1. Stevens, Sommelet-Hauser and Related Rearrangements Literature Presentation April 4 th, 2011 Presented by Louis-Philippe Beaulieu

2. Gatineau (Aylmer), Qc 2 1842 2011

3. Stevens and Sommelet Biographical Sketches 3 Marcel Sommelet (1877−1952) was born in Langes, France. He received his Ph.D. In 1906 at Paris where he joined the Faculté de Pharmacie after WWI and became the chair of organic chemistry in 1934. Thomas Stevens Stevens (1900−2000) was born in Renfrew, Scotland, UK. He received his Ph.D at Oxon, became University Assistant at Glasgow in 1925 and Lecturer in 1933. He is also known for the McFadyen-Stevens synthesis of aldehydes and the Bamford-Stevens elimination reaction, which converts ketones to alkenes.

4. Program 4 Biographical Sketches of Stevens and Sommelet The Stevens Rearrangement: Seminal Discovery Mechanistic Studies The Sommelet-Hauser Rearrangement: Seminal Discovery Mechanistic Studies Competition Between [1,2] and [2,3] Pathways Different Methods for Ylide Generation Asymmetric Versions: C to C Chirality Transfer C to N Chirality Transfer Strictly Enantioselective Stevens Rearrangement

5. The Stevens Rearrangement: Seminal Discovery 5 T. S. Stevens, E. M. Creighton, A. B. Gordon, M. MacNicol, J. Chem. Soc., 1928, 3193.

6. Intramolecular Nature of the Rearrangement 6 T. S. Stevens, J. Chem. Soc., 1930, 2107. R. A. W. Johnstone, T. S. Stevens, J. Chem. Soc. 1955, 4487.

7. Retention of Stereogenic Information 7 J. H. Brewster, M. W. Kline, J. Am. Chem. Soc. 1952, 74, 5179.

8. Involvement of a Nitrogen Ylide 8 R. W. Jemison, S. Mageswaran, W. D. Ollis, S. E. Potter, A. J. Pretty, I. O. Sutherland, Y. Thebtaranonth, J. Chem. Soc., Chem. Commun. 1970, 1201. T. Thomson, T. S. Stevens, J. Chem. Soc. 1932, 55. J. L. Dunn, T. S. Stevens, J. Chem. Soc. 1932, 1926.

9. Ion Pair Mechanism vs. Concerted Intramolecular Displacement 9 T. Thomson, T. S. Stevens, J. Chem. Soc. 1932, 55. J. L. Dunn, T. S. Stevens, J. Chem. Soc. 1932, 1926. R. Hoffmann, R. B. Woodward, Acc. Chem. Res. 1968, 1, 17.

10. Chemically Induced Dynamic Nuclear Polarization (CIDNP) Mechanistic Study 10 IUPAC Compendium of Chemical Terminology CIDNP : Non-Boltzmann nuclear spin state distribution produced in thermal or photochemical reactions, usually from colligation and diffusion, or disproportionation of radical pairs, and detected by NMR spectroscopy by enhanced absorption or emission signals.

11. Chemically Induced Dynamic Nuclear Polarization (CIDNP) Mechanistic Study 11 IUPAC Compendium of Chemical Terminology Pavia, D. L.; Lampman, G. M.; Kriz, G. S. Introduction to Spectroscopy; Vondeling, J., Kiselica, S., Eds.; Thomson Learning, 2001; p. 108. CIDNP : Non-Boltzmann nuclear spin state distribution produced in thermal or photochemical reactions, usually from colligation and diffusion, or disproportionation of radical pairs, and detected by NMR spectroscopy by enhanced absorption or emission signals. DNP : results from transferring spin polarization from electrons to nuclei, thereby aligning the nuclear spins to the extent that electron spins are aligned.

12. Chemically Induced Dynamic Nuclear Polarization (CIDNP) Mechanistic Study 12 A. R. Lepley, J. Am. Chem. Soc. 1969, 91, 1237.

13. Radical Pair Mechanistic Patway 13 W. D. Ollis, M. Rey, I. O. Sutherland, J. Chem. Soc., Perkin Trans. 1 1983, 1009.

14. Radical Pair Mechanistic Patway 14 W. D. Ollis, M. Rey, I. O. Sutherland, J. Chem. Soc., Perkin Trans. 1 1983, 1009.

15. Sommelet-Hauser Reaction: Seminal Discovery 15 Sommelet, M. Compt. Rend. 1937, 205, 56. S. W. Kantor, C. R. Hauser, J. Am. Chem. Soc. 1951, 73, 4122.

16. Mechanistic Insight Through Intermediate Isolation/Trapping 16 C. R. Hauser, D. N. Van Eenam, J. Am. Chem. Soc. 1957, 79, 5512. S. H. Pine, B. L. Sanchez, Tetrahedron Lett. 1969, 10, 1319.

17. Competition Between [1,2] and [2,3] Pathways 17 E. Tayama, K. Takedachi, H. Iwamoto, E. Hasegawa, Tetrahedron 2010, 66, 9389.

