title: Transition-Metal-Mediated Cleavage of Fluoro-Silanes under Mild Conditions.
abstract: Si-F bond cleavage of fluoro-silanes was achieved by transition-metal complexes under mild and neutral conditions. The Iridium-hydride complex [Ir(H)(CO)(PPh3 )3 ] was found to readily break the Si-F bond of the diphosphine- difluorosilane {(o-Ph2 P)C6 H4 }2 Si(F)2 to afford a silyl complex [{[o-(iPh2 P)C6 H4 ]2 (F)Si}Ir(CO)(PPh3 )] and HF. Density functional theory calculations disclose a reaction mechanism in which a hypervalent silicon species with a dative Ir→Si interaction plays a crucial role. The Ir→Si interaction changes the character of the H on the Ir from hydridic to protic, and makes the F on Si more anionic, leading to the formation of H(δ+) ⋅⋅⋅F(δ-) interaction. Then the Si-F and Ir-H bonds are readily broken to afford the silyl complex and HF through σ-bond metathesis. Furthermore, the analogous rhodium complex [Rh(H)(CO)(PPh3 )3 ] was found to promote the cleavage of the Si-F bond of the triphosphine-monofluorosilane {(o-Ph2 P)C6 H4 }3 Si(F) even at ambient temperature.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Gakuen-cho 1-1, Naka-ku, Sakai, Osaka, 599-8531, Japan. h.kameo@c.s.osakafu-u.ac.jp.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kameo
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto 3-3-138, Sumiyoshi-ku, Osaka, 558-8585, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kawamoto
authors.affiliation: Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-nishihiraki-cho 34-4, Sakyo-ku, Kyoto, 606-8103, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Sakaki
authors.affiliation: Laboratoire Hétérochimie Fondamentale et Appliquée, Universit Paul Sabatier/CNRS UMR 5069, 118 Route de Narbonne, 31062, Toulouse Cedex 09, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Bourissou
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto 3-3-138, Sumiyoshi-ku, Osaka, 558-8585, Japan. nakazawa@sci.osaka-cu.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakazawa
keywords: Si−F bond; Z-type ligands; cleavage reactions; sigma-bond metathesis; transition metals