Enantioselective conjugate addition of ketones to β-nitrostyrenes catalyzed by 1,2-amino alcohol-derived prolinamides

Various l-prolinamides 14, prepared from l-proline and chiral β-amino alcohols, are active bifunctional catalysts for the direct nitro-Michael addition of ketones to β-nitrostyrenes. In particular, catalyst 14e prepared from l-proline and (1S,2R)-cis-1-amino-2-indanol exhibits the highest catalytic performance working in polar aprotic solvents such as NMP. High syn-diastereoselectivities (up to 94% de) and good enantioselectivities (up to 80% ee) were obtained at rt.This work has been supported by the Dirección General de Investigación of the Ministerio de Educación y Ciencia (CTQ2004-00808/BQU), by the Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134, GRUPOS05/11 and GV05/157) and the University of Alicante

Work and energy in inertial and non inertial reference frames

It is usual in introductory courses of mechanics to develop the work and energy formalism from Newton's laws. On the other hand, literature analyzes the way in which forces transform under a change of reference frame. Notwithstanding, no analogous study is done for the way in which work and energy transform under those changes of reference frames. We analyze the behavior of energy and work under such transformations and show explicitly the expected invariance of the formalism under Galilean transformations for one particle and a system of particles. The case of non inertial systems is also analyzed and the fictitious works are characterized. In particular, we show that the total fictitious work in the center of mass system vanishes even if the center of mass defines a non inertial frame. Finally, some subtleties that arise from the formalism are illustrated by examples.Comment: 4 pages, 2 figures. LaTeX2e. Part of the approach has been changed but results are unaltered. Version to appear im American Journal of Physic

Graphene Oxide-Supported Oxime Palladacycles as Efficient Catalysts for the Suzuki–Miyaura Cross-Coupling Reaction of Aryl Bromides at Room Temperature under Aqueous Conditions

Palladacycles are highly efficient precatalysts in cross-coupling reactions whose immobilization on carbonaceous materials has been hardly studied. Herein, we report a detailed study on the synthesis and characterization of new oxime palladacycle-graphene oxide non-covalent materials along with their catalytic activity in the Suzuki–Miyaura reaction. Catalyst 1-GO, which has been fully characterized by ICP, XPS, TGA, and UV-Vis analyses has been demonstrated to be an efficient catalyst for the Suzuki–Miyaura coupling between aryl bromides and arylboronic acids using very low catalyst loadings (0.002 mol % of Pd) at room temperature under aqueous conditions.Financial support from the University of Alicante (UAUSTI16-03, UAUSTI16-10, VIGROB-173), the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P) is acknowledged

Organocatalytic Asymmetric α-Chlorination of 1,3-Dicarbonyl Compounds Catalyzed by 2-Aminobenzimidazole Derivatives

Bifunctional chiral 2-aminobenzimidazole derivatives 1 and 2 catalyze the enantioselective stereodivergent α-chlorination of β-ketoesters and 1,3-diketone derivatives with up to 50% ee using N-chlorosuccinimide (NCS) or 2,3,4,4,5,6-hexachloro-2,5-cyclohexadien-1-one as electrophilic chlorine sources.Financial support from the University of Alicante (VIGROB-173, VIGROB-285, GRE12-03, UAUSTI13-01, UAUSTI13-02), and Spanish Ministerio de Economía y Competitividad (CTQ2011-24151) is acknowledged

Advanced Nuclear Magnetic Resonance

Transparencias en inglés de la asignatura "Resonancia Magnética Nuclear Avanzada" (Advanced Nuclear Magnetic Resonance) (36643) que se imparte en el Máster de Química Médica como asignatura optativa de 3 créditos ECTS. En esta asignatura se completa el estudio iniciado en la asignatura de quinto curso de la licenciatura en Química "Determinación estructural" (7448) y en la del Grado de Química de tercer curso "Determinación estructural de los compuestos orgánicos" (26030) en lo referente a técnicas bidimensionales de resonancia magnética nuclear. Además se proporcionan los conocimientos necesarios para poder interpretar RMN de otros núcleos activos en RMN no estudiados hasta el momento como 19F, 31P, 2H, 28Si y 15N así como sus acoplamientos con los núcleos de 1H y 13C

Microwave-Promoted Copper-Free Sonogashira–Hagihara Couplings of Aryl Imidazolylsulfonates in Water

Aryl imidazol-1-ylsulfonates have been efficiently cross-coupled with aryl-, alkyl-, and silylacetylenes in neat water under copper-free conditions at 110 °C assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30 min.Financial support from the MICINN (Projects CTQ2007-62771/BQU, CTQ2010-20387 and Consolider INGENIO 2010 CSD2007-00006), FEDER, from the Generalitat Valenciana (Project PROMETEO/2009/038), and the University of Alicante is acknowledged

