Non-heme manganese complexes of C1-symmetric N4 ligands: Synthesis, characterization and asymmetric epoxidations of α,β-enones

A series of proline-derived C1-symmetric chiral tetradentate N ligands and their manganese complexes have been synthesized and characterized. Their applications in enantioselective epoxidations of α,β-enones were explored reaching good yields and up to 71% ee at room temperature.

The enantioselective epoxidation of α,β-enones is realized with C1-symmetric chiral manganese complexes of tetradentate N4 ligands derived from naturally occurring proline, up to 71% ee were observed at room temperature.Figure optionsDownload as PowerPoint slideHighlights
► The proline-derived C1-symmetric N4 ligands have been synthesized and characterized.
► The manganese complexes catalyzed epoxidations of α,β-enones were examined.
► Up to 71% ee was observed at room temperature.
► The 6-methyl substituents on the pyridine rings of ligands clearly inhibited the epoxidation.