title: A frustrated-Lewis-pair approach to catalytic reduction of alkynes to cis-alkenes.
abstract: Frustrated Lewis pairs are compounds containing both Lewis acidic and Lewis basic moieties, where the formation of an adduct is prevented by steric hindrance. They are therefore highly reactive, and have been shown to be capable of heterolysis of molecular hydrogen, a property that has led to their use in hydrogenation reactions of polarized multiple bonds. Here, we describe a general approach to the hydrogenation of alkynes to cis-alkenes under mild conditions using the unique ansa-aminohydroborane as a catalyst. Our approach combines several reactions as the elementary steps of the catalytic cycle: hydroboration (substrate binding), heterolytic hydrogen splitting (typical frustrated-Lewis-pair reactivity) and facile intramolecular protodeborylation (product release). The mechanism is verified by experimental and computational studies.
authors.affiliation: Department of Chemistry, Laboratory of Inorganic Chemistry, University of Helsinki PO Box 55, FIN-00014, Finland.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Chernichenko
authors.forename: Adám
authors.initials: A
authors.lastname: Madarász
authors.forename: Imre
authors.initials: I
authors.lastname: Pápai
authors.forename: Martin
authors.initials: M
authors.lastname: Nieger
authors.forename: Markku
authors.initials: M
authors.lastname: Leskelä
authors.forename: Timo
authors.initials: T
authors.lastname: Repo
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D010084:Oxidation-Reduction
chemical_list: D000475:Alkenes; D000480:Alkynes