View PDF Version
 
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

(Note: The full text of this document is currently only available in the PDF Version )

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.
Click here to see how this site uses Cookies. View our privacy policy here.