Ultrasonic-Assisted Preparation, Characterization, and Use of Novel Biocompatible Core/Shell Fe₃O₄@GA@Isinglass in the Synthesis of 1,4-Dihydropyridine and 4H-Pyran Derivatives

Abstract

This work focussed on the synthesis of a new catalytic material isinglass (IG)-based Fe 3 O 4 @GA@IG core/shell magnetic nanoparticles and the investigation of its catalytic activity in two important multicomponent reactions. Fe 3 O 4 nanoparticles were prepared using a simple coprecipitation method and then coated with IG consisting predominantly of the protein collagen in the presence of glutaraldehyde as a cross-linking agent. The obtained hybrid material has been characterized by Fourier transform infrared analysis, scanning electron microscopy, transmission electron microscopy (TEM), vibrating sample magnetometry, energy-dispersive X-ray, X-ray diffraction (XRD), and Brunauer–Emmett–Teller analyses. The results of XRD analysis implied that the prepared nanocomposite consists of two compounds of crystalline magnetite and amorphous IG, and the formation of its core/shell structure had been confirmed by TEM images. The catalytic performance of the as-prepared core/shell bionanocatalyst was evaluated for the first time in the synthesis of 1,4-dihydropyridine and 4 H -pyran derivatives under sonication in ethanol. This core/shell structure because of the superparamagnetic property of Fe 3 O 4 and unique properties of IG as a bifunctional biocatalyst offers a high potential for many catalytic applications. Recycling study revealed that no significant decrease in the catalytic activity was observed even after six runs.

Magnetically Recoverable Catalysts: Catalysis in Synthesis of Polyhydroquinolines

“…[131] As shown in Scheme 20, the Fe 3 O 4 @TDI@TiO 2 -SO 3 H which was fabricated in two steps involved the covalent grafting of n-TiO 2 to n-Fe 3 O 4 via 2,4-toluene diisocyanate as a regioselective S C H E M E 1 5 RuIII @CMC/Fe 3 O 4 MNPs catalyzed the synthesis of polyhydroquinolines linker (n-Fe 3 O 4 @TDI@TiO 2 ) and the subsequent sulfonating by chlorosulfunic acid. [38] Scanning electron microscopy affirmed that the particles are in nanometre range. Fe 3 O 4 @TDI@TiO 2 -SO 3 H rapidly catalysed the four-component reactions of aromatic aldehydes, ethyl acetoacetate, dimedone and ammonium acetate in the absence of solvent (Scheme 20); and the target products were obtained in good to excellent yields.…”

“…In an interesting publication, Amoozadeh and Tabrizian have fabricated SO 3 H‐functionalized magnetic‐titania nanoparticles (Fe 3 O 4 @TDI@TiO 2 ‐SO 3 H) as a new magnetically reusable catalyst for the synthesis of polyhydroquinoline derivatives . As shown in Scheme , the Fe 3 O 4 @TDI@TiO 2 ‐SO 3 H which was fabricated in two steps involved the covalent grafting of n‐TiO 2 to n‐Fe 3 O 4 via 2,4‐toluene diisocyanate as a regioselective linker (n‐Fe 3 O 4 @TDI@TiO 2 ) and the subsequent sulfonating by chlorosulfunic acid . Scanning electron microscopy affirmed that the particles are in nanometre range.…”

“…have reported the synthesis of a novel catalytic material isinglass (IG)‐based Fe 3 O 4 @GA@IG core/shell magnetic nanoparticles characterized by spectroscopy techniques: SEM, TEM, EDS, XRD, TGA, BET and VSM. Magnetic nanoparticles were fabricated using a simple coprecipitation strategy and, then, coated with IG . Stepwise preparation of the as‐fabricated catalyst was outlined in Scheme .…”

“…Several cardiovascular agents with polyhydroquinoline structural scaffolds are outlined in Figure . Molecules with polyhydroquinoline structural scaffolds possess a broad spectrum of biological and pharmacological activities such as antidiabetic, hepatoprotective, vasodilator, geroprotective, antiatherosclerotic, bronchodilator, anticancer, and antitumor activities . These important and valuable activities have encouraged chemists to design new, green, economical and efficient catalytic systems for the synthesis of molecules with polyhydroquinoline structural scaffolds.…”

“…Molecules with polyhydroquinoline structural scaffolds possess a broad spectrum of biological and pharmacological activities such as antidiabetic, hepatoprotective, vasodilator, geroprotective, antiatherosclerotic, bronchodilator, anticancer, and antitumor activities. [35][36][37][38][39][40][41] These important and valuable activities have encouraged chemists to design new, green, economical and efficient catalytic systems for the synthesis of molecules with polyhydroquinoline structural scaffolds. Recently, a large number of protocols for the synthesis of this class of N-containing heterocyclic molecules have been reported in the literature.…”