8-Purinyl versus 2-Benzimidazolyl Carbanions: Charge Demands of the Heterocycles and Ligand Properties of the Bis(heteroaryl)methanes

Journal of Organic Chemistry

Volumn 63, Issue 3, 1998, Pages 436-444

  Abbotto, Alessandro ^a   Facchetti, Antonio ^a   Bradamante, Silvia ^a   Pagani, Giorgio A ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0009870908     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970958l     Document Type: Article

References (31)

1. Part 7 in bis(heteroaryl)methanes. For part 6, see: Abbotto, A.; Bradamante, S.; Capri, N.; Rzepa, H.; Williams, D. J.; White, A. J. Org. Chem. 1996, 61, 1770-1778. For part 5, see ref 3.
2. (a) Bradamante, S.; Pagani, G. A. J. Org. Chem. 1984, 49, 2863-2870.
3. (b) Bradamante, S.; Pagani, G. A. J. Chem. Soc., Perkin Trans. 2 1986, 1035-1046.
4. (c) Bradamante, S.; Pagani, G. A. Pure Appl. Chem. 1989, 61, 709-716.
5. (d) Barchiesi, E.; Bradamante, S.; Ferraccioli, R.; Pagani, G. A. J. Chem. Soc., Perkin Trans. 2 1990, 375-383.
6. (e) Berlin, A.; Bradamante, S.; Pagani, G. A. J. Chem. Soc., Perkin Trans. 2 1988, 1525-1530.
7. (f) Abbotto, A.; Alanzo, V.; Bradamante, S.; Pagani, G. A. J. Chem. Soc., Perkin Trans. 2 1991, 481-488.
8. (g) Abbotto, A.; Bradamante, S.; Pagani, G. A. J. Org. Chem. 1993, 58, 444-448.
9. (h) Abbotto, A.; Bradamante, S.; Pagani, G. A. J. Org. Chem. 1993, 58, 449-455.
10. Abbotto, A.; Bradamante, S.; Pagani, G. A. J. Org. Chem. 1996, 61, 1761-1769.
11. 13C shift sensitivity (160 ppm/electron), see refs 2a,c and Bradamante, S.; Pagani, G. A. Benzyl and Heteroaryl-methyl Carbanions: Structure and Substituent Effects In Advances in Carbanion Chemistry; Snieckus, V., Ed.; Jai Press: London, 1996; Vol. 2, pp 189-263.
12. x is calculated and to which it refers. A detailed description of the significance of charge demands c can be found in refs 2b,d, 3, and 4.
13. Abbotto, A.; Bradamante, S.; Pagani, G. A.; Rzepa, H.; Stoppa, F. Heterocycles 1995, 40, 757-776.
14. Another factor exerted by the heterocycle that possibly affects the stability of chelates is the ring size of the heterocycles (five- or six-membered). An account describing the results of a detailed investigation into this subject will be submitted elsewhere; Abbotto, A.; Bradamante, S.; Pagani, G. A. Manuscript in preparation.
15. Abbotto, A.; Alanzo, V.; Bradamante, S.; Pagani, G. A.; Rizzoli, C.; Calestani, G. Gazz. Chim. Ital. 1991, 121, 365-368.
16. Abbotto, A. Ph.D. Thesis, University of Milano, Milano, Italy, 1993.
17. Bredereck, H.; Effenberger, F.; Rainer, G. J. Lieb. Ann. Chem. 1964, 673, 82.
18. For the synthesis of 8-alkylpurines, see: Bredereck, H.; Effenberger, F.; Österlin, H. G. Chem. Ber. 1967, 100, 2280-2291.
19. (a) Hogen-Esch, T. E.; Smid, J. J. Am. Chem. Soc. 1966, 88, 307-324.
20. (b) Arnett, E. M.; McKelvey, D. R. J. Am. Chem. Soc. 1966, 88, 2598-2599.
21. (c) Gutman, V. The Donor-Acceptor Approach to Molecular Interactions; Plenum Press: New York, 1978; Chapters 7 and 10.
22. Breitmaier, E.; Voelter, W. Carbon-13 NMR Spectroscopy; VCH: Weinheim, 1987; p 284.
23. See ref 13, p 290.
24. Witanowski, M.; Stefaniak, L.; Webb, G. A. In Annual Reports on NMR Spectroscopy; Webb, G. A., Ed.; Academic Press: London, 1986; Vol. 18, p 483.
25. MOPAC 6.0: Stewart, J. J. P. QCPE 1990, 455.
26. Abbotto, A.; Bradamante, S.; Pagani, G. A. Gazz. Chim. Ital. 1994, 124, 301-308.
27. Kalinowski, H. O.; Berger, S.; Braun, S. Carbon-13 NMR Spectroscopy; John Wiley & Sons: Chichester, 1988; p 297.
28. (a) Scheibe, G.; Friedrich, H. J. Chem. Ber. 1961, 94, 1336.
29. (b) Shivanyuk, A. F.; Dashkovskaya, E. V.; Lozinskii, M. O. Zh. Org. Khim. 1986, 22, 200.
30. Pugmuire, R. J.; Grant, D. M.; Townsend, L. B.; Robins, R. K. J. Am. Chem. Soc. 1973, 95, 2791.
31. Kenner, G. W.; Lythgoe, B.; Todd, A. R.; Topham, A. J. Chem. Soc. 1943, 574-575.