Gold(I)-catalyzed enantioselective synthesis of benzopyrans via rearrangement of allylic oxonium intermediates

Journal of the American Chemical Society

Volumn 131, Issue 10, 2009, Pages 3464-3465

  Uemura, Minoru ^a   Watson, Iain D G ^a   Katsukawa, Mikimoto ^a   Dean Toste, F ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

BENZOPYRANS; CARBOALKOXYLATION; CARBOCATIONS; CATALYZED REACTIONS; ENANTIOSELECTIVE SYNTHESIS; EXPERIMENTAL EVIDENCE; OXONIUM; PROPARGYL; QUATERNARY STEREOCENTERS;

CARBOXYLATION; ESTERS; GOLD COMPOUNDS; TRANSITION METALS;

ENANTIOSELECTIVITY;

ALLYL COMPOUND; BENZOPYRAN DERIVATIVE; ESTER DERIVATIVE; GOLD COMPLEX; GOLD;

ARTICLE; ASYMMETRIC CARBOALKOXYLATION; CATALYSIS; CHEMICAL MODEL; CHIRALITY; ENANTIOSELECTIVITY; REACTION ANALYSIS; STEREOCHEMISTRY; SYNTHESIS; CHEMISTRY; STEREOISOMERISM;

BENZOPYRANS; CATALYSIS; GOLD; STEREOISOMERISM;

EID: 70249142536     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja900155x     Document Type: Article

References (37)

1. For recent reviews of gold-catalyzed reactions, see:
2. (a) Jiménez-Núñez, E.; Echavarren, A. M. Chem. Commun. 2007, 333.
3. (b) Gorin, D. J.; Toste, F. D. Nature 2007, 446, 395.
4. (c) Fürstner, A.; Davies, P. W. Angew. Chem., Int. Ed. 2007, 46, 3410.
5. (d) Hashmi, A. S. K. Chem. ReV. 2007, 107, 3180.
6. (e) Shen, H. C. Tetrahedron 2008, 64, 3885.
7. (f) Gorin, D. J.; Sherry, B. D.; Toste, F. D. Chem. ReV. 2008, 108, 3351.
8. (a) Marion, N.; Nolan, S. P. Angew. Chem., Int. Ed. 2007, 46, 2750.
9. (b) Correa, A.; Marion, N.; Fensterbank, L.; Malacria, M.; Nolan, S. P.; Cavallo, L. Angew. Chem., Int. Ed. 2008, 47, 718.
10. (a) Miki, K.; Ohe, K.; Uemura, S. J. Org. Chem. 2003, 68, 8505.
11. (b) Fürstner, A.; Hannen, P. Chem. Commun. 2004, 2546.
12. (c) Johansson, M. J.; Gorin, D. J.; Staben, S. T.; Toste, F. D. J. Am. Chem. Soc. 2005, 127, 18002.
13. (d) Gorin, D. J.; Dubé, P.; Toste, F. D. J. Am. Chem. Soc. 2006, 128, 14480.
14. (e) Amijs, C. H. M.; López-Carrillo, V.; Echavarren, A. M. Org. Lett. 2007, 9, 4021.
15. (f) Gorin, D. J.; Watson, I. D. G.; Toste, F. D. J. Am. Chem. Soc. 2008, 130, 3736.
16. (g) Davies, P. W.; Albrecht, S. J.-C. Chem. Commun. 2008, 238.
17. (h) Shapiro, N. D.; Toste, F. D. J. Am. Chem. Soc. 2008, 130, 9244.
18. (i) Watson, I. D. G.; Ritter, S.; Toste, F. D. J. Am. Chem. Soc. 2009, 131, 2056.
19. Enantioselective rearrangements of allylic oxonium ylides catalyzed by Rh: (a) Pierson, N.; Fernández-Gárcia, C.; McKervey, M. A. Tetrahedron Lett. 1997, 38, 4705.
20. (b) Doyle, M. P.; Forbes, D. C.; Vasbinder, M. M.; Peterson, C. S. J. Am. Chem. Soc. 1998, 120, 7653.
21. (c) Kitagaki, S.; Yanamoto, Y.; Tsutsui, H.; Anada, M.; Nakajima, M.; Hashimoto, S. Tetrahedron Lett. 2001, 42, 6361.
22. (d) Hodgson, D. M.; Petroliagi, M. Tetrahedron: Asymmetry 2001, 12, 877. Cu:
23. (e) Clark, J. S.; Fretwell, M.; Whitlock, G. A.; Burns, C. J.; Fox, D. N. A. Tetrahedron Lett. 1998, 39, 97.
24. For examples of gold-catalyzed O to C transfers, see: (a) Dubé, P.; Toste, F. D. J. Am. Chem. Soc. 2006, 128, 12062.
25. (b) Bae, H. J.; Baskar, B.; An, S. E.; Cheong, J. Y.; Thangadurai, D. T.; Hwang, I.-C.; Rhee, Y. H. Angew. Chem., Int. Ed. 2008, 47, 2263. For related Pt-catalyzed reactions, see:
26. (c) Nakamura, I.; Mizushima, Y.; Yamamoto, Y. J. Am. Chem. Soc. 2005, 127, 15022.
27. (d) Fürstner, A.; Davies, P. W. J. Am. Chem. Soc. 2005, 127, 15024.
28. Reactions carried out in acetonitrile minimized the formation of the 2-acetoxyindene product. See: Nakanishi, Y.; Miki, K.; Ohe, K. Tetrahedron 2007, 63, 12138.
29. 2a (97% ee) was converted to the corresponding ketone without deterioration of the enantiomeric excess by treatment with 2 equiv of NaOMe in methanol (see Supporting Information).
30. Other unsubstituted biarylphosphine ligands also gave poor enantioselectivity. For example, the (R)-BINAP(AuCl)2 and (R)-Cl-MeO-BIPHEP- (AuCl)2 catalyzed reactions in nitromethane gave 2a in 16% ee and 6% ee, respectively.
31. Replacing AgSbF6 with AgBF4 (61% yield, 97% ee) or AgOTf (46% yield, 97% ee) in the (R)-MeO-DTBM-BIPHEP(AuCl)2 catalyzed reaction afforded 2a with identical ee's but diminished yields.
32. The absolute stereochemistry of 2c was assigned by X-ray crystallography (see Supporting Information), and that of the remaining structures was assigned by analogy.
33. The corresponding propargyl acetates and benzoates were prone to elimination to form the enyne.
34. Secondary propargyl esters (R2 ) H) afforded complex mixtures.
35. (a) Mamane, V.; Gress, T.; Krause, H.; Fürstner, A. J. Am. Chem. Soc. 2004, 126, 8654.
36. (b) Luzung, M. R.; Markham, J. P.; Toste, F. D. J. Am. Chem. Soc. 2004, 126, 10858.
37. A cross-over experiment using 1d and 1k (catalyzed by 5 mol% t-Bu3PAuCl/ AgSbF6) produced only 2d (68%) and 2k (70%), indicating that reaction of the allylgold(I) intermediate and the cation must be rapid.