Enantioselective epoxidation of non-functionalized alkenes using carbohydrate based salen-Mn(III) complexes.
Three new salen ligands with carbohydrate moieties were prepared from a salicylaldehyde derivative obtained by reaction of 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose with 3-tert-butyl-5-(chloro-methyl)-2-hydroxybenzaldehyde. These ligands were coordinated with Mn(III) to give three chiral salen-Mn(III) complexes. The complexes were characterized and employed in the asymmetric epoxidation of unfunctionalized alkenes. Catalytic results showed that although there are no chiral groups on the diimine bridge, these complexes had some enantioselectivity, which indicates the carbohydrate moiety has an asymmetric inducing effect in the epoxidation reaction.
Zhao
Shanshan
S
School of Chemical Engineering, Hebei University of Technology, Tianjin 300130, PR China.
Zhao
Jiquan
J
Zhao
Dongmin
D
D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D004852:Epoxy Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D008968:Molecular Conformation; D013237:Stereoisomerism
D000475:Alkenes; D004852:Epoxy Compounds; D005029:Ethylenediamines; D008345:Manganese; C011452:disalicylaldehyde ethylenediamine