Design and screening of biaryl phosphite-based ligand libraries for asymmetric reduction and c-c and c-x bond forming reactions
- Autores: Javier Mazuela Aragón
- Directores de la Tesis: Montserrat Diéguez Fernández (dir. tes.), Oscar Pàmies (codir. tes.)
- Lectura: En la Universitat Rovira i Virgili ( España ) en 2012
- Idioma: español
- Tribunal Calificador de la Tesis: Jan Erling Backvall (presid.), Ester Noemí Cabello Sánchez (secret.), Miguel Yus Astiz (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
During the last years, phosphite-containing compounds have proved to be efficient ligands for several metal-catalyzed transformations. Thanks to their high ¿-acceptor ability, high resistance to oxidation, facile synthesis from chiral alcohols and modular nature several series of ligands can be easily synthesized and screened in the search of the best catalyst. In this context, we have developed several phosphite-containing ligand libraries for their application in reactions leading to enantiomerically pure products of industrial interest. More concretely we have studied: (a) the synthesis and screening of 7 phosphite-nitrogen ligand libraries in the challenging Ir-catalyzed hydrogenation of minimally functionalized olefins, Pd-catalyzed allylic substitution and Heck reactions. These ligand libraries have been designed by systematic modification of several ligand parameters which are know to have a great influence in the catalytic performance. In all cases excellent activities, regio- and enantioselectivities (ee¿s up to >99%) have been obtained for a broad range of substrates. These results compete favorably with those reported previously in the literature, but these ligands have the additional advantage that they are inexpensive and easy to synthesize.
(b) the screening of several types of phosphite containing ligand libraries in the Rh-catalyzed hydroformylation of vinylarenes, heterocyclic olefins and 1,1¿-terminal enol esters obtaining promising results (ee¿s up to 76%).
