Manganese salen compounds embedded within cross-linked chiral polyethylenimine: Asymmetric epoxidation in an aqueous biphasic medium

Chiral cross-linked polyethylenimines were used to intercalate MnIII salen catalysts, thereby inducing a chiral environment upon an achiral metal complex. The synzyme, dispersed in water, catalyzes the aqueous biphasic asymmetric epoxidation of styrene derivatives (see structure; L=Cl, OAc, R=isopropyl, phenyl). In the presence of the chiral catalyst there is a significant synergistic effect that increases the enantioselectivity of epoxidation.