Transition‐Metal‐Mediated Cleavage of Fluoro‐Silanes under Mild Conditions

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)(PPh 3 ) 3 ] was found to readily break the Si−F bond of the diphosphine‐ difluorosilane {( o ‐Ph 2 P)C 6 H 4 } 2 Si(F) 2 to afford a silyl complex [{[ o ‐( i Ph 2 P)C 6 H 4 ] 2 (F)Si}Ir(CO)(PPh 3 )] 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)(PPh 3 ) 3 ] was found to promote the cleavage of the Si−F bond of the triphosphine‐monofluorosilane {( o ‐Ph 2 P)C 6 H 4 } 3 Si(F) even at ambient temperature.