Asymmetric epoxidation of alkenes with tert-butyl hydroperoxide catalyzed by a novel chiral complex of manganese(III) containing a sugar based tridentate Schiff-base ligand
The [MnIII(TDL1∗)(pic)(H2O)] (1) complex (where H2TDL1∗ = N-3,5-di-(t-butyl)salicylidine-d-glucosamine, pic− = picolinate) had been synthesized and characterized by analytical, spectral (UV–vis and IR), molar conductivity, magnetic moment and electrochemical studies. Complex 1 efficiently catalyzed the epoxidation of styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 1-methylcyclohexene and 1,2-dihydronaphthalene using aqueous tert-butyl hydroperoxide (t-BuOOH) as terminal oxidant. The selected alkenes were effectively converted to their organic epoxides in the 50–62% enantiomeric excess(ee) at ambient temperature.
Journal: Catalysis Communications - Volume 8, Issue 9, September 2007, Pages 1345–1348