Well-defined iron complex-mediated catalytic C-3-selective silylation of indole derivatives and stoichiometric C–H bond functionalization of arenes were achieved using an iron dicarbonyl complex containing the disilaferracycle moiety [o-(SiMe2)2C6H4]Fe(CO)2[o-{η2-(H-SiMe2)2}C6H4] (1). Facile liberation of the η2-(H-Si) groups in 1 was the key to effective promotion of these reactions.

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.

Reaction of 2 equiv of 1,2-bis(dimethylsilyl)benzene with [Fe(mesityl)2]2 in aromatic solvent under a nitrogen atmosphere afforded the dinuclear bis(silyl)iron complexes [(η6-arene)Fe(Me2SiC6H4SiMe2)]2(μ-η1:η1-N2) (1), which have an end-on-bound bridging dinitrogen ligand. The dinitrogen unit easily dissociated from the Fe center to generate the mononuclear (η6-arene)FeII(Si)2L or (η6-arene)FeIV(Si)2H2 complexes by the reactions with CO, PPh3, and H2.