Chelation-assisted metal-catalyzed functionalization of strong Csp2-H / Heteroatom bonds: trapping intermediate species and unveiling mechanistic details
- Autores: Lorena Capdevila i Güell
- Directores de la Tesis: Xavier Ribas Salamaña (dir. tes.)
- Lectura: En la Universitat de Girona ( España ) en 2022
- Idioma: inglés
- Tribunal Calificador de la Tesis: Bas de Bruin (presid.), Anna Pla Quintana (secret.), Noel Nebra Muñiz (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The development of new methodologies for the construction of complex molecules is one of the principal objectives in synthetic organic chemistry. Although huge advances have been made on cross-coupling reactions, there is continuous research on direct C-H functionalization of non-prefunctionalized substrates or more challenging substrates bearing strong C-F or C-OR groups. The first part of this PhD dissertation describes the advances reported in the literature in cobalt cross-coupling catalysis demonstrating the capability of cobalt to catalyze these transformations. Then, C–H amination reactions using a high valent cobalt system and azides are studied in order to elucidate the involvement of a Co-nitrene intermediate species. To do so, the reactivity of well-defined aryl–Co(III) organometallic complex towards inorganic and organic azides is tested. On the other hand, this thesis deals with the use of non-cyclic model platforms bearing direct groups to study Ni-catalyzed C–F and C–OMe functionalization. The synthesis of isoquinolones and aromatic homologation products using alkynes as coupling partner is explored. Thanks to coordination properties of 8-aminoquinoline bidentate directing group, a key double alkyne inserted intermediate species is isolated. Finally, the ability of 8-aminoquinoline directing group was also explored in the study of Ag-catalyzed aryl-halide cross-coupling transformations using several nucleophiles, where the two-electron redox Ag(I)/Ag(III) reactivity is operating.
