Descripción del proyecto
Catalizadores quirales eficientes para activar sustratos poliinsaturados
El objetivo del proyecto Foldmetcat, financiado con fondos europeos, es diseñar nuevos tipos de catalizadores con centros de metal de transición electrofílicos capaces simultáneamente de plegar y activar sustratos poliinsaturados y fomentar modos de ciclización no inherentes. Estas cascadas de ciclización atípicas desafían a las investigaciones existentes, que ven la reactividad intrínseca de los sustratos como el único factor determinante de la reactividad química en procesos iniciados por carbocationes. También proporcionan acceso a estructuras carbocíclicas grandes como las presentes en la síntesis enantioselectiva del taxol y la ofiobolina. El proyecto también pretende desarrollar catalizadores quirales electrofílicos eficientes y de uso general basados en metales distintos al oro.
Objetivo
Inspired by mimicking the characteristics of terpenoid cyclase enzymes, the goal of this proposal is to design new types of catalysts containing electrophilic transition metal centers that could simultaneously fold and activate polyunsaturated substrates promoting non-inherent cyclization modes. Our goal is unprecedented, although it is rooted on fundamental organometallic chemistry, in particular, on the known activation of polyunsaturated substrates by highly electrophilic transition metals. These unconventional cyclizations cascades challenge the paradigm that the intrinsic reactivity of the substrate is the relevant factor in carbocation-initiated processes and would provide access to large carbocyclic skeletons such as those present in taxol and ophiobolin enantioselectively in a single step under catalytic conditions. Although the initial work will be carried out with gold catalysts, a major goal of this research is to develop other general-purpose efficient chiral electrophilic catalysts based on zinc. To attain our goal, we will study more simple catalysts to delineate the factors that control the folding of polyenynes and polyenes. Thus, we will prepare new series of C2-chiral catalysts in which the stereogenic elements are close to the reaction site. Related C2-chiral systems will be generated by supramolecular hydrogen-bond pairing. A similar chiral arrangement could also be achieved by an intramolecular chiral anion translocation from the metal to a distant hydrogen-bond donor site. In addition, we will explore larger systems based on structurally well-defined metallic clusters to generate highly electrophilic chiral reactive sites. The folding and activation of polyunsaturated substrates will be studied first with a series of catalytic prototypes based on digold or heterobimetallic complexes with N-heterocyclic carbenes, diphosphines, mixed ligands of these types, as well as resorcinarene-phosphonite cavitant ligands.
Ámbito científico
Programa(s)
Régimen de financiación
ERC-ADG - Advanced GrantInstitución de acogida
43007 Tarragona
España