New Hydroformylation Catalysts
Dr. Jens Holz
The olefin hydroformylation reaction (synthesis of carbaldehydes by addition of carbon monoxide and hydrogen to an olefin) ranks among the most important technically applied reactions performed using homogeneous transition metal catalysts. Depending on the catalyst applied, either terminal aldehydes or isoaldehydes can be formed, which to a large extend are used as precursors for plasticizer alcohols. Enantiomerically-pure isoaldehydes may serve as intermediates in drug syntheses (antiphlogistica).1
Our work is focused on the syntheses of new and patent-free P(III)-compounds,2 their application in rhodium catalyzed hydroformylation and on the study of other catalytically active metals as well.3 We seek for a better description of catalysis by investigating mechanistic aspects and observing the concentration of organometallic intermediates in a time resolved manner. Chemometric tools are applied which allow for kinetic evaluation of spectroscopic data. Respective methods used by us are in-situ HP-NMR and in situ FTIR spectroscopy (for further details, see below).4,5 An interesting reaction is Isomerizing Hydroformylation, see figure 1, which gives access to terminal aldehydes starting from cheap internal olefins in a kinetically controlled fashion. Our rhodium catalysts achieve up to 99% n-regioselectivity and turn over frequencies up to 6000 mololefin x molcatalyst -1 x h -1.6-8There is currently a search for alternatives to the established hydroformylation reaction. Particularly for the syntheses of fine chemicals, e.g. aldehydes used as components in fragrances, it is a highly desirable goal and a challenging task to apply a syngas equivalent that is less toxic and can be handled better.9 Based on our results, 14 patent applications have been filed by our partner Evonik Industries AG in 2014, four more applications resulted in 2015.
- R. Franke, D. Selent, A. Börner, Chem. Rev. 2012, 112, 5675-5732.
- E. Benetskiy, S. Luehr, M. Vilches-Herrera, D. Selent, H. Jiao, L. Domke, K. Dyballa, R. Franke, A. Boerner, Armin, ACS Catal. 2014, 4, 2130-2136.
- C. Kubis, W. Baumann, E. Barsch, D. Selent, M. Sawall, R. Ludwig, K. Neymeyr, D. Hess, R. Franke, A. Boerner, ACS Catal. 2014, 4, 2097-2108.
- C. Kubis, D. Selent, M. Sawall, R. Ludwig, K. Neymeyr, W. Baumann, R. Franke, A. Börner, Chemistry-A European Journal 2012, 18, 8780-8794.
- M. Sawall, C. Kubis, A. Börner, D. Selent, K. Neymeyr, Analytica Chimica Acta 2015, 891, 101-112.
- D. Selent, K.-D. Wiese, A. Börner, in Catalysis of Organic Reactions, Edt. John R. Sowa, Taylor&Francis Group, Boca Raton, 2005, 20, 459-469.
- D. Selent, R. Franke, C. Kubis, A. Spannenberg, W. Baumann, B. Kreidler, A. Börner, Organometallics 2011, 30, 4509-4514.
- D. Selent, A. Boerner, A. Christiansen, R. Franke, D. Fridag, D. Hess, B. Kreidler, DE 102011085883 A1 20130508 (08.05.2013), D. Selent, C. Kubis, W. Baumann, A. Spannenberg, R. Franke, A. Börner, Publikation in Vorbereitung
- M. Uhlemann, S. Doerfelt, A. Boerner, Tetrahedron Letters 2013, 54, 2209-2211.