18. Competition Between [1,2] and [2,3] Pathways 18 E. Tayama, K. Takedachi, H. Iwamoto, E. Hasegawa, Tetrahedron 2010, 66, 9389.

19. Competition Between [1,2] and [2,3] Pathways 19 E. Tayama, K. Takedachi, H. Iwamoto, E. Hasegawa, Tetrahedron 2010, 66, 9389. G. Ghigo, S. Cagnina, A. Maranzana, G. Tonachini, J. Org. Chem. 2010, 75, 3608. Kürti, L.; Czakó, B. Strategic Applications of Named Reactions in Organic Synthesis; Hayhurst, J.; Marr, D., Eds.; Elsevier Academic Press, 2005; p. 422. [1,2] Stevens rearrangement Favored in nonpolar organic solvents (ether, hexanes) and high temperatures Sommelet-Hauser rearrangement Favored in polar solvents (NH 3, DMSO, HMPA) And low temperatures Formation of intermediate SHI is significantly less endoergic (35 kcal mol -1 ) according to M05-2x DFT calculations

20. Base-Mediated Formation of Ylides: Some Drawbacks 20 F. E. Ray, J. L. Farmer, J. Org. Chem. 1943, 08, 391. E. Vedejs, D. A. Engler, M. J. Mullins, The Journal of Organic Chemistry 1977, 42, 3109. Dealkylation

21. Base-Mediated Formation of Ylides: Some Drawbacks 21 L. P. A. Fery, L. van Hove, Bull. Soc. Chim. Belg. 1960, 69, 79. C. L. Bumgardner, H.-B. Hsu, F. Afghahi, W. L. Roberts, S. T. Purrington, J. Org. Chem. 1979, 44, 2348. Hoffmann Elimination Regioselectivity of Ylide Generation

22. Fluoride-Mediated Fromation of Ylides 22 E. Vedejs, G. R. Martinez, J. Am. Chem. Soc. 1979, 101, 6452.

23. Direct Formation of Ylides from Diazo Compounds Under Metal Catalysis 23 M. P. Doyle, W. H. Tamblyn, V. Bagheri, J. Org. Chem. 1981, 46, 5094. J. A. Vanecko, H. Wan, F. G. West, Tetrahedron 2006, 62, 1043.

24. Asymmetric Versions: C to C Chirality Transfer 24 S. Hanessian, M. Mauduit, Angew. Chem., Int. Ed. 2001, 40, 3810.

25. Asymmetric Versions: C to C Chirality Transfer 25 S. Hanessian, M. Mauduit, Angew. Chem., Int. Ed. 2001, 40, 3810.

26. Asymmetric Versions: C to C Chirality Transfer 26 S. Hanessian, M. Mauduit, Angew. Chem., Int. Ed. 2001, 40, 3810.

27. Asymmetric Versions: C to C Chirality Transfer 27 S. Hanessian, M. Mauduit, Angew. Chem., Int. Ed. 2001, 40, 3810.

28. Asymmetric Versions: C to C Chirality Transfer 28 S. Hanessian, C. Talbot, P. Saravanan, Synthesis 2006, 723.

29. Asymmetric Versions: C to C Chirality Transfer 29 S. Hanessian, C. Talbot, P. Saravanan, Synthesis 2006, 723.

30. Asymmetric Versions: C to C Chirality Transfer 30 S. Hanessian, C. Talbot, P. Saravanan, Synthesis 2006, 723.

31. Asymmetric Versions: C to C Chirality Transfer 31 S. Hanessian, C. Talbot, P. Saravanan, Synthesis 2006, 723.

32. Asymmetric Versions: N to C Chirality Transfer 32 K. W. Glaeske, F. G. West, Org. Lett. 1999, 1, 31.

33. Asymmetric Versions: N to C Chirality Transfer 33 K. W. Glaeske, F. G. West, Org. Lett. 1999, 1, 31.

34. Asymmetric Versions: N to C Chirality Transfer 34 E. Tayama, S. Nanbara, T. Nakai, Chem. Lett. 2006, 35, 478.

35. Asymmetric Versions: C to C Chirality Transfer 35 I. G. Stara, I. Stary, M. Tichy, J. Zavada, V. Hanus, J. Am. Chem. Soc. 1994, 116, 5084.

36. Asymmetric Versions: C to C Chirality Transfer 36 I. G. Stara, I. Stary, M. Tichy, J. Zavada, V. Hanus, J. Am. Chem. Soc. 1994, 116, 5084.

37. Strictly Enantioselective Stevens Rearrangement 37 M.-H. GonAalves-Farbos, L. Vial, J. m. Lacour, Chem. Commun. 2008, 829.

38. Strictly Enantioselective Stevens Rearrangement 38 M.-H. GonAalves-Farbos, L. Vial, J. m. Lacour, Chem. Commun. 2008, 829.

39. Strictly Enantioselective Stevens Rearrangement 39 M.-H. GonAalves-Farbos, L. Vial, J. m. Lacour, Chem. Commun. 2008, 829.