Unidad de diagnóstico rápido (UDR) en patología tumoral

Objetivos: Desarrollar una UDR, vinculada al Servicio de Urgencias Hospitalario (SUH), proporcionando prioridad en el radiodiagnóstico y mayor accesibilidad a las consultas de especializada, supone un abordaje de la patología tumoral más dinámico. Nuestro objetivo fue analizar el impacto de la UDR en el manejo de dicha patología. Metodología: Estudio descriptivo, retrospectivo, de base poblacional, realizado en la Clínica USP-Palmaplanas, hospital de 150 camas Analizando el manejo del total de pacientes con tumores atendidos en la UDR desde abril 2006 a marzo 2008. Se utilizaron los indicadores de actividad y calidad creados para dicho fin. Resultados: Total pacientes atendidos en la UDR 2473, total pacientes con diagnóstico de patología tumoral 73. Tiempo de espera desde su atención en el SUH hasta valoración en la UDR (<48h 41%, 2-4 días 36%), tiempo de espera desde atención inicial- final en las UDR (mismo día 17%, <8 días 64%), tiempo de espera desde alta UDR hasta su atención para el abordaje terapéutico (<48h en el 91%), se cursaron 11 ingresos hospitalarios tras el diagnóstico desde la UDR. Conclusiones: La UDR permite agilizar el diagnóstico y tratamiento precoces de la patología tumoral, mejorando claramente la eficiencia y la seguridad con una reducción en la estancia media hospitalaria y en la carga emocional del paciente.Objectives: The implementation of a Hospital Emergency Unit based RDU in order to prioritise diagnostic imaging and the access to specialised outpatient clinics, has dynamized the management of patients first diagnosed with cancer. Our objective was to analyze the impact of an RDU in the management of this group of patients. Methods: Descriptive, retrospective study of the population seen at USP Palmaplanas Clinic, a 150 bed hospital, which analyses the management of patients seen in the RDU from April 2006 to March 2008. Activity and quality indicators were created to support this study. Results: Total number of patients seen in the RDU: 2473. 73 of these patients were diagnosed with possible cancer. Waiting times to be seen in RDU from the Emergency Unit: <48 hours in 41% of the cases, 2-4 days in 36%. Waiting times from first visit at RDU to last visit: same day in 17%, <8 days in 64%. Waiting times from first visit to RDU to treatment: <48 hours in 91% of the cases. 11 patients were admitted to hospital for management. Discussion: RDU allows a dynamic management of patients with cancer, from first diagnosis to early treatment, improving patient care, efficiency and safety. It also reduces hospital stay and reduces patients’ emotional distress

Amino acid metabolism conflicts with protein diversity

The twenty protein coding amino acids are found in proteomes with different relative abundances. The most abundant amino acid, leucine, is nearly an order of magnitude more prevalent than the least abundant amino acid, cysteine. Amino acid metabolic costs differ similarly, constraining their incorporation into proteins. On the other hand, sequence diversity is necessary for protein folding, function and evolution. Here we present a simple model for a cost-diversity trade-off postulating that natural proteomes minimize amino acid metabolic flux while maximizing sequence entropy. The model explains the relative abundances of amino acids across a diverse set of proteomes. We found that the data is remarkably well explained when the cost function accounts for amino acid chemical decay. More than one hundred proteomes reach comparable solutions to the trade-off by different combinations of cost and diversity. Quantifying the interplay between proteome size and entropy shows that proteomes can get optimally large and diverse

Copper-Free Oxime–Palladacycle-Catalyzed Sonogashira Alkynylation of Deactivated Aryl Bromides and Chlorides in Water under Microwave Irradiation

Palladium-catalyzed Heck alkynylation cross-coupling reactions between terminal alkynes and deactivated aryl chlorides and aryl bromides can be performed in the absence of copper cocatalyst with water as solvent at 130 °C under microwave irradiation. An oxime-derived chloro-bridged palladacycle is an efficient precatalyst for this transformation with 2-dicyclohexylphosphanyl-2′,4′,6′-triisopropylbiphenyl (XPhos) as ancillary ligand, pyrrolidine as base, and SBDS as surfactant. All of the reactions can be performed under air and with reagent-grade chemicals under low loading conditions (0.1–1 mol-% Pd).Financial support from the Ministerio de Economía y Competitividad (MINECO) (project CTQ2010-20387), Consolider INGENIO (project 2010 CSD2007-00006), Fondos Europeos para el Desarrollo Regional (FEDER), the Generalitat Valenciana (project PROMETEO/2009/038), and the University of Alicante is acknowledged

Microwave-assisted palladium-catalyzed highly regio- and stereoselective head to head dimerization of terminal aryl alkynes in water

A highly regio- and stereoselective oxime palladacycle/imidazolinium-catalyzed head to head dimerization of terminal aryl alkynes in water is presented. The reaction, which is carried out at 130 °C under microwave irradiation in the presence of 1,3-bis-(2,6-diisopropylphenyl)imidazolinium chloride as ligand, triethylamine as base, and TBAB as surfactant, allows the synthesis of (E)-1,4-enynes as single stereoisomers in good isolated yields.Financial support from the MINECO (CTQ2010-20387), the Generalitat Valenciana (PROMETEO/2009/038), and the University of Alicante (VIGROB-173, UAUSTI13-01) is acknowledged