scholarly journals Recent Progresses in the Multicomponent Synthesis of Dihydropyridines by Applying Sustainable Catalysts Under Green Conditions

2021 ◽  
Vol 9 ◽  
Author(s):  
Immandhi Sai Sonali Anantha ◽  
Nagaraju Kerru ◽  
Suresh Maddila ◽  
Sreekantha B. Jonnalagadda
Keyword(s):  
Heterogeneous Catalysts ◽  
Reaction Times ◽  
Cost Effective ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Significant Efficacy ◽  
Magnetic Silica ◽  
Active Methylene

The synthesis of dihydropyridines, valuable molecules with diverse therapeutic properties, using eco-friendly heterogeneous catalysts as a green alternative received significant consideration. By selecting appropriate precursors, these compounds can be readily modified to induce the desired properties in the target product. This review focused on synthesising diverse dihydropyridine derivatives in single-pot reactions using magnetic, silica, and zirconium-based heterogeneous catalytic systems. The monograph describes preparation techniques for various catalyst materials in detail. It covers facile and benign magnetic, silica, zirconium-based, and ionic liquid catalysts, exhibiting significant efficacy and consistently facilitating excellent yields in short reaction times and in a cost-effective way. Most of the designated protocols employ Hantzsch reactions involving substituted aldehydes, active methylene compounds, and ammonium acetate. These reactions presumably follow Knoevenagel condensation followed by Michael addition and intra-molecular cyclisation. The multicomponent one-pot protocols using green catalysts and solvents have admirably increased the product selectivity and yields while minimising the reaction time. These sustainable catalyst materials retain their viability for several cycles reducing the expenditure are eco-friendly.

scholarly journals Reactions under increased pressure: The reactivity of functionally substituted 3-oxo-2-arylhydrazones toward active methylene reagents in Q-tube

2021 ◽  
Vol 12 (2) ◽  
pp. 154-158
Author(s):  
Douaa Salman AlMarzouq
Keyword(s):  
High Pressure ◽  
Reaction Time ◽  
Reaction Times ◽  
Acid Ethyl Ester ◽  
One Pot ◽  
Two Component ◽  
Percentage Yield ◽  
Active Methylene ◽  
Total Reaction Time ◽  
Increased Pressure

A one-pot two-component reaction of 3-oxo-2-arylhydrazones with active methylene nitriles under high pressure in a Q-tube safe reactor was reported. Comparison between conventional and Q-tube safe reactor-assisted synthesis of organic compounds was done by comparing total reaction time and percentage yield. The results show that the compound 5-cyano-6-oxo-1,4-diphenyl-1,6-dihydro-pyridazine-3-carboxylic acid ethyl ester (3) was synthesized within 2 h in a yield of 97%. In addition, the pyrazolo[3,4-c]pyridines 5b and 5c were obtained in yields of 93 and 95% within 1 h reaction time, respectively. The obtained results suggest that Q-tube safe reactor-assisted syntheses were led to higher product yields within very short reaction times.

scholarly journals Towards the Green Synthesis of Furfuryl Alcohol in A One-Pot System from Xylose: A Review

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1101
Author(s):  
Gerardo Gómez Millán ◽  
Herbert Sixta
Keyword(s):  
Green Synthesis ◽  
Furfuryl Alcohol ◽  
The Novel ◽  
Economic Aspects ◽  
Complex Matrix ◽  
One Pot ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Production Concept ◽  
Biobased Economy

In the pursuit of establishing a sustainable biobased economy, valorization of lignocellulosic biomass is increasing its value as a feedstock. Nevertheless, to achieve the integrated biorefinery paradigm, the selective fractionation of its complex matrix to its single constituents must be complete. This review presents and examines the novel catalytic pathways to form furfuryl alcohol (FuOH) from xylose in a one-pot system. This production concept takes on chemical, thermochemical and biochemical transformations or a combination of them. Still, the bulk of the research is targeted to develop heterogeneous catalytic systems to synthesize FuOH from furfural and xylose. The present review includes an overview of the economic aspects to produce this platform chemical in an industrial manner. In the last section of this review, an outlook and summary of catalytic processes to produce FuOH are highlighted.

