Supported l-tryptophan on Fe3O4@SiO2 as an efficient and magnetically separable catalyst for one-pot construction of spiro[indene-2,2′-naphthalene]-4′-carbonitrile derivatives

l-Tryptophan functionalized silica-coated magnetic nanoparticles were prepared and evaluated as a magnetic nanocatalyst for the synthesis of spiro[indene-2,2′-naphthalene]-4′-carbonitrile derivatives through the one-pot four-component reaction.

XPS and structural studies of Fe3O4-PTMS-NAS@Cu as a novel magnetic natural asphalt base network and recoverable nanocatalyst for the synthesis of biaryl compounds

In this research, natural asphalt as a mineral carbonuous material was converted to sodium natural asphalt sulfonate (Na-NAS) and, then, was linked to Fe3O4 MNPs in order to synthesize the magnetic nanocatalyst. Afterwards, Cupper (I) and Cu (II) was grafted on Fe3O4-PTMS-NAS. Moreover, it is worth mentioning that the synthesized the novel magnetic nanocatalyst (Fe3O4-PTMS-NAS@Cu) was successfully used in Suzuki and Stille coupling reactions. The Fe3O4-PTMS-NAS@Cu MNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), inductively coupled plasma (ICP), BET and X-ray photoelectron spectroscopy (XPS) analysis. Besides, sulfonation of natural asphalt, magnetization of catalyst, grafting of Cu (I) and Cu (II) to NAS and catalyst formation were investigated and proved carefully. This nanocatalyst can be comfortably separated from the reaction medium through an external magnetic field and can also be recovered and reused, while maintaining its catalytic activity.

Green Synthesis of Ag Nanoparticles by Celery Leaf Extract Supported on Magnetic Carbon-Based Biochar Substrate, as a Green Catalyst for Reduction Reactions

Green synthesis of a noble metal such as Ag nanoparticles is an enormously developed research area. In this study, biochar/Fe3O4-Ag magnetic nanocatalyst was produced via a green path by using Celery stalk as a carbon-based substrate, and Celery leaf extract as reducing and stabilizing agents to construct Ag nanoparticles. The synthesized nanocatalyst was determined using various techniques, such as UV-Vis, FT-IR spectroscopy, XRD (X-ray diffraction), SEM/EDX spectroscopy (scanning electron microscopy/energy-dispersive X-ray), TEM (transmission electron microscopy), and VSM (vibrating sample magnetometer). To survey the catalytic action of the biochar/Fe3O4-Ag nanocatalyst, it was used in the reduction reaction of disparate nitroaromatics, aldehydes, and ketones. This catalyst has demonstrated premier characteristics in terms of the amount, reusability, recoverability, activity, and structural integrity of the catalyst during the reaction. In addition, biochar/Fe3O4-Ag could be detached magnetically and recycled multiple times without significantly reducing its catalytic performance.

Fe3O4@chitosan-tannic acid bionanocomposite as a novel nanocatalyst for the synthesis of pyranopyrazoles

Recently magnetic nanocatalyst has attracted considerable attention because of its unique properties, including high performance, easy separation from the reaction mixture, and recyclability. In this study, a novel magnetic bionanocomposite was synthesized with chitosan and tannic acid as a natural material. The synthesized bionanocatalyst was characterized by essential analysis. Fe3O4@chitosan-tannic acid as a heterogeneous nanocatalyst was successfully applied to synthesize pyranopyrazole and its derivatives by a one-pot four-component reaction of malononitrile, ethyl acetoacetate, hydrazine hydrate, and various aromatic aldehyde. At the end of the reaction, the nanocatalyst was separated from the reaction mixture and was reused several times with no significant decrease in its catalytic performance. Simple purification of products, the ability for recovering and reusing the nanocatalyst, eco-friendliness, high yields of pure products, mild reaction conditions, short reaction time, non-toxicity, economically affordable are some of the advantages of using the fabricated nanocatalyst in the synthesis of pyranopyrazole.