Bioinspired Manganese and Iron Complexes with Tetradentate N Ligands for the Asymmetric Epoxidation of Olefins

The manganese and iron complexes with the tetradentate N ligand (1 R ,2 R )‐ N , N' ‐dimethyl‐ N , N' ‐bis(1‐methyl‐2‐benzimidazolylmethyl)cyclohexane‐1,2‐diamine have been synthesized and characterized. The crystal structure of the manganese complex demonstrates a cis ‐α configuration. Both the manganese and iron complexes are active catalysts for the asymmetric epoxidation of olefins with H 2 O 2 as an oxidant and acetic acid as an additive. Up to 96 % ee was observed for the epoxidation of α,β‐unsaturated ketones at −20 °C.