Metal-induced reductive cleavage reactions: An experimental and theoretical (MNDO) study on the stereochemical puzzle of birch and vinylogous birch processes

Journal of Organic Chemistry

Volumn 61, Issue 3, 1996, Pages 1035-1046

  Saá, José M ^a   Ballester, Pablo ^a   Deyá, Pere M ^a   Capó, Magdalena ^a   Garcías, Xavier ^a  

^a UNIVERSITAT DE LES ILLES BALEARS   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 84962359823     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo951834g     Document Type: Article

References (199)

1. (1)(a) Maercker, A. Angew Chem., Int. Ed. Engl 1987, 26, 972.
2. (b) Tiecco, M. Synthesis 1988, 749.
3. (c) Bhatt, M. V.; Kulkarni, S. U. Synthesis 1983, 249.
4. (d) Cohen, T. Bhupathy M. Acc. Chem. Res. 1989, 22, 152. For earlier literature on the subject, see the references cited in the above review articles.
5. (a) Hook, I. M.; Mander, L. N. Nat. Prod. Rep 1986, 3, 35.
6. (b) Birch, A. J. J. Chem. Soc. 1945, 89.
7. (c) Birch, A. J.; Maung, M.; Pelter, A. Aust. J. Chem. 1969, 22, 1923.
8. (d) Birch, A. J.; Maung, M. Tetrahedron Lett. 1967, 8, 3275.
9. (e) Flisak, J R.; Hall, S. S. J. Am. Chem. Soc. 1990, 112, 7299.
10. (f) McEnroe, F. J.; Sha, C.-K, Hall, S. S. J. Org. Chem. 1976, 41, 3465.
11. (g) Hall, S. S.; McEnroe, F. J. J. Org. Chem. 1975, 40, 271.
12. (h) Zilenovsky, J. S. R.; Hall, S. S. J. Org. Chem. 1981, 46, 4139.
13. (i) Hall, S. S.; Lipsky, S. D.; McEnroe, F J ; Bartels, A. P. J. Org. Chem. 1971, 36, 2588.
14. (j) Pak, C. S.; Lee, E.; Lee, G. H. J. Org. Chem. 1993, 58, 1523.
15. For an excellent review on the role of electrons as activating "messengers", see: Chanon, M.; Rajzmann, M.; Chanon, F. Tetrahedron 1990, 46, 6193.
16. The crystal structure of several clusters have been reported. See: (a) Marsch, M.; Harms, K.; Lochmann, L.; Boche, G. Angew. Chem., Int. Ed. Engl. 1990, 29, 308. (b) Harder, S.; Streitwieser, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 1066. For solution structures, see ref 17 and; (c) Lochmann, L; Pospisil, J.; Vodnansky, J.; Trekoval; J.; Lim, D. Collect. Czech Chem. Commun. 1965, 30, 2187. See also ref 11.
17. The crystal structure of several clusters have been reported. See: (a) Marsch, M.; Harms, K.; Lochmann, L.; Boche, G. Angew. Chem., Int. Ed. Engl. 1990, 29, 308. (b) Harder, S.; Streitwieser, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 1066. For solution structures, see ref 17 and; (c) Lochmann, L; Pospisil, J.; Vodnansky, J.; Trekoval; J.; Lim, D. Collect. Czech Chem. Commun. 1965, 30, 2187. See also ref 11.
18. The crystal structure of several clusters have been reported. See: (a) Marsch, M.; Harms, K.; Lochmann, L.; Boche, G. Angew. Chem., Int. Ed. Engl. 1990, 29, 308. (b) Harder, S.; Streitwieser, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 1066. For solution structures, see ref 17 and; (c) Lochmann, L; Pospisil, J.; Vodnansky, J.; Trekoval; J.; Lim, D. Collect. Czech Chem. Commun. 1965, 30, 2187. See also ref 11.
19. The stereochemical results observed with Li/THF were identical to those obtained with lithium in liquid ammonia. See: (a) Ballester, P.; Capo, M.; Garcías, X.; Saá, J. M. J. Org. Chem. 1993, 58, 328. (b) Ballester, P.; Capó, M.; Saá, J. M. Tetrahedron Lett. 1990, 31, 1339. (c) Garcías, X.; Ballester, P.; Capó, M.; Saá, J. M. J. Org. Chem. 1994, 59, 5093.
20. The stereochemical results observed with Li/THF were identical to those obtained with lithium in liquid ammonia. See: (a) Ballester, P.; Capo, M.; Garcías, X.; Saá, J. M. J. Org. Chem. 1993, 58, 328. (b) Ballester, P.; Capó, M.; Saá, J. M. Tetrahedron Lett. 1990, 31, 1339. (c) Garcías, X.; Ballester, P.; Capó, M.; Saá, J. M. J. Org. Chem. 1994, 59, 5093.
21. The stereochemical results observed with Li/THF were identical to those obtained with lithium in liquid ammonia. See: (a) Ballester, P.; Capo, M.; Garcías, X.; Saá, J. M. J. Org. Chem. 1993, 58, 328. (b) Ballester, P.; Capó, M.; Saá, J. M. Tetrahedron Lett. 1990, 31, 1339. (c) Garcías, X.; Ballester, P.; Capó, M.; Saá, J. M. J. Org. Chem. 1994, 59, 5093.
22. For the lithium-promoted clevage of in situ generated benzyl alcohols, see: (a) Flisak, J. R.; Hall, S. S. J. Am. Chem. Soc. 1990, 112, 7299. (b) Hall, S. S.; Lipsky, S. D. J. Org. Chem 1973, 38, 1735. (c) Hall, S. S. J. Org. Chem. 1973, 38, 1738. (d) Zilenovski, J. S. R.; Hall, S. S. J Org Chem 1981, 46, 4139.
23. For the lithium-promoted clevage of in situ generated benzyl alcohols, see: (a) Flisak, J. R.; Hall, S. S. J. Am. Chem. Soc. 1990, 112, 7299. (b) Hall, S. S.; Lipsky, S. D. J. Org. Chem 1973, 38, 1735. (c) Hall, S. S. J. Org. Chem. 1973, 38, 1738. (d) Zilenovski, J. S. R.; Hall, S. S. J Org Chem 1981, 46, 4139.
