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Combinatorial evolution of site- and enantioselective catalysts for polyene epoxidation Guillaume Pelletier Literature meeting - November 20 th 2012 Lichtor,

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Presentation on theme: "Combinatorial evolution of site- and enantioselective catalysts for polyene epoxidation Guillaume Pelletier Literature meeting - November 20 th 2012 Lichtor,"— Presentation transcript:

1 Combinatorial evolution of site- and enantioselective catalysts for polyene epoxidation Guillaume Pelletier Literature meeting - November 20 th 2012 Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

2 Analysis of biosynthetic patways reveals functional group selectivity For a review, see: Clardy, J.; Walsh, C. Nature 2004, 432, 829-837. Walker, K.; Croteau, R. Phytochemistry 2001, 58, 1-7. Mendoza, A.; Ishihara, Y.; Baran, P. S. Nature Chem. 2012, 4, 21-25.

3 Analysis of biosynthetic patways reveals functional group selectivity For a review, see: Clardy, J.; Walsh, C. Nature 2004, 432, 829-837. Novak, B. H.; Hudlicky, T.; Reed, J. W.; Mulzer, J.; Trauner, D. Curr. Org. Chem. 2000, 4, 343-362. Calderon, S. N. et al. J. Med. Chem. 1997, 40, 695.

4 Analysis of biosynthetic patways reveals functional group selectivity For a review, see: Clardy, J.; Walsh, C. Nature 2004, 432, 829-837. Novak, B. H.; Hudlicky, T.; Reed, J. W.; Mulzer, J.; Trauner, D. Curr. Org. Chem. 2000, 4, 343-362. Calderon, S. N. et al. J. Med. Chem. 1997, 40, 695.

5 Enzyme-mediated oxidation does preclude generality… Van Tamelen, E. E.; Heys, R. J. J. Am. Chem. Soc. 1975, 97, 1252-1253.

6 Small synthetic molecules meets some of these challenges Zhang, W.; Basak, A.; Kosugi, Y.; Hoshino, Y.; Yamamoto, H. Angew. Chem., Int. Ed. 2005, 44, 4389-4391. Egami, H.; Oguma, T.; Katsuki, T. J. Am. Chem. Soc. 2010, 132, 5886-5895.

7 Small synthetic molecules meets some of these challenges Zhang, W.; Basak, A.; Kosugi, Y.; Hoshino, Y.; Yamamoto, H. Angew. Chem., Int. Ed. 2005, 44, 4389-4391. Egami, H.; Oguma, T.; Katsuki, T. J. Am. Chem. Soc. 2010, 132, 5886-5895.

8 Small synthetic molecules meets some of these challenges Barlan, A. U.; Basak, A.; Yamamoto, H. Angew. Chem., Int. Ed. 2006, 45, 5849-5852. Chang, S.; Lee, N. H.; Jacobsen, E. N. J. Org. Chem. 1993, 58, 6939-6941.

9 Small synthetic molecules meets some of these challenges Barlan, A. U.; Basak, A.; Yamamoto, H. Angew. Chem., Int. Ed. 2006, 45, 5849-5852. Chang, S.; Lee, N. H.; Jacobsen, E. N. J. Org. Chem. 1993, 58, 6939-6941.

10 Template-directed internal epoxidation of polyenes Gnanadesikan, V.; Corey, E. J. J. Am. Chem. Soc. 2008, 130, 8089-8093.

11 The goal of the present study Sharpless Epoxidation Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

12 Literature precedents on small peptide mediated epoxidation Peris, G.; Jakobsche, C. E.; Miller, S. J. J. Am. Chem. Soc. 2007, 129, 8710-8711. Kolundzic, F.; Noshi, M. N.; Tjandra, M.; Movassaghi, M.; Miller, S. J. J. Am. Chem. Soc. 2011, 133, 9104-9111.

13 Proposed catalytic cycle for the asymmetric epoxidation Peris, G.; Jakobsche, C. E.; Miller, S. J. J. Am. Chem. Soc. 2007, 129, 8710-8711. Kolundzic, F.; Noshi, M. N.; Tjandra, M.; Movassaghi, M.; Miller, S. J. J. Am. Chem. Soc. 2011, 133, 9104-9111.

14 First screening of catalysts Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP. With initial peptide catalyst screening, the authors chose to run the reactions at low conversions in order to allow a preleminary assessment of catalyst k rel

15 Methodology employed for catalyst design Lam, K. S.; Lebl, M.; Krchň á k, V. Chem. Rev. 1997, 97, 411-448. Furka, A.; Sebestyen, F.; Asgedom. M.; Dibo, G. Int. J. Pept. Protein Res. 1991, 37, 487-493. The one-bead-one-compound concept is based on the fact that combinatorial beads beads prepared from the « split-pool synthesis » contain single beads displaying one type of compounds although there may be 10 13 copies on a 100 μm bead

16 One-bead-one-compound and split-pool synthesis Lam, K. S.; Salmon, S. E.; Hersh, E. M.; Hruby, V. J.; Kazmierski, W. M.; Knapp, R. J. Nature 1991, 354, 82-84.

17 One-bead-one-compound and split-pool synthesis Lam, K. S.; Salmon, S. E.; Hersh, E. M.; Hruby, V. J.; Kazmierski, W. M.; Knapp, R. J. Nature 1991, 354, 82-84.

18 Initial screening (with parallel peptide synthesis) Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

19 Initial screening (with parallel peptide synthesis) Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP. Lichtor, P. A.; Miller, S. J. ACS Comb. Sci. 2011, 13, 321-326.

20 Split-pool optimization and synthesis of a large OBOC library (iterative approach) Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP. Lichtor, P. A.; Miller, S. J. ACS Comb. Sci. 2011, 13, 321-326. The resulting library possess a theorical size of about 3000 unique peptide sequences (for the first directed library)

21 OBOC library results towards epoxidation of farnesol Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

22 Identification of peptides via sequencing and HPLC/MALDI-QToF analysis Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

23 Resynthesis and « in solution » trials with hits Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

24 Resynthesis and « in solution » trials with hits Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

25 Substrate scope with optimized 9b catalyst Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

26 Biased 2 nd OBOC directed at 6,7-selective epoxidation Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

27 Resynthesis and « in solution » trials with hits Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

28 2,3-Selectivity and 6,7-Selectivity is hydroxy driven in epoxidation Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

29 Validation of both 9b and 12d catalyst with geranylgeraniol in solution Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

30 Enzymes mediated approches are most often not general to a series of substrates. The application of diversity-based approaches may prove fruitful and may also offer analogy to the directed evolution of strategies employed by natural an bioengineered enzymatic systems. Peptide 9b and 12d found by one-bead-one-compound library screening are operating via a hydroxyl-mediated mechanism. They offer comparable selectivity to the well-known Sharpless epoxidation conditions and are amenable to new selectivity pattern. Conclusions Lichtor, P. A.; Miller, S. J. Nature Chem. 2012, ASAP.

31 Future aspects of peptide site-selectivity Fowler, B. S.; Laemmerhold, K. M.; Miller, S. J. J. Am. Chem. Soc. 2012, 134, 9755-9761. Pathak, T. P.; Miller, S. J. J. Am. Chem. Soc. 2012, 134, 6120-6123.


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