YANG Weijun, ZHANG Lei, LI Yongjin, GUO Cancheng

(College of Chemsitry and Chemical Engineering, Hunan University, Changsha 410082, China)

Abstract: The reaction of hydrogen peroxide, tert-butyl hydrogen peroxide or cumene hydrogen peroxide with tyrene, cyclohexene and trans-stilbene, catalyzed by phenyl ortho or para Cl substituent position of tetraphenylmetalloporphyrins, have been studied in this paper. Effect of different Cl substituent position on the catalytic performance for olefins epoxidation of tetraphenylmetalloporphyrins has been investigated. The results show that 5,10,15,20-tetrakis-(2,6-dichlorophenyl)porphyrin iron (or manganese) chloride(Fe^Ⅲ(TDCPP)Cl or Mn^Ⅲ(TDCPP)Cl) on the epoxidation of olefin exhibits excellent catalytic properties, which the olefins conversion and epoxide selectivity is better than the tetra-(p-chorophenyl)-porphyrin iron (or manganese) chloride(Fe^ⅢT(p-Cl)PPCl or Mn^ⅢT(p-Cl)PPCl), and the reaction conditions is mild. Fe^Ⅲ(TDCPP)Cl exhibits the best catalytic performance and epoxide selectivity. When it applied to catalyze oxidation of styrene, the styrene oxide selectivity reached 90.4%. The catalytic performance of different metalloporphyrin ligands with same metal ions are in the following order: TDCPP>T(p-Cl)PP>TPP. Oxidant structure affects the selectivity of epoxides. Cumene hydroperoxide, which peroxy bond links with electron drawing groups, gets the highest epoxide selectivity. According to the experimental results, the metalloporphyrins’ epoxidation mechanism is also analyzed.

Key words: Tetraphenylmetalloporphyrin; Peroxide; Catalytic epoxidation; Olefins Epoxide

E-mail: wjyang@hnu.edu.cn 

Journal of Molecular Catalysis, Vol. 26, Issue 4, 2012,341-321