Polyaniline Salt Catalyzed Cycloaddition of CO₂ to Epoxides

Significance

The catalytic activity of polyaniline-HX (X = I, Br, Cl) (PANI-HI, PANI-HBr, PANI-HCl), as heterogeneous catalysts, was studied for the cycloaddition of carbon dioxide to propylene oxide. Thus, the reaction of CO₂ and propylene oxide (17.4 mmol) was carried out with PANI-HI (0.2 g) at 115 °C under 5 MPa for 5 hours to give propylene carbonate in 99%. PANI-HI was reused four times without any significant loss of catalytic acitivity. The reaction of CO₂ with epichlorohydrin was also carried out for 4 hours under similar conditions to give the corresponding carbonate in >95% yield.