1 / 25

Synthesis of chiral p -conjugated assemblies using aza helicene-phosphole ligands

Synthesis of chiral p -conjugated assemblies using aza helicene-phosphole ligands. Sébastien Graule Phosphorus and Molecular Materials UMR 6226. Challenge : chiral wave-guides (information encoding). Synthesis of stable materials displaying huge optical rotation !

dima
Télécharger la présentation

Synthesis of chiral p -conjugated assemblies using aza helicene-phosphole ligands

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. Synthesis of chiral p-conjugated assemblies using azahelicene-phosphole ligands Sébastien Graule Phosphorus and Molecular Materials UMR 6226

  2. Challenge : chiral wave-guides (information encoding) Synthesis of stable materials displaying huge optical rotation ! Optimisation = structural diversity Cécile Le Luyer , Claudine Garapon, Stéphan Guy (LPCML, Villeurbanne, France) L. Guy (ENS Lyon)

  3. Advantages Drawbacks Difficulty to get structural diversity! Long and hard synthetic route! P Hexahelicene M Hexahelicene • Chiral derivatives : • high specific optical rotations • ([]D25= +3600) • Thermally and chemically • stable Helicenes : helicoidal shape + p-conjugated system

  4. p Pd(CH3CN)42+ P,Nchelates : Stereoselective coordination chemistry Trans-effect p p C. Fave, M. Hissler, K. Sénéchal, I. Ledoux, J. Zyss, R. Réau Chem. Commun.,2002, 1674 Pyridyl-phosphole : Easily delocalised p-system Reactive P-atom Chem. Rev. 2006, 106, 4681

  5. Our approach : phosphole-based azahelicenes - Synthesis of phosphole based azahelicenes • Stereoselective self-assembly of these P,N-ligands with • metallic ions Metal ions • Chiroptical properties M= Pd, Pt

  6. Synthesis of (phospholyl)aza[4]-helicenes Model molecules

  7. UV-Vis: l= 406 nm l = 390 nm Synthesis of (phospholyl)aza[4]-helicenes Model molecules Inversion of the helix and P-atom 15 Å

  8. P N Pd 4.1 Å Structural diversity using coordination chemistry A 77% - 82% B Only one pair of enantiomers (among 26 stereoisomers) !

  9. P N Cu 15Å Chem. Commun., 2008, 850 Structural diversity using coordination chemistry A 77% - 82% Only one pair of enantiomers (among 25 stereoisomers) ! B

  10. P N Cu P N Pd Model molecules with sophisticated architectures: Go beyond model molecules : chiral phosphole-based azalicenes

  11. 31P NMR CDCl3 Synthesis of Racemic(phospholyl)aza[6]-helicenes

  12. 81 MHz31P NMR in CDCl3 Resolution of azahelicene-diyne Chiral HPLC Chiralcel OD-H, Hexane/ethanol 1:1, 1ml/min Dr. Nicolas Vanthuyne and Pr. Christian Roussel (ENSSPICAM, Marseille)

  13. Mixture of diastereoisomers in equilibrium (P-inversion) 15 kcal.mol-1 P, Sp P, Rp configuration

  14. Specific Optical Rotations (CH2Cl2, 0.01 - 0.02 M) = +1273 = +908 = +13116 Molar rotations (CH2Cl2) = +23082 x MM / 100 Chiroptical properties of hexaazahelicene complexes N P Optically pure helix (chiral HPLC) Square-planar Tetrahedral =

  15. PdII PdII Synthesis of helically molecules via Coordination New investigation

  16. Conclusion Structural diversity… … With other metals (Pt, Au, Ru…) Optical rotation Tuning of chiroptical properties ! Focus on formation of helicoidal molecules upon coordination

  17. Thanks • Pr Régis Réau, Dr Jeanne Crassous • Dr Christophe Lescop • Shen Wenting HPLC: Dr. Nicolas Vanthuyne and Pr. Christian Roussel (ENSSPICAM, Marseille) X-Ray : Dr. Heinz Gornitzka PHOSHELIX

  18. Optical rotation or optical activity is the rotation of linearly polarized light as it travels through certain materials Biot law : [a]Td= a/lC

  19. NMR 31P 81 MHz31P NMR in CDCl3 δ : 19,6ppm 81 MHz31P NMR in CDCl3 δ : 13,2ppm

  20. Eyring equation: ΔG ~ 16 kcal. mol-1 313K Coalescence temperature 323K 333K 328K NMR 31P :Temperature evolution 298K

  21. Pd(II) Cu(I) Coordination 81 MHz31P NMR in CD2Cl2 δ : 5-6ppm 81 MHz31P NMR in CD2Cl2 δ : 76,1ppm

  22. Circular Dichroism and Optical Rotation *[α]D23 = +2010 *[Φ]D23 = +10240 *[α]D23 = +1273 *[Φ]D23 = +23082 *[α]D23 = +908 *[Φ]D23 = +13116 * in CH2Cl2, 293K CD in CH2Cl2, 293K

  23. UV-Visible

More Related