24. For the lithium-promoted clevage of in situ generated benzyl alcohols, see: (a) Flisak, J. R.; Hall, S. S. J. Am. Chem. Soc. 1990, 112, 7299. (b) Hall, S. S.; Lipsky, S. D. J. Org. Chem 1973, 38, 1735. (c) Hall, S. S. J. Org. Chem. 1973, 38, 1738. (d) Zilenovski, J. S. R.; Hall, S. S. J Org Chem 1981, 46, 4139.
25. For the lithium-promoted clevage of in situ generated benzyl alcohols, see: (a) Flisak, J. R.; Hall, S. S. J. Am. Chem. Soc. 1990, 112, 7299. (b) Hall, S. S.; Lipsky, S. D. J. Org. Chem 1973, 38, 1735. (c) Hall, S. S. J. Org. Chem. 1973, 38, 1738. (d) Zilenovski, J. S. R.; Hall, S. S. J Org Chem 1981, 46, 4139.
26. The electrochemical reduction of both cinnamyl alcohols and ethers has been reported to yield 1-phenyl-1-propene and 1-phenyl propane. See: (a) Mairanovsky, V. G. Angew. Chem., Int. Ed. Engl. 1976, 15, 281 and references therein. (b) Santiago, E., Simonet, J. Electrochim. Acta 1975, 20, 853. (c) Lund, H.; Doupeux, H.; Michel, M. A ; Mousset, G.; Simonet, J. Electrochim. Acta, 1974, 19, 629. (d) Horner, L.; Roder, H. Ann. Chem. 1969, 723, 11. Nuntnarumit, C.; Hawley, M. D. J. Electroanal. Chem. 1982, 133, 57.
27. The electrochemical reduction of both cinnamyl alcohols and ethers has been reported to yield 1-phenyl-1-propene and 1-phenyl propane. See: (a) Mairanovsky, V. G. Angew. Chem., Int. Ed. Engl. 1976, 15, 281 and references therein. (b) Santiago, E., Simonet, J. Electrochim. Acta 1975, 20, 853. (c) Lund, H.; Doupeux, H.; Michel, M. A ; Mousset, G.; Simonet, J. Electrochim. Acta, 1974, 19, 629. (d) Horner, L.; Roder, H. Ann. Chem. 1969, 723, 11. Nuntnarumit, C.; Hawley, M. D. J. Electroanal. Chem. 1982, 133, 57.
28. The electrochemical reduction of both cinnamyl alcohols and ethers has been reported to yield 1-phenyl-1-propene and 1-phenyl propane. See: (a) Mairanovsky, V. G. Angew. Chem., Int. Ed. Engl. 1976, 15, 281 and references therein. (b) Santiago, E., Simonet, J. Electrochim. Acta 1975, 20, 853. (c) Lund, H.; Doupeux, H.; Michel, M. A ; Mousset, G.; Simonet, J. Electrochim. Acta, 1974, 19, 629. (d) Horner, L.; Roder, H. Ann. Chem. 1969, 723, 11. Nuntnarumit, C.; Hawley, M. D. J. Electroanal. Chem. 1982, 133, 57.
29. The electrochemical reduction of both cinnamyl alcohols and ethers has been reported to yield 1-phenyl-1-propene and 1-phenyl propane. See: (a) Mairanovsky, V. G. Angew. Chem., Int. Ed. Engl. 1976, 15, 281 and references therein. (b) Santiago, E., Simonet, J. Electrochim. Acta 1975, 20, 853. (c) Lund, H.; Doupeux, H.; Michel, M. A ; Mousset, G.; Simonet, J. Electrochim. Acta, 1974, 19, 629. (d) Horner, L.; Roder, H. Ann. Chem. 1969, 723, 11. Nuntnarumit, C.; Hawley, M. D. J. Electroanal. Chem. 1982, 133, 57.
30. The electrochemical reduction of both cinnamyl alcohols and ethers has been reported to yield 1-phenyl-1-propene and 1-phenyl propane. See: (a) Mairanovsky, V. G. Angew. Chem., Int. Ed. Engl. 1976, 15, 281 and references therein. (b) Santiago, E., Simonet, J. Electrochim. Acta 1975, 20, 853. (c) Lund, H.; Doupeux, H.; Michel, M. A ; Mousset, G.; Simonet, J. Electrochim. Acta, 1974, 19, 629. (d) Horner, L.; Roder, H. Ann. Chem. 1969, 723, 11. Nuntnarumit, C.; Hawley, M. D. J. Electroanal. Chem. 1982, 133, 57.
31. The radical anion/cation and dianion/dication nomenclature is used throughout for clarity. By dianion/dication we mean to describe not only plain ion pairs but also triple ion species (i.e , cation/dianion/ cation) presumably resulting from reactions that employ alkali metals (with or without a carrier) as reductants.
32. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
33. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
34. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
35. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
36. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
37. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
38. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
39. For a recent incisive analysis into the stepwise versus concerted nature of the reductive eliminations induced by electron transfer (mostly electrochemicaily mediated), see: (a) Andrieux, C. P.; Le Gorande, A.; Savéant, J.-M. J. Am. Chem. Soc. 1992, 114, 6892. (b) Bertrán, J.; Gallardo, I.; Moreno, M.; Savéant J.-M. J. Am. Chem. Soc. 1992, 114, 9576. (c) Lexa, D.; Savéant, J.-M.; Su, K B.; Wang, D. L. J. Am. Chem. Soc. 1988, 110, 7617. (d) Andrieux, C. P.; Blochman, C.; Dumas-Bouchiat, J.-M.; Savéant, J.-M. J. Am. Chem. Soc. 1979, 101, 3431. (e) Andrieux, C. P.; Gallardo, I.; Savéant, J.-M.; Su, K. B. J. Am. Chem. Soc. 1986, 108, 638. (f) Andrieux, C. P.; Differding, E.; Robert, M.; Savéant, J.-M. J. Am. Chem. Soc. 1993, 115, 6592. (g) Andrieux, C. P.; Savéant, J -M. J. Am. Chem. Soc. 1993, 113, 8044. (f) Savéant, J.-M. Tetrahedron 1994, 50, 10117 and references therein.
40. Caubère, P. Chem Rev. 1993, 93, 2317 and references therein. For some recent monographs on "complex bases" or "super bases", see also: Schlosser, M. Pure Appl. Chem. 1988, 60, 1627. Mordini, A. In Advances in Carbanion Chemistry; Snieckus, V., Ed.; JAI Press; Greenwich, CT, 1992. Multimetal superbases are also the matter of current interest and controversy. See, for example: Bauer, W.; Lochman, L. J. Am. Chem. Soc. 1992, 114, 7482.
