A brønsted acid catalyst for the enantioselective protonation reaction

Journal of the American Chemical Society

Volumn 130, Issue 29, 2008, Pages 9246-9247

  Cheol, Hong Cheon ^a   Yamamoto, Hisashi ^a  

^a UNIVERSITY OF CHICAGO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

BRONSTED ACID; N TRIFLYL PHOSPHORAMIDE; NITROGEN; PHOSPHORAMIDIC ACID DERIVATIVE; PHOSPHORIC ACID;

ACIDITY; ARTICLE; CATALYST; CHEMICAL REACTION; CHEMICAL STRUCTURE; ENANTIOSELECTIVITY; HIGH PERFORMANCE LIQUID CHROMATOGRAPHY; PROTON NUCLEAR MAGNETIC RESONANCE; PROTON TRANSPORT; STOICHIOMETRY; X RAY CRYSTALLOGRAPHY;

AMIDES; CATALYSIS; ETHERS; PHOSPHORIC ACIDS; PROTONS; SILANES; STEREOISOMERISM; SULFHYDRYL COMPOUNDS;

EID: 47749084742     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja8041542     Document Type: Article

References (20)

1. For a review of enantioselective organocatalysis, see: Pihko, P. M.; Moisan, L. Angew. Chem., Int. Ed. 2004, 43, 2062, and see Supporting Information for more references.
2. For a review of hydrogen bond organic catalysis, see: Doyle, A. G.; Jacobsen, E. N. Chem. Rev. 2007, 107, 5713, and see Supporting Information for more references.
3. Akiyama, T.; Itoh, J.; Yokota, D.; Fuchibe, K. Angew. Chem., Int. Ed. 2004, 43, 1566.
4. Uraguchi, D.; Terada, M. J. Am. Chem. Soc. 2004, 126, 5356.
5. For a review of chiral phosphoric acid catalysis, see: Akiyama, T Chem. Rev. 2007, 107, 5744, and see Supporting Information for more references.
6. (a) Nakashima, D.; Yamamoto, H. J. Am. Chem. Soc. 2006, 128, 9626.
7. (b) Jiao, P.; Nakashima, D.; Yamamoto, H. Angew. Chem., Int. Ed. 2008, 47, 2411.
8. After our publication of N-triflyl phosphamide, two other examples of carbonyl activation with this reagent were published; see: (a) Rueping, M.; Ieawsuwan, D.; Antonchick, A. P.; Nachtsheim, B. J. Angew. Chem., Int. Ed. 2007, 46, 2097.
9. (b) Rueping, M.; Nachtsheim, B. J.; Moreth, S. A.; Bolte, M. Angew. Chem., Int. Ed. 2008, 47, 593.
10. Bordwell, F. G. Acc. Chem. Res. 1988, 21, 456.
11. Similar acidity enhancement by substitution of the oxygen with sulfur was observed in the urea/thiourea catalyst. See ref 2 and Robak, M. T.; Trincado, M.; Ellman, J. A. J. Am. Chem. Soc. 2007, 129, 15110.
12. For a review of enantioselective protonation, see: Duhamel, L.; Duhamel, P.; Plaquevent, J. C. Tetrahedron: Asymmetry 2004, 15, 3653, and see Supporting information for more references.
13. For the asymmetric protonation with LBA, see: Nakashima, D.; Yamamoto, H. Synlett 2006, 150, and see Supporting Information for more references.
14. For another example of asymmetric protonation of silyl enol ether with Binap·AgF complex, see: Yanagisawa, A.; Touge, T.; Arai, T. Angew. Chem., Int. Ed. 2005, 44, 1546.
15. For another excellent organocatalytic asymmetric protonation of silyl enol ethers in different systems was reported, see: Poisson, T.; Dalla, V.; Marsais, F.; Dupas, G.; Oudeyer, S.; Levacher, V. Angew. Chem., Int. Ed. 2007, 46, 7090.
16. See Supporting Information for more detailed experimental results.
17. For another excellent example of high S/C ratio with phosphoric acid, see: Terada, M.; Machioka, K.; Sorimachi, K. Angew. Chem., Int. Ed. 2006, 45, 2254.
18. For a concept of asymmetric counteranion-directed catalysis, see: (a) Mayer, S.; List, B. Angew. Chem., Int. Ed. 2005, 45, 4193.
19. (b) Hamilton, G. L.; Kang, E. J.; Mba, M.; Toste, F. D. Science 2007, 317, 496.
20. Similar reaction rate enhancement of phosphoric acid catalysis in alcoholic solvents: Sickert, M.; Schneider, C. Angew. Chem., Int. Ed. 2008, 47, 3631.