Estudios sobre las reacciones de hidrogenación e hidroformilación enantioselectiva de olefinas con catalizadores de rodio basados en ligandos fosforados

Tesis descargada desde TESEOLa presente Tesis Doctoral pretende abordar algunos estudios relacionados con la aplicación de los ligandos P-OP en la hidrogenación de olefinas catalizadas por complejos de rodio. En la primera parte del Capítulo 1 se abordará un estudio sobre las propiedades conformacionales de los ligandos P-OP y su influencia en la reacción catalítica. Este estudio tiene carácter fundamental y tiene interés en relación a las aplicaciones catalíticas en general de los ligandos P-OP. Por otra parte, la segunda mitad del Capítulo 1 se dedica al estudio de la hidrogenación de enamidas derivadas de la 2-tetralona. Esta es una reacción con un gran interés para la industria farmacéutica, para la que no se han obtenido resultados satisfactorios hasta el momento. En este apartado se incluirá un estudio amplio de la influencia de la naturaleza del catalizador en la reacción así como sobre varios aspectos mecanicistas. Por otra parte el Capítulo 2 de esta Tesis se ha dedicado a la síntesis de un nuevo tipo de ligandos de tipo bis(1,3,2-diazafosfolidina).El diseño de estos ligandos se ha realizado por analogía con la estructura de los de tipo bis(fosfolano) que constituyen una de las clases más importantes de ligandos en el área de la Catálisis Asimétrica. En este apartado se tratará la síntesis de estos ligandos, algunas características estructurales, así como su aplicación en varias transformaciones catalíticas enantioselectivas

Novel bis (1,3,2-diazaphospholidine) ligands for asymmetric catalysis

A family of modularly designed chiral bis(1,3,2-diazaphospholidines) with N-aryl substituents (NP-PN) is reported. These compounds have been prepared in two steps from readily available (R,R)-1,2-diaminocyclohexane and tetrachlorodiphosphines. Examples in the set differ in the backbone and the aryl substituents, aiming at their application in asymmetric catalysis. Thus, [Rh(NBD)(NP-PN)]BF4 complexes lead to active catalysts in the hydrogenation of methyl α-acetamidoacrylate, which provide enantioselectivities up to 96% ee. In addition, NP-PN ligands also generate active catalysts in the hydroformylation of vinyl acetate, leading to high regioselectivities (iso:n ratio higher than 99:1) and enantioselectivities up to 65% ee. © 2013 American Chemical Society.Ministerio de Ciencia e Innovación CTQ2009-11867, CONSOLIDER-INGENIO CSD 2007- 00006Junta de Andalucía 2008/ FQM-3830, 2009/FQM-483

Rhodium phosphine-phosphite catalysts in the hydrogenation of challenging N-(3,4-dihydronaphthalen-2-yl) amide derivatives

The enantioselective catalytic hydrogenation of N-(3,4-dihydronaphthalen-2- yl) amides (1) with rhodium catalysts bearing phosphine-phosphite ligands 4 has been studied. A wide catalyst screening, facilitated by the modular structure of 4, has found a highly enantioselective catalyst for this reaction. This catalyst gives a 93% ee in the hydrogenation of 1a and also produces high enantioselectivities, ranging from 83 to 93% ee, in the hydrogenation of several OMe- and Br-substituted substrates. In contrast, the structurally related enol esters 2 are very reluctant to undergo hydrogenation. A coordination study of the representative enamide 1d has shown an unusual η6-arene coordination mode, over the typical O,C,C chelating mode for enamides, as the preferred one for this substrate in a Rh(I) complex. Deuteration reactions of 1c,d indicate a clean syn addition of deuterium to the double bond without an isotopic effect on the enantioselectivity.Ministerio de Ciencia e Innovación CTQ2009-11867, CSD2007-00006Junta de Andalucía 2008/FQM-3830, 2009/FQM-483

El uso de levaduras inactivas puede preservar el aroma de vinos jóvenes

Publicado en Tecnovino: el portal para el profesional de la industria vitivinícola.Investigadores de la Universidad Politécnica de Madrid (UPM), en colaboración con el Instituto de Investigación en Ciencias de la Alimentación (CIAL- CSIC), demuestran que el empleo de preparados de levaduras inactivas ricas en glutatión puede preservar el aroma de los vinos jóvenes.Peer Reviewe

