title: Cationic zinc organyls as precatalysts for hydroamination reactions.
abstract: The cationic zinc triple-decker complex [Zn2 Cp*3 ](+) [BAr(F) 4 ](-) (BAr(F) 4 =B(3,5-(CF3 )2 C6 H3 )4 ) exhibits catalytic activity in intra- and intermolecular hydroamination reactions in the absence of a cocatalyst. These hydroaminations presumably proceed through the activation of the C-C multiple bond of the alkene or alkyne by a highly electrophilic zinc species, which is formed upon elimination of the Cp* ligands. The reaction of [Zn2 Cp*3 ](+) [BAr(F) 4 ](-) with henylacetylene gives the hydrocarbonation product (Cp*)(Ph)CCH2 , which might be formed via a similar reaction pathway. Additionally, several other structurally well-defined cationic zinc organyls have been examined as precatalysts for intermolecular hydroamination reactions without the addition of a cocatalyst. These studies reveal that the highest activity is achieved in the absence of any donor ligands. The neutral complex [ZnCp(2S) 2 ] (Cp(2S) =C5 Me4 (CH2 )2 SMe) shows a remarkably high catalytic activity in the presence of a Brønsted acid.
authors.affiliation: Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin (Germany).
authors.forename: Maren A
authors.initials: MA
authors.lastname: Chilleck
authors.forename: Larissa
authors.initials: L
authors.lastname: Hartenstein
authors.forename: Thomas
authors.initials: T
authors.lastname: Braun
authors.forename: Peter W
authors.initials: PW
authors.lastname: Roesky
authors.forename: Beatrice
authors.initials: B
authors.lastname: Braun
keywords: alkynes; homogeneous catalysis; hydroamination; zinc organyls