New procedure for recycling homogeneous catalyst: propylene carbonate synthesis under supercritical CO2 conditions

Polyfluoroalkyl phosphonium iodides, RfRPI (Rf = CFCH, CFCH, CFCH; R = Me, Rf), catalyzed propylene carbonate synthesis from propylene oxide and carbon dioxide under supercritical CO conditions, where propylene carbonate was spontaneously separated out of the supercritical CO phase. The RfRPI catalyst could be recycled with maintaining a high CO pressure and temperature by separating the propylene carbonate from the bottom of the reactor followed by supplying propylene oxide and CO to the upper supercritical CO phase in which the RfRPI remained.