| The behavior of fluorous biphasic systems (FBS) as followed were studied: perfluorodecalin/toluene (C10F18/CH3C6H5), perfluorodecalin/fluorobenzene (C10F18/ C6H5F), perfluorodecalin/anisole (C10F18/C6H5OCH3), perfluoromethylcyclohexane /toluene (CF3C6F11/CH3C6H5), perfluoromethylcyclohexane/benzene (CF3C6F11/C6H6), perfluoromethylcyclohexane/hexane (CF3C6F11/C6H14), perfluorooctyl bromide/toluene (C8F17Br/CH3C6H5).The catalyst of rare earth(III) perfluorooctanesulfonates (RE(OPf)3, RE=Sc,Y, La～ Lu) were prepared from either rare earth chlorides(III) or oxides and perfluorooctane-sulfonic acid. The perflates obtained were characterized by DSC, ICP, IR, and Elemental Analysis. The perflates thus acted as novel catalysts for nitration, esterification, Friedel-Crafts acylation and alkylation, synthesis of acetal, aldol-condensation, condensation of alcohol with amine, Mannich reaction, and oxidation in fluorous biphasic system. Perfluorohexane (C6F14), perfluoromethylcyclohexane (C7F14), perfluorotoluene (C7F8), perfluorooctane (C8F18), perfluorooctyl bromide (C8F17Br) and perfluorodecalin (C10F18 , cis and /ram-mixture) can be used as fluorous solvents for these reactions. Effects of reaction temperature, reaction time, amount and species of catalyst, species of fluorous solvent, and the ratio of fluorous phase/organic phase on these reactions were investigated. Yb(OPf)3 and C10F18 were the best catalyst and fluorous solvent respectively. By simple phase separation the fluorous phase containing catalyst could be re-utilized up to five times only with a little decrease in activity.The perfluorinated metal catalysts (M(OPf)x, M = Ti～Zn, x = 2,3,4,5) were also prepared for Friedel-Crafts alkylation, aldol-condensation, and oxidation. It was found that Co(OPf)2 was the most active catalyst.A novel catalytic system named 'RE(OPf)3-PfOH-PFC' has been found highly effective for Friedel-Crafts reaction and dinitration. |
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