1 / 29

Immobilised Phosphines for Catalysis

Immobilised Phosphines for Catalysis. Prof. Dr. Evamarie Hey-Hawkins. Kick-off Meeting SusPhos 18 March 2013. What makes phosphorus so special?. strong phosphorus-metal bond: σ -donating and π -accepting properties great potential for steric and electronic modification

maine
Download Presentation

Immobilised Phosphines for Catalysis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Immobilised Phosphines for Catalysis Prof. Dr. Evamarie Hey-Hawkins Kick-off Meeting SusPhos 18 March 2013

  2. What makes phosphorus so special? • strong phosphorus-metal bond: σ-donating and π-accepting properties • great potential for steric and electronic modification • trivalent phosphorus can be a chiral centre • 31P NMR spectroscopy • many applications in catalysis; mostly aryl substituents, e.g., PPh3 • heterocyclic phosphorus-based ligands, e.g. phospholanes and phosphinanes, are in the focus of interest

  3. Phospholanes • five-membered cyclic phosphines • ring structure reduces the flexibility → well-defined geometry • electron-rich ligands → strong electron donors • especially bisphospholanes have many applications in asymmetric catalysis H. Brunner, R. Sievi, J. Organomet. Chem.1987, 328, 71. M. J. Burk, J. E. Feaster, R. L. Harlow, Organometallics 1990, 9, 2653.

  4. From the literature… cis with C4-chain trans with C5-chain mononuclear dinuclear, bridged 7-membered chelate 16-membered macrocycle Rieger et al.,1999, priv. comm. to the CSD, dep. nr. CCDC 136185. H. Bittig, Masters thesis, Universität Leipzig 2009.

  5. Theory Number of C atoms in the spacer (calculated by DC Marc Brüssel)

  6. Phospholane-based Ligands 1st Generation Spacer = (CH2)n with n = 5, 6, 7, 8, 9, 10, 11, …

  7. Bisphospholane-based ligands • Old strategy using phenylphospholane [1] M. F. Haddow , A. J. Middleton, A. G. Orpen, P. G. Pringle, R. Papp, Dalton Trans. 2009, 202.

  8. Bisphospholane-based ligands • Alternative strategy using benzylphospholane

  9. Metal-based Nano-frames • Coordination behaviour using 1:1 ratios

  10. Palladium-based Paddel Wheel 31P{1H}-NMR: δ = 31.8 ppm (d, 2P, 2JP-P = 24.5 Hz) δ = 35.6 ppm (t, 1P, 2JP-P = 24.5 Hz) free ligand: δ = −27.0 ppm (s) • yield: 60 %, yellow crystals, soluble in DCM, less soluble in toluene, n-hexane

  11. Nickel-based Nano-Frames 31P{1H}-NMR in ppm: complexes: δ = 18.1 free ligands: δ = −27.0 C2/c Z = 4 Pnnm Z = 2 • yield: both 85 %, dark red crystals, soluble in DCM, solubility in non-polar solvents like toluene increases with increasing number of carbon atoms in the spacer • solid compounds are air stable

  12. Silver-based Nano-frames • from AgBF4 (BF4 anions are omitted for clarity) 31P{1H}-NMR in ppm: complexes: δ = −0.6 free ligands: δ = −27.0 − P1 Z = 1 P21/n Z = 2 • yield: both 95 %, colourless crystals, soluble in DCM • no high-dilution techniques necessary to form these macrocyles

  13. Gold-based Nano-frames 31P{1H}-NMR: complexes: δ = 24.3 ppm (s) free ligands: δ = −27.0 ppm (s) • yield: both 90 %, colourless crystals, soluble in DCM, less soluble in toluene • untypical [2+1] coordination mode • no high-dilution techniques necessary to form these macrocyles

  14. Gold-based Nano-frames • space filling model: • cavity: circa 1 x 15 Å2 C H P Au

  15. Phospholane-based Ligands 2nd Generation Spacer with functional groups (e.g. C=C, easily modified;

  16. Phospholane-based Ligands 2nd Generation Spacer with functional groups (e.g. C=C, easily modified; polyether

  17. Phospholane-based Ligands 2nd Generation Spacer with functional groups (e.g. C=C, easily modified; polyether; ferrocenes,..)

  18. Ligand Pool

  19. Selected Bisphospholes

  20. Phospholane-based Ligands 3rd Generation N, O donor atoms e.g. RhI, Pd0,II e.g. TiIV, ZnII

  21. Tasks Preparation of bifunctional linkers with functionalised backbone Synthesis of homo- and heterometallic metallamacrocyles (nano-frames) Use the cavity of the nano-fames to increase the selectivity of a catalytic reaction Activity in homogeneous catalysis Use functionalised backbone forimmobilisation (C=C) Activity of immobilised dimetalla-macrocycles

  22. Thanks to • BASF • Cytec • Umicore, PreciousMetals Chemistry • Witco GmbH • H.C. Starck GmbH & Co. KG • Chemetall • Fonds der chemischen Industrie (VCI) • German Research Council (DFG) • Graduate School “BuildMoNa“ • EU COST “PhoSciNet“ • VW Foundation • Alexander-von-Humboldt Foundation • German Academic Exchange Service (DAAD) • Studienstiftung des Deutschen Volkes • Fundedbythe European Union andthe Free State ofSaxony

  23. Coworkers AnupAdhikari Paul Boar Solveig BoehnkeMarta Kunig Anne Grundmann Dr. Julia Haushälter Dr. Alexandra Hildebrand Dr. Ivana Jevtovikj Dr. Goran Kaluderovic Anika KreienbrinkWitriWahyuLestariYinghui Lin Dr. Peter Lönnecke Dr. MartynaMadalska Michael Miertzschke Tobias Möller Michèle Münzenberg Paul Neumann Wilma Neumann Dr. SouvikPandey Stefan Richter Dr. ImolaSarosi Dr. MenyhartSarosiAndy Schmied Gunther Speichert J. Pritzwald-Stegmann Markus Streitberger Carlotta Taddei Felix Windisch HaldorZaake-Hertling Brisca Kretzschmar Stefanie Märcker Regina Zäbe Annette Zacharias …. andmanydedicatedbachelorandmastersstudentsandvisitingscientists…

  24. The End

  25. Dimetallamacrocyles • dinuclear, trans-coordinated, macrocycliccomplexes • dimensions in the nanometre range • 1970s Shaw, Pryde, Weeks: gem-tert-butyl-effect for phosphorus • J. Pryde, B. Shaw, B. Weeks, Chem. Comm. 1973, 947 – 948.

  26. Chiral Binol Backbone

  27. Chiral Binol Backbone

  28. Chiral Binol Backbone

More Related