41. Caubère, P. Chem Rev. 1993, 93, 2317 and references therein. For some recent monographs on "complex bases" or "super bases", see also: Schlosser, M. Pure Appl. Chem. 1988, 60, 1627. Mordini, A. In Advances in Carbanion Chemistry; Snieckus, V., Ed.; JAI Press; Greenwich, CT, 1992. Multimetal superbases are also the matter of current interest and controversy. See, for example: Bauer, W.; Lochman, L. J. Am. Chem. Soc. 1992, 114, 7482.
42. Caubère, P. Chem Rev. 1993, 93, 2317 and references therein. For some recent monographs on "complex bases" or "super bases", see also: Schlosser, M. Pure Appl. Chem. 1988, 60, 1627. Mordini, A. In Advances in Carbanion Chemistry; Snieckus, V., Ed.; JAI Press; Greenwich, CT, 1992. Multimetal superbases are also the matter of current interest and controversy. See, for example: Bauer, W.; Lochman, L. J. Am. Chem. Soc. 1992, 114, 7482.
43. Caubère, P. Chem Rev. 1993, 93, 2317 and references therein. For some recent monographs on "complex bases" or "super bases", see also: Schlosser, M. Pure Appl. Chem. 1988, 60, 1627. Mordini, A. In Advances in Carbanion Chemistry; Snieckus, V., Ed.; JAI Press; Greenwich, CT, 1992. Multimetal superbases are also the matter of current interest and controversy. See, for example: Bauer, W.; Lochman, L. J. Am. Chem. Soc. 1992, 114, 7482.
44. (a) Lochmann, L.; Pospisil, J.; Lim, D. Tetrahedron Lett. 1966, 257.
45. (b) Schlosser, M. J. Organomet. Chem. 1967, 8, 9.
46. (c) McGarrity, J. F.; Ogle, C. A. J. Am. Chem. Soc. 1985, 107, 1805.
47. (d) McGarrity, J. F.; Ogle, C. A.; Brich, Z.; Loosh, H. R. J. Am. Chem. Soc. 1985, 107, 1810.
48. (e) Al-Aseer, M. A.; Allison, B. D.; Smith, S. G. J. Org. Chem 1985, 50, 2715.
49. (f) Baryshnikov, Yu N.; Kaloshina, N. N.; Vernovskaya, G. I. J. Gen Chem. USSR 1977, 47, 2535.
50. For a recent review on polar allyl-type organometallics, see: Schlosser, M.; Desponds, O.; Lehmann, R.; Moret, E.; Rauchswalbe, G. Tetrahedron 1993, 49, 10203.
51. Setzer, W.; Schleyer, P. v. R. Adv. Organomet. Chem. 1983, 24, 353.
52. For a recent review on the NMR structural investigation of organolithium compounds, see: Bauer, W.; Schleyer, P. v. R. In Advances in Carbanion Chemistry; Snieckus, V., Ed.; JAI Press; Greenwich, CT, 1992; Vol. 1.
53. Benzyllithium X-ray structures: (a) Patterman, S. P.; Karle, I. L.; Shicky, G. D. J. Am. Chem. Soc. 1970, 92, 1150. (b) Beno, M. A.; Hope, H.; Olmstead, M. M.; Power, P. P. Organometallics 1985, 4, 2117. (c) Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 2303. For some theoretical studies on the structure of benzyllithium, see: (d) Lipkowitz, K. B.; Uhegbu, C.; Naylor, A. M.; Vance, R. J. Comput. Chem. 1985, 6, 62. (e) Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1992, 114, 821.
54. Benzyllithium X-ray structures: (a) Patterman, S. P.; Karle, I. L.; Shicky, G. D. J. Am. Chem. Soc. 1970, 92, 1150. (b) Beno, M. A.; Hope, H.; Olmstead, M. M.; Power, P. P. Organometallics 1985, 4, 2117. (c) Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 2303. For some theoretical studies on the structure of benzyllithium, see: (d) Lipkowitz, K. B.; Uhegbu, C.; Naylor, A. M.; Vance, R. J. Comput. Chem. 1985, 6, 62. (e) Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1992, 114, 821.
55. Benzyllithium X-ray structures: (a) Patterman, S. P.; Karle, I. L.; Shicky, G. D. J. Am. Chem. Soc. 1970, 92, 1150. (b) Beno, M. A.; Hope, H.; Olmstead, M. M.; Power, P. P. Organometallics 1985, 4, 2117. (c) Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 2303. For some theoretical studies on the structure of benzyllithium, see: (d) Lipkowitz, K. B.; Uhegbu, C.; Naylor, A. M.; Vance, R. J. Comput. Chem. 1985, 6, 62. (e) Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1992, 114, 821.
56. Benzyllithium X-ray structures: (a) Patterman, S. P.; Karle, I. L.; Shicky, G. D. J. Am. Chem. Soc. 1970, 92, 1150. (b) Beno, M. A.; Hope, H.; Olmstead, M. M.; Power, P. P. Organometallics 1985, 4, 2117. (c) Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 2303. For some theoretical studies on the structure of benzyllithium, see: (d) Lipkowitz, K. B.; Uhegbu, C.; Naylor, A. M.; Vance, R. J. Comput. Chem. 1985, 6, 62. (e) Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1992, 114, 821.
57. Benzyllithium X-ray structures: (a) Patterman, S. P.; Karle, I. L.; Shicky, G. D. J. Am. Chem. Soc. 1970, 92, 1150. (b) Beno, M. A.; Hope, H.; Olmstead, M. M.; Power, P. P. Organometallics 1985, 4, 2117. (c) Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 2303. For some theoretical studies on the structure of benzyllithium, see: (d) Lipkowitz, K. B.; Uhegbu, C.; Naylor, A. M.; Vance, R. J. Comput. Chem. 1985, 6, 62. (e) Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1992, 114, 821.
58. For an example in which lithiotropicity has been observed in the solid state, see: Boche, G.; Etzrodt, H.; Massa, W. Baum, G. Angew. Chem., Int. Ed. Engl 1985, 24, 863.
59. (a) Schleyer, P. v. R. Pure Appl. Chem. 1983, 55, 355.
60. (b) Schleyer, P. v. R. Pure Appl. Chem. 1984, 56, 151.
61. (c) Streitwieser, A., Jr. Acc. Chem. Res. 1984, 17, 353.
