Examinando por Autor "Soriano, Elena"

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  • Miniatura
    Publicación
    Eco-friendly catalytic systems based on MgO- Supporting carbon materials for the Friedländer condensation
    (Wiley, 2014-12) Godino Ojer, Marina; López Peinado, Antonio José; Przepiórski, J.; Pérez Mayoral, María Elena; Soriano, Elena; Martín Aranda, Rosa María
    Carbon-supported MgO materials are excellent and sustainable catalysts for the synthesis of N-containing heterocyclic compounds by the Friedländer condensation under mild, solvent-free conditions. The results reported herein indicate that MgO is the most active catalytic species that accelerates the reaction compared with the catalytic behavior observed for the carbon material Norit RX3. On the basis of DFT calculations, a reaction mechanism that involves dual activation of the reacting structures by the catalyst is proposed. Oxide, outside: MgO supported on carbon is able to catalyze the synthesis of interesting N-containing heterocyclic compounds efficiently under mild conditions. MgO on the carbon surface is responsible for the catalytic behavior. These carbon materials are environmentally friendly catalysts for the Friedländer reaction.
  • Miniatura
    Publicación
    Metal-free synthesis of quinolines catalyzed by carbon aerogels: Influence of the porous texture and surface chemistry
    (Elsevier, 2017-04-17) Godino Ojer, Marina; Soriano, Elena; Calvino Casilda, Vanesa; Maldonado-Hódar, Francisco J.; Pérez Mayoral, María Elena
    We report herein an experimental and theoretical study of the Friedländer reaction, from 2-amino-5-chlorobenzaldehyde and ethyl acetoacetate, catalyzed by free-metal nanocatalysts based on carbon aerogels, to afford quinoline 3a. The developed methodology implies the combined use of carbon aerogels with solvent-free technologies under MW irradiation yielding the corresponding quinoline with moderated yield (66%) in only 5 min of reaction time. Our results demonstrated that the reactivity of the samples upon MW irradiation is strongly dependent on the porosity and surface chemistry of the carbon aerogels, the most active catalytic species being the most acidic oxygenated functional groups, –CO2H groups originated by oxidant treatment, or even in situ by hydrolysis of –CO–O–CO–, over the carbon surface. The theoretical investigation of the reaction mechanism, by using computational methods, demonstrated that the synthesis of quinoline 3a in the absence or in the presence of carbon aerogels takes place by aldolization, subsequent heterocyclization and finally double dehydration. Relatively strong π-π stacking interactions between carbon support and reagents could be behind of the observed catalytic performance also extended for the oxygenated models. Furthermore, the concentration of –CO2H groups over the carbon surface is a key factor favoring each step of the reaction but acting as individual catalytic sites.
  • Miniatura
    Publicación
    Sistemas catalíticos activos en la preparación de compuestos heterocíclicos de interés
    (Universidad Nacional de Educación a Distancia (España). Facultad de Ciencias. Departamento de Química Inorgánica y Química Técnica, 2016-02-05) Velasco Rebolledo, Jacinto; Pérez Mayoral, María Elena; Soriano, Elena; López Peinado, Antonio José