Highly 1,2-trans stereoselective allyations of 1,2-o-isopropylidene-protected glycofuranosides

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Coupled domino processes: Synthesis of 3,5,8-trisubstituted coumarins from propargyl vinyl ethers

The generation of a small and representative library of 3,5,8-trisubstituted coumarins (21 compounds, 7 families, 3 groups) is described. The library was built from the corresponding propargyl vinyl ethers and three different 1,3-dicarbonyl derivatives using a one-pot coupled domino strategy. These coumarins constitute a novel chemotype defined by the presence of a chemical handle in the pyranone ring and a varied substitution pattern adorning the aromatic ring, which includes fluorine- or oxygen-containing functionalities. © 2013 American Chemical Society.This research was supported by the Spanish Ministerio de Economía y Competitividad (MICINN) and the European Regional Development Fund (CTQ2011- 28417-C02-02). L.C. thanks the Spanish MEC for an FPI grant.Peer Reviewe

Synthesis of Fully Substituted Pyrimidines

A novel approach to the synthesis of fully substituted pyrimidine derivatives armed with an oxy-functionalized acetate chain at the ring is described. The manifold uses amidines as the nitrogen source and activated skipped diynes as the electrophilic reactive partners in a coupled domino strategy. In the first domino reaction, two consecutive aza-Michael additions assemble the six-membered ring heterocycle, while in the second domino process, a [H]-shift and a [3,3]-sigmatropic rearrangement lead to the aromatization of the product.This research was supported by the Spanish Ministerio de Economía y Competitividad (MICINN) and the European Regional Development Fund (CTQ2011- 28417-C02-02). S.L.T. thanks the Spanish MEC for an FPU grant.Peer Reviewe

Sodium borohydride-amberlyst-15 (H+): An effective reductor for hindered and unreactive ketones in aprotic solvent

The combination of sodium borohydride and amberlyst-15 (H+) in tetrahydrofurane is a powerful reductor for unreactive ketones. The reduction is fast, high-yielding and the work-up is extremely simple. Ketals, silyl ethers and other organic functions are not disturbed during the reduction.This work was supported by the Spanish DGICYT (PB94-0028). JRC thanks the ICI for a predoctoral fellowship.Peer Reviewe

A convenient domino access to substituted alkyl 1,2-dihydropyridine- 3carboxylates from propargyl enol ethers and primary amines

A convenient domino access to substituted alkyl 1,2-dihydropyridine-3- carboxylates from propargyl enol ethers and primary amines was reported. A solution of propargyl sinyl ether 1a and p-anisidine in toluene was placed in a microwave-special closed vial and the solution was irradiated for 30 minutes in a single-mode microwave oven. The reaction mixture was dried over anhydrous sodium sulfate and filtrated using dichloromethane as solvent. After removing the solvent at reduced pressure the products were purified by flash column chromatography. Accordingly, the microwave irradiation of an ethanolic mixture of propargyl enol ether 1 a and MeONH2.HCl in the presence of NaOAc yielded the methyl 2-phenyl-4-pyridinecarboxylate in a convenient 54% yield. These results seem to point out to a new reaction pathway involving different thermally-driven rearrangements of the 2,4-dienal 3 intermediate.This research was supported by the Spanish Ministerio de Ciencia e Innovación, the European Regional Development Fund (CTQ2005-09074-C02-02 and CTQ2008-06806-C02-02) and the Spanish MSC ISCIII (RETICS, RD06/0020/1046, and RD06/0020/0041), CSIC (Proyecto Intramural Especial 200719), FUNCIS (REDESFAC PI01/06 and 35/06) and the Fundación Instituto Canario de Investigación del Cancer (FICI-G.I.N808/2007). G.M.-A. thanks Spanish MEC for a FPU grant.Peer Reviewe

Water-compatible hydrogen-bond activation: A scalable and organocatalytic model for the stereoselective multicomponent aza-henry reaction