62. Counterion-free "carbanions" are more a pedagogic aid than really abundant chemical species. See: Lambert, C.; Schleyer, P v. R Angew. Chem., Int. Ed. Engl. 1994, 33, 1129.
63. Szwarc, M. Ions and Ion-Pairs in Organic Reactions; Wiley-Interscience: New York, 1972; Vol. 1.
64. The structure of solvent-separated ion pairs is much more dynamic than that of contact ion pairs, the distance between ions being no less than 7 A. See: Weller, A. Z. Phys Chem. 1982, 130, 129. Our choice of a model for SSIP's, though static, mets two of these criteria, namely: (1) there is no interaction between ions, and (2) they are strongly solvated by the medium.
65. Electrochemically-induced reductive cleavage reactions are ususally written as involving counterion-free species. See, for example: (a) Savéant, J.-M. Tetrahedron 1994, 34, 10117. (b) Savéant, J.-M. Adv. Phys. Org. Chem. 1990, 26, 1. (c) Bunnett, J. F. Acc. Chem. Res. 1978, 11, 413.
66. Electrochemically-induced reductive cleavage reactions are ususally written as involving counterion-free species. See, for example: (a) Savéant, J.-M. Tetrahedron 1994, 34, 10117. (b) Savéant, J.-M. Adv. Phys. Org. Chem. 1990, 26, 1. (c) Bunnett, J. F. Acc. Chem. Res. 1978, 11, 413.
67. Electrochemically-induced reductive cleavage reactions are ususally written as involving counterion-free species. See, for example: (a) Savéant, J.-M. Tetrahedron 1994, 34, 10117. (b) Savéant, J.-M. Adv. Phys. Org. Chem. 1990, 26, 1. (c) Bunnett, J. F. Acc. Chem. Res. 1978, 11, 413.
68. Maslak, P.; Narvaez, J. N.; Parvez, M. J. Org. Chem. 1991, 56, 602,
69. Bock, H.; Nather, C.; Havlas, Z.; John, A.; Arad, C. Angew. Chem., Int. Ed Engl. 1994, 33, 875. See also ref 37.
70. Garst, J. F. Acc. Chem. Res. 1971, 4, 400. See also ref 34.
71. (a) Screttas, C. G ; Screttas, M. M. J. Org. Chem. 1978, 43, 1064. Cohen, T.; Bupathy, M. Acc. Chem. Res. 1989, 22, 152. For electrochemical studies see the following:
72. (a) Screttas, C. G ; Screttas, M. M. J. Org. Chem. 1978, 43, 1064. Cohen, T.; Bupathy, M. Acc. Chem. Res. 1989, 22, 152. For electrochemical studies see the following:
73. (b) Severin, M. G.; Farnia, G.; Vianello, E.; Arevalo, M. C. J. Electroanal. Chem 1988, 251, 369.
74. (c) Severin, Arevalo, M. C.; M. G.; Farnia, G.; Vianello, E. J. Phys. Chem. 1987, 91, 466.
75. (d) Arevalo, M. C; Farnia, G.; Severin, M. G.; Vianello, E. J. Electroanal. Chem. 1987, 220, 201.
76. (e) Griggio, L.; Severin, M. G. J. Electroanl. Chem. 1987, 223, 185.
77. (f) Griggio, L. J. Electroanal. Chem. 1982, 140, 155.
78. (a) Fish, R.; Dupon, J. W. J. Org. Chem. 1988, 53, 5230.
79. (b) Koppang, M. D.; Woolsey, N. F.; Bartak, D. E. J. Am. Chem. Soc. 1984, 106, 2799.
80. (c) Thornton, T. A.; Woolsey, N. F.; Bartak, D. E. J. Am. Chem. Soc. 1986, 108, 6497.
81. (d) Masnovi, J., Maticic, J. J Am. Chem. Soc. 1988, 110, 5189.
82. Maslak, P.; Guthrie, R. D. J. Am. Chem. Soc. 1986, 108, 2628. Maslak, P.; Guthrie, R. D. J. Am. Chem. Soc. 1986, 108, 2637.
83. Maslak, P.; Guthrie, R. D. J. Am. Chem. Soc. 1986, 108, 2628. Maslak, P.; Guthrie, R. D. J. Am. Chem. Soc. 1986, 108, 2637.
84. (a) Lexa, D.; Saveánt, J.-M.; Schafer, H J.; Su, K-B.; Vering, B.; Wang, D. L. J. Am. Chem. Soc. 1990, 112, 6162 and references therein.
85. (b) Dorigo, A. E.; Houk, K. N ; Cohen, T. J. Am. Chem. Soc. 1989, 111, 8976.
86. (a) Hobey, W. D.; McLachlan, A. D. J. Chem. Phys. 1960, 33, 1695.
87. (b) McConnell, H. M.; McLachlan, A. D. J Chem Phys. 1961, 34, 1
88. (c) McConnell, H. M. J. Chem. Phys. 1961, 34, 13.
89. (d) Gerson, F.; Huber, W.; Mullen, K. Helv. Chim. Acta 1981, 64, 2766.
90. (e) Tuttle, T. R., Jr.; Danner, J. C ; Graceffa, P. J. Chem. Phys. 1972, 76, 2866.
91. (f) Hirota, N. J. Am. Chem. Soc. 1968, 90, 3603.
92. (g) Hirota, N.; Carraway, R.; Schook, W. J. Am. Chem. Soc. 1968, 90, 3611.
93. (h) Hirota , N.; Kreilick, R. J Am. Chem. Soc 1966, 88, 615.
94. Lazana, M. C. R. L. R.; Franco, M. L. T. M. B.; Herold, B. J. J. Am. Chem. Soc 1989, 111, 8640.
95. (a) Goldberg, I. B.; Bolton, J. R. J. Chem Phys. 1970, 74, 1965.
96. (b) Mao, S. W., Nakamura, K.; Hirota, N. J. Am. Chem. Soc. 1974, 96, 5341.
97. (c) Chen, K. S.; Mao, S. W.; Nakamura, K.; Hirota, N. J. Am. Chem. Soc 1971, 93, 6004.
98. Bock, H.; Ruppert, K.; Näther, C.; Havlas, Z.; Herrmann, H.-F.; Arad, C.; Gobel, I.; John, A.; Meuret, J.; Nick, S.; Rauschenbach, A.; Seitz, W.; Vaupel, T.; Solouki, B. Angew. Chem., Int. Ed. Engl. 1992, 31, 550.
