Cu(I)-catalyzed hetero-Diels-Alder reaction between danishefsky-type siloxy dienes and ketones

Organic Letters

Volumn 10, Issue 22, 2008, Pages 5151-5154

  Chen, I Hon ^a   Oisaki, Kounosuke ^a   Kanai, Motomu ^a   Shibasaki, Masakatsu ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALKENE; COPPER; KETONE; SILOXANE;

ARTICLE; CATALYSIS; CHEMISTRY;

ALKENES; CATALYSIS; COPPER; KETONES; SILOXANES;

EID: 58149186762     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol802134a     Document Type: Article

References (43)

1. (a) Corey, E. J.; Guzman-Perez, A. Angew. Chem., Int. Ed. 1998, 37, 388.
2. (b) Fuji, K. Chem. Rev. 1993, 93, 2037.
3. (c) Christoffers, J.; Mann, A. Angew. Chem., Int. Ed. 2001, 40, 4591.
4. (d) Denissova, I. Tetrahedron 2003, 59, 10105.
5. (e) Ramon, D. J.; Yus, M. Angew. Chem., Int. Ed. 2004, 43, 284.
6. (f) Shibasaki, M.; Kanai, M. Chem. Rev. 2008, 108, 2853.
7. (g) Riant, O.; Hannedouche, J. Org. Biomol. Chem. 2007, 5, 873.
8. (h) Cozzi, P. G.; Hilgraf, R.; Zimmermann, N. Eur. J. Org. Chem. 2007, 5969.
9. (i) Hatano, M.; Ishihara, K. Synthesis 2008, 1647.
10. For examples, see: (a) Pommier, Y.; Kohlhagen, G.; Kohn, K. W.; Leteurtre, F.; Wani, M. C.; Wall, M. E. Proc. Natl Acad. Sci. U.S.A. 1995, 92, 8861 (camptothecins).
11. (b) Como, J. A.; Dismukes, W. J. New Engl. J. Med. 1994, 330, 263 (triazole antifungals).
12. For example, see: Li, H.; Tatlock, J.; Linton, A.; Gonzalez, J.; Borchardt, A.; Dragovich, P.; Jewell, T.; Prins, T.; Zhou, R.; Blazel, J.; Parge, H.; Love, R.; Hickey, M.; Doan, C.; Shi, S.; Duggal, R.; Lewisc, C.; Fuhrman, S. Bioorg. Med. Chem. Lett. 2006, 16, 4834 (HCV RNA polymerase inhibitors).
13. For reviews of hetero-Diels-Alder reactions, see: (a) Kobayashi, S.; Jørgensen, K. A. Cycloaddition Reactions in Organic Synthesis; Wiley-VCH: Weinheim, Germany, 2002.
14. (b) Jørgensen, K. A. Angew. Chem., Int. Ed. 2000, 39, 3558.
15. (c) Jørgensen, K. A. Eur. J. Org. Chem. 2004, 2093.
16. (d) Gouverneur, V.; Reiter, M. Chem. Eur. J. 2005, 11, 5806.
17. (e) Lin, L.; Liu, X.; Feng, X. Synlett 2007, 2147.
18. For examples, see: (a) Doyle, M. P.; Phillips, I. M.; Hu, W. J. Am. Chem. Soc. 2001, 123, 5366, and references cited therein.
19. (b) Yang, X.-B.; Feng, J.; Zhang, J.; Wang, N.; Wang, L.; Liu, J.-L.; Yu, X.-Q. Org. Lett. 2008, 10, 1299.
20. (c) Du, H.; Zhang, X.; Wang, Z.; Bao, H.; You, T.; Ding, K. Eur. J. Org. Chem. 2008, 2248, and references cited therein.
21. (a) Yao, S.; Johannsen, M.; Audrain, H.; Hazell, R. G.; Jørgensen, K. A. J. Am. Chem. Soc. 1998, 120, 8599.
22. (b) Ghosh, A. K.; Shirai, M. Tetrahedron Lett. 2001, 42, 6231.
23. (c) Dalko, P. I.; Moisan, L.; Cossy, J. Angew. Chem., Int. Ed. 2002, 41, 625.
24. (d) Furuno, H.; Kambara, T.; Tanaka, Y.; Hanamoto, T.; Kagawa, T.; Inanaga, J. Tetrahedron Lett. 2003, 44, 6129.
25. (e) Zhuang, W.; Poulsen, T. B.; Jørgensen, K. A. Org. Biomol. Chem. 2005, 3, 3284.
26. (f) Akullian, L. C.; Snapper, M. C.; Hoveyda, A. H. J. Am. Chem. Soc. 2006, 128, 6532.
27. (g) Landa, A.; Richter, B.; Johansen, R. L.; Minkkilä, A.; Jørgensen, K. A. J. Org. Chem. 2007, 72, 240.
28. For a racemic example using ketones, see: Liu, J.; Li, X.; Wang, J.; Feng, X. Adv. Synth. Catal. 2006, 348, 939.
29. (a) Huang, Y.; Rawal, V. H. J. Am. Chem. Soc. 2002, 124, 9662.
30. (b) Kitazawa, T.; Mukaiyama, T. Heterocycles 2006, 69, 417.
31. (c) Guay, V.; Brassard, P. Tetrahedron 1984, 40, 5039.
32. Danishefsky, S.; Kitahara, T.; Yan, C. F.; Morris, J. J. Am. Chem. Soc. 1979, 101, 6996.
33. (a) Oisaki, K.; Suto, Y.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 2003, 125, 5644.
34. (b) Oisaki, K.; Zhao, D.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 2006, 128, 7164.
35. For pioneering studies on transmetalation from a silyl enolate to a copper enolate, see: Pagenkopf, B. L.; Krüger, J.; Stojanovic, A.; Carreira, E. M. Angew. Chem., Int. Ed. 1998, 37, 3124.
36. 2 catalyst.
37. Pilcher, A. S.; Ammon, H. L.; DeShong, P. J. Am. Chem. Soc. 1995, 117, 5166.
38. 4, Table 1, entry 2) supports this consideration. We assume that the tetrabutylammonium cation facilitates the catalyst regeneration step from intermediate 6 via ion exchange. See the Supporting Information for detailed discussion.
39. Triphenylphosphine oxide would coordinate to the silicon atom and generate a pentacoordinated silicon. This species is more Lewis acidic than the original tetracoordinated silicon (for a leading reference, see: Denmark, S. E.; Beutner, G. L.; Wynn, T.; Eastgate, M. D J. Am. Chem. Soc. 2005, 127, 3774.), and should readily accept the counterion (fluoride or alkoxide) of copper. Because copper silicate formation is the initiating step of transmetalation between silicon and copper, formation of a pentacoordinated silicon would facilitate the active copper enolate formation from 1a and 1b. See the Supporting Information for details.
40. Trost, B. M. Science 1991, 254, 1471.
41. See the Supporting Information for details.
42. 3SiF produced comparable yields and enantioselectivities to the simplified method with 1b shown in Table 3. The observed comparable enantioselectivities between the two methods strongly support that the actual active species is the identical copper enolate, which is generated through transmetalation of the siloxy dienes.
43. Interestingly, the aryl group, which is bulkier than the methyl group, exists at the axial position in this crystal structure.