Asymmetric organocatalytic cascade reactions

302 p. : gráf.

Geochemical characterization of the fire-fountain fed deposits of Las Herrerias volcano (Campo de Calatrava Volcanic Field, Ciudad Real)

The Las Herrerias volcano (Bolanos de Calatrava, Campo de Calatrava Volcanic Field) is characterized by the great amount and variety of fire-fountain fed deposits. All these deposits are compositionally similar, being constituted by magnesium-rich (MgO = 11.58-4.19%), aluminium-poor (Al2O3 = 9.64-10.99%) highly sodic (Na2O = 2.24-3.81%) melanephelinites, with high contents in rare earth-elements (10x-200x chondrite), particularly in light-rare earth elements with respect to the heavy ones [(La/Lu)(N) = 32-35]. Contrary to the equivalent melanephelinites of this volcanic field, the relatively low contents in Ni (233-286 ppm), Cr (393-520 ppm) and magnesium number (Mg* = 45-54) indicate that these rocks do not correspond with primary melts. On the other hand, the variable distribution of clinopyroxene in the magma during eruption would be responsible for the slight compositional differences observed in the studied samples. Finally, we argue that these fire fountains were developed in a continental intraplate setting.

Activación de aldehídos a,b-insaturados mediante aminocatálisis en procesos enantioselectivos. Cicloadiciones (3+2) y reacciones en cascada Michael/Henry

During the research that it is summarized in the present memory, the activation of enals via iminium ion catalysis in different transformations has been studied. Firstly, a 1,3-dipolar cycloaddition between stable azomethine ylides and a,b-unsaturated aldehydes catalyzed by a chiral imidazolidinone derivative has been optimized. Employing this methodology we have synthesized a large range of densely substituted pyrroloisoquinolines and pyrrolophthalazines with good yields and high values of diastereo- and enantioselectivity. Moreover, a mechanistic study has been carried out based on DFT calculations and experimental data which have allowed us to propose that the (3+2) cycloaddition reaction follows a sequential Michael addition/Mannich cyclization pathway. The formation of the iminium ion as a result of the condensation between the a,b-unsaturated aldehyde and the catalyst plays an essential role, regarding both reactivity and stereoselectivity. On the other hand we have developed a methodology to carry out a cascade Michael/Henry reaction followed by a sequential dehydration. Starting from simple substrates (2-nitromethylacrilates and a,b-unsaturated aldehydes) and employing a prolinol-derivative catalyst a series of quiral nitrocyclohexadienes have been synthesized.

Systematic Studies on 3d- and 4f-Metal Containing Polyoxometalates Suitable for Organic Derivatization

232 p.

Impacto de la web 2.0 en los perfiles profesionales

En pleno siglo XXI, el uso de Internet y los avances no sólo afectan a las personas sino que las empresas también deben evolucionar al mismo ritmo y adaptar todas sus prácticas a dichos avances. Con la aparición de la Web 2.0, ciertos aspectos de las empresas han quedado obsoletos y se han debido adaptar a la nueva era: la era de la comunicación e de la interacción a través de Internet. Se han creado nuevos modelos de negocio, se han mejorado actividades de la cadena de valor, han surgido nuevas estrategias de marketing y comunicación corporativa y se han creado unos nuevos canales de venta, alrededor del fenómeno e-Commerce. En cuanto a los trabajadores, las empresas han comenzado a valorar nuevas competencias relacionadas con el uso de Internet y la Web 2.0. Dichas competencias pueden ser comunes para muchos puestos de trabajo, por ejemplo el uso de redes sociales o la gestión de la información, otras son más específicas y dependen del puesto de trabajo que consideremos. Finalmente, la aparición de la Web 2.0 ha exigido a las empresas a crear nuevas áreas y puestos de trabajo o modificar los actuales para adecuarse a los nuevos tiempos y tendencias. Así surgen los diferentes perfiles profesionales de las áreas de Estrategia Digital, Marketing Digital, Contenido Digital, Social Media, Análisis Big Data, e-Commerce y Mobile Marketing. Estos perfiles gozan de mucha popularidad y demanda por parte de las empresas y se estima que va a crecer aún más el número de puestos relacionados con el ámbito digital, ya que son las profesiones del futuro.

Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)-amino]acetyl}amino) benzophenone; a case of configurationally stable stereogenic nitrogen

A family of chiral ligands derived from alpha-phenylethylamine and 2-aminobenzophenone were prepared by alkylation of the nitrogen atom. Upon reaction with glycine and a Ni(II) salt, these ligands were transformed into diastereomeric complexes, as a result of the configurational stability of the stereogenic nitrogen atom. Different diastereomeric ratios were observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements.

Heterogeneous catalytic properties of unprecedented m-O-[FeTCPP]2 dimers (H2TCPP = meso-tetra(4-carboxyphenyl)porphyrin): unusual superhyperfine EPR structure

Articulo científico Dalton Transactions

M(C6H16N3)2(VO3)4 as heterogeneous catalysts. Study of three new hybrid vanadates of cobalt(II), nickel(II) and copper(II) with 1-(2-aminoethyl)piperazonium.

postprint