99. The formation of multiply charged ions resulting from the two successive one-electron reductions of conjugated cyclic hydrocarbons can be monitored by appropriately combining ESR and NMR measurements. See, for example. (a) Mullen, K. Angew. Chem., Int. Ed. Engl. 1987, 26, 204 (b) Mullen, K. Chem Rev. 1984, 84, 603. (c) K. Müllen, Huber, W ; Neumann, G.; Schmieders, C.; Unterberg, H. J. Am. Chem. Soc. 1985, 107, 801. Müllen, K. Pure Appl. Chem. 1986, 58, 177.
100. The formation of multiply charged ions resulting from the two successive one-electron reductions of conjugated cyclic hydrocarbons can be monitored by appropriately combining ESR and NMR measurements. See, for example. (a) Mullen, K. Angew. Chem., Int. Ed. Engl. 1987, 26, 204 (b) Mullen, K. Chem Rev. 1984, 84, 603. (c) K. Müllen, Huber, W ; Neumann, G.; Schmieders, C.; Unterberg, H. J. Am. Chem. Soc. 1985, 107, 801. Müllen, K. Pure Appl. Chem. 1986, 58, 177.
101. The formation of multiply charged ions resulting from the two successive one-electron reductions of conjugated cyclic hydrocarbons can be monitored by appropriately combining ESR and NMR measurements. See, for example. (a) Mullen, K. Angew. Chem., Int. Ed. Engl. 1987, 26, 204 (b) Mullen, K. Chem Rev. 1984, 84, 603. (c) K. Müllen, Huber, W ; Neumann, G.; Schmieders, C.; Unterberg, H. J. Am. Chem. Soc. 1985, 107, 801. Müllen, K. Pure Appl. Chem. 1986, 58, 177.
102. The formation of multiply charged ions resulting from the two successive one-electron reductions of conjugated cyclic hydrocarbons can be monitored by appropriately combining ESR and NMR measurements. See, for example. (a) Mullen, K. Angew. Chem., Int. Ed. Engl. 1987, 26, 204 (b) Mullen, K. Chem Rev. 1984, 84, 603. (c) K. Müllen, Huber, W ; Neumann, G.; Schmieders, C.; Unterberg, H. J. Am. Chem. Soc. 1985, 107, 801. Müllen, K. Pure Appl. Chem. 1986, 58, 177.
103. Holy, N. L. Chem Rev. 1974, 74, 243.
104. Walsh, T. D. J. Am. Chem. Soc. 1987, 109, 1511.
105. Disproportionation has been shown to be dependent on the counterion. See: Jensen, B. S.; Parker, V. D. J. Am. Chem. Soc. 1974, 97, 5211 See also ref 19.
106. (a) Birch, A. J. J. Chem. Soc. 1944, 430.
107. (b) Birch, A. J. J. Chem. Soc. 1947, 102.
108. (c) Eisch, J. J. J. Org. Chem. 1963, 28, 707.
109. (d) Normant, H.; Cuvigny, T. Bull. Soc. Chim. Fr. 1966, 3344.
110. (e) Testaferri, L.; Tiecco, M.; Tingoli, M.; Chianelli, D.; Montanucci, M. Tetrahedron 1982, 38, 3687.
111. (f) Itoh, M.; Yoshida, S.; Ando, T.; Miyaura, N. Chem Lett. 1976, 271.
112. (g) Eargle, D. H., Jr. J. Org. Chem. 1963, 28, 1703.
113. (h) Grovenstein, E. Jr.; Bhatti, A. M.; Quest, D. E.; Sengupta, D.; VanDerveer, D. J. Am. Chem. Soc. 1983, 105, 6290.
114. (i) Gerdil R. Helv. Chim. Acta 1973, 56, 196.
115. (j) Cox, J. A.; Ozment, C. L. Electroanal. Chem. Interfac. Electrochem. 1974, 51, 75.
116. (k) Oku, A.; Yoshida, M.; Matsumoto, K. Bull. Chem. Soc. Jpn. 1979, 52, 524
117. (l) Kawase, T.; Fujino, S.; Oda, M. Tetrahedron Lett. 1990, 31, 545.
118. (m) Kawase, T.; Fujino, S.; Oda, M. Chem. Lett. 1990, 1683. Kawase, T.; Kurata, H.; Fujino, S.; Ekinaka, T.; Oda, M. Tetrahedron Lett. 1992, 33, 7201.
119. (m) Kawase, T.; Fujino, S.; Oda, M. Chem. Lett. 1990, 1683. Kawase, T.; Kurata, H.; Fujino, S.; Ekinaka, T.; Oda, M. Tetrahedron Lett. 1992, 33, 7201.
120. (n) Farnia, G.; Marcuzzi, F.; Melloni, G.; Sandonà, G. J. Am. Chem. Soc. 1984, 106, 6503.
121. (o) Farnia, G.; Marcuzzi, F.; Melloni, G.; Sandonà, G. Zucca, M. V. J. Am. Chem. Soc. 1989, 111, 918.
122. Kiesele, H. Angew. Chem., Int. Ed. Engl. 1987, 109, 1511.
123. (b) Kiesele, H. Tetrahedron Lett. 1981, 22, 1097.
124. According to calculations, delocalized "carbanions" have a very flat potential hypersurface. See: (a) Schleyer, P. v. R.; Kos, A. J.; Wilhelm, D.; Clark, T.; Boche, G.; Decher, H.; Etzrodt, H.; Dietrich, H.; Mahdi, W. J. Chem. Soc., Chem. Commun. 1984, 22, 1495. (b) Bushby, R. J.; Tytko, M. P. J. Organomet. Chem. 1984, 270, 265. (c) Morton-Blake, D. A.; Corish, J.; Béniere, F. Theor. Chim. Acta 1985, 68, 389. See also ref 23.
125. According to calculations, delocalized "carbanions" have a very flat potential hypersurface. See: (a) Schleyer, P. v. R.; Kos, A. J.; Wilhelm, D.; Clark, T.; Boche, G.; Decher, H.; Etzrodt, H.; Dietrich, H.; Mahdi, W. J. Chem. Soc., Chem. Commun. 1984, 22, 1495. (b) Bushby, R. J.; Tytko, M. P. J. Organomet. Chem. 1984, 270, 265. (c) Morton-Blake, D. A.; Corish, J.; Béniere, F. Theor. Chim. Acta 1985, 68, 389. See also ref 23.
