Chelation-assisted metal-catalyzed functionalization of strong Csp2-H/Heteroatom bonds: trapping intermediate species and unveiling mechanistic details

Capdevila Güell, Lorena
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 ​
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