Asymmetric Epoxidation of α,β‐Unsaturated Ketones Catalyzed by Chiral Iron Complexes of (R,R)‐3,4‐Diaminopyrrolidine Derived N4‐Ligands with Camphorsulfonyl Sidearms

Abstract

Three (R,R)‐3,4‐diaminopyrrolidine‐based chiral N4 ligands and corresponding iron complexes were synthesized. The complexes were applied to the asymmetric epoxidation of various α,β‐unsaturated ketones with H2O2 as an oxidant and carboxylic acid as auxiliary. Good to excellent enantioselectivity (up to 97%) was achieved in the case of 2,2‐dimethylbutyric acid as an auxiliary.