scholarly journals Microwave-Assisted, One-Pot Synthesis of Doxycycline under Heterogeneous Catalysis in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1084
Author(s):  
Fabio Bucciol ◽  
Elia Maffeis ◽  
Emanuela Calcio Gaudino ◽  
László Jicsinszky ◽  
Silvia Tagliapietra ◽  
...  

The selective synthesis of active pharmaceutical molecules is a challenging issue, particularly when attempting to make the reactions even more sustainable. The present work focuses on the microwave-assisted hydrogenolysis of oxytetracycline to selectively produce α-doxycycline. Although the combination of microwave irradiation and a heterogeneous rhodium catalyst provided good conversions, the selective synthesis of active α-doxycycline was only achieved when an oxytetracycline-cyclodextrin complex was used as the starting material, giving the desired product at 34.0% yield in a one-step reaction under very mild conditions.

2007 ◽  
Vol 72 (8) ◽  
pp. 1014-1024 ◽  
Author(s):  
Pedro Cintas ◽  
Katia Martina ◽  
Bruna Robaldo ◽  
Davide Garella ◽  
Luisa Boffa ◽  
...  

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.


2016 ◽  
Vol 12 ◽  
pp. 1772-1777 ◽  
Author(s):  
Lena Huck ◽  
Juan F González ◽  
Elena de la Cuesta ◽  
J Carlos Menéndez

A sequential three-component process is described, starting from 3-arylmethylene-2,5-piperazinediones and involving a one-pot sequence of reactions achieving regioselective opening of the 2,5-diketopiperazine ring and diastereoselective generation of an aziridine ring. This method allows the preparation of N-unprotected, trisubstituted aziridines bearing a peptide side chain under mild conditions. Their transformation into β-trifluoroacetamido-α-ketoamide and α,β-diketoamide frameworks was also achieved in a single step.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 38
Author(s):  
Fernando J. Lorenzo ◽  
Romina A. Ocampo ◽  
Sandra D. Mandolesi

We present here a new proposal for the “one pot” generation of new 4-thiazolidinones (9a–e) through a multicomponent reaction under microwave irradiation conditions, using aromatic and heteroaromatic amines (8a–e), absolute ethanol as a “green” solvent and modifying the aldehyde group in the glycosidic residue, synthesized from D-mannitol. The study is focused in the variation of the irradiation times and the concentration of thioglycolic acid in order to study the possibility of controlling the structure and/or stereochemistry of the products formed in the reaction. Thiazolidinones 9a–d were obtained with a 69–82% The generation of the corresponding reaction products were monitored by TLC and CG-MS, taking reaction aliquots. The conditions reaction proved to be chemoselective depending on the excess of acid and irradiation times.


ChemInform ◽  
2012 ◽  
Vol 43 (7) ◽  
pp. no-no
Author(s):  
Evelyn Cuevas Creencia ◽  
Masayuki Tsukamoto ◽  
Takaaki Horaguchi

2016 ◽  
Vol 4 (10) ◽  
pp. 3865-3871 ◽  
Author(s):  
Yuchen Qin ◽  
Xiaoping Dai ◽  
Xin Zhang ◽  
Xingliang Huang ◽  
Hui Sun ◽  
...  

Multiply-twinned Au–Ag NCs/rGO are prepared by a one-pot method under microwave irradiation and exhibit excellent HER activity and stability.


2013 ◽  
Vol 37 (1) ◽  
pp. 25-27 ◽  
Author(s):  
Maaroof Zarei

Cyanuric fluoride works as an efficient acid activator reagent for the direct [2+2] ketene–imine cycloaddition of substituted acetic acids and imines in a one-pot synthesis under mild conditions. The yields are good to excellent and the reaction conditions are mild, simple and efficient.


2019 ◽  
Vol 15 ◽  
pp. 378-387
Author(s):  
Adrián A Heredia ◽  
Martín G López-Vidal ◽  
Marcela Kurina-Sanz ◽  
Fabricio R Bisogno ◽  
Alicia B Peñéñory

A preparation of β-ketosulfides avoiding the use of thiols is described. The combination of a multicomponent reaction and a lipase-catalysed hydrolysis has been developed in order to obtain high chemical diversity employing a single sulfur donor. This methodology for the selective synthesis of a set of β-ketosulfides is performed under mild conditions and can be set up in one-pot two-step and on a gram-scale.


RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29939-29946 ◽  
Author(s):  
Beatriz Fresco-Cala ◽  
M. Laura Soriano ◽  
Alice Sciortino ◽  
Marco Cannas ◽  
Fabrizio Messina ◽  
...  

Graphene quantum dot (GQDs) assemblies from a one-step microwave reaction as bifunctional materials in remediation of triazines.


RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 44756-44763 ◽  
Author(s):  
Aditi A. Jadhav ◽  
Pawan K. Khanna

In this work a one-pot microwave assisted synthesis of selenium nanoparticles and their different forms, by decomposition of cyclo-octeno-1,2,3-selenadiazole is described first ever time.


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