1. New silanimine and NSi…H…M agostic complexes for coupling
with petroleum derived products
Georgii I. Nikonov, Department of Chemistry, Brock University
Free silanimines are so highly reactive species that when coordinated to transition metals they still maintain a lot of their original reactivity. Because free silanimnes are highly unstable, their few known metal complexes were prepared by a multistage pathway, which hampers further development of this field to synthesis and catalysis. Our research is focused on the generation of reactive silanimine complexes by the direct coupling of imido complexes with silanes.
The final goal is to achieve a catalytic tri-component coupling of amines, silanes, and petroleum derived unsaturated organic products that would be mediated by transition metal complexes in a regio- and sterioselective manner.
Our main accomplishments in the final grant period include:
Coupling of three silane molecules with
the imido complex (tBuN=)2Mo(PMe3)2
to give the tris(silyl) hydride
{2-tBuN(PhHSi)2}Mo(PMe3)2(H)(SiH2Ph) (1),
thus proving our notion that the imido ligand
can be coupled with silanes and eventually detached from the metal, which may be a step in the proposed tricomponent coupling of an amine, silane, and unsaturated organic substrate.
Mechanistic study shows that this coupling proceeds via the new agostic species {3-(tBuN)(PhHSi)(SiHPh-H…}Mo(PMe3)2(H) (2).
When the coupling is attempted in the exact 1:3 stoichiometry, the silanimine 3 is formed along with the complex 1.