14 research outputs found

    Enantioselective amination of 4-substituted pyrazolones catalyzed by oxindole-containing thioureas and by a recyclable linear-polymer-supported analogue in a continuous flow process

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    Producción CientíficaA highly efficient organocatalytic amination of 4-substituted pyrazolones with azodicarboxylates mediated by a novel quinine-derived thiourea with a 3,3-diaryl-oxindole scaffold is reported. This synthetic method furnished 4-amino-5-pyrazolones in high yields and with excellent enantioselectivities (up to 97:3 er) at room temperature in short reaction times. Moreover, a linear-polymer-supported bifunctional thiourea, synthesized by reacting a bifunctional aromatic monomer (biphenyl) with isatin in superacidic media and further derivatization, was proven to be also an efficient heterogeneous organocatalyst for this α-amination reaction. The practical value of this process was demonstrated by the use of the immobilized catalyst in recycling experiments, maintaining the activity without additional reactivation, and in flow processes, allowing the synthesis of 4-amino-pyrazolone derivatives in a gram scale with high yield and enantioselectivity.Agencia Estatal de Investigación- FEDER-UE (PID2020-118547GB-I00)Junta de Castilla y León (VA224P20

    Porous organic polymers containing active metal centers for Suzuki–Miyaura heterocoupling reactions

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    Producción CientíficaA new generation of confined palladium(II) catalysts covalently attached inside of porous organic polymers (POPs) has been attained. The synthetic approach employed was straightforward, and there was no prerequisite for making any modification of the precursor polymer. First, POP-based catalytic supports were obtained by reacting one symmetric trifunctional aromatic monomer (1,3,5-triphenylbenzene) with two ketones having electron-withdrawing groups (4,5-diazafluoren-9-one, DAFO, and isatin) in superacidic media. The homopolymers and copolymers were made using stoichiometric ratios between the functional groups, and they were obtained with quantitative yields after the optimization of reaction conditions. Moreover, the number of chelating groups (bipyridine moieties) available to bind Pd(II) ions to the catalyst supports was modified using different DAFO/isatin ratios. The resulting amorphous polymers and copolymers showed high thermal stability, above 500 °C, and moderate–high specific surface areas (from 760 to 935 m2 g–1), with high microporosity contribution (from 64 to 77%). Next, POP-supported Pd(II) catalysts were obtained by simple immersion of the catalyst supports in a palladium(II) acetate solution, observing that the metal content was similar to that theoretically expected according to the amount of bipyridine groups present. The catalytic activity of these heterogeneous catalysts was explored for the synthesis of biphenyl and terphenyl compounds, via the Suzuki–Miyaura cross-coupling reaction using a green solvent (ethanol/water), low palladium loads, and aerobic conditions. The findings showed excellent catalytic activity with quantitative product yields. Additionally, the recyclability of the catalysts, by simply washing it with ethanol, was excellent, with a sp2–sp2 coupling yield higher than 95% after five cycles of use. Finally, the feasibility of these catalysts to be employed in tangible organic reactions was assessed. Thus, the synthesis of a bulky compound, 4,4′-dimethoxy-5′-tert-butyl-m-terphenylene, which is a precursor of a thermal rearrangement monomer, was scaled-up to 2 g, with high conversion and 96% yield of the pure product.Agencia Estatal de Investigación (projects PID2019-109403RB-C22, MAT2016-76413-C2-R2, CTQ2017-89217- P and MAT2016-76413-C2-R1)Junta de Castilla y León (project VA038G18

    Pyrrolidine-based catalytic microporous polymers in sustainable C=N and C=C bond formation via iminium and enamine activation

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    Producción CientíficaA new set of catalytic materials having a pyrrolidine moiety confined in microporous organic polymer networks (POPs) has been attained. These catalytic polymers have been prepared by a straightforward synthesis starting from microporous polymer networks made from isatin (or a mixture of isatin and trifluoroacetophenone) and 1,3,5-triphenylbenzene. The polymers efficiently catalyzed the formation of nitrones under very mild and sustainable conditions using green solvents through an iminium ion activation mechanism. The reactions are scalable, and polymers are easily recycled. Special attention has been paid to understanding all the factors that could affect the efficiency of the confined catalysts. The electronic and conformational characteristics of the pyrrolidine moiety attached to the porous polymers, as well as other features that could affect the transport through the network, such as molecular volume and shape of reactants and products, and even hydrophilic or hydrophobic properties, have been systematically evaluated. In addition, the heterogeneous polymers are also useful in Cdouble bondC bond formation through both iminium ion and enamine activation.Gobierno de España (Agencia Estatal de Investigación) - (Projects CTQ2016-78779-R, PID2019-109403RB-C22, RTI2018-096328-B-I00, CTQ2017-89217-P and PID2020-118547GBI00)Junta de Castilla y León, Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Project VA224P20)

