Cleavage of Si–H and Si–C Bonds by Metal–Ligand Cooperation: Formation of Silyl Anion and Silylene Equivalents from Tertiary Silanes

The
cleavage of silicon–hydrogen bonds to generate silicon-containing
metal complexes has played an essential role in the preparation of
organosilicon compounds. Herein, we report the reaction of cyclopentadienone
iridium complex 1 with hydrosilanes to afford hydroxycyclopentadienyl
iridium silyl complexes 4 via the umpolung of the Si–H
bond. The nucleophilicity of the Ir–Si bond in the resulting
complex was demonstrated in the reaction with an allyl halide and
ethyl acrylate. Furthermore, a silylene complex was formed from hydroxy­cyclopentadienyl
silyliridium complex 4 via the formal reductive elimination
of the C–H bond at the silicon center to release benzene. The
silylene complex synthesized from tricarbylsilane showed ambiphilic
reactivities, which are consistent with the classical reactivities
of silylenes.