title: [3+2] versus [2+2] addition of metal oxides across C=C bonds. Reconciliation of experiment and theory.
abstract: The reaction of a metal oxide with a double bond is the initial step in the osmium-catalyzed cis-dihydroxylation of olefins. The mechanism of the addition of osmium tetraoxide and rhenium(VII) oxides across C=C bonds was controversial. Early work indicated a [3+2] addition, and later kinetic studies suggested an initial [2+2] addition, whereas recent quantum-chemical calculations showed the [3+2] addition to be favored. Experiment and theory have now become reconciled. In this Account, we discuss recent contributions to the mechanistic debate as well as future challenges.
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany. deubel@cscs.ch
authors.forename: Dirk V
authors.initials: DV
authors.lastname: Deubel
authors.forename: Gernot
authors.initials: G
authors.lastname: Frenking