Fluorous hydrophobic fluorescent (E)-Stilbene derivatives for application on security paper

(E)-Stilbene hydrophobic fluorophores possessing long perfluorinated or hydrocarbonated chains have been prepared through a stereoselective Wittig-Schlosser reaction. When covalently grafted upon paper, they give rise to a fluorescent-labeled paper upon irradiation with UV light. The hydrophobicity and oleophobicity of the fluorous (E)-stilbene derivative furnish self-cleaning properties. Application in the detection of money counterfeiting is envisioned

Asymmetric Preparation of α-Quaternary Fluorinated β-keto Esters. Review

In this review, recent advances over the past decade in the preparation of fluorinated stereogenic quaternary centers on β-keto esters compounds are analyzed. Since the incorporation of fluorine and fluorinated groups is of special interest in pharmaceutical chemistry, a range of metal-catalyzed and organocatalyzed methods have been developed. Herein, we review the enantioselective fluorination, trifluoromethylation and trifluoromethylthiolation of 3-oxo esters. The scope, the induction of enantioselectivity and mechanistic investigations are presented

Nanopartícules d'osmi i iridi estabilitzades amb fluor en reaccions d'oxidació

Fa uns anys, l'ús d'estabilitzadors altament fluorats per la preparació de nanopartícules metàl·liques no semblava gaire adequat. Tanmateix, des del Departament de Química de la UAB, s'ha demostrat la possibilitat de preparar i estabilitzar nanopartícules metàl·liques, en concret d'iridi i d'osmi, utilitzant un estabilitzant altament fluorat. A més, un cop sintetitzades, se n'ha estudiat la seva aplicabilitat en reaccions d'oxidació.Hace unos años, el uso de estabilizadores altamente fluorados para la preparación de nanopartículas metálicas no parecía muy adecuado. Sin embargo, desde el Departamento de Química de la UAB, se ha demostrado la posibilidad de preparar y estabilizar nanopartículas metálicas, en concreto de iridio y de osmio, utilizando un estabilizador altamente fluorado. Además, una vez sintetizadas, se ha estudiado su aplicabilidad en reacciones de oxidación.A few years ago, the use of highly fluorinated stabilizers for the preparation of metal nanoparticles did not seem appropriate. However, researchers from the UAB Chemistry Department showed the possibility of preparing and stabilizing metallic nanoparticles, in particular iridium and osmium, using a highly fluorinated stabilizer compound. In addition, once synthesized, they studied its applicability in oxidation reactions as well

Difluoroalkylation of Anilines via Photoinduced Methods

Altres ajuts: acords transformatius de la UABThe development of sustainable and mild protocols for the fluoroalkylation of organic backbones is of current interest in chemical organic synthesis. Herein, we present operationally simple and practical transition-metal-free methods for the preparation of difluoroalkyl anilines. First, a visible-light organophotocatalytic system working via oxidative quenching is described, providing access to a wide range of difluoroalkyl anilines under mild conditions. In addition, the formation of an unprecedented electron donor-acceptor (EDA) complex between anilines and ethyl difluoroiodoacetate is reported and exploited as an alternative, efficient, and straightforward strategy to prepare difluoroalkyl derivatives

Fluorous l -Carbidopa Precursors : Highly Enantioselective Synthesis and Computational Prediction of Bioactivity

New fluorous enantiopure (S)-α-aminated β-keto esters were prepared through a highly enantioselective electrophilic α-amination step in the presence of europium triflate and (R,R)-phenyl-pybox. These compounds are precursors of fluorinated analogues of l-carbidopa, which is known to inhibit DOPA decarboxylase (DDC), a key protein in Parkinson's disease. Fluorination provides better stability for biological applications, which could possibly lead to DDC inhibitors better than l-carbidopa itself. Induced fit docking computational simulations performed on the new structures interacting with DDC highlight that for an efficient binding at the DDC site, at least one hydroxyl substituent must be present at the aromatic ring of the l-carbidopa analogues and show that the presence of fluorine can further fix the position of the ligand in the active site

15-Membered triolefinic macrocycles, their coordination chemistry with transition metals, and the catalytic properties of their palladium metal complexes : A review

(E,E,E)-1,6,11-Tris(arenesulfonyl)-1,6,11-triazacyclopentadeca-3,8,11-trienes, 1, are prepared from arenesulfonamides and trans-1,4-dibromo-2-butene. Macrocycles 1 coordinate palladium(0), platinum(0), and silver(I), and the palladium complexes are useful and reutilizable catalysts or precatalysts in Suzuki cross-couplings, butadiene telomerizations, hydroarylation of alkynes, and in the Heck reaction. Structurally related macrocycles are also available by similar synthetic procedures

