Mechanistic Studies on Gold(I) and Gold(III) Catalytic Transformations

Identifier:  TDX:4522

Handle: https://hdl.handle.net/20.500.11797/TDX4522

Authors:  Arranz De la Calle, Isabel

Abstract:
The potential of gold as a catalyst was largely dismissed until the late 20th century due to its assumed inertness. This situation has significantly shifted in both gold(I) and gold(I)/(III) catalysis. The ability of gold(I) to selectively activate alkynes has led to the construction of molecular complexity over the years, generally under mild conditions. Moreover, gold(I) linear complexes have been recently shown to promote oxidative addition, via rational ligand design, giving access to square planar gold(III) complexes. Both modes of gold catalysis have been explored in different systems in this Doctoral Thesis. A mechanistic study of biaryl-pyrrolidinyl phosphine gold(I) complexes explored their mode of action. The chiral gold(I) complex family was expanded with electron-withdrawing substituents, and gold was substituted with silver and copper, revealing a trend in enantioinduction and reactivity in asymmetric catalysis (Au > Ag > Cu). Kinetic studies of the [4+2] cycloaddition of 1,6-enyne catalyzed by a cationic gold(I) complex suggested two competing rate-determining steps. Additionally, the oxidative addition of allyl halides to gold(I) complexes bearing simple alkylphosphines was examined experimentally and computationally, showing an unexpected effect on the DFT description of the system.