Aerobic enantioselective epoxidation of olefins mediated by an easy-to-prepare recyclable manganese-porphyrin

- First new simple-to-synthesis chiral Mn-porphyrin based nanocomposite was synthesized.
- Asymmetric oxidation of unfunctionalized olefins was achieved with high conversion and ee% by using catalyst/RCHO/O2 system.
- The chiral nanocomposite is recyclable at least seven times.

Asymmetric catalysis is limited by using complex catalyst synthesis and enantioselectivity of the catalyst. Here, we report a simple and an easy to synthesis recyclable chiral manganese-porphyrin (Fe3O4-[Mn(TPyP)tart]) for enantioselective aerobic epoxidation of olefins. With magnetite nanoparticles as support, the immobilized cationic manganese-porphyrin system showed high activity and selectivity for the oxidation of olefins (cis- and trans-stilbene, styrene, 1-decene, 1-phenyl-1-cyclohexene) by RCHO/O2 to give optically active epoxides (enantiomeric excess up to 97%). The effects of solvent and reaction time and the performance of the recovered catalysts were studied.

A new chiral Mn-porphyrin based nanocomposite was synthesized and used for asymmetric oxidation of unfunctionalized olefins by RCHO/O2.