title: Highly Efficient and Selective Hydrogenation of Aldehydes: A Well-Defined Fe(II) Catalyst Exhibits Noble-Metal Activity.
abstract: The synthesis and application of [Fe(PNPMe-iPr)(CO)(H)(Br)] and [Fe(PNPMe-iPr)(H)2(CO)] as catalysts for the homogeneous hydrogenation of aldehydes is described. These systems were found to be among the most efficient catalysts for this process reported to date and constitute rare examples of a catalytic process which allows selective reduction of aldehydes in the presence of ketones and other reducible functionalities. In some cases, TONs and TOFs of up to 80000 and 20000 h-1, respectively, were reached. On the basis of stoichiometric experiments and computational studies, a mechanism which proceeds via atrans-dihydride intermediate is proposed. The structure of the hydride complexes was also confirmed by X-ray crystallography.
authors.affiliation: Institute of Applied Synthetic Chemistry and Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9, A-1060 Vienna, Austria.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Gorgas
authors.affiliation: Institute of Applied Synthetic Chemistry and Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9, A-1060 Vienna, Austria.
authors.forename: Berthold
authors.initials: B
authors.lastname: Stöger
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , Av. Rovisco Pais No. 1, 1049-001 Lisboa, Portugal.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Veiros
authors.affiliation: Institute of Applied Synthetic Chemistry and Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9, A-1060 Vienna, Austria.
authors.forename: Karl
authors.initials: K
authors.lastname: Kirchner
keywords: DFT calculations; aldehyde hydrogenation; homogeneous catalysis; iron pincer complexes; mechanistic studies