Divergent reaction pathways for one-pot, three-component synthesis of novel 4H-pyrano[3,2-h]quinolines under ultrasound irradiation

Simultaneous water and ethanol-based synthesis and coating of copper and zinc oxide (CuO/ZnO) nanoparticles (NPs) on bandages was carried out by ultrasound irradiation. High resolution-transmission electron microscopy demonstrated the effects of the solvent on the particle size and shape of metal oxide NPs. An antibacterial activity study of metal-oxide-coated bandages was carried out against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). CuO NP-coated bandages made from both water and ethanol demonstrated complete killing of S. aureus and E. coli bacteria within 30 min., whereas ZnO NP-coated bandages demonstrated five-log reductions in viability for both kinds of bacteria after 60 min of interaction. Further, the antibacterial mechanism of CuO/ZnO NP-coated bandages is proposed here based on electron spin resonance studies. Nanotoxicology investigations were conducted via in vivo examinations of the effect of the metal-oxide bandages on frog embryos (teratogenesis assay—Xenopus). The results show that water-based coatings resulted in lesser impacts on embryo development than the ethanol-based ones. These bandages should therefore be considered safer than the ethanol-based ones. The comparison between the toxicity of the metal oxide NPs prepared in water and ethanol is of great importance, because water will replace ethanol for bulk scale synthesis of metal oxide NPs in commercial companies to avoid further ignition problems. The novelty and importance of this manuscript is avoiding the ethanol in the typical water:ethanol mixture as the solvent for the preparation of metal oxide NPs. Ethanol is ignitable, and commercial companies are trying the evade its use. This is especially important these days, as the face mask produced by sonochemistry (SONOMASK) is being sold all over the world by SONOVIA, and it is coated with ZnO.

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Production of lactic acid from cellulose using solid catalyst

MATEC Web of Conferences ◽

10.1051/matecconf/201926807006 ◽

2019 ◽

Vol 268 ◽

pp. 07006 ◽

Cited By ~ 1

Author(s):

Sujitra Doungsri ◽

P. Rattanaphanee ◽

Aatichat Wongkoblap

Keyword(s):

Lactic Acid ◽

Batch Reactor ◽

Nitrogen Pressure ◽

Reaction Pathways ◽

Solid Catalyst ◽

One Pot ◽

Solid Catalysts ◽

Platform Chemicals ◽

Acid And Base ◽

The One

Lactic acid (LA), one of the important biomass derived platform chemicals, has been used in food and chemical industries, especially in biodegradable polymer as polylactic acid (PLA). The aim of this work is to study the one-pot production of LA from cellulose by using different solid catalysts. The reaction was conducted in a high pressure batch reactor and the catalyst used in this study were ZrO2 and Al2O3. The reaction was carried out at temperature of 200oC for 6 hr. and under nitrogen pressure of 1 MP. It was found that the production yield of LA were 8.02% and 6.63%, when the ZrO2 and Al2O3 catalysts were used respectively. The result indicated that the ZrO2 may effect on the LA production because of the acid and base sites of the ZrO2. Therefore, the reaction pathways for conversion of cellulose into lactic acid have been investigated, and developed the new conditions to achieve the higher yield.

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Catalyst-free, one-pot, four-component green synthesis of functionalized 1-(2-fluorophenyl)-1,4-dihydropyridines under ultrasound irradiation

New Journal of Chemistry ◽

10.1039/c5nj03574k ◽

2016 ◽

Vol 40 (6) ◽

pp. 5107-5112 ◽

Cited By ~ 29

Author(s):

Nhlanhla Shabalala ◽

Suresh Maddila ◽

Sreekantha B. Jonnalagadda

Keyword(s):

Green Synthesis ◽

Ultrasonic Irradiation ◽

Aqueous Ethanol ◽

Ultrasound Irradiation ◽

One Pot ◽

Catalyst Free ◽

New Compounds ◽

Synthesis Protocol

A catalyst-free synthesis protocol for functionalized 1,4-dihydropyridines under ultrasonic irradiation in aqueous ethanol is reported with excellent yields. Eleven new compounds are synthesized using dimethylacetylenedicarboxylate, 2-fluoroaniline, malononitrile and various substituted aldehydes.

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One-pot easy conversion of Baylis-Hillman adducts into arylpyrazoles under ultrasound irradiation

ARKIVOC ◽

10.3998/ark.5550190.0010.217 ◽

2009 ◽

Vol 2009 (2) ◽

pp. 168-173 ◽

Cited By ~ 8

Author(s):

Manouchehr Mamaghani ◽

Sahar Dastmard

Keyword(s):

Ultrasound Irradiation ◽

One Pot

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Silica sulfuric acid magnetic nanoparticle: an efficient and ecofriendly catalyst for synthesis of spiro[2-amino-4H-pyran-oxindole]s

Canadian Journal of Chemistry ◽

10.1139/cjc-2014-0345 ◽

2015 ◽

Vol 93 (5) ◽

pp. 546-549 ◽

Cited By ~ 10

Author(s):

Ali Reza Karimi ◽

Meysam Sourinia ◽

Zeinab Dalirnasab ◽

Marzie Karimi

Keyword(s):

Sulfuric Acid ◽

Magnetic Nanoparticle ◽

Ultrasound Irradiation ◽

Significant Loss ◽

Silica Sulfuric Acid ◽

One Pot ◽

External Magnet ◽

Three Component Reaction ◽

The One ◽

High Yields

Silica sulfuric acid magnetic nanoparticles efficiently catalyze the one-pot, three-component reaction of isatins and malononitrile with dimedone, 1,3-dimethylbarbituric acid or 4-hydroxycoumarin in EtOH–H2O to afford the corresponding spiro[2-amino-4H-pyran-oxindole] derivatives in high yields under ultrasound irradiation at 60 °C. The heterogeneous nanocatalyst could be recovered easily from the reaction mixture using an external magnet and reused many times without significant loss of its catalytic activity.

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Improved Protocols for Microwave-Assisted Cu(I)-Catalyzed Huisgen 1,3-Dipolar Cycloadditions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20071014 ◽

2007 ◽

Vol 72 (8) ◽

pp. 1014-1024 ◽

Cited By ~ 27

Author(s):

Pedro Cintas ◽

Katia Martina ◽

Bruna Robaldo ◽

Davide Garella ◽

Luisa Boffa ◽

...

Keyword(s):

Heterogeneous Catalysis ◽

Microwave Irradiation ◽

Ultrasound Irradiation ◽

Conventional Heating ◽

Dipolar Cycloaddition ◽

One Pot ◽

Click Reactions ◽

Dipolar Cycloadditions ◽

Microwave Assisted ◽

New Applications

The Huisgen 1,3-dipolar cycloaddition of azides and acetylenes catalyzed by Cu(I) salts, leading to 1,2,3-triazoles, is one of the most versatile "click reactions". We have developed a series of optimized protocols and new applications of this reaction starting from several substrates, comparing heterogeneous vs homogeneous catalysis, conventional heating vs microwave irradiation or simultaneous microwave/ultrasound irradiation. Both non-conventional techniques strongly promoted the cycloaddition (bromide → azide → triazole), that could be conveniently performed in a one-pot procedure. This was feasible even with such bulky molecules as functionalized β-cyclodextrins (β-CD), starting from 61-O-tosyl-β-CD or from heptakis[6-O-(tert-butyldimethylsilyl)]-21-O-propargyl-β-CD. "Greener" heterogeneous catalysis with charcoal-supported Cu(II) or Cu(I) (prepared under ultrasound) was advantageously employed.

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