Iron(III) <i>N</i>,<i>N</i>‐Dialkylcarbamate‐Catalyzed Formation of Cyclic Carbonates from CO₂ and Epoxides under Ambient Conditions by Dynamic CO₂ Trapping as Carbamato Ligands

Abstract

Easily available and inexpensive Fe^III carbamates were employed in the solvent-free synthesis of a series of cyclic carbonates from epoxides and CO₂ at room temperature and atmospheric pressure, in the presence of a cocatalyst. Different experimental conditions (type and concentration of catalyst and cocatalyst, as well as reaction time) were investigated: Fe(O₂ CNEt₂ )₃ and NBu₄ Br acted as the best catalyst/cocatalyst combination, allowing the formation of propylene carbonate and 1,2-butylene carbonate with quantitative yield and selectivity in 24 h. According to NMR and DFT studies, the reaction proceeds with the dynamic trapping of carbon dioxide as a carbamato ligand.