Abstract

Amberlyst-21, a kind of well-known and cheap polymeric material, was treated with ytterbium perfluorooctanesulfonate [Yb(OPf)3] giving a reagent with a ytterbium loading of 1.34 (wt %). The polymer-supported fluorous ytterbium catalyses the highly efficient synthesis of 1,5-benzodiazepine derivatives. The catalyst can be recovered by simple filtration under fluorous-solvent-free conditions and used again without a significant loss of catalytic activity.

Keywords: Ytterbium perfluorooctanesulfonate, Amberlyst A-21, polymer supported catalyst, 1,5-benzodiazepines, fluoroussolvent- free