126. According to calculations, delocalized "carbanions" have a very flat potential hypersurface. See: (a) Schleyer, P. v. R.; Kos, A. J.; Wilhelm, D.; Clark, T.; Boche, G.; Decher, H.; Etzrodt, H.; Dietrich, H.; Mahdi, W. J. Chem. Soc., Chem. Commun. 1984, 22, 1495. (b) Bushby, R. J.; Tytko, M. P. J. Organomet. Chem. 1984, 270, 265. (c) Morton-Blake, D. A.; Corish, J.; Béniere, F. Theor. Chim. Acta 1985, 68, 389. See also ref 23.
127. Stewart, J. J. P. MOPAC 93, Fujitsu Limited, Tokyo, Japan, 1993. Available from Quantum Chemistry Program Exchange, University of Indiana, Bloomington, IN.
128. A detailed account of pros and cons is provided by: Clark, T. A Handbook of Computational Chemistry; Wiley Interscience: New York, 1985; Chapter 4. MNDO overestimates C-Li bond covalency and its energy. See: Schleyer, P. v. R Pure Appl. Chem. 1983, 55, 355. Li-H interactions are overestimated by MNDO. See: Kauffmann, E.; Raghavachari, K.; Reed, A., Schleyer, P. v. R. Organometallics 1988, 7, 1597. Streitweiser has stressed the inadequacy of MNDO to deal with dilithioacetaldoxime derivatives. See: Glaser, R.; Streitweiser, A. J. Org. Chem. 1989, 54, 5491.
129. A detailed account of pros and cons is provided by: Clark, T. A Handbook of Computational Chemistry; Wiley Interscience: New York, 1985; Chapter 4. MNDO overestimates C-Li bond covalency and its energy. See: Schleyer, P. v. R Pure Appl. Chem. 1983, 55, 355. Li-H interactions are overestimated by MNDO. See: Kauffmann, E.; Raghavachari, K.; Reed, A., Schleyer, P. v. R. Organometallics 1988, 7, 1597. Streitweiser has stressed the inadequacy of MNDO to deal with dilithioacetaldoxime derivatives. See: Glaser, R.; Streitweiser, A. J. Org. Chem. 1989, 54, 5491.
130. A detailed account of pros and cons is provided by: Clark, T. A Handbook of Computational Chemistry; Wiley Interscience: New York, 1985; Chapter 4. MNDO overestimates C-Li bond covalency and its energy. See: Schleyer, P. v. R Pure Appl. Chem. 1983, 55, 355. Li-H interactions are overestimated by MNDO. See: Kauffmann, E.; Raghavachari, K.; Reed, A., Schleyer, P. v. R. Organometallics 1988, 7, 1597. Streitweiser has stressed the inadequacy of MNDO to deal with dilithioacetaldoxime derivatives. See: Glaser, R.; Streitweiser, A. J. Org. Chem. 1989, 54, 5491.
131. A detailed account of pros and cons is provided by: Clark, T. A Handbook of Computational Chemistry; Wiley Interscience: New York, 1985; Chapter 4. MNDO overestimates C-Li bond covalency and its energy. See: Schleyer, P. v. R Pure Appl. Chem. 1983, 55, 355. Li-H interactions are overestimated by MNDO. See: Kauffmann, E.; Raghavachari, K.; Reed, A., Schleyer, P. v. R. Organometallics 1988, 7, 1597. Streitweiser has stressed the inadequacy of MNDO to deal with dilithioacetaldoxime derivatives. See: Glaser, R.; Streitweiser, A. J. Org. Chem. 1989, 54, 5491.
132. (a) Wilhelm, D.; Clark, T.; Schleyer, P. v. R.; Dietrich, H.; Mahdi, W J. Organomet. Chem. 1985, 280, C6.
133. (b) Streitwieser, A., Jr.; Swanson, J. T. J. Am. Chem. Soc. 1983, 105, 2502.
134. (c) Boche, G.; Decher, H.; Etzrodt, H.; Dietrich, H.; Mahdi, W.; Kos, A. J.; Schleyer, P. v. R. J. Chem. Soc., Chem. Commun. 1984, 22, 1493.
135. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
136. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
137. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
138. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
139. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
140. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
141. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
142. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
143. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
144. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
145. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
146. (d) Boche, G.; Fraenkel, G.; Cabral, J.; Harms, K.; Hommes, N. J. R. v. E. Lohrenz, J.; Marsch, M. Schleyer, P. v. R. J. Am. Chem. Soc. 1992, 114, 1562. Dietrich, H.; Mahdi, W.; Wilhelm, D.; Clark, T.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1984, 23, 621. Schleyer, P. v. R.; Hacker, R., Dietrich, H., Mahdi, W. Chem. Commun. 1985, 622. Neugebauer, W.; Geiger, G. A..P.; Kos, A. J.; Stezowski, J. J.; Schleyer, P. v. R. Chem. Ber. 1985, 118, 1504. Stezowski, J. J.; Hoier, H.; Wilhelm, D.; Clark, T.; Schleyer, P.v.R. Chem. Comm. 1985, 1263. Hacker, R.; Schleyer, P. v. R.; Reber, G.; Muller, G.; Brandsma, L. J. Organomet. Chem. 1986, 316, C4. McKee, M. L. J. Am. Chem. Soc. 1987, 109, 559. Hacker, R.; Kauffmann, E.; Schleyer, P. v. R.; Mahdi, W.; Dietrich, H. Chem. Ber. 1987, 120, 1033. Bausch, J. W.; Gregory, P. S.; Olah, G. A.; Prakasch, G. K.; Schleyer, P. v. R.; Segal, G. A. J. Am. Chem. Soc. 1989, 111, 3633. Paquette, L. A.; Bauer, W.; Sivik, M. R.; Bühl, M.; Feigel, M.; Schleyer, P. v R. J. Am. Chem. Soc. 1990, 112, 8776. Bauer, W.; O'Doherty, G. A.; Schleyer, P. v. R.; Paquette, L. A. J. Am. Chem. Soc. 1991, 113, 7093. Romesberg, F. E.; Colum, D. B. J. Am. Chem. Soc. 1992, 114, 2112.
147. (a) Suñer, G. A.; Deyá, P. M.; Saá, J. M. J. Am. Chem. Soc. 1990, 112, 1467.
