Study of metal acetylacetonates as catalyst in the reaction of CO2 and styrene oxide to produce styrene carbonate

Employing carbon dioxide as a renewable C1 building block in chemical reactions is attracting attentions in recent years. Reacting CO2 with high energy reagents such as H2 and epoxides in the presence of suitable catalysts is a strategy to overcome the thermodynamic stability of CO2. Reaction of CO2 and epoxides produces polymeric carbonates and cyclic carbonates with several practical and potential applications such as reagents in polyurethane synthesis, biodegradable polymers, and as green solvents in various reactions. In this research, metal acetylacetonate complexes of Fe(III)(acac-F3), Fe(III)(acac)3 , Ni(II)(acac)2, Ni(II)(acac-F6)2, and Co(II)(acac)2, Co(II)(acac-F6)2 are investigated as easily available catalysts in the reaction of styrene oxide and CO2 in the presence of organic halides. The effect of CO2 pressure, catalyst and co-catalyst structure is investigated. A high yield as 61% was observed at 80 ºC and 1 bar of CO2 after 3h. Increasing the CO2 pressure up to 80 bar had a significant effect on the carbonate conversion as 88% yield was obtained. With fluorinated complexes increasing the yield was even more and up to 92% yield was observed.