Caracterización gravimétrica y magnética de controles estructurales en depósitos de Sn-W. Ejemplo del yacimiento de San Finx (A Coruña)

Critical raw materials are essential for the development of our society. However, most shallow ores have already been exploited and only deep targets remain unexplored. This work aims to apply indi-rect geophysical techniques to the San Finx Sn-W deposit (A Coruña) in order to get further constrains of its deep structure and geometry. Accordingly, a magnetic and a gravity survey have been carried out in the area (SE of Noia, A Coruña), at the southern part of the Mal-pica-Tui Complex. The resulting absolute magnetic anomaly and the relative gravity anomaly have been studied analytically and through 2-2.75D forward modeling. Results indicate that, the sampling inter-val (~1 km) is too high to characterize the anomalies related to the Sn-W mineralization. Contrarily, they show the potential field imprint of the regional Variscan tectonics. To better assess the relationship between the regional Variscan tectonics and the mineralization, a higher resolution survey should be acquired to detect this depositLas materias primas críticas son fundamentales para el desarro-llo de nuestra sociedad. Sin embargo, la mayoría de los yacimientos poco profundos ya han sido explotados, quedando únicamente sin explorar los objetivos profundos. En este trabajo se presentan los re-sultados de la aplicación de técnicas geofísicas indirectas al estudio del yacimiento de Sn-W de San Finx (A Coruña). Su objetivo es cons-treñir la geometría y estructura del yacimiento en profundidad. En este sentido, se ha realizado una campaña de adquisición de datos magnéticos y gravimétricos en dicha zona (SE de Noia, A Coruña) en la parte sur del Complejo Malpica-Tui. La anomalía magnética absoluta y la anomalía gravimétrica relativa resultante se han estu-diado analíticamente y mediante modelización directa 2-2,75D. Los resultados indican que el intervalo de muestreo usado (~1 km) es muy alto para individualizar la respuesta magnética y gravimétrica del yacimiento. Sin embargo, los mapas obtenidos muestran que la signatura de campos potenciales está ligada a la tectónica Varisca a gran escala. Encontrar la relación entre esta última y la mineraliza-ción y hacer un muestreo geofísico de alta resolución en la zona son la clave para entender este depósit

Impact of using new commercial glutathione enriched inactive dry yeast oenological preparations on the aroma and sensory properties of wines

The effect of the addition of a commercial enriched glutathione inactive dry yeast oenological preparation in the volatile and sensory properties of industrially manufactured rosé Grenache wines was evaluated during their shelf-life. In addition, triangle tests were performed at different times during wine aging (among 1 and 9 months) to determine the sensory differences between wines with and without glutathione inactive dry yeast preparations. Descriptive sensory analysis with a trained panel was carried out when sensory differences in the triangle test were noticed. In addition, consumer tests were performed in order to investigate consumers’ acceptability of wines. Results revealed significant sensory differences between control and glutathione inactive dry yeast wines after 9 months of aging. At that time, glutathione inactive dry yeast wines were more intense in fruity aromas (strawberry, banana) and less intense in yeast notes than control wine. The impact of the glutathione inactive dry yeast in the aroma might be the consequence of different effects that these preparations could induce in wine composition: modification of yeast byproducts during fermentation, release of volatile compounds from inactive dry yeast, interaction of wine volatile compounds with yeast macromolecules from inactive dry yeast and a possible antioxidant effect of the glutathione released by the inactive dry yeast preparation on some specific volatile compounds

Lithospheric image of the Central Iberian Zone(Iberian Massif) using global-phase seismic interferometry

This paper presents the lithospheric structure of Central Iberia on the basis of seismic interferometry of teleseismic dat

Transfers of Care between Healthcare Professionals in Obstetric Units of Different Sizes across Spain and in a hospital in Ireland : the MidconBirth Study

