabilization of sub-nanometric Pd colloids on kryptofix functionalized MCM-41: nanoengineered material for Stille coupling transformation

The stabilization of sub-nanometric metal particles (< 1 nm) with suitable distribution remained challenging in the catalytic arena. Herein, an intelligent strategy was described to anchoring and stabilizing sub-nanometric Pd colloids with an average size of 0.88 nm onto Kryptofix 23 functionalized MCM-41. Then, the catalytic activity of Pd@Kryf/MCM-41 was developed in Stille coupling reaction with a turnover frequency (TOF) value of 247 h-1. The findings demonstrate that porous MCM-41 structure and high-affinity Kryptofix 23 ligand toward adsorption of Pd colloids has a vital role in stabilizing the sub-nanometric particles and subsequent catalytic activity. Overall, these results suggest that Pd@Kryf/MCM-41 is a greener, more suitable option for large-scale applications and provides new insights into the stabilization of sub-nanometric metal particles.

Rice husk-SiO2 supported bimetallic Fe-Ni nanoparticles: as a new, powerful magnetic nanocomposite for the aqueous reduction of nitro compounds to amines

This paper reports a novel green procedure for immobilization of bimetallic Fe/Ni on amorphous silica nanoparticles extracted from rice husk (RH-SiO₂). The heterogeneous nanocomposite (Fe/Ni@RH-SiO₂) was identified using SEM, EDX, TEM, BET, H₂-TPR, TGA, XRD, VSM, ICP-OES, and FT-IR analyses. The Fe/Ni@RH-SiO₂ nanocomposite was applied as a powerful catalyst for the reduction of structurally diverse nitro compounds with sodium borohydride (NaBH₄) in green conditions. This procedure suggests some benefits such as green chemistry-based properties, short reaction times, non-explosive materials, easy to handle, fast separation and simple work-up method. The catalyst was separated by an external magnet from the reaction mixture and was reused for 9 successive cycles with no detectable changes of its catalytic efficiency.

This paper reports a novel green procedure for immobilization of bimetallic Fe/Ni on amorphous silica nanoparticles extracted from rice husk (RH-SiO₂).