Ytterbium perfluorooctanesulfonates catalyzed synthesis of benzimidazole derivatives in fluorous solvents

Catalytic condensation of o-phenylenediamine and aldehydes was accomplished using rare earth(III)perfluorooctane sulfonates (RE(OPf)3), RE = Sc, Y, La ∼ Lu) as catalysts in fluorous solvents. Ytterbium perfluorooctanesulfonates (Yb(OPf)3) catalyzes the high-efficient synthesis of benzimidazole derivatives in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.