title: Catalytic sulfoxidation and epoxidation with a Mn(III) triazacorrole: evidence for a "third oxidant" in high-valent porphyrinoid oxidations.
abstract: The reaction between (TBP)8(Cz)Mn(III) (1) and the oxygen atom donors iodosylbenzene (PhIO) or p-cyanodimethylaniline-N-oxide (CDMANO) leads to the manganese(V)-oxo complex (TBP)8(Cz)Mn(V)O (2), which has been isolated and characterized previously. Under catalytic conditions with 1 as added catalyst and PhIO as oxidant, both sulfoxidation of PhSMe and epoxidation of cis-stilbene is observed, whereas with CDMANO no sulfoxidation takes place, suggesting that 2 is not the active oxidant. Examination of the independent reactivity of isolated 2 toward PhSMe and cis-stilbene supports this conclusion. A mechanism which relies on a novel type of oxidant involving Lewis acid activation of PhIO by the Mn(V)-oxo complex 2 accounts for these observations and is confirmed by 18O-labeling experiments.
authors.affiliation: Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Sheena Hailin
authors.initials: SH
authors.lastname: Wang
authors.forename: Beaven S
authors.initials: BS
authors.lastname: Mandimutsira
authors.forename: Ryan
authors.initials: R
authors.lastname: Todd
authors.forename: Bobby
authors.initials: B
authors.lastname: Ramdhanie
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Fox
authors.forename: David P
authors.initials: DP
authors.lastname: Goldberg
mesh_terms: D004852:Epoxy Compounds / Q000138:chemical synthesis*; D008345:Manganese / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010103:Oxygen Isotopes; D011166:Porphyrins / Q000737:chemistry*; D013454:Sulfoxides / Q000138:chemical synthesis*
chemical_list: D004852:Epoxy Compounds; D008665:Metalloporphyrins; D010103:Oxygen Isotopes; D011166:Porphyrins; D013454:Sulfoxides; C431863:corrole; D008345:Manganese