Observations and comments on the mechanism of epoxidation of alkenes by manganese(III) porphyrins with hypochlorite.
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.
Lee
R W
RW
Department of Chemistry, University of California, Santa Barbara 93106.
Nakagaki
P C
PC
Balasubramanian
P N
PN
Bruice
T C
TC
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
D000475:Alkenes; D004852:Epoxy Compounds; D004988:Ethers, Cyclic; D008665:Metalloporphyrins; D008345:Manganese; D006997:Hypochlorous Acid