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DOI: 10.1039/A700686A (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1997, 1493-1498

Nucleophilic displacement at the benzoyl centre: a study of the change in geometry at the carbonyl carbon atom

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Matthew J. Colthurst and Andrew Williams

Abstract

The second-order rate constants for the reaction between hydroxide ion and phenoxide ion with 4-nitrophenyl esters of substituted benzoic acids in 10% acetonitrile–water (v/v) solution obey Hammett σ correlations. The values of the Hammett ρ of 1.67 (kArO) and 2.14 (kOH) are consistent with a large change in hybridization at the central carbon by comparison with the ρ value for a standard reaction where a full sp2 to sp3 change occurs. The transition state for the concerted reaction thus has a substantially tetrahedral geometry. The observation of the anti-Hammond effect whereby the ρ value for the hydroxide ion exceeds that of the less reactive phenoxide ion is consistent with a concerted, ANDN, mechanism for these reactions. A stepwise mechanism, AN + DN, is unlikely to yield a measurable break in the Hammett correlation for a change in the benzoyl substituent if the partitioning of the putative tetrahedral intermediate involves forward and reverse reactions with Hammett correlations possessing similar ρ values.

References

  1. (a) S. Ba-Saif, A. K. Luthra and A. Williams, J. Am. Chem. Soc., 1987, 109, 6362 CrossRef CAS ; (b) S. Ba-Saif, A. K. Luthra and A. Williams, J. Am. Chem. Soc., 1989, 111, 2647 CrossRef CAS ; (c) S. Ba-Saif, M. Colthurst, M. A. Waring and A. Williams, J. Chem. Soc., Perkin Trans. 2, 1991, 1901 RSC ; (d) A. Williams, Acc. Chem. Res., 1989, 22, 387 CrossRef CAS ; (e) M. J. Colthurst, M. Nanni and A. Williams, J. Chem. Soc., Perkin Trans. 2, 1996, 2285 RSC .
  2. (a) A. C. Hengge, J. Am. Chem. Soc., 1992, 114, 6575 CrossRef CAS ; (b) A. C. Hengge and R. A. Hess, J. Am. Chem. Soc., 1992, 114, 11256 ; (c) W. W. Cleland and A. C. Hengge, FASEB J., 1995, 9, 1585 Search PubMed .
  3. P. J. Guthrie, J. Am. Chem. Soc., 1991, 113, 3941 CrossRef CAS .
  4. A. Williams and K. T. Douglas, Chem. Rev., 1975, 75, 627 CrossRef CAS .
  5. M. L. Bender, Chem. Rev., 1960, 60, 53 CrossRef CAS ; S. L. Johnson, Adv. Phys. Org. Chem., 1967, 5, 237 CAS .
  6. (a) E. A. Castro, M. T. Borquez and P. M. Parada, J. Org. Chem., 1986, 51, 5072 CrossRef CAS ; (b) M. J. Gresser and W. P. Jencks, J. Am. Chem. Soc., 1977, 99, 6963, 6970 ; (c) E. A. Castro and F. J. Gil, J. Am. Chem. Soc., 1977, 99, 7611 CrossRef CAS ; (d) E. A. Castro, F. Ibanez, S. Lagos, M. Schick and J. G. Santos, J. Org. Chem., 1992, 57, 2691 CrossRef CAS .
  7. (a) L. do Amaral, M. P. Bastos, H. G. Bull, J. J. Ortiz and E. H. Cordes, J. Am. Chem. Soc., 1979, 101, 169 CrossRef CAS ; (b) Z. Bilkadi, R. deLorimer and J. F. Kirsch, J. Am. Chem. Soc., 1975, 97, 4317 CrossRef CAS ; (c) M. M. Kreevoy and I. S. H. Lee, J. Am. Chem. Soc., 1984, 106, 2550 CrossRef CAS ; (d) A. Williams, Adv. Phys. Org. Chem., 1992, 27, 1 CAS .
  8. S. L. Shames and L. D. Byers, J. Am. Chem. Soc., 1981, 103, 6170 CrossRef CAS .
  9. M. S. Kanchuger and L. D. Byers, J. Am. Chem. Soc., 1979, 101, 3005 CrossRef CAS .
  10. R. A. McClelland and M. Coe, J. Am. Chem. Soc., 1983, 105, 2178 CrossRef .
  11. W. J. Bover and P. Zuman, J. Chem. Soc., Perkin Trans. 2, 1973, 786 RSC .
  12. (a) J. F. Kirsch, W. Clewell and A. Simon, J. Org. Chem., 1968, 33, 127 CrossRef CAS ; (b) M. J. Collins and D. R. Goddard, J. Chem. Soc., 1958, 1952 RSC ; (c) C. D. Hubbard and J. F. Kirsch, Biochemistry, 1972, 11, 2483 CrossRef CAS ; (d) T. Matsukawa, S. Ban and T. Imada, J. Pharm. Soc. Jpn., 1951, 71, 477 (Chem. Abstr., 46, 454) Search PubMed ; (e) G. Neumann, Chem. Ber., 1886, 19, 2018 Search PubMed ; (f) Y. Akahori, Chem. Pharm. Bull., 1965, 13, 368 (Chem. Abstr., 1965, 61, 550b) CAS .
  13. (a) M. Caplow and W. P. Jencks, Biochemistry, 1962, 1, 883 CrossRef CAS ; (b) V. R. Correia, I. M. Cuccovia and H. Chaimovich, J. Phys. Org. Chem., 1991, 4, 13 CrossRef CAS .
  14. (a) E. Tommila and C. N. Hinshelwood, J. Chem. Soc., 1938, 1801 RSC ; (b) E. Tommila, Ann. Acad. Sci. Fenn., Ser. A57, 1941, 3 Search PubMed .
  15. I.-H. Um. J.-S. Min, J.-S. Jeon and D.-S. Kwon, Bull. Korean Chem. Soc., 1995, 16, 569 .
  16. I.-H. Um. S.-J. Oh and D.-S. Kwon, Bull. Korean Chem. Soc., 1996, 17, 802 .
  17. (a) E. A. Castro and R. B. Moodie, J. Chem. Soc., Chem. Commun., 1973, 828 RSC ; (b) P. M. Bond, E. A. Castro and R. B. Moodie, J. Chem. Soc., Perkin Trans. 2, 1976, 68 RSC .
  18. (a) C. F. Bernasconi and G. D. Leonarduzzi, J. Am. Chem. Soc., 1982, 104, 5133 CrossRef CAS ; (b) N. Gravitz and W. P. Jencks, J. Am. Chem. Soc., 1974, 96, 507 CrossRef CAS .
  19. B. M. Anderson and W. P. Jencks, J. Am. Chem. Soc., 1960, 82, 1773 CrossRef CAS .
  20. D. S. Noyce, A. T. Bottini and S. G. Smith, J. Org. Chem., 1958, 23, 752 CrossRef CAS .
  21. D. D. Perrin, B. Dempsey and E. P. Serjeant, pKaPrediction for Organic Acids and Bases, Chapman and Hall, London and New York, 1981 Search PubMed .
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