Hydrothermal Synthesis of CuFe₂O₄ Magnetic Nanoparticles as Active and Robust Catalyst for N‐arylation of Indole and Imidazole with Aryl Halide

Abstract

Spinel ferrite magnetic nanoparticles are superior to the conventional catalysts. Here we report the synthesis of different types of spinel ferrite nanoparticles, MFe 2 O 4 (M = Cu, Mn, Mg, Co, Ni), by a hydrothermal method. The prepared spinel ferrite nanoparticles were used for the N-arylation reaction of indole with iodobenzene. Among these CuFe 2 O 4 nanoparticles exhibited the best activity and selectivity for N-arylation under ligand free condition. The prepared spinel ferrite microspheres were well characterised by using various characterization techniques such as TEM, XRD, XPS, SEM, EDXA, FT-IR, N 2 adsorption desorption measurements and TGA. The effect of various parameters were studied such as solvent, base, speed of agitation, mole ratio, catalyst loading and temperature in the reaction of indole with iodobenzene. Best conversion and yield were achieved at 110 8C and 1 3 10 -3 g/cm 3 catalyst loading. Notably, CuFe 2 O 4 magnetic nanoparticles were completely recovered and could be reused six times without any noticeable loss of activity. Reaction mechanism and kinetics are also presented.[a] Dr.

Preparation, Characterization and Application of Copper Schiff base Complex Supported on MCM‐41 as a Recyclable Catalyst for the Ullmann‐type N‐arylation Reaction

“…The most promising method in the literature for the N‐arylation reaction is Copper‐catalyzed Ullmann‐type transformation. Unfortunately, this method requires a stoichiometric amount of copper catalyst at high temperatures, which eventually produce a large amount of hazardous copper‐based waste and are thus not considered to be environmentally benign and economic processes . To circumvent this issue, many attempts have been made to develop efficient catalytic systems by introducing new and efficient ligands …”

“…Unfortunately, this method requires a stoichiometric amount of copper catalyst at high temperatures, which eventually produce a large amount of hazardous copper-based waste and are thus not considered to be environmentally benign and economic processes. [9][10][11][12] To circumvent this issue, many attempts have been made to develop efficient catalytic systems by introducing new and efficient ligands. [13,14] Recently, copper complexes of various ligands including diamines, glycols, Schiff bases, amino acids, diketones, phenanthroline, 2,2-bipyridine, carbohydrates, oxalamic acid and Nhetrocyclic carbene have been utilized as outstanding homogeneous catalysts for the N-arylation reaction.…”

Design and preparation of ZnS‐ZnFe2O4: a green and efficient hybrid nanocatalyst for the multicomponent synthesis of 2,4,5‐triaryl‐1H‐imidazoles

“…Categories of MTMOs include MMn 2 O 4 (M = Zn, Ni and Co), MCo 2 O 4 (M = Mn, Ni, Zn and Fe) and MFe 2 O 4 (M = Co, Ni, Mn and Zn) . Due to considerable magnetic properties of spinel‐type complexes of MFe 2 O 4 has widely been used in various fields such as magnetic resonance imaging (MRI), biomolecular sensors, electronic storage, frequency core, data storage and drug delivery . Spinel nanocrystalline zinc ferrites have been applied in various organic reactions as effective photocatalysts .…”

Solvothermal Synthesis of CuFe2O4@rGO: Efficient Catalyst for C‐O Cross Coupling and N‐arylation Reaction under Ligand‐Free Condition

“…Metal and metal oxide nanoparticles such as Pd, Cu and Au composites with reduced GO (rGO) have been explored in various organic transformations such as coupling, hydrogenation and oxidation reactions . Extensive efforts have gone into selective C‐O and C‐N ( N‐ arylation) cross coupling reactions . These reactions play a significant role in the synthesis of a variety of biologically active pharmaceutical ingredients and natural products .…”

“…[20][21][22][23] Extensive efforts have gone into selective C-O and C-N (N-arylation) cross coupling reactions. [24] These reactions play a significant role in the synthesis of a variety of biologically active pharmaceutical ingredients and natural products. [25] Diaryl ethers are used in the synthesis of compounds having antibiotic activity such as antitumor riccardin C, bouvardin, [26][27][28] hormone thyroxin, [29] antiviral peptide K-133 and antibiotic piperazinomycin.…”