Fluorosilane Activation by Pd/Ni→Si-F→Lewis Acid Interaction: An Entry to Catalytic Sila-Negishi Coupling.

A new mode of bond activation involving M→Z interactions is disclosed. Coordination to transition metals as σ-acceptor ligands was found to enable the activation of fluorosilanes, opening the way to the first transition-metal-catalyzed Si-F bond activation. Using phosphines as directing groups, sila-Negishi couplings were developed by combining Pd and Ni complexes with external Lewis acids such as MgBr2. Several key catalytic intermediates have been authenticated spectroscopically and crystallographically. Combined with DFT calculations, all data support cooperative activation of the fluorosilane via Pd/Ni→Si-F→Lewis acid interaction with conversion of the Z-type fluorosilane ligand into an X-type silyl moiety.

Pd/Ni-Catalyzed Germa-Suzuki coupling via dual Ge-F bond activation.

Pd/Ni → Ge-F interactions supported by phosphine-chelation were found to trigger dual activation of Ge-F bonds under mild conditions. This makes fluoro germanes suitable partners for catalytic Ge-C cross-coupling and enables Germa-Suzuki reactions to be achieved for the first time.