New Directions in Aminocatalysis: Vinylogy and Photochemistry

Identificador:  TDX:2483

Handle: https://hdl.handle.net/20.500.11797/TDX2483

Autors:  Silvi, Mattia

Resum:
Over the past 15 years organocatalysis attracted a great number of research groups, for this reason finding new concepts in this field is nowadays remarkably difficult. In this manuscript, we successfully merge the concept of aminocatalysis with the principle of vinylogy (the propagation of the electronic effects through the conjugated π-system of poly-unsaturated compounds) in order to stereoselectively address γ and δ functionalizations of unsaturated aldehydes. This approach led to the synthesis of γ-alkylated aldehydes from α,β-unsaturated aldehydes with high enantiomeric excess. In the same time, the employment of α,β,γ,δ-diunsaturated aldehydes under iminium ion activation led to the highly stereoselective synthesis of spirooxindoles, valuable scaffolds for development of biologically interesting compounds. In the second part of this manuscript, we successfully merge the concept of aminocatalysis with photochemistry, in order to realize novel asymmetric functionalizations of aldehydes that would be otherwise unaccessible through standard ground-state reactivity. Notably, easily available light sources (LEDs of compact fluorescent lamps) were used for the development of the chemistry reported.