Fe3O4@chitosan nanoparticles: a valuable heterogeneous nanocatalyst for the synthesis of 2,4,5-trisubstituted imidazoles

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 20932-20939 ◽  
Author(s):  
Zohre Zarnegar ◽  
Javad Safari
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Ammonium Acetate ◽  
Chitosan Nanoparticles ◽  
One Pot ◽  
Heterogeneous Nanocatalyst ◽  
Aryl Aldehydes ◽  
One Pot Condensation ◽  
Co Precipitation

Chitosan-coated Fe3O4 nanoparticles (Fe3O4@CS) were prepared simply through in situ co-precipitation of Fe2+ and Fe3+ ions via NH4OH in an aqueous solution of chitosan and their catalytic activity was investigated in the synthesis of 2,4,5-trisubstituted imidazoles by a one-pot condensation of benzil derivatives, aryl aldehydes and ammonium acetate in EtOH.

scholarly journals In situ synthesis of SO3H supported Fe3O4@resorcinol–formaldehyde resin core/shell and its catalytic evaluation towards the synthesis of hexahydroquinoline derivatives in green conditions

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41703-41712
Author(s):  
Aliyeh Barzkar ◽  
Alireza Salimi Beni
Keyword(s):  
Ammonium Acetate ◽  
Aromatic Aldehydes ◽  
In Situ Synthesis ◽  
Formaldehyde Resin ◽  
One Pot ◽  
Resorcinol Formaldehyde ◽  
Resin Core ◽  
One Pot Condensation ◽  
Green Conditions

A novel core@double-shell acidic nanocatalyst (Fe3O4@SiO2@RF–SO3H) was prepared, characterized and applied in catalytic one-pot condensation between aromatic aldehydes, dimedone, malononitrile, and ammonium acetate for synthesis of hexahydroquinoline derivatives.

scholarly journals ZnS/CuFe2O4: Magnetic Hybrid Nanocomposite to Catalyze the Synthesis of 2,4,5-triaryl-1H-imidazole Derivatives

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 44
Author(s):  
Fereshte Hassanzadeh-Afruzi ◽  
Shahrzad Bahrami ◽  
Ali Maleki
Keyword(s):  
Catalytic Activity ◽  
Ammonium Acetate ◽  
Aromatic Aldehydes ◽  
Cost Effective ◽  
Pharmacological Activities ◽  
One Pot ◽  
Imidazole Derivatives ◽  
The One ◽  
Co Precipitation ◽  
Appreciable Reduction

Integration of nanomaterials is an entirely new method to synthesis efficient catalysts. These compounds provided new characteristics and distinctive application which is not accessible in the single-particle nanostuctures. Although there is little catalytic activity in each component of the hybrid material, their hybrid displays much higher activity. Indeed, the presence of intermediate metal and their oxides in the framework of hybrid catalyst caused a synergistic effect, thus facilitate the organic reaction more effectively. The extensive biochemical and pharmacological activities of imidazole-containing compounds have required the development of efficient methods for synthesizing these compounds, which is a significant topic in organic chemistry. The imidazole nucleus function as a main scaffold for constructing of biologically important molecules. The ZnS/CuFe2O4 magnetic hybrid nanocatalyst was synthesized by a simple co precipitation and characterized by conventional analyses successfully. Synthesized nanocomposite was utilized as a magnetic and heterogeneous catalyst for the one-pot synthesis of 2,4,5-triaryl-1H-imidazole derivatives with condensation of various aromatic aldehydes, benzil and ammonium acetate. The presented method shows some advantages such as mild conditions, good yields, and simple separation of products from the reaction mixture and cost-effective catalyst. The experimental data showed ZnS/CuFe2O4 nanocatalyst were easily separated from the reaction mixture using an external magnetic field and use again five times in subsequent reactions without appreciable reduction in catalytic activity.