One-pot multicomponent synthesis of β-acetamidoketones catalysed by pTSA1

2007 ◽  
Vol 85 (7-8) ◽  
pp. 479-482 ◽  
Author(s):  
Biswanath Das ◽  
Kongara Ravinder Reddy ◽  
Yallamalla Srinivas ◽  
Rathod Aravind Kumar
Keyword(s):  
Multicomponent Reaction ◽  
Acetyl Chloride ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Catalytic Amount ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
High Yields ◽  
Three Component Coupling

A catalytic amount of pTSA has been found to be effective to carry out a one-pot three-component coupling of aromatic aldehydes, enolizable ketones or ketoesters, and acetonitrile in the presence of acetyl chloride to afford β-acetamidoketones in high yields. Short reaction times and inexpensive catalyst are main advantages of this protocol.Key words: β-acetamidoketone, pTSA, multicomponent reaction, diastereoselectivity.

scholarly journals On the Effectiveness of Zeolite-Based Catalysts in the CO2 Recycling to DME: State of the Art and Perspectives

2017 ◽  
Author(s):  
Enrico Catizzone ◽  
Giuseppe Bonura ◽  
Massimo Migliori ◽  
Francesco Frusteri ◽  
Girolamo Giordano
Keyword(s):  
Industrial Development ◽  
Heterogeneous Catalysts ◽  
Environmental Issues ◽  
Oxide Phase ◽  
One Pot ◽  
Catalytic Systems ◽  
Warming Climate ◽  
New Concepts ◽  
Co2 Recycling ◽  
The One

Starting from the environmental issues related to global warming, climate change and reduction of greenhouse gas emissions, this review paper describes how CO2 recycling can represent a challenging strategy suitable to explore new concepts and opportunities for catalytic and industrial development. In this view, the production of dimethyl ether (DME) from catalytic hydrogenation of CO2 appears as a viable technology, able to meet also the ever-increasing need for alternative environmentally-friendly fuels and energy carriers. Basic considerations on thermodynamic aspects controlling DME production from CO2 are presented, then summarizing the main catalytic systems developed in such a field. Special attention is paid on the role assumed during last years by zeolite-based systems, either in the methanol-to-DME dehydration step or in the one-pot CO2-to-DME hydrogenation. On the whole, the productivity of DME results significantly to be dependent on several catalyst features, linked not only to the metal-oxide phase responsible for CO2 activation/hydrogenation, but also to specific properties of the zeolites (i.e., topology, porosity, surface area, acidity, interaction with active metals, distributions of metal particles, …) influencing activity and stability of hybridized bifunctional heterogeneous catalysts.

Design and Preparation of Heterogeneous Catalysts by Controlled Chemical Reactions with Oxygen and Hydrogen

1994 ◽  
Vol 368 ◽  
Author(s):  
David L. Cocke ◽  
Donald G. Naugle ◽  
Thomas R. Hess
Keyword(s):  
Chemical Reactions ◽  
Heterogeneous Catalysts ◽  
Formation Processes ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Reduction Processes ◽  
Alloy Oxidation ◽  
Reaction Models ◽  
Catalyst Systems ◽  
Insight Into

ABSTRACTChemical reactions of metals and strongly interacting alloys such as Cu-Mn, Ni-Ti, Ni-Hf and Ni-Zr with oxygen and hydrogen play important roles in the preparation, activation, and regeneration of many important heterogeneous catalytic systems involving supported and unsupported metals and alloys. Recent advances in the understanding of metal and alloy oxidation is bringing new insight into the reactive design and activation of bi- and multi-metallic catalysts. By surface studies of oxidation, thermal annealing and reduction of selected alloys and their thin films and reaction layers and products we have been able to delineate the factors which are most important to the oxide formation processes and the oxide reduction processes. Reaction models developed from these results are permitting the design of new catalyst systems and providing long sought understanding to explain specific aspects of well established metallic catalysts.

scholarly journals Ultrasound Promoted Green and Facile One-Pot Multicomponent Synthesis of 3,4-dihydropyrano[c]chromene Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ravikumar Nagalapalli ◽  
Satyanarayana Reddy Jaggavarapu ◽  
Venkata Prasad Jalli ◽  
Anand Solomon Kamalakaran ◽  
Gopikrishna Gaddamanugu
Keyword(s):  
Aqueous Media ◽  
Reaction Times ◽  
Environmentally Benign ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
High Yields

Ultrasound promoted mild one-pot multicomponent synthesis of 3,4-dihydropyrano[c]chromenes from 4-hydroxycoumarin, arylaldehydes and malononitrile was achieved in aqueous media. The methodology promises advantages of short reaction times, environmentally benign conditions, high yields, and operational convenience.

scholarly journals Copper nanoparticles grafted on carbon microspheres as novel heterogeneous catalysts and their application for the reduction of nitrophenol and one-pot multicomponent synthesis of hexahydroquinolines

2018 ◽  
Vol 42 (2) ◽  
pp. 1092-1098 ◽  
Author(s):  
Tibor Pasinszki ◽  
Melinda Krebsz ◽  
Győző György Lajgut ◽  
Tünde Kocsis ◽  
László Kótai ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Cu Nanoparticles ◽  
Carbon Microspheres ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Carbon Microsphere

Carbon microsphere-supported Cu nanoparticles were fabricated, characterized, and applied for synthesis.

scholarly journals Diastereoselective Synthesis of some pyrrolidin-2-ones azasugars and study of their stereochemistry

