Disilametallacycles as a Platform for Stabilizing M(II) and M(IV) (M = Fe, Ru) Centers: Synthesis and Characterization of Half-Sandwich Complexes and Their Application to Catalytic Double Silylation of Alkenes and Alkynes

A series of group 8 half-sandwich
disilametallacycles, (η6-arene)­MII(Me2SiC6H4SiMe2)­L and (η6-arene)­MIV(H)2(Me2SiC6H4SiMe2) (M = Fe, Ru) in the formal
oxidation states of M­(II) and M­(IV)
were synthesized and characterized. Both the M­(II) and the M­(IV) oxidation
states were effectively stabilized by the disilametallacycle skeleton,
and facile interconversion between (η6-arene)­MII–dinitrogen, (η6-arene)­MII–carbonyl, and (η6-arene)­MIV–dihydride
complexes bearing a disilaferracycle framework was accomplished. These
M­(II) and M­(IV) complexes can easily generate coordinatively unsaturated
16e disilametallacycles, (η6-arene)­MII(Me2SiC6H4SiMe2), by
dissociation of L or H2, and stoichiometric and/or catalytic
double silylation of alkenes and alkynes was realized thorough this
16e intermediate.