Search results for "combinatorial"

An Atom-Economical Approach to Functionalized Single-Walled Carbon Nanotubes: Reaction with Disulfides

2013

Owing to their unique structure, thermal stability, and mechanical and electronic properties, single-walled carbon nanotubes (SWCNTs) have been a subject of continuous and intense interest. However, various applications in many fields, such as molecular electronics, solar cells, and nanomedicine, often require the development of reproducible protocols for the chemical modification of SWCNTs. In fact, one of the main drawbacks of the use of SWCNTs is their tendency to aggregate and intrinsic poor solubility, which prevent their manipulation and limit their potential. To date, several methods have been described for the chemical functionalization of SWCNTs; however, new versatile and reliable…

Prodrugs of sulfacetamide: Synthesis, X-ray structure, Hirshfeld analysis, antibacterial assessment, and docking studies

2022

Abstract New prodrugs of sulfacetamide as azo compounds were synthesized and have been evidenced through elemental and spectral analyses. Their synthesis was carried out by coupling the diazonium salt of sulfacetamide with activated carbanion salt of ethyl acetoacetate at 0 ˚C to afford the hydrazono derivative 3. Other prodrugs as sulfacetamide-pyrazoles, 5a, 5b and 5c were furnished via cyclocondensation of 3 with aryl/heteroaryl hydrazines. X-ray diffraction for single crystal was used to confirm the molecular and supramolecular structures of 3. In addition, DFT studies were performed to analyze the geometric parameters and compute the electronic properties of 3 and 5a-c. Hirshfeld analy…

A frozen analogue approach to aminopyridinylimidazoles leading to novel and promising p38 MAP kinase inhibitors.

2012

In this study we report the design, synthesis, and biological evaluation of constrained aminopyridinylimidazoles as p38α MAP kinase inhibitors. The frozen analogue approach focused on the pyridinyl unit, using purine bioisosteres as constrained structure analogues. The identification of the most potent bioisostere was followed by a further derivatization to address hydrophobic region II. In combination with C-2 modifications of the imidazole core, we were able to design highly active inhibitors on the p38α MAP kinase. The inhibitor design presented herein represents a promising and highly efficient advancement of recent stages of development in this class of p38 MAP kinase inhibitors. In co…

Iron oxide superparamagnetic nanocarriers bearing amphiphilic N-heterocyclic choline analogues as potential antimicrobial agents

2015

Magnetic nanoparticles represent an advanced tool in biomedicine because they can be simultaneously functionalized and guided using a magnetic field. Iron oxide magnetic nanoparticles precoated with oleic acid and bearing novel antimicrobial N-heterocyclic choline analogues, namely O-, N- and O,N-bis-undecyl-substituted N-(2-hydroxyethyl)-1,2,3,4-tetrahydroisoquinolinium derivatives, have been obtained as potential biomedical agents for drug delivery and antimicrobial therapy. Structural and size determinations for the novel synthesized magnetic nanosystems were carried out based upon magnetogranulometry, dynamic light-scattering measurements and X-ray diffraction analysis. The most expecte…

Self-assembly of monodisperse oligonucleotide-elastin block copolymers into stars and compound micelles.

2010

Palladium-catalyzed heteroaryl thioethers synthesis overcoming palladium dithiolate resting states inertness: Practical road to sulfones and NH-sulfo…

2018

International audience; We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium-1,1'-bis [(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance. In the palladium catalyzed C-S coupling of heteroaromatic thiols, reactivity limitation is attached with electron-deficient thiols. We show that this limitation can be resolved by the successful use of 2-bromoheteroarenes in the C-S coupling. We established herein…

The “green” electrochemical synthesis of periodate

2020

Abstract High‐grade periodate is relatively expensive, but is required for many sensitive applications such as the synthesis of active pharmaceutical ingredients. These high costs originate from using lead dioxide anodes in contemporary electrochemical methods and from expensive starting materials. A direct and cost‐efficient electrochemical synthesis of periodate from iodide, which is less costly and relies on a readily available starting material, is reported. The oxidation is conducted at boron‐doped diamond anodes, which are durable, metal‐free, and nontoxic. The avoidance of lead dioxide ultimately lowers the cost of purification and quality assurance. The electrolytic process was opti…

Electrochemical C−H Functionalization of (Hetero)Arenes—Optimized by DoE

2020

Abstract A novel approach towards the activation of different arenes and purines including caffeine and theophylline is presented. The simple, safe and scalable electrochemical synthesis of 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) aryl ethers was conducted using an easy electrolysis setup with boron‐doped diamond (BDD) electrodes. Good yields up to 59 % were achieved. Triethylamine was used as a base as it forms a highly conductive media with HFIP, making additional supporting electrolytes superfluous. The synthesis was optimized using Design of Experiment (DoE) techniques giving a detailed insight to the significance of the reaction parameters. The mechanism was investigated by cyclic volt…

Direct electrochemical generation of organic carbonates by dehydrogenative coupling.

2018

Organic carbonates are an important source for polycarbonate synthesis. However, their synthesis generally requires phosgene, sophisticated catalysts, harsh reaction conditions, or other highly reactive chemicals. We present the first direct electrochemical generation of mesityl methyl carbonate by C–H activation. Although this reaction pathway is still challenging concerning scope and efficiency, it outlines a new strategy for carbonate generation.

Coupling Proteomics and Fermentation Technology for the Improvement of Bioactive Molecule Production Yield in Actinomycetes

2013

Copyright: © 2013 Gallo. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most bioactive molecules (like anticancers, antitumors, antibiotics, immunosuppressants, insecticidals, antivirals, herbicidals, antifungals) with valuable industrial and market value are naturally produced by actinomycetes [1-4], Gram-positive filamentous bacteria widespread in both terrestrial and aquatic environments [5,6]. Out of thousands of bioactive molecules, also known as secondary metabolites since they are not essential for…