Remarkable enhancement of nucleophilicity of tin enolates toward nitro-or cyanoalkenes by tetrabutylammonium halides

Chemistry Letters

Volumn , Issue 11, 2000, Pages 1266-1267

  Yasuda, Makoto ^a   Ohigashi, Noriyuki ^a   Baba, Akio ^a  

^a OSAKA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0034344675     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2000.1266     Document Type: Article

References (18)

1. a) P. J. Smith, Chemistry of Tin, Blackie Academic & Professional, London (1998).
2. b) M. Pereyre, J.-P. Quintard, and A. Rahm, Tin in Organic Synthesis, Butterworth, London (1987).
3. c) A. G. Davies, Organotin Chemistry, VCH (1997).
4. R. Hulme, J. Chem. Soc., 1963, 1524.
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9. M. Yasuda, N. Ohigashi, I. Shibata, and A. Baba, J. Org. Chem., 64, 2180 (1999).
10. Organotin enolates exist as equilibrium mixtures of keto-and/or enol-forms, the ratio of which largely depends on their substituents and conditions. M. Pereyre, B. Bellegarde, J. Mendelsohn, and J. Valade, J. Organometal. Chem., 11, 97 (1968). Since higher reactivity is generally shown by enol-types than keto-ones (K. Kobayashi, M. Kawanisi, T. Hitomi, and S. Kozima, Chem. Lett., 1983, 851), all structures of tin enolates in this paper are drawn in enol-forms.
11. Organotin enolates exist as equilibrium mixtures of keto-and/or enol-forms, the ratio of which largely depends on their substituents and conditions. M. Pereyre, B. Bellegarde, J. Mendelsohn, and J. Valade, J. Organometal. Chem., 11, 97 (1968). Since higher reactivity is generally shown by enol-types than keto-ones (K. Kobayashi, M. Kawanisi, T. Hitomi, and S. Kozima, Chem. Lett., 1983, 851), all structures of tin enolates in this paper are drawn in enol-forms.
12. 2O, 5/2) of the resultant residue on silica gel gave 3a as a pure form.
13. The spectral data of 5 were reported. E. Juaristi, A. K. Bech, J. Hansen, T. Matt, T. Mukhopadhyay, M. Simson, and D. Seebach, Synthesis, 1993, 1271.
14. In this case, the Michael adduct was obtained although the yield was very low. The tin enolate 4 has higher reactivity than 1 because the enol ratio in tautomerism is highly favorable (ref 5).
15. Either an acyclic or a cyclic transition state is proposed for the reaction of metal enolates with unsaturated carbonyls.
16. a) C. H. Heathcock, M. H. Norman, and D. E. Uehling, J. Am. Chem. Soc., 107, 2797 (1985).
17. b) D. A. Oare and C. H. Heathcock, J. Org. Chem., 55, 157 (1990).
18. The spectral data of 8 were reported. F. Felluga, P. Nitti, G. Pitacco, and E. Valentin, Tetrahedron, 45, 2099 (1989).