Donor-Promoted 1,2-Hydrogen Migration from Silicon to a Saturated Ruthenium Center and Access to Silaoxiranyl and Silaiminyl Complexes

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• 作者：Hsueh-Ju Liu ; Clark Landis ; Christophe Raynaud ; Odile Eisenstein ; T. Don Tilley
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：July 22, 2015
• 年：2015
• 卷：137
• 期：28
• 页码：9186-9194
• 全文大小：557K
• ISSN：1520-5126

文摘

Masked silylene complexes Cp*(IXy-H)(H)RuSiH₂R (R = Mes (3) and Trip (4); IXy = 1,3-bis(2,6-dimethylphenyl)imidazol-2-ylidene; 鈥淚Xy-H鈥?is the deprotonated form of IXy) exhibit metallosilylene-like (L_nM鈥揝i鈥揜) reactivity, as observed in reactions of nonenolizable ketones, enones, and tosyl azides, to give unprecedented silaoxiranyl, oxasilacyclopentenyl, and silaiminyl complexes, respectively. Notably, these silicon-containing complexes are derived from the primary silanes MesSiH₃ and TripSiH₃ via activation of all three Si鈥揌 bonds. DFT calculations suggest that the mechanism of formation for the silaoxiranyl complex Cp*(IXy)(H)₂Ru鈥揝i(OCPh₂)Trip (6) involves coordination of benzophenone to a silylene silicon atom, followed by a single-electron transfer in which Si-bonded, non-innocent benzophenone accepts an electron from the reactive, electron-rich ruthenium center. Importantly, this electron transfer promotes an unusual 1,2-hydrogen migration to the resulting, more electron-deficient ruthenium center via a diradicaloid transition state.