Solvent-Free Iridium-Catalyzed Reactivity of CO₂ with Secondary Amines and Hydrosilanes

The complex [Ir(H)(CF₃SO₃)(NSiN)(coe)] (NSiN=bis(pyridine-2-yloxy)methylsilyl fac-coordinated) (1) is an effective catalyst precursor for the solvent-free synthesis of silyl carbamates from reaction of aliphatic secondary amines with CO₂ and HSiMe(OSiMe₃)₂. The preferential formation of the silyl carbamate instead of the expected formamide or methylamine has proven to be consequence of an iridium-catalyzed dehydrogenative Si-N coupling between the silane and the amine to afford the corresponding silyl amine, which under the reaction conditions reacts with CO₂ to give the corresponding silyl carbamate. No solvent, please! This work constitutes a first example of an iridium-catalyzed methodology for the solvent-free synthesis of silyl carbamates from secondary amines, CO₂, and hydrosilanes.