LAUSR

A new mode of bond activation involving M->Z interactions is disclosed. Coordination to transition metals as sigma-acceptor ligands was found to enable the activation of fluoro silanes, opening the way to the first transition met-al-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 crystallo-graphically. Combined with DFT calculations, all data support cooperative activation of the fluoro silane via Pd/Ni->Si-F->Lewis acid interaction with conversion of the Z-type fluoro silane ligand into an X-type silyl moiety.