title: Control of the Regioselectivity in Cobalt- versus Ruthenium-Catalyzed Alder-ene Reaction of Unsymmetrical 1,3-Diynes.
abstract: The Alder-ene reaction of trialkylsilyl-substituted 1,3-butadiynes with terminal alkenes was investigated utilizing a cobalt-based catalyst, and the results were compared with Alder-ene rections catalyzed by the [CpRu(H3CCN)3]PF6catalyst. Obviously, the two catalysts gave complementary results of yn-dienes differing in the site where the new carbon-carbon bond was formed. Of particular interest are observations concerning the double bond migration within the alkene component. While simple alkenes gave exclusively the E-configuration, the application of 3-buten-1-ol resulted in the corresponding Z-double bond, indicating that the hydroxyl group acts as donor coordinating to the cobalt center and thereby altering the reaction pathway.
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg , Hans-Meerwein-Straße 4, D-35043 Marburg, Germany.
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Weber
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg , Hans-Meerwein-Straße 4, D-35043 Marburg, Germany.
authors.forename: Gerhard
authors.identifier: 0000-0002-5279-3378
authors.initials: G
authors.lastname: Hilt