9 resultados para K. Michael Haywood

em Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco


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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.

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[EN] Language Down the Garden Path traces the lines of research that grew out of Bever's classic paper. Leading scientists review over 40 years of debates on the factors at play in language comprehension, production, and acquisition (the role of prediction, grammar, working memory, prosody, abstractness, syntax and semantics mapping); the current status of universals and narrow syntax; and virtually every topic relevant in psycholinguistics since 1970. Written in an accessible and engaging style, the book will appeal to all those interested in understanding the questions that shaped, and are still shaping, this field and the ways in which linguists, cognitive scientists, psychologists, and neuroscientists are seeking to answer them.

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Este artículo se ha realizado dentro del Proyecto de Investigación «Identidades y diversidad cultural en la Hispania Antigua: Bilingüismo y Cultura Epigráfica» (HUM 2006-13424-C04-02/Filo).

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[EUS] Foruako aztarnategi arkeologikotik datozen erromatar garaiko forja zepa metalikoen karakterizazioa, garai hartan indarrean zegoen siderurgiari buruzko ezagutza handitzeko asmoz.