Transition‐Metal‐Mediated Cleavage of Fluoro‐Silanes under Mild Conditions |
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| Authors: | Dr. Hajime Kameo Tatsuya Kawamoto Prof. Shigeyoshi Sakaki Prof. Didier Bourissou Prof. Hiroshi Nakazawa |
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| Affiliation: | 1. Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Osaka, Japan;2. Department of Chemistry, Graduate School of Science, Osaka City University, Osaka, Japan;3. Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-nishihiraki-cho 34-4, Sakyo-ku, Kyoto, Japan;4. Laboratoire Hétérochimie Fondamentale et Appliquée, Universit Paul Sabatier/CNRS UMR 5069, Toulouse Cedex 09, France |
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| 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‐Ph2P)C6H4}2Si(F)2 to afford a silyl complex [{[o‐(iPh2P)C6H4]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 Hδ+???Fδ? 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‐Ph2P)C6H4}3Si(F) even at ambient temperature. |
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| Keywords: | cleavage reactions Si− F bond transition metals sigma-bond metathesis Z-type ligands |
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