Design, preparation and characterization of Cu/GA/Fe₃O₄@SiO₂ nanoparticles as a catalyst for the synthesis of benzodiazepines and imidazoles

Abstract

The synthesis and characterization of an efficient and reusable nanocatalyst, Cu/GA/Fe3O4@SiO2, obtained by ultrasonic‐assisted grafting of guanidineacetic acid on modified Fe3O4@SiO2 core–shell nanocomposite spheres and subsequent immobilization of Cu(II), are described. The catalyst was characterized by means of X‐ray diffraction, scanning and transmission electron microscopies, energy‐dispersive X‐ray spectroscopy, elemental analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrating sample magnetometry and inductively coupled plasma optical emission spectrometry. The prepared nanocatalyst facilitated an efficient and straightforward friendly procedure for the synthesis of benzodiazepines and imidazoles in ethanol and under solvent‐free conditions, respectively. The nanocatalyst can be easily recovered using a magnet and reused several times without any significant loss of activity. Copyright © 2016 John Wiley & Sons, Ltd.

Copper(I) oxide nanoparticles supported on magnetic casein as a bio‐supported and magnetically recoverable catalyst for aqueous click chemistry synthesis of 1,4‐disubstituted 1,2,3‐triazoles

“…For Casein@Fe 3 O 4 NPs, diffraction peaks at various angles (2 θ ) are in good agreement with the reported XRD pattern of Fe 3 O 4 NPs (JCPDF no. 03‐0863) . For Cu 2 O/Casein@Fe 3 O 4 NPs, all of the diffraction peaks match well with the normal characteristic diffractions of Fe 3 O 4 and Cu 2 O nanoparticles.…”

“…The diffraction peaks at 30.34°, 35.40°, 43.42°, 57.19° and 62.86° correspond to the Fe 3 O 4 nanoparticles (JCPDF no. 03‐0863) and those at 29.74°, 35.74° and 43.12° correspond to the Cu 2 O nanoparticles (JCPDF no. 78‐2076) …”

The efficient in‐situ reduction and cyclization reaction of aromatic aldehyde, 1,3‐cyclopentanedione (tetronic acid), and nitro‐compound under SnCl2·2H2O‐THF medium

“…The results showed that the reaction at low temperature was unfavorable, but higher temperature on the reaction was also harmful (Entries [11][12][13][14]. It was found that the suitable reaction time was about 10 h. Under too long reaction time, the yield of the reaction was not obviously improved (Entries [15][16][17][18]. The Fe(0) -HCl system was also investigated in this research, but, the yield of the reaction was not as good as that of the SnCl 2 ·2H 2 O (Entries [19][20][21].…”

“…[13] As reported literatures, anilines, aldehyde and ketones were often used for the synthesis of nitrogen-containing heterocyclic compounds. [14][15][16][17][18] Recently, pyrazolo[4,3-f] quinoline, pyrazolo [3,4-f]quinoline derivatives were also effectively obtained from amino compounds, such as 5aminoindazole, 6-aminoindazole, 5-amine-1H-indole, and so on. [19][20][21][22][23][24][25][26][27][28][29] Because amino compounds are more expensive and easily oxidizable, it is very important to find an alternative approach and the cheap reagents for the synthesis of pyrazoloquinoline derivatives.…”

Rhodanine‐Furan Bis‐Heterocyclic Frameworks Synthesis via Green One‐Pot Sequential Six‐Component Reactions: A Synthetic and Computational Study

“…Inspired by the above facts and encouraged by our previous studies in development of MCRs particularly based on higher‐order MCRs, herein, we describe an efficient construction of novel rhodanine‐furan bis ‐heterocyclic frameworks based on the union of MCRs synthetic routes via a tandem Michael/domino cycloaddition/zwitterionic adduct formation/Mumm rearrangement/[1+4] cycloaddition processes sequence. This synthetic route is directly carried out by a one‐pot sequential six‐component reaction from commercially available substrates such as diverse of primary amines, carbon disulfide, maleic anhydride, dialkyl acetylenedicarboxylates as well as various isocyanides in water under ultrasound irradiation conditions at ambient temperature within 80–100 minutes without using any catalyst, additive or organic solvents (Scheme ).…”