1,4-Dihydropyridines as Versatile Reagents in Photochemical Carbon-Carbon Bond-Forming Processes

Identificador:  TDX:3091

Handle: https://hdl.handle.net/20.500.11797/TDX3091

Autores:  Alandini, Nurtalya

Resumen:
Photochemical transformations rely on the ability of organic molecules or catalysts to absorb light and reach the electronically excited states. Since the chemical and physical properties of excited-state molecules significantly differ from the ground state, light-mediated chemistry can offer interesting new reactivity patterns that are unavailable under thermal activation. The main objective of this doctoral studies was to implement photochemical strategies suitable for developing useful synthetic transformations not achievable using established thermal approaches. In particular, I investigated and exploited the unique ability of 4-substituted-1,4-dihydropyridines (DHPs) to form carbon-centered radicals under mild conditions. In the first project (Chapter III), 4-alkyl-1,4-dihydropyridines (alkyl-DHPs) were employed as alkyl radical precursors in the enantioselective alkylation of enals triggered by the visible-light excitation of in situ generated chiral iminium salts. In the second part of the doctoral studies (discussed in Chapter IV), 4-carbamoyl-1,4-dihydropyridines (carbamoyl-DHP) were employed as carbamoyl radical sources and applied in nickel-catalyzed radical cross-coupling reactions for the synthesis of a wide range of (hetero)aryl amides.