Organic Condensation Reactions In Fluorous Biphasic System

The catalysts of rare earth(â…¢) perfluorooctanesulfonates (RE(OPf)₃, RE=Yb, Sc, La,Eu, Tm, Y) were prepared from either rare earth chlorides(â…¢) or oxides andperfluorooctane sulfonic acid. The perflates obtained were characterized by DSC, ICP, IR,and elemental analysis.Yb(OPf)₃ acted as a efficient catalyst for Knoevenagel condensation, Diacetatescondensation, Baylis-Hillmann condensation, in fluorous biphasic system usingperfluorodecalin (C₁₀F₁₈, cis and trans-mixture) as fluorous solvent. Effects of reactiontemperature, reaction time, amount of catalyst, and the ratio of fluorous phase/organicphase on Knoevenagel and Diacetates reactions were investigated. The reactionmechanisms were proposed. By simple phase separation the fluorous phase containingcatalyst could be re-utilized up to five times only with a little decrease in activity.