148. (b) Bauer, W.; Feigel, M.; Muller, G.; Schleyer, P. v. R. J. Am. Chem. Soc. 1988, 110, 6033.
149. (c) Bauer, W.; Clark, T.; Schleyer, P. v. R. J. Am. Chem. Soc. 1987, 109, 970.
150. (d) Saá, J. M.; Deyâ, P. M.; Suñer, G. A.; Frontera, A. J. Am. Chem. Soc. 1992, 114, 9093.
151. (e) Saá, J. M.; Morey, J.; Frontera, A.; Deyá, P. M. J. Am. Chem. Soc. 1995, 117, 1105.
152. Bauer, W.; Lochmann, L. J. Am. Chem. Soc. 1992, 114, 7482. Best fit with experiment was achieved when real (dimethyl ether) ligands were employed in MNDO calculations.
153. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge distribution derived from a distributed multipole analysis: Klamt, A.; Schuurmann, G. J. Chem. Soc., Perkin Trans. 2 1993, 799. For a number of other "dielectric continuum" solvation models, see: (a) Katritzky, A. R.; Karelson, M. J. J. Am. Chem. Soc. 1991, 113, 1561. (b) Cramer, C. J.; Truhlar, D. G. Science 1992, 256, 231. Cramer, C. J.; Truhlar, D. G. J. Am. Chem. Soc. 1991, 113, 8552 and 8305. (c) Miertus, S.; Serocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117. (d) Ford, G. P.; Wang, B. J. Am. Chem. Soc 1992, 114, 10563.
154. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge distribution derived from a distributed multipole analysis: Klamt, A.; Schuurmann, G. J. Chem. Soc., Perkin Trans. 2 1993, 799. For a number of other "dielectric continuum" solvation models, see: (a) Katritzky, A. R.; Karelson, M. J. J. Am. Chem. Soc. 1991, 113, 1561. (b) Cramer, C. J.; Truhlar, D. G. Science 1992, 256, 231. Cramer, C. J.; Truhlar, D. G. J. Am. Chem. Soc. 1991, 113, 8552 and 8305. (c) Miertus, S.; Serocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117. (d) Ford, G. P.; Wang, B. J. Am. Chem. Soc 1992, 114, 10563.
155. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge distribution derived from a distributed multipole analysis: Klamt, A.; Schuurmann, G. J. Chem. Soc., Perkin Trans. 2 1993, 799. For a number of other "dielectric continuum" solvation models, see: (a) Katritzky, A. R.; Karelson, M. J. J. Am. Chem. Soc. 1991, 113, 1561. (b) Cramer, C. J.; Truhlar, D. G. Science 1992, 256, 231. Cramer, C. J.; Truhlar, D. G. J. Am. Chem. Soc. 1991, 113, 8552 and 8305. (c) Miertus, S.; Serocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117. (d) Ford, G. P.; Wang, B. J. Am. Chem. Soc 1992, 114, 10563.
156. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge distribution derived from a distributed multipole analysis: Klamt, A.; Schuurmann, G. J. Chem. Soc., Perkin Trans. 2 1993, 799. For a number of other "dielectric continuum" solvation models, see: (a) Katritzky, A. R.; Karelson, M. J. J. Am. Chem. Soc. 1991, 113, 1561. (b) Cramer, C. J.; Truhlar, D. G. Science 1992, 256, 231. Cramer, C. J.; Truhlar, D. G. J. Am. Chem. Soc. 1991, 113, 8552 and 8305. (c) Miertus, S.; Serocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117. (d) Ford, G. P.; Wang, B. J. Am. Chem. Soc 1992, 114, 10563.
157. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge distribution derived from a distributed multipole analysis: Klamt, A.; Schuurmann, G. J. Chem. Soc., Perkin Trans. 2 1993, 799. For a number of other "dielectric continuum" solvation models, see: (a) Katritzky, A. R.; Karelson, M. J. J. Am. Chem. Soc. 1991, 113, 1561. (b) Cramer, C. J.; Truhlar, D. G. Science 1992, 256, 231. Cramer, C. J.; Truhlar, D. G. J. Am. Chem. Soc. 1991, 113, 8552 and 8305. (c) Miertus, S.; Serocco, E.; Tomasi, J. Chem. Phys. 1981, 55, 117. (d) Ford, G. P.; Wang, B. J. Am. Chem. Soc 1992, 114, 10563.
158. COSMO (conductor-like screening model) evaluates the solvent screening energy for a cavity based on the solvent-accesible surfaces and for a charge
159. For prior theoretical studies on cation-free radical anions, see: (a) Casado, J.; Gallardo, I.; Moreno, M. J. Electroanal. Chem. 1987, 219, 197. (b) Andrieux, C. P.; Savéant, J.-M.; Zann, D. Nouv. J. Chim. 1984, 8, 107. (c) Beland, F. A.; Farwell, S. O.; Callis, P. R.; Geer R. D. J. Electroanal. Chem. 1977, 78, 145.
160. For prior theoretical studies on cation-free radical anions, see: (a) Casado, J.; Gallardo, I.; Moreno, M. J. Electroanal. Chem. 1987, 219, 197. (b) Andrieux, C. P.; Savéant, J.-M.; Zann, D. Nouv. J. Chim. 1984, 8, 107. (c) Beland, F. A.; Farwell, S. O.; Callis, P. R.; Geer R. D. J. Electroanal. Chem. 1977, 78, 145.
161. For prior theoretical studies on cation-free radical anions, see: (a) Casado, J.; Gallardo, I.; Moreno, M. J. Electroanal. Chem. 1987, 219, 197. (b) Andrieux, C. P.; Savéant, J.-M.; Zann, D. Nouv. J. Chim. 1984, 8, 107. (c) Beland, F. A.; Farwell, S. O.; Callis, P. R.; Geer R. D. J. Electroanal. Chem. 1977, 78, 145.
162. McIver, J W.; Komornicki, A. J Am. Chem. Soc. 1972, 94, 2625.
163. (a) Freedman, H. H.; Sandel, V. R.; Thill, B. P. J. Am. Chem. Soc. 1967, 89, 1762.
164. (b) Sandel, V. R ; Freedman, H. H.; McKinley, S. V. J. Am. Chem. Soc. 1968, 90, 495.
165. (a) Bauer, W.; Muller, G.; Pi, R.; Schleyer, P. v. R. Angew. Chem., Int. Ed. Engl. 1986, 25, 1103.