Solvent-free, one-pot synthesis of 2,4,6-triarylpyridines using trichloroisocyanuric acid or N-bromosuccinimide as a novel and neutral catalyst

2011 ◽  
Vol 76 (11) ◽  
pp. 1307-1315 ◽  
Author(s):  
Behrooz Maleki ◽  
Hafezeh Salehabadi ◽  
Zeinalabedin Sepehr ◽  
Mina Kermanian
Keyword(s):  
Ammonium Acetate ◽  
Solvent Free ◽  
One Pot ◽  
Aryl Aldehydes ◽  
One Pot Synthesis ◽  
Solvent Free Conditions ◽  
Trichloroisocyanuric Acid

A simple and benign protocol has been explored for the preparation of 2,4,6-triarylpyridines by a one-pot reaction between aryl aldehydes, enolizable ketones and ammonium acetate in the presence of N-bromosuccinimide or trichloroisocyanuric acid as green and neutral catalysts. The reactions proceed smoothly at 130 °C under solvent-free conditions to provide 2,4,6-triarylpyridines in good yields.

An efficient, one-pot three-component synthesis of 4H-thiazolo[3,2-a][1,3,5]triazin-6-one derivatives

2016 ◽  
Vol 22 (1) ◽  
pp. 43-47
Author(s):  
Mustafa T. Ubeid ◽  
Hamdy K. Thabet ◽  
Said A. El-Feky
Keyword(s):  
Ammonium Acetate ◽  
Thioglycolic Acid ◽  
Condensation Reaction ◽  
One Pot ◽  
Spectroscopic Analyses ◽  
One Pot Condensation

AbstractA simple and efficient protocol was established to synthesize thiazolo[3,2-a][1,3,5]triazin-6-ones via three-component one-pot condensation reaction of readily available thioglycolic acid or ethyl thioglycolate, aldehydes or ketones and dicyandiamide in the presence of ammonium acetate. All of the newly synthesized compounds were characterized by spectroscopic analyses.

High Catalytic Activity and Stability of Hexaaluminate Catalysts for N2O Decomposition

2013 ◽  
Vol 320 ◽  
pp. 665-669
Author(s):  
Chao Zhang ◽  
Yong Ji Song ◽  
Feng Hua Shi ◽  
Cui Qing Li ◽  
Hong Wang
Keyword(s):  
Catalytic Activity ◽  
Decomposition Reaction ◽  
Precipitation Method ◽  
High Catalytic Activity ◽  
Structure And Properties ◽  
Active Components ◽  
Co Precipitation ◽  
Hexaaluminate Catalysts

In this paper, hexaaluminate oxides LaMAl12O19-σwere prepared by using M=Cu ,Ce and Zn as active components to substitute Al in the hexaaluminate lattice by co-precipitation method. The structure and properties of LaMAl11O19-σcatalyst was characterized with XRD and BET. The results showed LaCuAl11O19-σexhibited significant high catalytic activity for the decomposition reaction of N2O. Under the simulated in situ condition, LaCuAl11O19-σalso indicated significant catalytic activity and stability, with N2O conversion of 90% at 635°C.

scholarly journals Preparation of Metal Oxides Containing ppm Levels of Pd as Catalysts for the Reduction of Nitroarene and Evaluation of Their Catalytic Activity by the Fluorescence-Based High-Throughput Screening Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Co Precipitation

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.

Sulfonated multiwalled carbon nanotubes (MWCNTs) as a new, efficient, and recyclable heterogeneous nanocatalyst for the synthesis of amines

2012 ◽  
Vol 90 (8) ◽  
pp. 701-707 ◽  
Author(s):  
M. M. Doroodmand ◽  
S. Sobhani ◽  
A. Ashoori
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Chemical Vapor ◽  
Catalytic Amount ◽  
Multiwalled Carbon ◽  
One Pot ◽  
Heterogeneous Nanocatalyst ◽  
Aldehydes And Ketones ◽  
Simple Filtration

