Catalytic enantioselective Mannich-type reactions of ketoimines

Journal of the American Chemical Society

Volumn 129, Issue 3, 2007, Pages 500-501

  Suto, Yutaka ^a   Kanai, Motomu ^a   Shibasaki, Masakatsu ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

IMINE; KETONE DERIVATIVE;

ALDOL REACTION; ARTICLE; CATALYSIS; CATALYST; CHEMICAL STRUCTURE; ENANTIOSELECTIVITY; MANNICH REACTION; QUANTUM YIELD; REACTION ANALYSIS;

AMINO ACIDS; CATALYSIS; CHROMATOGRAPHY, HIGH PRESSURE LIQUID; IMINES; KETONES; MODELS, CHEMICAL; STEREOISOMERISM;

EID: 33846409049     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja068226a     Document Type: Article

References (18)

1. (a) Liu, M.; Sibi, M. P. Tetrahedron 2002, 58, 7991.
2. (b) Abele, S.; Seebach, D. Eur. J. Org. Chem. 2000, 1.
3. (c) Fulop, F. Chem. Rev. 2001, 101, 2181.
4. (d) Gellman, S. H. Acc. Chem. Res. 1998, 31, 173.
5. For reviews of asymmetric Mannich reactions, see: (a) Kobayashi, S.; Ishitani, H. Chem. Rev. 1999, 99, 1069.
6. (b) Taggi, A. E.; Hafez, A. M.; Lectka, T. Acc. Chem. Res. 2003, 36, 10.
7. (c) Marques, M. M. B. Angew. Chem., Int. Ed. 2006, 45, 348.
8. To date, two examples of tetrasubstituted carbon-forming catalytic enantioselective Mannich reactions of special ketoiminoesters have been reported. See: (a) Saaby, S.; Nakama, K.; Lie, M. A.; Hazell, R. G.; Jørgensen, K. A. Chem.-Eur. J. 2003, 9, 6145.
9. (b) Zhuang, W.; Saaby, S.; Jørgensen, K. A. Angew. Chem., Int. Ed. 2004, 43, 4476.
10. Mapp recently reported a general β,β-disubstituted amino acid synthesis utilizing diastereoselective nitrile oxide [3 + 2] cycloaddition as a key step. See: (a) Minter, A. R.; Fuller, A. A.; Mapp, A. K. J. Am. Chem. Soc. 2003, 125, 6846.
11. (b) Fuller, A. A.; Chen, B.; Minter, A. R.; Mapp, A. K. J. Am. Chem. Soc. 2005, 127, 5376.
12. Oisaki, K.; Zhao, D.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 2006, 128, 7164.
13. For pioneering studies on transmetalation from a silyl enoate to a copper enolate, see: Pagenkopf, B. L.; Krüger, J.; Stojanovic, A.; Carreira, E. M. Angew. Chem., Int. Ed. 1998, 37, 3124.
14. The trimethylsilyl enolate derived from methyl acetate produced comparable results: however, in this case, isolation of the product from 1d was difficult.
15. tBuOH) did not improve the yield in this case. On the other hand, a protic additive facilitated the catalyst turnover in Cu-catalyzed enantioselective allylation of ketoimines: Wada, R.; Shibuguchi, T.; Makino, S.; Oisaki, K.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 2006, 128, 7687.
16. August, J. M. J. Org. Chem. 1988, 53, 3364.
17. 2 can be easily synthesized in a multi-gram scale. See Supporting Information.
18. The yield was slightly lower when using 2d rather than 1d as a substrate. In many substrates shown in Table 3, however, both yield and enantioselectivity were improved using a N-di(3,5-xylyl)phosphinoyl protecting group rather than a simple N-diphenylphosphinoyl group.