RESUMEN
We describe the first gram scale preparation of the reagent dichlorotrifluoromethoxyacetic acid. This stable compound is obtained in five steps starting from the cheap diethylene glycol. The reactivity of the sodium salt of this fluorinated acid was also tested and allowed the preparation of new amides.
Asunto(s)
Acetatos/síntesis química , Amidas/síntesis química , Flúor/química , Indicadores y Reactivos/síntesis química , Éteres Fenílicos/síntesis química , Técnicas de Química Sintética , Glicoles de Etileno/química , Cinética , Estructura MolecularRESUMEN
In order to target and image MMP-2 activity using optical imaging, we developed a panel of new MMP-2 probes based on Cy5 and QSY21 as fluorophore/quencher FRET partners, separated by various MMP-2 specific peptide substrates. We compared these probes for their specificity against other MMPs, their rate of activation by MMP-2 and their initial quenching.
Asunto(s)
Carbocianinas , Colorantes Fluorescentes , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Imagen Molecular/métodos , Sondas Moleculares , Fragmentos de Péptidos/metabolismo , Transferencia Resonante de Energía de Fluorescencia , Humanos , Espectrometría de Masas , Metaloproteinasas de la Matriz/análisis , Metaloproteinasas de la Matriz/químicaRESUMEN
Chemo- and stereoselective transformations of 3-hydroxy-1,5-allenynes 1 into a variety of new and potentially useful cyclic compounds have been achieved. Substrates bearing a silyl group at the alkyne moiety undergo purely thermal or Lewis acid catalyzed Alder-ene type transformations into 2-methylene-3-vinylcyclopent-3-enol derivatives 2. When heated in the presence of a catalytic amount of PtCl(2) or PtCl(4), these incipient cyclopentenols could be further transformed into 3-vinylcyclopent-2-enones 3. On the other hand, alkyl-substituted 3-hydroxy-1,5-allenynes proved to be stable under refluxing conditions. Nevertheless, PtCl(2) and PtCl(4) could selectively activate the alkyne moiety of these substrates toward intramolecular nucleophilic attack of the internal allene double bond to yield unprecedented 6-methylenebicyclo[3.1.0]hexan-3-one derivatives 4. With gold-based catalysts, provided that the reaction is carried out in dichloromethane, both Au(I) and Au(III) complexes selectively activate the allene fragment of the substrates toward intramolecular nucleophilic attack of the hydroxyl group to yield 2-ethynyl-3,6-dihydro-2H-pyrans 5. Compounds of type 4 can also be formed with Au(I) and Au(III) complexes if the reaction is carried out in toluene. The reactivity of these new compounds has been partially investigated, and polycyclic ketones were obtained after oxidation under mild conditions or gold-catalyzed cycloisomerization.