Nitrogen-nitrogen bond cleavage catalyzed by ruthenium complexes

Several ruthenium complexes have been tested as catalysts for the cleavage of nitrogen-nitrogen bonds of mono, di and trisubstituted hydrazine derivatives. Better results were obtained using Ru(CO) as catalyst in this type of reactions. Addition of hydrogen sources, such as isopropanol or sodium hydride, to the reaction mixtures has been studied in order to improve the cleavage proces

Estabilització de nanopartícules de plata amb antibiòtics per a l'obtenció de teixits amb capacitat microbicida

Cada vegada més, s'utilitzen les nanopartícules de plata (AgNPs) com agents antibacterians per la fabricació de materials tèxtils amb propietats microbicides. Des del Departament de Química de la UAB, s'ha aconseguit estabilitzar satisfactòriament aquestes nanopartícules de plata, a partir de la síntesi de lligands derivats d'antibiòtics i s'ha demostrat eficaçment que la seva dispersió en la superfície de materials tèxtils els confereix activitat antimicrobiana.Cada vez más a menudo se utilizan las nanopartículas de plata (AgNPs) como agentes antibacterianos para la fabricación de materiales textiles con propiedades microbicidas. Desde el Departamento de Química de la UAB, se ha conseguido estabilizar satisfactoriamente estas nanopartículas de plata, a partir de la síntesis de ligandos derivados de antibióticos y se ha demostrado que su dispersión en la superficie de materiales textiles les confiere de forma eficaz actividad microbicida.Silver nanoparticles (AgNPs) are used as antibacterial agents for the manufacture of textile materials with microbicidal properties. Researchers from the UAB Department of Chemistry, have satisfactorily stabilized these silver nanoparticles, synthesizing ligands derived from antibiotics and they have effectively shown that their dispersion on textile materials confers them antimicrobial activity

Silica nanostructures against fungal growth : design and preparation of antifungal cotton fabrics

Altres ajuts: acord transformatiu CRUE-CSICThe preparation of antifungal-functionalized silica nanoparticles by covalent attachment of several silylated derivatives based on the topical antifungal agent Micozanole is described. Grafting and co-condensation procedures are used to obtain mesoporous or dense nanoparticles. Cotton fabrics have been coated with these antifungal-functionalized silica nanoparticles under ultrasonic conditions. The characterization of the functionalized nanoparticles and coated cotton fabrics is performed by microscopic and spectroscopic techniques. The antifungal activity of all the modified cotton textiles is tested against Trichophyton mentagrophytes CECT 2783, Aspergillus brasiliensis CECT 2091, Penicillium chrysogenum CECT 2307 and Candida albicans CECT 1001, resulting to be highly dependent on the microorganism. Remarkably, all of the modified fabrics are active against Candida albicans and Trichophyton mentagrophytes, with up to 75 and 90% effectiveness, respectively. High expectations arise for topical cutaneous applications in wound dressings (bandages, gauzes, strips)

Preparació in situ de nous reactius de iode hipervalent per a la síntesi de cloroarens

El grup Catalysis and New synthetic Methodologies with Application to Nanotechnology and Materials Science de la UAB ha dissenyat dos procediments sintètics en els quals combina iode hipervalent (PIFA) i una font senzilla de clor per tal d'obtenir cloroarens. Es destaca l'ús del clorur de potassi (KCl) o el TMSCl com a reactius econòmics i no tòxics. Segons la font de clor utilitzada es generen dos intermedis reactius diferents, com són l'intermediari: PhI(Cl)O2CCF3; i el diclorat: PhI(Cl)2. (Reacció que s'observa en la imatge).El grupo Catalysis and New synthetic Methodologies with Application to Nanotechnology and Materials Science de la UAB ha diseñado dos procedimientos sintéticos en los que combina yodo hipervalente (PIFA) y una fuente sencilla de cloro para obtener cloroarenos. Se destaca el uso del cloruro de potasio (KCl) o el TMSCl como reactivos económicos y no tóxicos. Según la fuente de cloro utilizada se generan dos intermedios reactivos diferentes, como son el intermediario: PhI(Cl)O2CCF3 ; y el diclorato: PhI(Cl)2. (Reacción que se observa en la imagen).The Catalysis and New Synthetic Methodologies with Application to Nanotechnology and Materials Science research's group from UAB has designed two synthetic methodologies that combine hypervalent iodine reagent (PIFA) and a simple chlorine source to synthesize chloroarenes. We highlight the use of potassium chloride (KCl) or TMSCl as economical and non-toxic reagents. Depending on the chlorine source used, two different reactives intermediates are generated, such as the intermediari: PhI(Cl)O2CCF3 ; and dichlorate: PhI(Cl)2 (Both seen in this figure)