The Julia-Colonna asymmetric epoxidation reaction of chalcone catalyzed by length defined oligo-L-leucine: Importance of the N-terminal functional group and helical structure of the catalyst in the asymmetric induction

Article abstract of DOI:10.1246/bcsj.73.2115

Catalysts, oligo-L-leucine, for the Julia-Colonna asymmetric epoxidation of chalcone with defined degrees of polymerization were prepared by a stepwise elongation method. The yield and enantioselectivity in the epoxidation increased with the degree of polymerization of the catalyst. The presence of an unprotected amine moiety at the N-terminus proved to be essential for high asymmetric induction. The IR characteristic absorption bands (the amide I region) of the catalysts suggested that helical structure in the catalyst is related to asymmetric induction.