title: Observations and comments on the mechanism of epoxidation of alkenes by manganese(III) porphyrins with hypochlorite.
abstract: The kinetics of olefin epoxidation in a methylene chloride/water biphase containing a phase-transfer agent with hypochlorite as oxygen transfer reagent and manganese(III) tetraphenylporphyrin catalysts has been reinvestigated. The results do not support the accumulation of an intermediate composed of an alkene and a hypervalent metaloxo porphyrin. Second-order rate constants for oxygen transfer from hypochlorite to the manganese porphyrin, comproprotionation of the hypervalent manganese-oxo porphyrin with manganese(III) porphyrin, and olefin epoxidation by the hypervalent manganese-oxo porphyrin were obtained from experiments in a wet organic monophase.
authors.affiliation: Department of Chemistry, University of California, Santa Barbara 93106.
authors.forename: R W
authors.initials: RW
authors.lastname: Lee
authors.forename: P C
authors.initials: PC
authors.lastname: Nakagaki
authors.forename: P N
authors.initials: PN
authors.lastname: Balasubramanian
authors.forename: T C
authors.initials: TC
authors.lastname: Bruice
mesh_terms: D000475:Alkenes; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D004988:Ethers, Cyclic / Q000138:chemical synthesis*; D006997:Hypochlorous Acid; D007700:Kinetics; D008345:Manganese / Q000378:metabolism; D008665:Metalloporphyrins
chemical_list: D000475:Alkenes; D004852:Epoxy Compounds; D004988:Ethers, Cyclic; D008665:Metalloporphyrins; D008345:Manganese; D006997:Hypochlorous Acid