1176
S. Zhang et al. / Tetrahedron Letters 50 (2009) 1173–1176
O
O
O
H
O
N
H
H
R2
O
H
O
O
N
N
R2
N
H
R2
H
O
H
H
O
H
O
N
N
H
O
R1
HO
R1
R1
TS c
TS a
TS b
Scheme 3. Proposed transition structures.
2. (a) Eder, U.; Sauer, G.; Wiechert, R. Angew. Chem, Int. Ed. Engl. 1971, 10, 496; (b)
Hajos, Z. G.; Parrish, D. R. J. Org. Chem. 1974, 39, 1615; (c) List, B.; Lerner, R. A.;
Barbas, C. F., III. J. Am. Chem. Soc. 2000, 122, 2395.
3. (a) Berkessel, A.; Groger, H. Asymmetric Organocatalysis-From Biomimetic
Concepts to Applications in Asymmetric Synthesis; Wiley-VCH Verlag GmbH &
Co. KGaA: Weinheim, Germany, 2005; (b) Dalko, P. I.; Moisan, L. Angew. Chem.,
Int. Ed. 2004, 43, 5138; (c) Special Issue on Asymmetric Organocatalysis. Acc.
Chem. Res. 2004, 37, 487.; (d) List, B. Chem. Commun. 2006, 819; (e) Guillena, G.;
In conclusion, we have developed highly 4-phenoxy substituted
prolinamide phenols organocatalyst, which can promote the direct
asymmetric aldol reaction of aldehydes and ketones with high dia-
stereo- and enantioselectivities in large amount of water. Further
efforts are currently underway in this direction. This approach is
also particularly attractive in view of the green chemistry. Further
studies focusing on the full scope of this and related systems
including mechanistic studies, generality of more substrates and
the application of 1a–c in other reactions are in progress and will
be reported in due course in our laboratory.
´
Ramon, D. J. Tetrahedron: Asymmetry 2006, 17, 1465.
4. (a) Organic Synthesis in Water; Grieco, P. A., Ed.; Blackie Academic
&
Professional: London, 1998; (b) Ribe, S.; Wipf, P. Chem. Commun. 2001,
299.
5. (a) Dziedzic, P.; Zou, W.; Hafren, J.; Cordova, A. Org. Biol. Chem. 2006, 4, 38; (b)
Guillena, G.; Hita, M.; Najera, C. Tetrahedron: Asymmetry 2006, 17, 1493.
6. Luo, S.; Mi, X.; Liu, S.; Xu, H.; Cheng, J.-P. Chem. Commun. 2006, 3687.
7. (a) Wu, Y.; Zhang, Y.; Yu, M.; Zhao, G.; Wang, S. Org. Lett. 2006, 8, 4417; (b) Font,
D.; Jimeno, C.; Pericas, M. A. Org. Lett. 2006, 8, 4653.
Acknowledgment
8. (a) Mase, N.; Nakai, Y.; Ohara, N.; Yoda, H.; Takabe, K.; Tanaka, F.; Barbas, C. F.,
III. J. Am. Chem. Soc. 2006, 128, 734; (b) Hayashi, S.; Aratake, S.; Okano, T.;
Takahashi, J.; Sumiya, T.; Shoji, M. Angew. Chem., Int. Ed. 2006, 45, 5527.
9. Fu, Y.-Q.; Li, Z.-C.; Ding, L.-N.; Tao, J.-C.; Zhang, S.-H.; Tang, M.-S. Tetrahedron:
Asymmetry 2006, 17, 3351.
10. For a very interesting discussion of enantioselective organocatalysis ‘in water’
or ‘in the presence of water’, see: (a) Brogan, A. P.; Dickerson, T. J.; Janda, K. D.
Angew. Chem., Int. Ed. 2006, 45, 8100; (b) Hayashi, Y. Angew. Chem., Int. Ed.
2006, 45, 8103.
11. (a) Tang, Z.; Jiang, F.; Yu, L.-T.; Gong, L.-Z.; Mi, A.-Q.; Jiang, Y.-Z.; Wu, Y.-D. J. Am.
Chem. Soc. 2003, 125, 5262; (b) Tang, Z.; Jiang, F.; Cui, X.; Gong, L. Z.; Mi, A. Q.;
Jiang, Y. Z.; Wu, Y. D. Proc. Natl. Acad. Sci. U.S.A. 2004, 101, 5755.
12. (a) Hayashi, Y.; Sumiya, T.; Takahashi, J.; Gotoh, H.; Urushima, T.; Shoji, M.
Angew. Chem., Int. Ed. 2006, 118, 972; (b) Hayashi, Y.; Sumiya, T.; Takahashi, J.;
Gotoh, H.; Urushima, T.; Shoji, M. Angew. Chem., Int. Ed. 2006, 45, 958; (c) Mase,
N.; Watanabe, K.; Yoda, H.; Takabe, K.; Tanaka, F.; Barbas, C. F., III. J. Am. Chem.
Soc. 2006, 128, 4966; (d) Hayashi, Y.; Aratake, S.; Okano, T.; Takahashi, J.;
Sumiya, T.; Shoji, M. Angew. Chem., Int. Ed. 2006, 118, 5653.
The authors are grateful to Southwest University of China for
financial support.
Supplementary data
General experimental methods and spectra of the correspond-
ing compounds are available. Supplementary data associated with
this article can be found, in the online version, at doi:10.1016/
References and notes
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