2019 ◽  
Vol 8 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Chahrazed Benhaoua ◽  
Mustapha Rahmouni ◽  
Hadj Benhaoua
Keyword(s):  
Reaction Times ◽  
Diastereoselective Synthesis ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Cyanide Group ◽  
Iminium Ions ◽  
In Situ Generation ◽  
Work Up ◽  
Reaction Profile

The microwave-promoted one-pot multicomponent synthesis of substituted pyrrolidinols using a bifunctional sugar-derived hydroxy-[gamma]-lactone component of amine component or cyanide group is reported. Clean reaction profile, easy work-up procedure, excellent yields and short reaction times are some remarkable features of this method.This modular approach features the in situ-generation of iminium ions intermediate that allows the diastereoselective assembly of the diverse pyrrolidinones efficiently under microwave irradiation has been used.

Sustainable CeO2/ZrO2 Mixed Oxide Catalyst For the Green Synthesis of Highly Functionalized 1,4-Dihydropyridine-2,3-dicarboxylate Derivatives

2018 ◽  
Vol 15 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Sebenzile Shabalala ◽  
Suresh Maddila ◽  
Werner E. van-Zyl ◽  
Sreekantha B. Jonnalagadda
Keyword(s):  
Alternative Energy ◽  
Reaction Times ◽  
Cost Effective ◽  
15N Nmr ◽  
Reusable Catalyst ◽  
Impregnation Method ◽  
Pyrazole Derivatives ◽  
One Pot ◽  
Product Yields ◽  
Solvent Free Conditions

Aim and Objective: Ceria loaded on solid zirconia was employed as heterogeneous catalyst for the synthesis of pyridine derivatives via a one-vessel, four-component reaction consisting of substituted aldehyde, malononitrile, dimethylacetylenedicarboxylate and dimethylaniline with good to excellent product yields (87 to 95%). The noteworthy advantages of the facile method with ethanol as solvent are excellent yields with short reaction times. Catalyst is reusable with little loss of activity up to six rounds. Materials and Method: All the catalyst materials were synthesized by using simple wet-impregnation method. The powder X-ray diffraction, TEM, SEM and N2 adsorption/desorption analysis techniques were employed for the structural interpretation of CeO2/ZrO2, the identity of target products were established and confirmed by diverse spectral (1H NMR, 13C NMR, 15N NMR, FT-IR and HRMS) techniques. Results: As convincingly demonstrated by the synthetic approaches reported in this review, MCRs have facilitated many new methodologies with significant advantages for efficient and well organized synthesis of varied pyrazole derivatives. The methodology involved variety of options for catalysts that can be chosen using different solvents or solvent-free conditions and/or using alternative energy-efficient options such as microwave irradiation and sonification. This review brings together ample material about synthesis of varied pyrazole derivatives that may have prodigious scope, in drug design and therapeutics. It is anticipated that research efforts in this direction will endure in the search for novel, atom efficient, small molecules with excellent drug-like properties. Conclusion: In this study, we report on a green and efficient one-pot protocol for the synthesis of functionalized 1,4-dihydropyridine-2,3-dicarboxylate derivatives through a four-component reaction between malononitrile, dimethylacetylenedicarboxylate, dimethylaniline and substituted aldehydes using 2.5% CeO2/ZrO2 as a catalyst in EtOH and at room temperature. This methodology has several advantages such as short reaction times (< 30 min), high product yields (87-95%), ease of handling, facile and green work-up. The easy recoverable and reusable catalyst meets the industrial and environmental requirements and is versatile and cost effective.

2-Hydroxyethylammonium acetate as a reusable and cost-effective ionic liquid for the efficient synthesis of bis(pyrazolyl)methanes and 2-pyrazolyl-1-nitroalkanes

2012 ◽  
Vol 90 (10) ◽  
pp. 798-804 ◽  
Author(s):  
Sara Sobhani ◽  
Razieh Nasseri ◽  
Moones Honarmand
Keyword(s):  
Ionic Liquid ◽  
Michael Reaction ◽  
Scale Up ◽  
Reaction Times ◽  
Cost Effective ◽  
Environmentally Benign ◽  
One Pot ◽  
High Yields ◽  
Reaction Media ◽  
Task Specific Ionic Liquid

A new and convenient method for the synthesis of bis(pyrazolyl)methanes by one-pot tandem Knoevenagel–Michael reaction of 3-methyl-1-phenyl-5-pyrazolone with aryl, heteroaryl, or alkyl aldehydes in the presence of 2-hydroxyethylammonium acetate (2-HEAA) as a task-specific ionic liquid is described. This method was also successfully applied for the synthesis of 2-pyrazolyl-1-nitroalkanes by Michael addition of 3-methyl-1-phenyl-5-pyrazolone with β-nitrostyrenes in short reaction times. The present protocol offers several advantages such as using a reusable and cost-effective ionic liquid, an environmentally benign reaction media, being amenable to scale-up and good to high yields of the products.

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