    Polymer materials derived from the SEAr reaction for gas separation applications

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    Producción CientíficaA set of linear polymers were synthesized utilizing an electrophilic aromatic substitution reaction (SEAr) between biphenyl and ketone containing electron-withdrawing groups (isatin, IS; N-methylisatin, MeIS; and 4,5-diazafluoren-9-one, DF). Optimization of the polycondensation reaction was made to obtain high molecular weight products when using DF, which has not previously been used for linear polymer synthesis. Due to the absence of chemically labile units, these polymers exhibited excellent chemical and thermal stability. Linear SEAr polymers were blended with porous polymer networks derived from IS and MeIS, and both neat/mixed materials were tested as membranes for gas separation. The gas separation properties of both pristine polymers and mixed matrix membranes were good, showing some polymer membrane CO2 permeability values higher than 200 barrer

    Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)

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    This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe

    Estudio del comportamiento electroquímico del Yb(III) en Cloruro de 1-Butil-3 Metil-Imidazolio (BMIMCl)

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    El presente trabajo forma parte de un proyecto de investigación cuyo objetivo es la separación electroquímica de metales (especialmente de TR) o, al menos proporcionar datos sobre el comportamiento de sus iones en líquidos iónicos. En la primera parte se estudian las propiedades físico-químicas del Cloruro de 1-Butil-3-Metil-Imidazolio (BMIMCl) que posteriormente se utiliza como electrolito para estudiar las propiedades electroquímicas del YbCl3 sobre un electrodo de Carbono vitrificado (GC), en un rango de temperaturas comprendidas entre los 343-363 K. La electro-reducción del Yb(III) tiene lugar via una etapa Yb(III)/Yb(II), sin que pueda observarse el sistema Yb(II)/Yb(0) dentro de la venta electroquímica, debido a que previamente se produce la reducción del catión imidazol del disolvente, que inhíbe la electroextracción del Yb sobre el sustrato de Carbono vitrificado. Mediante diversas técnicas, voltamperometría cíclica (CV), voltamperometría semiintegral (CPSV), cronoamperometría (CA) y cronopotenciometría (CP) se determinarán los valores del coeficiente de difusión (D), el coeficiente de transferencia de carga (α) y la constante de velocidad de intercambio de electrones (k0) a las diferentes temperaturas, así como la energía de activación (Ea) del sistema.Grado en Químic

    Prevenir para vivir en igualdad

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    Convocatoria Proyectos de innovación de Extremadura 2017/2018Valorando que la familia y la escuela proporcionan modelos de conducta que se mantienen no solo durante la infancia si no también en la edad adulta, y observando que aún hay matices que pueden mejorarse en la coeducación de los diferentes sexos, se describe un proyecto llevado a cabo en el CEIP De Prácticas (Cáceres) que englobaba una serie de actividades que tenían como objetivos principales: reconocer las diferencias de sexo, aceptándolas y convirtiéndolas en algo positivo; incentivar las relaciones sociales de los alumnos desechando prejuicios que lleven a la exclusión social; desarrollar prácticas educativas que lleven a identificar estereotipos sexistas de la comunidad escolar y de la sociedad; promover una convivencia pacífica encaminada a la igualdad entre ambos sexos y a la prevención de la violencia; implicar a la comunidad educativa en una educación basada en la igualdad; inculcar el ámbito de la igualdad en todas las áreas curriculares posibles; facilitar instrumentos y materiales de apoyo a las familias que garanticen condiciones de igualdad en la participación en el ámbito educativo; modificar el sentido de la autoestima de los alumnos en la escuela, en la familia y en el entorno y educar en la empatíaExtremaduraES
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