scholarly journals Copper Phosphotungstate-Catalyzed Microwave-Assisted Synthesis of 5-Hydroxymethylfurfural In A Biphasic System

2021 ◽  
Author(s):  
Gabriel Abranches Dias Castro ◽  
Neide Paloma Gonçalves Lopes ◽  
Sergio Antonio Fernandes ◽  
Márcio José da Silva
Keyword(s):  
Transition Metal ◽  
Reaction Medium ◽  
Water Soluble ◽  
Biphasic System ◽  
Lewis Acidity ◽  
Microwave Assisted Synthesis ◽  
Water Molecules ◽  
Microwave Assisted ◽  
Keggin Heteropolyacids ◽  
Fructose Dehydration

Abstract In this paper, we have described a novel route to produce 5-hydroxymethylfurfural (HMF), a valuable platform-molecule obtained from biomass, using transition metal-exchanged Keggin heteropolyacid salts as catalysts, in microwave-assisted reactions carried out in a water-ethyl acetate biphasic system. To avoid the use of homogenous Brønsted acid catalysts, which are corrosive and difficult to be reused, we have exchanged the protons of the Keggin heteropolyacids by transition metal cations. These salts were evaluated in the fructose dehydration, being the Cu3/2PW12O40 the most active and selective catalyst, achieving 81 % of HMF yield, after 15 min reaction at 413 K under microwave irradiation (MWI). The effects of metal cation, anion, and heteropolyanion present in the catalyst were evaluated. The greatest efficiency of Cu3/2PW12O40 was attributed to its high Lewis acidity strength, which allows that it coordinate with water molecules, consequently generating H3O+ ions in the reaction medium. Even though the catalyst has been water-soluble, it was easily reused removing the extracting phase, and adding a new load of the substrate to the remaining aqueous phase. This way, it was successfully reused without loss activity.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

scholarly journals One-Pot Microwave-Assisted Synthesis of Water-Soluble Pyran-2,4,5-triol Glucose Amine Schiff Base Derivative: XRD/HSA Interactions, Crystal Structure, Spectral, Thermal and a DFT/TD-DFT

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Yousef Hijji ◽  
Rajeesha Rajan ◽  
Hamdi Ben Yahia ◽  
Said Mansour ◽  
Abdelkader Zarrouk ◽  
...  
Keyword(s):  
Schiff Base ◽  
Molecular Orbital ◽  
Density Functional ◽  
Condensation Reaction ◽  
3D Structure ◽  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Td Dft

The(3R,4R,6R)-3-(((E)-2-hydroxybenzylidene)amino)-6-(hydroxymethyl)tetrahydro-2H-pyran-2,4,5-triol water-soluble Glucose amine Schiff base (GASB-1) product was made available by condensation of 2-hydroxybenzaldehyde with (3R,6R)-3-amino-6-(hydroxymethyl)-tetra-hydro-2H-pyran-2,4,5-triol under mono-mode microwave heating. A one-pot 5-minute microwave-assisted reaction was required to complete the condensation reaction with 90% yield and without having byproducts. The 3D structure of GASB-1 was solved from single crystal X-ray diffraction data and computed by DFT/6-311G(d,p). The Hirshfeld surface analysis (HSA), molecular electronic potential (MEP), Mulliken atomic charge (MAC), and natural population analysis (NPA) were performed. The IR and UV-Vis spectra were matched to their density functional theory (DFT) relatives and the thermal behavior was resolved in an open-room condition via thermogravimetry/Derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). The highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO), density of state (DOS), and time-dependence TD-DFT computations were correlated to the experimental electron transfer in water and acrylonitrile solvents.

Water-soluble TRIS-terminated PAMAM dendrimers: microwave-assisted synthesis, characterization and Cu(ii) intradendrimer complexes

RSC Advances ◽  
2015 ◽  
Vol 5 (74) ◽  
pp. 60581-60595 ◽  
Author(s):  
Ali Serol Ertürk ◽  
Mustafa Ulvi Gürbüz ◽  
Metin Tülü ◽  
Abdürrezzak Emin Bozdoğan
Keyword(s):  
Drug Carriers ◽  
Pamam Dendrimers ◽  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
Potential Drug ◽  
Microwave Assisted

Microwave-assisted synthesis, characterization and Cu(ii) complexes of water-soluble TRIS-terminated PAMAM dendrimers as novel potential drug carriers and templates for nanomaterials.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

Microwave-assisted synthesis of highly water-soluble graphene towards electrical DNA sensor

Nanoscale ◽  
2010 ◽  
Vol 2 (12) ◽  
pp. 2692 ◽  
Author(s):  
Bong Gill Choi ◽  
HoSeok Park ◽  
Min Ho Yang ◽  
Young Mee Jung ◽  
Sang Yup Lee ◽  
...  
Keyword(s):  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
Dna Sensor ◽  
Microwave Assisted

Microwave‐assisted synthesis of water‐soluble styrylpyridine dye‐capped zinc oxide nanoparticles for antibacterial applications

2019 ◽  
Vol 67 (2) ◽  
pp. 316-323 ◽  
Author(s):  
Manjunath Giridhar ◽  
Halehatty S. Bhojya Naik ◽  
Chatnalli N. Sudhamani ◽  
Mustur C. Prabakara ◽  
Rajappa Kenchappa ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
Oxide Nanoparticles ◽  
Microwave Assisted

Microwave-assisted Efficient One-pot Synthesis of Nitriles Using Recyclable Magnetite (Fe3O4) Nanoparticles as Catalyst and Water as Solvent: A Greener Approach

2020 ◽  
Vol 10 (4) ◽  
pp. 507-517
Author(s):  
Prashant Chavan ◽  
Suhas Pednekar ◽  
Ramesh Chaughule ◽  
Anushree Lokur
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Reaction Medium ◽  
Chemical Yield ◽  
Significant Loss ◽  
Microwave Assisted Synthesis ◽  
Microwave Activation ◽  
One Pot ◽  
Microwave Assisted ◽  
Magnetite Fe3o4 ◽  
Water As Solvent

Background: There has been an increasing curiosity over the past few years to carry out organic reactions over heterogeneous nanocatalysts. Microwave activation coupled with a nanocatalyst along with water as a reaction medium makes the process further green. Microwave activation as a green process reduces reaction times, enhances product purity and improves chemical yield. Methods: Nitrile group chemistry has been explored by many researchers across the globe owing to its interesting properties and its importance in synthetic chemistry. Despite several methods being available for the synthesis of nitriles, microwave assisted synthesis of nitriles using Fe3O4 nanoparticles appears more promising. The present study is intended at developing a recyclable magnetite (Fe3O4) nanoparticles catalyzed protocol towards the synthesis of organonitrile derivatives using one pot reaction. Results: The above protocol incorporates the use of microwave for heating and water as reaction medium. Several substituted nitriles could be synthesized for excellent yields. The magnetite nanoparticles can be reused for new reaction without significant loss in activity. Conclusion: The experiment makes the protocol simple, environment friendly and economically feasible.

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