ACRYLAMIDE-CO-METHACRYLAMIDE COPOLYMERS CARRYING PEPTIDE SIDE-CHAINS - APPLICATION TO ASYMMETRIC CATALYSIS

The stereoselective epoxidation of chalcone, catalyzed by poly(L-alanine) (PLA)-grafted N-benzylacrylamide-co-N-aminopropyl methacrylamide copolymers, was carried out in the ternary system water/CCl4/polymer catalyst. The resulting oxirane was obtained with about 60% yield with an enantiomeric excess (e. e.) of 80%. A good catalytic efficiency was observed even under conditions of high dilution. When the same catalyst was used a third time, an important racemization of supported PLA gave a strong decrease of yield and e. e. values of the resulting epoxide. Better results with a lower benzylacrylamide moiety content in the copolymer backbone might be due to a higher density of PLA chains.