Bioinspired Manganese Complexes and Graphene Oxide Synergistically Catalyzed Asymmetric Epoxidation of Olefins with Aqueous Hydrogen Peroxide

Bioinspired manganese complexes of N4 ligands and graphene oxide (GO) synergistically catalyze the highly enantioselective epoxidation of olefins (up to 99% ee), which is a rare example with GO as a co‐catalyst in asymmetric catalysis. GO as a new and key additive not only successfully functions in catalytic amounts, but also has a positive effect for improving the enantioselectivity of the asymmetric epoxidation compared with the traditional stoichiometric organic carboxylic acid method [e.g., chalcone, 95% ee (3.5 mg GO) vs. 84% ee (5 equiv., 75 mg acetic acid), ethyl cinnamate, 84% ee (3.5 mg GO) vs. 19% ee (5 equiv., 75 mg acetic acid)]. The X‐ray photoelectron spectroscopy (XPS) spectra of GO before and after the reaction indicate that the intensities of C–O become stronger after the reaction, which may have a certain relationship with hydrogen peroxide (H2O2) and gives a reasonable rationale for the large consumption of H2O2. Also, part of the hydrogen peroxide was used for the oxidation of GO. magnified image