Kinetic Explanation for the Temperature Dependence of the Regioselectivity in the Hydroformylation of Neohexene

Sabriye Güven, Marko M. L. Nieuwenhuizen, Bart Hamers, Robert Franke, Markus Priske, Marc Becker, Dieter Vogt

Research output: Contribution to journalArticlepeer-review

Abstract

The kinetics of Rh-catalyzed neohexene hydroformylation were investigated with the bulky monodentate ligand tris(2,4-di-tert-butylphenyl)phosphite. The hydrogenolysis of the Rh–acyl intermediate was identified as the rate-limiting step for both the linear and the branched aldehydes. Rate equations for both aldehydes were derived and kinetic parameters were estimated. Increased aldehyde linearity at higher temperatures, frequently observed in hydroformylation, was elucidated by deuterioformylation experiments. These showed that at 100 °C the formation of linear Rh–alkyl was more reversible than the formation of the branched derivative. The ratio of linear to branched Rh–acyl species was determined by in situ high-pressure IR spectroscopy experiments, which allowed the difference in the activation energies for the hydrogenolysis steps towards the aldehyde isomers to be quantified. The hydrogenolysis of Rh–acyl was found to be the step that caused the greatest temperature effect on the regioselectivity.
Original languageEnglish
Pages (from-to)603-610
JournalChemCatChe
Volume6
Issue number2
Early online date8 Jan 2014
DOIs
Publication statusPublished - 1 Feb 2014

Keywords

  • deuterioformylation
  • hydroformylation
  • IR spectroscopy
  • kinetics
  • phosphite

Fingerprint Dive into the research topics of 'Kinetic Explanation for the Temperature Dependence of the Regioselectivity in the Hydroformylation of Neohexene'. Together they form a unique fingerprint.

Cite this