title: Alkyl migration aptitudes in the vinylidene-acetylene rearrangement and isotope effect in the vinylidene formation process from a deuterium-labeled cyclopropene.
abstract: The secret of the mechanism of vinylidene rearrangements has been unlocked by the use of specifically labeled cyclopropenes under mild thermal conditions (see the Equations). (13) C labeling gives the surprising 1,2-alkyl migratory aptitude sequence Et>iPr>Me. Deuterium labeling yields the first measurement of the primary kinetic isotope effect in the ring opening of a cyclopropene to form a vinylidene.
authors.affiliation: Institut für Organische Chemie der Technischen Universität, Hagenring 30, D-38106 Braunschweig, Germany, Fax: (+49) 531-3915388.
authors.forename: W
authors.initials: W
authors.lastname: Graf von der Schulenburg
authors.forename: H
authors.initials: H
authors.lastname: Hopf
authors.forename: R
authors.initials: R
authors.lastname: Walsh
keywords: Cyclopropene; Isotope effects; Reaction mechanisms; Rearrangements; Vinylidene