Abstract: Background: In Europe, the majority of healthy women give birth at conventional obstetric units with the assistance of registered midwives. This study examines the relationships between the intrapartum transfer of care (TOC) from midwife to obstetrician-led maternity care, obstetric unit size (OUS) with different degrees of midwifery autonomy, intrapartum interventions and birth outcomes. Methods: A prospective, multicentre, cross-sectional study promoted by the COST Action IS1405 was carried out at eight public hospitals in Spain and Ireland between 2016-2019. The primary outcome was TOC. The secondary outcomes included type of onset of labour, oxytocin stimulation, epidural analgesia, type of birth, episiotomy/perineal injury, postpartum haemorrhage, early initiation of breastfeeding and early skin-to-skin contact. A logistic regression was performed to ascertain the effects of studied co-variables on the likelihood that participants had a TOC; Results: Out of a total of 2,126 low-risk women, those whose intrapartum care was initiated by a midwife (1772) were selected. There were statistically significant differences between TOC and OUS (S1 = 29.0%, S2 = 44.0%, S3 = 52.9%, S4 = 30.2%, p < 0.001). Statistically differences between OUS and onset of labour, oxytocin stimulation, type of birth and episiotomy or perineal injury were observed (p = 0.009, p < 0.001, p < 0.001, p < 0.001 respectively); Conclusions: Findings suggest that the model of care and OUS have a significant effect on the prevalence of intrapartum TOC and the birth outcomes. Future research should examine how models of care differ as a function of the OUS in a hospital, as well as the cost-effectiveness for the health care system

Seismic imaging and modelling of the lithosphere of SW-Iberia.

[EN]Data from a closely spaced wide-angle transect has been used to study the middle-to-lower crust and the Moho in SW-Iberia. A low-fold wide-angle stack image reveals a highly heterogeneous seismic signature at lower-crustal levels changing laterally along the profile. The lower crust features an irregular distribution of the reflectivity that can be explained by a heterogeneous distribution of physical properties. The Moho discontinuity also features a high variability in its seismic character that correlates with the different tectonic terranes in the area. A 2D finite difference code was used for solving the elastic wave equation and to provide synthetic wide-angle shots. Relatively simple layer cake model derived from conventional refraction interpretation generates the main events of the shot records. However, these models cannot account for the lateral variability of the seismic signature. In order to obtain more realistic simulations, the velocity model was modified introducing stochastic lensing at different levels within the crust. The Moho was modelled as a 3 km thick layered structure. The resulting average velocity models include a high velocity layer at mid-crustal depth, a highly reflective lower crust and a relatively thin horizontal Moho. This heterogeneous model can be achieved by lensing within the crust, a layered mafic intrusion and a strongly laminated lower crust and Moho

Quality of anticoagulation with vitamin K antagonists

[Abstract] Background. Vitamin K antagonists (VKA) have a narrow therapeutic range, and literature analysis reveals poor quality of anticoagulation control. We sought to assess the prevalence of poor anticoagulant control in patients under VKA treatment in the prevention of stroke for atrial fibrillation (AF). Hypothesis.Control of anticoagulation with VKA is inadequate in a high percentage of patients with AF. Methods.Patients with AF under VKA treatment were prospectively recruited in this observational registry. The sample comprised 948 patients. The estimated time spent in the therapeutic range (TTR) was calculated, and variables related with a TTR >65% were analyzed. Results.Mean age was 73.8 ± 9.4 years, and 42.5% of the patients were women. Mean TTR was 63.77% ± 23.80% for the direct method and 60.27% ± 24.48% for the Rosendaal method. Prevalence of poor anticoagulation control was 54%. Variables associated with good anticoagulation control were university studies (odds ratio [OR]: 1.99, 95% confidence interval [CI]: 1.08-3.64), chronic hepatic disease (OR: 8.15, 95% CI: 1.57-42.24), low comorbidity expressed as Charlson index (OR: 0.87, 95% CI: 0.76-0.99), no previous cardiac disease (OR: 0.64, 95% CI: 0.41-0.98), lower risk of bleeding assessed as hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly age, and use of drugs or alcohol (HAS-BLED; OR: 0.81, 95% CI: 0.69-0.95), and lower heart rate (OR: 0.99, 95% CI: 0.98-0.99). Conclusions.Patients who receive VKA to prevent stroke for AF spend less than half the time within therapeutic range.Instituto de Salud Carlos III; RD12/0042/0068Instituto de Salud Carlos III; RD12/0042/0010Instituto de Salud Carlos III; RD12/0042/0069Instituto de Salud Carlos III; RD12/0042/0049Instituto de Salud Carlos III; RD12/0042/006