Three complexes of tetrachlorophenylporphyrinatomanganese acetates have been synthesized and characterized by IR and UV spectra. The asymmetric epoxdation of styrene has been investigated by using these three complexe...Three complexes of tetrachlorophenylporphyrinatomanganese acetates have been synthesized and characterized by IR and UV spectra. The asymmetric epoxdation of styrene has been investigated by using these three complexes as catalysts, chiral quaternary ammonium salts as phase transfer catalysts, and quinine as chiral auxiliary, sodium hypochlorite as oxidant. The results showed that the structure of manganese porphyrins, the chiral auxiliaries and temperature of reaction affected the asymmetric induction. The best enantiomer excess reached 12 8%.展开更多
Asymmetric epoxidation of olefins with oxone was first catalyzed by chiral iminium salts generated in situ from chiral amines and aldehydes. With 2S,5S-2,5-dicyclohexylaminocarbonylpyrolidine and t-butylacetaldehyde, ...Asymmetric epoxidation of olefins with oxone was first catalyzed by chiral iminium salts generated in situ from chiral amines and aldehydes. With 2S,5S-2,5-dicyclohexylaminocarbonylpyrolidine and t-butylacetaldehyde, trans-stilbene were epoxdized in 80% conversion, 93% yield and 65% e.e. at 0 ℃.展开更多
文摘Three complexes of tetrachlorophenylporphyrinatomanganese acetates have been synthesized and characterized by IR and UV spectra. The asymmetric epoxdation of styrene has been investigated by using these three complexes as catalysts, chiral quaternary ammonium salts as phase transfer catalysts, and quinine as chiral auxiliary, sodium hypochlorite as oxidant. The results showed that the structure of manganese porphyrins, the chiral auxiliaries and temperature of reaction affected the asymmetric induction. The best enantiomer excess reached 12 8%.
文摘Asymmetric epoxidation of olefins with oxone was first catalyzed by chiral iminium salts generated in situ from chiral amines and aldehydes. With 2S,5S-2,5-dicyclohexylaminocarbonylpyrolidine and t-butylacetaldehyde, trans-stilbene were epoxdized in 80% conversion, 93% yield and 65% e.e. at 0 ℃.
