1 / 44

Baeyer-Villiger Oxidation: Mechanism and Enantioselective Systems

Literature Meeting. Baeyer-Villiger Oxidation: Mechanism and Enantioselective Systems. Jean-Nicolas Desrosiers January 31, 2005. Outline. 1. Introduction 2. BV mechanistic studies 3. Enantioselective reactions 3.1 Seminal work by Strukul and Bolm 3.2 Katsuki's systems

jack
Download Presentation

Baeyer-Villiger Oxidation: Mechanism and Enantioselective Systems

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. Literature Meeting Baeyer-Villiger Oxidation:Mechanism and Enantioselective Systems Jean-Nicolas Desrosiers January 31, 2005

  2. Outline 1. Introduction 2. BV mechanistic studies 3. Enantioselective reactions 3.1 Seminal work by Strukul and Bolm 3.2 Katsuki's systems 3.2.1 Bidentate ligands 3.2.2 Multidentate salen ligands

  3. The Discovery of the Baeyer-Villager Oxidation

  4. Well-Known and Widely Applied Reaction [O] = peroxides (R2O), peracids (RCOOOH), persulfuric acid... ten Brink et al.Chem. Rev. 2004, 104, 9, 4105.

  5. Well-Known and Widely Applied Reaction ten Brink et al.Chem. Rev. 2004, 104, 9, 4105.

  6. Exploration of the Mechanism Renz, M.; Meunier, B. Eur. J. Org. Chem. 1999, 737.

  7. 18O-Labeled Experiment Confirmed the presence of the Criegee intermediate Doering, W. v.; Dorfman, E. J. Am. Chem. Soc. 1953, 75, 5595.

  8. Retention of the Stereochemistry of the Migrating Group based on m.p. Turner, R. B. J. Am. Chem. Soc. 1950, 72, 878. based on opt. rot. Mislow, K.; Brenner, J. J. Am. Chem. Soc. 1953, 75, 2318.

  9. Competitive Migration p-MeO-Ar > p-Me-Ar > Ph > p-Cl-Ar > p-Br-Ar > p-NO2-Ar Doering, W. v. et al. J. Am. Chem. Soc. 1950, 72, 5515.

  10. Relative Migration Aptitude

  11. The Primary and Secondary Effect

  12. The Secondary Effect Noyori, R.; Kobayashi, H.; Sato, T. Tetrahedron Lett.1980, 21, 2573.

  13. The Secondary Effect

  14. The Primary Effect According to the migratory aptitudes Crudden, C. M. etal. Angew. Chem. Int. Ed. 2000, 39, 16, 2851.

  15. The Primary Effect Violation of the accepted migratory aptitudes Crudden, C. M. etal. Angew. Chem. Int. Ed. 2000, 39, 16, 2851.

  16. Is the Dipole/Dipole Interaction the Primary Factor? Crudden, C. M. etal. Angew. Chem. Int. Ed. 2000, 39, 16, 2851.

  17. Is the Dipole/Dipole Interaction the Primary Factor? Crudden, C. M. etal. Angew. Chem. Int. Ed. 2000, 39, 16, 2851.

  18. The Rate-Determining Step of the BV oxidation The rate-determining step changes from addition to migration with a change of substituents. Palmer, B.W. et al. J. Am. Chem. Soc. 1970, 92, 2580.

  19. Electrophilic and Nucleophilic Activation of the BV reaction.

  20. Outline 1. Introduction 2. BV mechanistic studies 3. Enantioselective reactions 3.1 Seminal work by Strukul and Bolm 3.2 Katsuki's systems 3.2.1 Bidentate ligands 3.2.2 Multidentate salen ligands

  21. Seminal Work on Enantioselective BV

  22. Proposed Mechanism for the Enantioselective BV

  23. Bolm's Enantioselective System

  24. Bolm's Enantioselective System

  25. Bolm's Optimized Results Bolm, C. et al. Synlett2004, 9, 1619.

  26. Katsuki's Biography Tsutomu Katsuki 1988 University of Kyushu, Professor 1980 University of Stanford & MIT, Post-doctoral fellow Prof. K. B. Sharpless 1976 University of Kyushu, Ph.D. Prof. M. Yamaguchi 1969 University of Kyushu, B.Sc.

  27. Proposed Enantioselective BV System high conformational freedom bulky R' selective migration selective addition A metal complex bearing two vacant cis-coordinating sites should be suitable for asymmetric B-V reaction. Katsuki, T. et al. Helv. Chim. Acta. 2002, 85, 3078.

  28. Screening Palladium(II) Complexes With Bidentate Ligands Katsuki, T. et al. Synlett 2003, 5, 643.

  29. Optimization of Solvent and Temp Katsuki, T. et al. Synlett 2003, 5, 643.

  30. Few Substrates Tried Katsuki, T. et al. Synlett 2003, 5, 643.

  31. Square Planar Complexes Square planar complex with trans vacant coordinating sites Katsuki, T. et al. Tet. Lett. 2001, 41, 6911.

  32. Obtaining Vicinal Vacant Coordinating Sites cis-b [Mn(III) L1(acac)] Che, C.-M. et al. J. Chem. Soc. Dalton Trans. 1997, 3479.

  33. Enantioselectivity with cis- Complex - The control of the chelate conformation is not sufficient Katsuki, T. et al. Tet. Lett. 2001, 41, 6911.

  34. Forced cis- Structure via a Zr Complex Fixed conformation of the moiety Katsuki, T. et al. Tetrahedron Lett. 2001, 42, 3873. slow opening active species

  35. Results Obtained With Zr Complexes Katsuki, T. et al. Tetrahedron Lett. 2002, 43, 4481.

  36. Optimization of Reaction Conditions Katsuki, T. et al. Tetrahedron Lett. 2002, 43, 4481.

  37. Formation of Normal and Abnormal Lactones Katsuki, T.et al. Proc. Natl. Acad. Sci. USA 2004, 101, 5737.

  38. Relative Reaction Ratio of Enantiomers

  39. Increasing Conversions Katsuki, T.et al. Proc. Natl. Acad. Sci. USA 2004, 101, 5737.

  40. Screening Substrates

  41. Conformation Study of the Catalyst Katsuki, T.et al. Proc. Natl. Acad. Sci. USA 2004, 101, 5737.

  42. Conformation Study of the Catalyst

  43. Conformation Study of the Catalyst

  44. Conclusions

More Related