Unusual activity and selectivity in alkyne hydrosilylation with an iridium catalyst stabilized by an O-donor ligand
- Yale Univ., New Haven, CT (USA)
Catalytic alkyne hydrosilylation has been found for iridium in the O-donor ligand environment of Grim's triso ligand (=tris(diphenyloxophosphoranyl)methanide). The reaction is selective for 1-alkynes and regioselective for {beta}-products and gives the thermodynamically less favored cis-vinylsilane products by an unexpected anti addition of Si-H to the triple bond. Mechanistic studies suggest that the alkyne first inserts into the M-Si, not the M-H, bond and that a trans to cis rearrangement occurs via an {eta}{sup 2}-vinyl intermediate before reductive elimination. A number of Rh and Ir complexes of the type ((triso)ML{sub 2}) are prepared. IR studies on the CO complexes show that the donor power of triso compares with that of other related ligands in an unexpected order: Tp < P{sub 3}O{sub 9}{sup 3{minus}} < triso < Cp.
- OSTI ID:
- 6347432
- Journal Information:
- Journal of the American Chemical Society; (USA), Journal Name: Journal of the American Chemical Society; (USA) Vol. 112:22; ISSN 0002-7863; ISSN JACSA
- Country of Publication:
- United States
- Language:
- English
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