A study was conducted to demonstrate that H-bond based asymmetric organocatalysis can be performed under the so-called in the presence of water conditions. Nitroalkane, catalyst, dimethylcyclohexylamine, benzaldehyde and aniline were mixed to a 0°C cooled and vigorously stirred aqueous solution of NaOAc/AcOH saturated with NaCl. The organic residues were taken into dichloromethane and decanted off. The combined organic fractions were dried over Na2SO4, filtered and the filtrate was concentrated. The residue was purified by flash column chromatography (silica gel) using a mixture of hexanes/ethyl acetate. From a synthetic point of view, the reaction furnishes enantioenriched b-nitroamines decorated with aromatic or aliphatic substituents at the amine center and a different set of alkyl chains or rings attached to the carbon bearing the nitro functionality. Importantly, the reaction can be scaled up without losing yield and stereoselectivity and with full recovery of the catalyst.We thank the Spanish MICINN (FEDER) for financial support (CTQ2011-28417-C02-02) and CSIC for a JAE-PRE grant (F. C.-A.).Peer Reviewe

Educación especial y diversidad educativa

[Resumen] Nuestra felicitación a los Profesores Barca y Duarte, en su calidad de Presidentes del Comité Organizador, por el nivel de los temas propuestos para este Congreso, su buena marcha y, sobre todo, por el éxito obtenido en la convocatoria para la realización de este gran evento. La pretensión en esta ponencia, Educación Especial y Diversidad Educativa, es darles a conocer algunos aspectos del trabajo que en este momento estamos realizando un grupo de profesores del Departamento de Psicología Evolutiva y de la Educación en la Universidad de Vigo. Para ello, en primer lugar, nos referiremos brevemente a la consideración de la Diversidad y de la Educación Especial; en segundo lugar hablaremos de los procesos cognitivos en cuanto maximizadores del aprendizaje y que se ponen de manifiesto cuando se aprende, de cuáles son y de su medida y, en tercer lugar, de la intervención consiguiente centrada en el curriculum escolar y en el contexto del grupo clase

A modular, one-pot, four-component synthesis of polysubstituted 1,3-oxazolidines

4 pages, 1 figure, 1 table, 1 scheme.-- PMID: 15675866 [PubMed].-- Printed version published Feb 4, 2005.Supporting information available: Spectroscopic and analytical data for compounds 3c-j.-- Available at: http://pubs.acs.org/doi/suppl/10.1021/jo048469qA modular, one-pot, two-step, four-component synthesis of polysubstituted 1,3-oxzolidines is described. The method comprises two linked domino processes: an organocatalyzed domino reaction of alkyl propiolate and an aliphatic aldehydes and a microwave-assisted amine addition cyclization domino process. An alternative modular, one-pot, three-step, four-component synthesis has also been developed by linking the organocatalyzed domino process to a sequential amine addition/Yb(OTf)3-catalyzed enamine cyclization reaction.This research was supported by the Spanish Ministerio de Educación y Ciencia (PPQ-2002-04361-C04-03). D.G.C. thanks the Spanish Ministerio de Educación y Ciencia for a FPI grant. F.G.T. and D.T. thank the Instituto Canario de Investigación del Cáncer for financial support (ICIC-PI. No. 07/2004; ISCIII, RTICCC C03/10)

Propargyl Claisen rearrangement: Allene synthesis and beyond

The propargyl Claisen rearrangement is a known protocol to gain access to functionalized allenes through the [3,3]-sigmatropic transformation of propargyl vinyl ethers. The correct use of appropriate propargyl vinyl ethers as starting materials coupled with suitable reaction conditions can aid in the development of new domino methodologies in which the allenes are valuable intermediates in route to a wide range of important classes of organic compounds. © The Royal Society of Chemistry 2013.This research was supported by the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (CTQ2011-28417-C02-02). G.M.A. and L.C. thank the Spanish MEC for FPU and FPI grants, respectively.Peer Reviewe

Merging domino and redox chemistry: Stereoselective access to di- and trisubstituted β,γ-unsaturated acids and esters

Merging is the game! The coupling of a domino reaction and an internal neutral redox reaction constitutes an excellent manifold for the stereoselective synthesis of di- and trisubstituted olefins featuring a malonate unit, an ester, or a free carboxylic acid as substituents at the allylic position (see scheme; MW=microwave). The reaction utilizes simple starting materials (propargyl vinyl ethers), methanol or water as solvents, and a very simple and bench-friendly protocol. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.This research was supported by the Spanish MICINN and the European RDF (CTQ2008–06806-C02–02), the Spanish MSC ISCIII (RETICS RD06/0020/1046), FUNCIS (REDESFAC PI01/06). G. M.-A. and L. C. thank Spanish MEC for FPU and FPI grants, respectively.Peer Reviewe