196929-83-6Relevant academic research and scientific papers
A homogeneous chiral manganese(III)-salphe catalyst for enantioselective epoxidation of olefins
Wei, Saili,Tang, Yuhai,Zhao, Ruiqin,Xu, Xiaoqian,Xu, Guojin,Yu, Yong,Zheng, Yuansuo
, p. 2134 - 2146 (2013)
A new chiral Mn(III)-Salphe catalyst was synthesized from natural amino acid (R)-phenylalanine and 3,5-di-tert-butyl-hydroxybenzaldehyde and applied to the asymmetric epoxidations of unfunctionalized olefins in ionic liquids. Satisfactory enantioselectivities (79% 4O Ac was unnecessary. We proposed that alcoholic hydroxyls in the Mn(III)-Salphe compound played the role of axial ligand. However, the reaction time was longer than when using Jacobsen's catalyst because of the structure of the Mn(III)-Salphe compound, in which coordination geometries by the two alcoholic hydroxyls with certain angles affected the substrate approaching the Mn(V) = 0 center. The chiral ligand was characterized by the combination of infrared, ultraviolet, and visible spectra and 1H NMR. Copyright
