Novel CuFe₂O₄@SiO₂‐OP₂O₅H magnetic nanoparticles: Preparation, characterization and first catalytic application to the synthesis of 1,8‐dioxo‐octahydroxanthenes

Abstract

New functionalized magnetic core-shell nanoparticles, CuFe 2 O 4 @SiO 2 -OP 2 O 5 H, were prepared by grafting of phosphorus pentoxide on CuFe 2 O 4 @SiO 2 nanoparticles and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, inductively coupled plasma optical emission spectrometry and vibrating sample magnetometry. The catalytic activity of CuFe 2 O 4 @SiO 2 -OP 2 O 5 H as a novel catalyst was evaluated in the synthesis of 1,8-dioxo-octahydroxanthenes under solvent-free conditions. The results showed that the catalyst has high activity and the desired products are obtained in high yields within short reaction times. The catalyst is readily recovered using magnetic decantation and can be used at least four times without noticeable deterioration in catalytic activity.

Phosphomolybdic acid supported on Schiff base functionalized graphene oxide nanosheets: Preparation, characterization, and first catalytic application in the multi‐component synthesis of tetrahydrobenzo[a]xanthene‐11‐ones

“…Taking all these facts into consideration, and in line with our interest in catalysis, in this paper, for the first time, a new SB functionalized GO containing a phosphomolybdic counter‐anion H 2 PMo 12 O 40 ¯ (H 2 PMo) was prepared by grafting of APTS on GO nanosheets followed by condensation with benzil and finally reaction with phosphomolybdic acid (H 3 PMo 12 O 40 , denoted as H 3 PMo) and fully characterized (Scheme ). The catalytic activity of this new material which was denoted as GO‐SB‐H 2 PMo was also investigated in one‐pot synthesis of tetrahydrobenzo[ a ]xanthene‐11‐ones by reaction of β ‐naphthol, aldehydes, and dimedone (Scheme ).…”

Phosphotungstic acid supported on functionalized graphene oxide nanosheets (GO-SiC3-NH3-H2PW): Preparation, characterization, and first catalytic application in the synthesis of amidoalkyl naphthols

“…Based on these precedents and in line with our interest in catalysis [47][48][49][50][51][52][53][54][55], herein, we report the preparation of a new functionalized GO containing a phosphotungstic counter-anion H2PW12O40¯ (H2PW) by grafting of APTS on GO nanosheets followed by a reaction with phosphotungstic acid (H3PW12O40, denoted as H3PW) which was fully characterized (Scheme 1). The catalytic activity of this new material which was denoted as GO-SiC3-NH3-H2PW was then investigated in one-pot synthesis of amidoalkyl naphthols by reaction of β-naphthol, aromatic aldehydes, and acetamide (Scheme 2).…”

Synthesis and characterization of Fe3O4@THAM‐SO3H as a highly reusable nanocatalyst and its application for the synthesis of dihydropyrano[2,3‐c]pyrazole derivatives

“…In recent years, magnetic nanoparticles (MNPs) (especially superparamagnetic Fe 3 O 4 nanoparticles) are used in various applications in pharmaceutical industries and green chemistry such as drug delivery vehicles, sensors, and catalysts . MNPs received considerable attention due to their superior characteristics such as high surface energies, high surface to volume ratios, easy recoverability, enhanced dispersion, high catalytic performance, and reusing without loss of their catalytic activity .…”