Design of tailor-made chiral ligand libraries for C-X bond forming reactions. Study of the key intermediates by NMR and DFT

Identificador:  TDX:2385

Handle: https://hdl.handle.net/20.500.11797/TDX2385

Autors:  Magre Rosich, Marc

Resum:
Fine chemicals and natural product chemistry rely on enantiomerically pure compounds. The growing demand on these compounds has stimulated the research for efficient asymmetric processes, which provided high activity and selectivity with minimum energy consumption and minimum generation of byproducts. In drugs and also in natural product chemistry, one enantiomer has the desired properties whereas the opposite enantiomer is either inactive or has undesirable side-effects. The discovery of synthetic routes for obtaining enantiomerically pure compounds is therefore one of the most pursued goals in chemistry. Particularly, asymmetric catalysis is one of the most attractive approach because it can provide very high reactivity and selectivity. Usually, with this strategy, a transition-metal complex containing a chiral ligand catalyzes the transformation of a prochiral substrate to one enantiomer as major product. To reach high levels of reactivity and selectivity, several reaction parameters need to be optimized. For example, the design of a chiral ligand is perhaps one of the most crucial step. In this context, this thesis focuses on the development of new chiral ligand libraries, the synthesis of new chiral catalyst and their application in the Pd-catalyzed asymmetric allylic substitution, Pd-catalyzed decarboxylative protonation of oxindoles, Ir-catalyzed asymmetric hydrogenation, Ir-catalyzed asymmetric hydroboration and Ni-1,2-addition of organoaluminum to aldehydes.