Catalytic Cyclic Carbonate Synthesis with Sustainable Metals

Abstract

Cyclic carbonates, which are useful and nontoxic electrolytes, solvents, and chemical intermediates, can be produced by the 100% atom efficient addition of carbon dioxide to epoxides. In this chapter, we discuss the use of sustainable catalysts based on earth‐abundant metals potassium, aluminum, and iron for this reaction, showcasing the most important and recent examples and their mechanism of operation.

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

“…In the light of environmental issues, the development of simple and efficient catalytic systems based on non toxic and earth abundant metals is of ultimate importance to modern synthetic chemistry, 16 and iron certainly plays a central role in this scenario. 17 Various iron compounds have been proposed to catalyze the coupling of CO2 with propylene oxide or more complex epoxides, working either in the presence or in the absence of a co-catalyst; 18 in most of the cases, the use of high CO2 pressure (5-90 bar) and/or high temperature (>80 °C) are generally required in order to achieve satisfactory performances. 13c,19 Remarkably, only few examples of iron complexes, all containing macrocyclic amino-phenolato ligands, are effective in the CO2/epoxide conversion to cyclic carbonates under mild conditions (RT, pCO2 = 1-2 bar), even when the simplest epoxide (i.e., propylene oxide) is concerned.…”