Sulfonated multiwalled carbon nanotubes (MWCNTs) were synthesized by chemical vapor deposition (CVD) as a new and facile one-pot method using acetylene (as the CNT precursor), thiophene (as the sulfur precursor), and ferrocene (for in situ liberation of metal nanoparticles as the CNT nanocatalyst). A low catalytic amount of the resulting sulfonated MWCNTs with a turnover number (TON) up to 980 and a turnover frequency (TOF) up to 11 160 h–1 was utilized as a new and recyclable heterogeneous nanocatalyst for the efficient one-pot synthesis of various amines (secondary and tertiary) by direct reductive amination of aldehydes and ketones using NaBH4. The catalyst was easily isolated from the reaction mixture by simple filtration and reused at least five times without significant degradation in activity.

In situ Synthesis of Reduced Graphene Oxide Supported CoMo Nanoparticles as Efficient Catalysts for Hydrogen Generation from NH3BH3

2018 ◽  
Vol 232 (3) ◽  
pp. 431-443 ◽  
Author(s):  
Xigang Du ◽  
Yonghua Duan ◽  
Jun Zhang ◽  
Gang Mi
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Reduced Graphene Oxide ◽  
Hydrogen Generation ◽  
Sodium Molybdate ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Reduced Graphene

AbstractCoMo nanoparticles (NPs) supported on reduced graphene oxide (RGO) were synthesized by a one-stepin situco-reduction of an aqueous solution of cobalt(II) chloride, sodium molybdate dihydrate and graphene oxide (GO) using NaBH4as the sole reductant under ambient conditions. The powder XRD, FTIR, EDS and TEM were employed to characterize the structure, size and composition of the CoMo/RGO catalysts. The as-synthesized Co0.9Mo0.1/RGO catalysts exhibited high catalytic activity for the hydrolytic dehydrogenation of ammonia borane (AB) at room temperature. The as-synthesized Co0.9Mo0.1/RGO nanocatalysts exhibited much higher catalytic activity than Co/RGO, Mo/RGO and the RGO-free Co0.9Mo0.1counterpart. Moreover, kinetic studies indicate that the catalytic hydrolysis of AB by Co0.9Mo0.1/RGO has first order kinetics with respect to the the catalyst concentration, but zero order kinetics with respect to the substrate concentration. The Co0.9Mo0.1/RGO catalyst has a turnover frequency (TOF) of 15.8 mol H2·(mol·Co0.9Mo0.1/RGO)−1·min−1at 25°C. Furthermore, the Co0.9Mo0.1/RGO show good recyclability for hydrogen generation from an aqueous solution of AB, which enables the practical reuse of the catalysts. Hence, this general method can be easily extended to the facile preparation of other RGO-based metallic systems.

An Efficient Synthesis of Substituted Pyrazoles from One-Pot Reaction of Ketones, Aldehydes, and Hydrazine Monohydrochloride

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1071-1075 ◽  
Author(s):  
Vit Lellek ◽  
Cheng-yi Chen ◽  
Wanggui Yang ◽  
Jie Liu ◽  
Xuebao Ji ◽  
...  
Keyword(s):  
Efficient Synthesis ◽  
One Pot ◽  
Metal Free ◽  
Mild Conditions ◽  
Free Process ◽  
One Pot Condensation ◽  
Substituted Pyrazoles

An efficient, one-pot and metal-free process for the preparation of 3,5-disubstituted and 3,4,5-trisubstituted pyrazoles on multi-gram scale was developed. One-pot condensation of ketones, aldehydes and hydrazine monohydrochloride readily formed pyrazoline intermediates under mild conditions. Oxidation of pyrazolines, in situ, employing bromine afforded a wide variety of pyrazoles. The methodology offers a fast, and often chromatography-free protocol for the synthesis of 3,4,5-substituted pyrazoles in good to excellent yields. Alternatively, a more benign oxidation protocol affords 3,5-disubstituted or 3,4,5-trisubstituted pyrazoles by simply heating pyrazolines in DMSO under oxygen.

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