Amidinate Aluminium Complexes as Catalysts for Carbon Dioxide Fixation into Cyclic Carbonates

A series of inexpensive and sustainable amidinate aluminium complexes has been developed as catalysts for the chemical fixation of carbon dioxide into cyclic carbonates. The reactions using terminal epoxides as substrates were carried out at room temperature and one bar of carbon dioxide pressure in the presence of tetrabutylammonium iodide as cocatalyst in the absence of solvent. Under these reaction conditions, excellent conversions and selectivities were achieved for a broad range of terminal epoxides. Moreover, the optimal catalyst could be used for the synthesis of disubstituted cyclic carbonates from internal epoxides and carbon dioxide, highlighting the potential of these amidinate aluminium complexes as catalysts.