Practical and efficient enantioselective borohydride reduction of aromatic ketones catalyzed by optically active cobalt(II) complexes using pre-modified borohydride

Chemistry Letters

Volumn , Issue 12, 1996, Pages 1081-1082

  Sugi, Kiyoaki D ^a   Nagata, Takushi ^a   Yamada, Tohru ^a   Mukaiyama, Teruaki ^b  

^a MITSUI CHEMICALS INC   (Japan)

^b TOKYO UNIVERSITY OF SCIENCE   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0002775186     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.1996.1081     Document Type: Article

References (17)

1. J.-C. Caille, M. Bulliard, and B. Laboue, Chim. Oggi., 13, 17 (1995).
2. T. Ohkuma, H. Ooka, M. Yamakawa, T. Ikariya, and R. Noyori, J. Org Chem., 61, 4872 (1996) and references cited therein.
3. A. Fujii, S. Hashiguchi, N. Uematsu, T. Ikariya, and R. Noyori, J. Am. Chem. Soc., 118, 2521 (1996) and references cited therein.
4. T. Nagata, K. Yorozu, T. Yamada, and T. Mukaiyama, Angew. Chem., Int. Ed. Engl., 34, 2145 (1995).
5. K. D. Sugi, T. Nagata, T. Yamada, and T. Mukaiyama, Chem Lett., 1996, 737.
6. Review: D. C. Wigfield, Tetrahedron 35, 449 (1979) and references cited therein.
7. 4 in the mixture was discarded prior to the examination.
8. 4. When only ethanol was used to modify borohydride, the resulting optically active alcohol 5 possessed non-reproducible values of 61 to 81% ee, and these were probably associated with disproportion of alkoxyborohydrides; B. Rickborn and M. T. Wuesthoff, J. Am. Chem. Soc., 92, 6894 (1970) and references cited therein.
9. No further reaction of THFA with borohydride was observed for given conditions for 24 h, and its mixture could be stored for a few days at below 0 °C.
10. 3, and the mixture was continued to stirred for 30 min at 0 °C. The reaction was quenched by the addition of saturated aqueous ammonium chloride, and extracted with diethyl ether. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate, and then the excess solvents were removed under reduced pressure. The purification by column chromatography on silica gel (hexane/ethyl acetate) gave 88.2 mg of the corresponding alcohol 5; 99% yield. The optical purity was determined by using Daicel Chiralpak AD (hexane/2-propanol).
11. Review: H. B. Kagan and J. C. Fiaud, Top. Stereochem., 18, 249 (1988).
12. When 0.38 equiv. of borohydride was used for in situ method, the conversion of the reduction of 7 was 47%. The optical purities of recovered 7 and cis-alcohol were 80% and 87%, ee, respectively.
13. Review: R. Noyori, M. Tokunaga, and M. Kitamura, Bull. Chem. Soc. Jpn., 68, 36 (1995).
14. The in situ method gave 13-cis in 97% yield with 48% ee.
15. Absolute configuration was determined by sign of rotation; D. Buisson, R. Cecchi, J.-A. Laffitte, U. Guzzi, and R. Azerad, Tetrahedron Lett., 35, 3091 (1994).
16. For ketone 8: G. Jaouen and A. Meyer, J. Am. Chem. Soc., 97, 4667 (1975); for 1,2,3,4-tetrahydro-2-methyl-1-naphthol: A. Schoofs, J. P. Gutte, and A. Horeau Bull. Soc. Chim. Fr., 1976, 1215.
17. For ketone 8: G. Jaouen and A. Meyer, J. Am. Chem. Soc., 97, 4667 (1975); for 1,2,3,4-tetrahydro-2-methyl-1-naphthol: A. Schoofs, J. P. Gutte, and A. Horeau Bull. Soc. Chim. Fr., 1976, 1215.