Ultrasound-Promoted preparation and application of novel bifunctional core/shell Fe3O4@SiO2@PTS-APG as a robust catalyst in the expeditious synthesis of Hantzsch esters

Abstract

In this work, D-(–)-α-phenylglycine (APG)-functionalized magnetic nanocatalyst (Fe3O4@SiO2@PTS-APG) was designed and successfully prepared in order to implement the principles of green chemistry for the synthesis of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives under ultrasonic irradiation in EtOH. After preparing of the nanocatalyst, its structure was confirmed by different spectroscopic methods or techniques including Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TGA). The performance of Fe3O4@SiO2@PTS-APG nanomaterial, as a heterogeneous catalyst for the Hantzsch condensation, was examined under ultrasonic irradiation and various conditions. The yield of products was controlled under various conditions to reach more than 84% in just 10 min, which indicates the high performance of the nanocatalyst along with the synergistic effect of ultrasonic irradiation. The structure of the products was identified by melting point as well as FTIR and 1H NMR spectroscopic methods. The Fe3O4@SiO2@PTS-APG nanocatalyst is easily prepared from commercially available, lower toxic and thermally stable precursors through a cost-effective, highly efficient and environmentally friendly procedure. The advantages of this method include simplicity of the operation, reaction under mild conditions, the use of an environmentally benign irradiation source, obtaining pure products with high efficiency in short reaction times without using a tedious path, which all of them address important green chemistry principles. Finally, a reasonable mechanism is proposed for the preparation of polyhydroquinoline (PHQ) and 1,4-dihydropyridine (1,4-DHP) derivatives in the presence of Fe3O4@SiO2@PTS-APG bifunctional magnetic nanocatalyst.

Magnetic DL-methionine grafted to chitosan by EDTA linker nanomaterial: a highly efficient multifunctional organocatalyst for the synthesis of highly substituted imidazole derivatives under green conditions

“…In this research and in continuing our previous works 29,30,40 , we have reported a novel sustainable green nanomagnetic catalytic system (CS-EDTA-MET@Fe 3 O 4 catalyst, 1) based on modi ed naturally-occurring biopolymeric chitosan, by using methionine amino acid through grafting of EDTA dianhydride linker followed by Fe 3 O 4 decoration. The catalyst (1) was examined in both 3-and 4-components reactions for successful synthesis of corresponding imidazole derivatives in high to excellent yields and short reaction time (Fig.…”

“…All these criteria make the processes greener and more sustainable, especially for atom-/step economic multicomponent reactions (MCRs) 28,31,[33][34][35][36] . Nowadays, MCRs are effective tools and procedures to prepare complex scaffolds, which are important in the ne chemical industry including pharmaceutical, dyes and color industries, etc [37][38][39][40][41][42] .…”

An Fe3O4 supported O-phenylenediamine based tetraaza Schiff base-Cu(ii) complex as a novel nanomagnetic catalytic system for synthesis of pyrano[2,3-c]pyrazoles

“…11–15 These catalysts offer advantages such as enhanced catalyst recovery, recyclability, and improved reaction kinetics. 15–18 Compared to traditional catalysts, heterogeneous magnetic catalysts simplify catalyst recovery, reduce costs, and minimize environmental impact. 19,20 Additionally, their recyclability ensures long-term viability and economic feasibility, making them an attractive option in catalysis applications.…”

Assessment of the synthesis method of Fe3O4 nanocatalysts and its effectiveness in viscosity reduction and heavy oil upgrading

“…These nanocatalysts are used in military, medical, and pharmaceutical industries, oil extraction, and water or soil treatment 1 – 3 . One of the reasons for the widespread use of iron oxide nanocatalysts is their magnetic properties 4 , 5 Due to the properties of nanocatalysts, more attention has been paid to these materials 6 – 9 . The synthesis and preparation of nanocatalysts affect their properties, such as chemical composition, morphology, and particle size, and play an essential role in applying nanocatalysts in various engineering industries.…”