Stoichiometric Reactions of CO₂ and Indium-Silylamides and Catalytic Synthesis of Ureas

The indium compounds In(N(SiMe₃ )₂ )₂ Cl⋅THF (2) and In(N(SiMe₃ )₂ )Cl₂ ⋅(THF)_n (3) were shown to react with CO₂ to give [(Me₃ Si)₂ N)InX(μ-OSiMe₃ )]₂ (X=N(SiMe₃ )₂ 4, Cl 5). 0.05-2.0 mol % of the species 3 acts as a pre-catalyst for the conversion of aryl and alkyl silylamines under CO₂ (2-3 atm) to give the corresponding ureas in 70-99 % yields. A proposed mechanism is supported by experimental and computational data.