A novel synthesis of chiral tetrahydroisoquinolines employing silyl enol ethers in the presence of chiral acyl chlorides

Synlett

Volumn , Issue 7, 1999, Pages 1154-1156

  Itoh, Takashi ^a   Nagata, Kazuhiro ^a   Miyazaki, Michiko ^a   Ohsawa, Akio ^a  

^a SHOWA UNIVERSITY   (Japan)

Author keywords

6,7 Dimethoxyisoquinoline; Asymmetric addition; Chiral acyl chloride; Homolaudanosine; Silyl enol ether

Indexed keywords

ALANINE; CHLORIDE; ETHER DERIVATIVE; HOMOLAUDANOSINE; TETRAHYDROISOQUINOLINE DERIVATIVE;

ARTICLE; CHEMICAL REACTION; DRUG SYNTHESIS; STEREOSPECIFICITY; STRUCTURE ACTIVITY RELATION;

EID: 0032805195     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1999-3160     Document Type: Article

References (18)

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3. Comins, D. L.; Badawi, M. M. Heterocycles 1991, 32, 1869.
4. The overall yield of (+)-carnegine was not shown in ref. 3.
5. a) Itoh, T.; Hasegawa, H.; Nagata, K.; Ohsawa, A. J. Org. Chem. 1994, 59, 1319,
6. b)Itoh, T.; Hasegawa, H.; Nagata, K.; Okada, M.; Ohsawa, A. Tetrahedron 1994, 50, 13089.
7. a) Itoh, T.; Miyazaki, M.; Hasegawa, H.; Nagata, K.; Ohsawa, A. Chem, Commun. 1996, 1217.
8. b) Itoh, T.; Matsuya, Y.; Hasegawa, H.; Nagata, K.; Okada, M.; Ohsawa, A. J. Chem. Soc., Perkin Trans. I 1996, 2511.
9. c) Itoh, T.; Miyazaki, M.; Nagata, K.; Ohsawa, A. Heterocycles 1997, 46, 83.
10. d) Itoh, T.; Miyazaki, M.; Nagata, K.; Hasegawa, H.; Ohsawa, A.; Nakamura, K. T. Heterocycles 1998, 47, 125.
11. Other amino acids were also investigated. L-Phenylalanine and L-proline derived acyl chlorides afforded comparable yields and diastereoselectivities to those obtained with the alanine derivatives. The details will be disclosed in a separate paper.
12. In ref. 6d, 4-bromoisoquinoline was shown to be more reactive to silyl enol ethers than parent isoquinoline.
13. It is possible that p-(nitrophenyl)sulfonyl-L-alanyl group is labile enough to racemize under these conditions. However, no racemization was observed in our reaction processes, which was confirmed by chiral HPLC.
14. Wanner, K. T.; Praschak, I. Heterocycles 1989, 29, 29.
15. Compound 5 was recrystallized with hexane/AcOEt to give a single diastereomer.
16. Aladesanmi, A. J.; Kelley, C. J.; Leary, J. D. J. Nat. Prod. 1983, 46, 127.
17. In the reaction mixture, the N-acylated quaternary salt was not detected by NMR due to its low concentration.
18. de Koning, H.; Speckamp, W. N. in Stereoselective Synthesis; Helmchen, G.; Hoffmann, R. W.; Mulzer, J.; Schaumann, E. Ed.; Houben-Weyl: Stuttgart, 1996, Vol. 3, pp 1953-2009.