Enantioselective borohydride 1,4-reduction of α,β-unsaturated carboxamides using optically active cobalt(II) complex catalysts

Chemistry Letters

Volumn , Issue 11, 1998, Pages 1129-1130

  Yamada, Tohru ^a   Ohtsuka, Yuhki ^a   Ikeno, Taketo ^a  

^a KEIO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0003064233     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.1998.1129     Document Type: Article

References (14)

1. T. Nagata, K. Yorozu, T. Yamada, and T. Mukaiyama, Angew. Chem., Int. Ed. Engl., 34, 2145 (1995); K. D. Sugi, T. Nagata, T. Yamada, and T. Mukaiyama, Chem. Lett., 1996, 737, 1081; T. Nagata, K. D. Sugi, T. Yamada, and T. Mukaiyama, Synlett. 1996, 1076.
2. T. Nagata, K. Yorozu, T. Yamada, and T. Mukaiyama, Angew. Chem., Int. Ed. Engl., 34, 2145 (1995); K. D. Sugi, T. Nagata, T. Yamada, and T. Mukaiyama, Chem. Lett., 1996, 737, 1081; T. Nagata, K. D. Sugi, T. Yamada, and T. Mukaiyama, Synlett. 1996, 1076.
3. T. Nagata, K. Yorozu, T. Yamada, and T. Mukaiyama, Angew. Chem., Int. Ed. Engl., 34, 2145 (1995); K. D. Sugi, T. Nagata, T. Yamada, and T. Mukaiyama, Chem. Lett., 1996, 737, 1081; T. Nagata, K. D. Sugi, T. Yamada, and T. Mukaiyama, Synlett. 1996, 1076.
4. K. D. Sugi, T. Nagata, T. Yamada, and T. Mukaiyama, Chem. Lett., 1997, 493.
5. H. Fritschi, U. Leutenegger, K. Siegmann, A. Pfaltz, W. Keller, and C. Kratky, Helv. Chim. Acta, 71, 1541 (1988); H. Fritschi, U. Leutenegger, and A. Pfaltz, Helv. Chim. Acta, 71, 1553 (1988); U. Leutenegger, A. Madin, and A. Pfaltz, Angew. Chem., Int. Ed Engl., 28, 60 (1989).
6. H. Fritschi, U. Leutenegger, K. Siegmann, A. Pfaltz, W. Keller, and C. Kratky, Helv. Chim. Acta, 71, 1541 (1988); H. Fritschi, U. Leutenegger, and A. Pfaltz, Helv. Chim. Acta, 71, 1553 (1988); U. Leutenegger, A. Madin, and A. Pfaltz, Angew. Chem., Int. Ed Engl., 28, 60 (1989).
7. H. Fritschi, U. Leutenegger, K. Siegmann, A. Pfaltz, W. Keller, and C. Kratky, Helv. Chim. Acta, 71, 1541 (1988); H. Fritschi, U. Leutenegger, and A. Pfaltz, Helv. Chim. Acta, 71, 1553 (1988); U. Leutenegger, A. Madin, and A. Pfaltz, Angew. Chem., Int. Ed Engl., 28, 60 (1989).
8. P. von Matt and A. Pfaltz, Tetrahedron: Asym., 2, 691 (1991).
9. Semicorrin ligands are available from Fluka (Cat. No. 28600 and 14556), however they are considerably costly.
10. The cobalt(II) complex, (S)-MPAC and (R)-MPAC, are available from Tokyo Kasei Kogyo Co. Ltd. (S)-MPAC: B1845, (R)-MPAC:B1844.
11. K. Soai and A. Ookawa, J. Org. Chem., 5 1, 4000 (1986).
12. (S)-3-Phenylbutylic acid, which is commercially available, was converted to the corresponding N-methylanilide in a conventional manner.
13. 2, and then was converted to the corresponding N-methylanilide.
14. 2. The combined organic layers were washed with brine and dried over anhydrous sodium sulfate, and then solvents were removed under the reduced pressure. The purification by silica-gel column chromatography (hexane/EtOAc) gave the corresponding carboxamide ((S)-N-methyl-N-phenyl-3-cyclohexylbutanamide, 128.5 mg) in 99% yield. The optical purity was determined by HPLC analysis (Daicel Chiralpak AD, hexane/EtOH) to be 86% ee.