Unprecedent formation of methylsilylcarbonates from iridium-catalyzed reduction of CO(2) with hydrosilanes

The iridium complex [Ir(μ-CF(3)SO(3))(κ(2)-NSi(Me2))(2)](2) (3) (NSi(Me2) = {4-methylpyridine-2-yloxy}dimethylsilyl) has been prepared by reaction of [Ir(μ-Cl)(κ(2)-NSi(Me2))(2)](2) (1) with two equivalents of AgCF(3)SO(3). The solid structure of 3 evidenced its dinuclear nature, being a rare example of an iridium species with triflate groups acting as bridges. The 3-catalyzed reduction of CO(2) with HSiMe(OSiMe(3))(2) affords a mixture of the corresponding silylformate and methoxysilane together with the silylcarbonate CH(3)OCO(2)SiMe(OSiMe(3))(2) (4a). This is the first time that the formation of silylcarbonates has been observed from the catalytic reduction of CO(2) with silanes. Analogous behaviour has been observed when HSiMe(2)Ph and HSiMePh(2) were used as reductants.