Confinement-Induced Selectivities in Gold(I) Catalysis-The Benefit of Using Bulky Tri-(ortho-biaryl)phosphine Ligands.

The confinement of a catalytic site is an efficient strategy to control a reaction and modulate its selectivity. In the present work, a new class of structurally simple and easily accessible bulky tri-(ortho-biaryl)phosphine ligands were accessed, and their gold(I) complexes synthesized. Their X-ray diffraction analysis and the comparative evaluation of their V Bur % and G steric parameters against a series of gold complexes commonly employed in catalysis demonstrated their confined nature. Despite their notable steric congestion, these complexes exhibited remarkable catalytic activities and unusual selectivities, both in nature and level, that make them unique in the field of synthetic homogeneous gold catalysis.