Efficiency of proton transfer catalysis. Intramolecular general acid catalysis of the hydrolysis of dialkyl acetals of benzaldehyde

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Christopher J. Brown and Anthony J. Kirby


Abstract

Intramolecular general acid catalysis is demonstrated for the first time for the hydrolysis of dialkyl acetals of benzaldehyde. Effective molarities (EM) ranging from 810 to over 104 mol dm-3 are observed for the hydrolysis of the carboxylic acid 4 and for the three dimethylammonium systems 5·H+–7·H+, which show pH–rate profile plateaux extending as far as pH 7–9. Reactivity is shown to depend significantly on the strength of the general acid involved. Efficient catalysis depends on the development of a strong hydrogen bond in the transition state for the reaction, but efficiency is reduced when significant intramolecular hydrogen bonding is present in the ground state. The most reactive acetal, the carboxylic acid 4, is hydrolysed with a halflife of 1.15 s at 20 °C, fast enough to become complicated kinetically by the build up of the hemiacetal intermediate (Scheme 2). It does not, however, show the highest EM.


References

  1. M. L. Sinnott, Chem. Rev., 1990, 90, 1171 CrossRef.
  2. Q. Wang, R. W. Graham, D. Trimbur, R. A. J. Warren and S. G. Withers, J. Am. Chem. Soc., 1994, 116, 11 595–5.
  3. A. J. Kirby, Angew. Chem., Int. Ed. Engl., 1996, 35, 707 CrossRef CAS.
  4. S. G. Withers, K. Rupitz, D. Trimbur and R. A. J. Warren, Biochemistry, 1992, 31, 9979 CrossRef CAS.
  5. A. J. Kirby and J. M. Percy, J. Chem. Soc., Perkin Trans. 2, 1989, 907 RSC.
  6. A. J. Kirby and A. Parkinson, J. Chem. Soc., Chem. Commun., 1994, 707 RSC.
  7. A. J. Kirby, Adv. Phys. Org. Chem., 1980, 17, 183 CAS.
  8. A. J. Kirby and A. R. Fersht, in Intramolecular Catalysis, eds. E. T. Kaiser and F. J. Kezdy, New York, 1971 Search PubMed.
  9. B. Capon, M. C. Smith, E. Anderson, R. H. Dahm and G. H. Sankey, J. Chem. Soc., B, 1969, 1038 RSC.
  10. G.-A. Craze and A. J. Kirby, J. Chem. Soc., Perkin Trans. 2, 1974, 61 RSC.
  11. A. A. Frost and R. G. Pearson, Kinetics and Mechanism, Wiley, 1961 Search PubMed.
  12. J. L. Jensen and P. A. Lenz, J. Am. Chem. Soc., 1978, 100, 1291 CrossRef CAS.
  13. J. L. Jensen, A. B. Martinez and C. L. Shimazu, J. Org. Chem., 1983, 48, 4175 CrossRef CAS.
  14. T. L. Amyes and W. P. Jencks, J. Am. Chem. Soc., 1989, 111, 7888 CrossRef CAS.
  15. B. Capon, K. Nimmo and G. L. Reid, J. Chem. Soc., Chem. Commun., 1976, 871 RSC.
  16. C. J. Brown, Efficient Intramolecular General Acid Catalysis, Thesis, Cambridge, 1995 Search PubMed.
  17. J. L. Jensen and K. S. Yamaguchi, J. Org. Chem., 1984, 49, 2613 CrossRef CAS.
  18. W. P. Jencks and J. Regenstein, in Ionisation Constants, ed. H. A. Sober, Cleveland, Ohio, 1970 Search PubMed.
  19. A. Awwal and F. Hibbert, J. Chem. Soc., Perkin Trans. 2, 1977, 152 RSC.
  20. A. J. Kirby and F. O'Carroll, J. Chem. Soc., Perkin Trans. 2, 1994, 649 RSC.
  21. M. I. Page, personal communication.
  22. J. L. Jensen, L. R. Herold, P. A. Lenz, S. Trusty, V. Sergi, K. Bell and P. Rogers, J. Am. Chem. Soc., 1979, 101, 4672 CrossRef CAS.
  23. C. J. Brown and A. J. Kirby, Chem. Commun., 1996, 2355 RSC.
  24. T. H. Fife and T. J. Przystas, J. Am. Chem. Soc., 1979, 101, 1202 CrossRef CAS.
  25. R. H. Bromilow and A. J. Kirby, J. Chem. Soc., B, 1972, 149 RSC.
  26. A. J. Kirby and D. H. Williams, Phil. Trans. Roy. Soc. (London), Ser. A, 1993, 345, 1 Search PubMed.
  27. S. E. Barber and A. J. Kirby, J. Chem. Soc., Chem. Commun., 1987, 1775 RSC.
  28. D. D. Perrin and W. F. Armarego, Purification Methods, Pergamon Press, 1988 Search PubMed.
  29. K. Glasoe and F. A. Long, J. Phys. Chem., 1960, 64, 188 CrossRef CAS.
  30. J. Colonge and R. Vuillemet, Bull. Soc. Chim. Fr., 1961, 2235 CAS.
  31. F. Straus and H. Heinze, Liebigs Ann. Chem., 1932, 292, 191 Search PubMed.
  32. L. N. Mander and S. P. Sethi, Tetrahedron Lett., 1983, 24, 5425 CrossRef.
  33. E. D. Laganis and B. L. Chenard, Tetrahedron Lett., 1984, 25, 5831 CrossRef CAS.
  34. P. Beak and B. J. Kokko, J. Org. Chem., 1982, 47, 2822 CrossRef CAS.
  35. A. J. Kirby and J. M. Percy, Tetrahedron, 1988, 44, 6919.
  36. K.-I. Morita and T. Kobayashi, J. Org. Chem., 1966, 31, 229 CAS.
  37. Huang-Minlon, J. Am. Chem. Soc., 1946, 68, 2483 CrossRef.
  38. M. Harwood and C. Moody, Experimental Organic Chemistry, Blackwell, 1989 Search PubMed.
  39. M. Demuynck, P. D. Clercq and M. Vandewalle, J. Org. Chem., 1979, 44, 4863 CrossRef CAS.
  40. R. E. Marriott, Accelerated Cleavage of Phosphate Esters, Thesis, Cambridge, 1994 Search PubMed.
  41. C. Beckmann, Built-in Polyamine Catalyst for Phosphate Transfer, Thesis, Cambridge, 1997 Search PubMed.
  42. S. Kim, C. H. Oh, J. S. Ko, K. H. Ahn and V. J. Kim, J. Org. Chem., 1985, 50, 1927 CrossRef CAS.
  43. F. C. M. Chen and N. L. Benoit, Can. J. Chem., 1976, 54, 3310 CAS.
  44. R. O. Hutchins and F. J. Dux, J. Org. Chem., 1973, 38, 1961 CrossRef CAS.
  45. Prepared by Dr R. M. Schonk of this laboratory.
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