N-Alkyl Imidazoles as Effective Axial Ligands in the Aerobic Asymmetric Epoxidation of Unfunctionalized Olefins Catalyzed by Optically Active Manganese(III)-salen-type Complex

Article abstract of DOI:10.1246/cl.1994.527

N-Alkyl imidazoles are effective axial ligands to achieve highly enantioselective epoxidation of unfunctionalized olefins by combined use of molecular oxygen and pivalaldehyde with optically active Mn(III)-salen-type complex catalysts.In the presence of N-alkyl imidazole, the epoxidation od 2,2-dimethylchromene proceeded smoothly to afford the corresponding optically active epoxide in 92percent enantiomeric excess.