A stable 16-electron iridium(III) hydride complex grafted on SBA-15: a single-site catalyst for alkene hydrogenation
Martino Rimoldi1, Daniel Fodor, Jeroen A van Bokhoven
1Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Str. 10, CH-8093 Zurich, Switzerland.
Abstract:
The dihydride pincer complex [IrH2(POCOP)] reacts with surface silanols of mesoporous silica (SBA-15) to give the coordinatively unsaturated, yet stable hydridesiloxo Ir(III) species [IrH(O-SBA-15)(POCOP)]. The silica-grafted complex catalyses the hydrogenation of ethene and propene at low temperature and pressure without prior activation.
More Related Videos
09:37Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
10:39Heterogeneous Removal of Water-Soluble Ruthenium Olefin Metathesis Catalyst from Aqueous Media Via Host-Guest Interaction
Published on: August 23, 2018
Related Concept Videos
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
