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Updated: Apr 7, 2026
Heterogeneous Removal of Water-Soluble Ruthenium Olefin Metathesis Catalyst from Aqueous Media Via Host-Guest Interaction
Published on: August 23, 2018
Donor-Promoted 1,2-Hydrogen Migration from Silicon to a Saturated Ruthenium Center and Access to Silaoxiranyl and
Hsueh-Ju Liu1, Clark Landis2, Christophe Raynaud3,4
1†Department of Chemistry, University of California, Berkeley, California 94720-1460 United States.
Abstract:
Masked silylene complexes Cp*(IXy-H)(H)RuSiH2R (R = Mes (3) and Trip (4); IXy = 1,3-bis(2,6-dimethylphenyl)imidazol-2-ylidene; "IXy-H" is the deprotonated form of IXy) exhibit metallosilylene-like (LnM-Si-R) 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-H bonds. DFT calculations suggest that the mechanism of formation for the silaoxiranyl complex Cp*(IXy)(H)2Ru-Si(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.
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