Documents disponibles écrits par cet auteur

Regioselective synthesis of monoepoxides from terpenic diolefins over alumina at high temperature and pressure / María A. Uguina in Industrial & engineering chemistry research, Vol. 48 N° 10 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 4671–4680 Titre : Regioselective synthesis of monoepoxides from terpenic diolefins over alumina at high temperature and pressure Type de document : texte imprimé Auteurs : María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur Année de publication : 2009 Article en page(s) : pp. 4671–4680 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Alumina  Terpenic  diolefins  Epoxidation  Water Résumé : Alumina is a heterogeneous catalyst for the regioselective epoxidation of terpenic diolefins that deactivates in presence of water. The reactions can be carried out at high temperature, above the boiling point of the solvent, increasing the pressure to maintain the reaction mixture in the liquid phase, yielding conversions between 41% and 96% and selectivities between 19% and 75% to monoepoxides with a significant decrease of reaction times. Deactivated alumina was analyzed, and an effective regeneration method was proposed. Furthermore, to improve the monoepoxide productivity, the effects of temperature, pressure, stirring rate, water concentration, alumina loading, and reactive concentrations were studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801763e [article] Regioselective synthesis of monoepoxides from terpenic diolefins over alumina at high temperature and pressure [texte imprimé] / María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur . - 2009 . - pp. 4671–4680. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 4671–4680 Mots-clés : Alumina  Terpenic  diolefins  Epoxidation  Water Résumé : Alumina is a heterogeneous catalyst for the regioselective epoxidation of terpenic diolefins that deactivates in presence of water. The reactions can be carried out at high temperature, above the boiling point of the solvent, increasing the pressure to maintain the reaction mixture in the liquid phase, yielding conversions between 41% and 96% and selectivities between 19% and 75% to monoepoxides with a significant decrease of reaction times. Deactivated alumina was analyzed, and an effective regeneration method was proposed. Furthermore, to improve the monoepoxide productivity, the effects of temperature, pressure, stirring rate, water concentration, alumina loading, and reactive concentrations were studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801763e

Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin / María A. Uguina in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10217–10221 Titre : Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin Type de document : texte imprimé Auteurs : María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur Année de publication : 2010 Article en page(s) : pp. 10217–10221 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Regiospecific--Epoxidation--Carvone  α,β-Unsaturated--Ketone  Group--Basic  Resin Résumé : A basic resin in OH− form (Amberlite IRA-900) has been used to catalyze the regiospecific epoxidation of carvone with H2O2 to obtain 5,6-epoxycarvone, showing high activity and selectivity (>99%). The effects of solvent, temperature, stirring rate, catalyst loading, oxidant/substrate ratio, and oxidant dosage have been analyzed. A second-order kinetic model has been proposed to describe the effect of substrate concentration, catalyst loading, and temperature on reaction rate, and the apparent activation energy of the reaction has been estimated. The catalyst has been tested in five consecutive runs and it has shown to be completely reusable after regeneration of its hydroxyl groups before each use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010723 [article] Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin [texte imprimé] / María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur . - 2010 . - pp. 10217–10221. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10217–10221 Mots-clés : Regiospecific--Epoxidation--Carvone  α,β-Unsaturated--Ketone  Group--Basic  Resin Résumé : A basic resin in OH− form (Amberlite IRA-900) has been used to catalyze the regiospecific epoxidation of carvone with H2O2 to obtain 5,6-epoxycarvone, showing high activity and selectivity (>99%). The effects of solvent, temperature, stirring rate, catalyst loading, oxidant/substrate ratio, and oxidant dosage have been analyzed. A second-order kinetic model has been proposed to describe the effect of substrate concentration, catalyst loading, and temperature on reaction rate, and the apparent activation energy of the reaction has been estimated. The catalyst has been tested in five consecutive runs and it has shown to be completely reusable after regeneration of its hydroxyl groups before each use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010723