166. (b) Bauer, W.; Feigel, M.; Muller, G.; Schleyer, P. v. R. J. Am. Chem Soc. 1988, 110, 6033.
167. (c) Kaufmann, E.; Raghavachari, K.; Reed, A. E.; Schleyer, P. v. R. Organometallics 1988, 7, 1597.
168. (d) Bauer, W.; Clark, T.; Schleyer, P. v. R. J. Am. Chem. Soc. 1987, 109, 970.
169. (e) Gregory, K.; Bremer, M.; Bauer, W.; Schleyer, P. v. R.; Lorenzen, N. P.; Kopf, J.; Weiss, E.
170. (f) Bauer, W.; Schleyer, P. v. R. J. Am. Chem. Soc. 1989, 111, 7191.
171. Bauer, W.; Schleyer, P. v R. Magn. Reson. Chem. 1988, 26, 827.
172. 1H HOESY experiments in boxes), cannot be discarded with the available NMR data. MNDO calculations reveal that these haptomeric structures are separated by only 1 kcal/mol. (Matrix Presented)
173. Tanaka, J.; Nojima, M.; Kusabayashi, S. J. Chem. Soc., Perkin Trans. 2 1987, 673.
174. Eppers, O.; Fox, T.; Gunther, H. Helv. Chim. Acta 1992, 75, 883.
175. 6Li NMR spectra), thus proving that lithium methoxide prefers to aggregate rather than form a mixed complex with a π-type organolithium species. Actually, lithium methoxide is seen as a suspension in the NMR tube.
176. 55b (a) Rabideau, P. W. Tetrahedron 1989, 45, 1579. Rabideau, P. W.; Marcinow, Z. In Organic Reactions, John Wiley & Sons: New York, 1992; Vol. 42. (b) Rabideau, P. W.; Huser, D. L. J. Org. Chem 1983, 48, 4266.
177. 55b (a) Rabideau, P. W. Tetrahedron 1989, 45, 1579. Rabideau, P. W.; Marcinow, Z. In Organic Reactions, John Wiley & Sons: New York, 1992; Vol. 42. (b) Rabideau, P. W.; Huser, D. L. J. Org. Chem 1983, 48, 4266.
178. 55b (a) Rabideau, P. W. Tetrahedron 1989, 45, 1579. Rabideau, P. W.; Marcinow, Z. In Organic Reactions, John Wiley & Sons: New York, 1992; Vol. 42. (b) Rabideau, P. W.; Huser, D. L. J. Org. Chem 1983, 48, 4266.
179. AMI has been reported to behave well in a simple test case, namely the self-exchange electron transfer reactions between a neutral aromatic and the corresponding cation radical. See: Rauhut, G., Clark, T. J. Am. Chem. Soc. 1993, 115, 9127.
180. Freeman, P. K.; Hutchinson, L. L. J. Org. Chem. 1980, 45, 1924. Choi, H.; Pinkerton, A. A.; Fry, J. L. J. Chem. Soc., Chem. Commun. 1987, 225. Yus, M.; Ramon D. J. J. Chem. Soc., Chem. Commun. 1991, 398.
181. Freeman, P. K.; Hutchinson, L. L. J. Org. Chem. 1980, 45, 1924. Choi, H.; Pinkerton, A. A.; Fry, J. L. J. Chem. Soc., Chem. Commun. 1987, 225. Yus, M.; Ramon D. J. J. Chem. Soc., Chem. Commun. 1991, 398.
182. Freeman, P. K.; Hutchinson, L. L. J. Org. Chem. 1980, 45, 1924. Choi, H.; Pinkerton, A. A.; Fry, J. L. J. Chem. Soc., Chem. Commun. 1987, 225. Yus, M.; Ramon D. J. J. Chem. Soc., Chem. Commun. 1991, 398.
183. 2 is endothermic by 13.4 kcal/mol. See: Sygula, A.; Rabideau, P. W. J. Am. Chem. Soc. 1991, 113, 7797.
184. This is remarkable in light of the well-known tendency of MNDO to overestimate repulsive steric repulsions.
185. (a) Gerson, F.; Huber, W.; Mullen, K. Angew. Chem., Int. Ed. Engl. 1978, 17, 208.
186. (b) Gerson, F.; Moshuk, G.; Schwyzer, M. Helv Chim. Acta 1971, 54, 361.
187. (c) Bauld, N. L.; Hudson, C. E. Tetrahedron Lett. 1974, 3174.
188. (d) Dodd, J. R.; Pagni, R. M.; Watson, C. R. J. Org. Chem. 1981, 46, 1688.
189. (e) Dodd, J. R.; Winton R. F.; Pagni, R. M.; Watson, C. R.; Bloor, J. J. Am Chem. Soc. 1974, 96, 7846.
190. (f) Rieke, R.; Ogliaruso, M., McClung, R.; Winstein, S. J. Am. Chem. Soc. 1966, 88, 4729.
191. (g) Nelson, S. F.; Gillespie, J. P. J. Org. Chem. 1973, 38, 3592.
192. (h) Hartman, R. F.; Van Camp, J. R.; Rose, S. D. J. Org. Chem. 1987, 52, 2684.
193. (i) Bauld, N. L.; Chang, C. S.; Farr, F. R. J. Am. Chem Soc. 1972, 94, 7164.
194. (a) Ratner, M. A. Int. J. Quant. Chem 1978, 14, 675.
195. (b) Hale, P. D.; Ratner, M. A. Int. J. Quant. Chem. 1984, 18, 195.
196. (c) Wong, K. Y.; Schatz, P. N. Prog. Inorg. Chem. 1981, 28, 369.
197. At least in one case calculations have been used to determine the position of the counterion. See: Bolton, J. R.; Goldberg, I. B. J. Chem Phys. 1970, 74, 1965. For controversy with the electrostatic model, see. Brooles, J. J.; Rhine, W.; Stuky, G. J. Am. Chem. Soc. 1972, 94, 7346.
198. At least in one case calculations have been used to determine the position of the counterion. See: Bolton, J. R.; Goldberg, I. B. J. Chem Phys. 1970, 74, 1965. For controversy with the electrostatic model, see. Brooles, J. J.; Rhine, W.; Stuky, G. J. Am. Chem. Soc. 1972, 94, 7346.
199. Wakefield, B. J. The Chemistry of Organolithium Compounds; Pergamon Press: New York, 1974.