Enantioposition-selective alkynylation of biaryl ditriflates by palladium-catalyzed asymmetric cross-coupling

Tetrahedron Letters

Volumn 37, Issue 18, 1996, Pages 3161-3164

  Kamikawa, Takashi ^a   Uozumi, Yasuhiro ^a   Hayashi, Tamio ^a  

^a KYOTO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALKYNE DERIVATIVE;

ARTICLE; DRUG PURITY; DRUG SYNTHESIS; ENANTIOMER; REACTION ANALYSIS;

EID: 0029864744     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)00517-5     Document Type: Article

References (12)

1. Hayashi, T.; Niizuma, S.; Kamikawa, T.; Suzuki, N.; Uozumi, Y. J. Am. Chem. Soc. 1995, 117, 9101.
2. The starting ditriflates 1, 4, and 5 were prepared by Suzuki coupling of 2,6-dimethoxyphenyl bromide with aryl boronic acids follwed by conversion of the methoxy groups into triflate groups. formula represented
3. (a) Tsuji, J. Palladium Reagents and Catalysts; Wiley: New York, 1995.
4. (b) Heck, R. F. Palladium Reagents in Organic Syntheses; Academic Press: New York, 1985.
5. (c) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett. 1975, 4467.
6. (d) Weir, J. R.; Patel, B. A.; Heck, R. F. J. Org. Chem. 1980, 45, 4926.
7. (a) Hayashi, T.; Konishi, M.; Fukushima, M.; Kanehira, K.; Hioki, T.; Kumada, M. J. Org. Chem. 1983, 48, 2195.
8. (b) Hayashi, T.; Fukushima, M.; Konishi, M.; Kumada, M. Tetrahedron Lett. 1980, 21, 79.
9. To our best knowledge, this is the first example for the palladium-catalyzed cross-coupling of aryl triflates with alkynyl Grignard reagents.
10. 3SiC≡CMgBr can not be used because of their insolubility in the reaction solvent (ether/toluene = 1/1).
11. In the absence of lithium bromide, the present cross-coupling reaction is very slow. For the effects of lithium bromide, see ref 1.
12. 20 -104 (c 0.2, chloroform), respectively.