Advertisement

Copper(II)-Induced Oxygenolysis of o-Benzoquinones, Catechols, and Phenols: The Active Copper(II)-Species, Role of Cupric Chloride, and the General Question of Activation of Molecular Oxygen by Dioxygenases

  • Milorad M. Rogić
  • Timothy R. Demmin

Abstract

The chemical energy required by biological systems to do work is derived primarily by oxidation of complex organic molecules to carbon dioxide and water. Since, in the overall process, oxygen acts as a final acceptor of electrons from the substrates and is converted to water, a special mechanism for the activation of molecular oxygen is not required. Nevertheless, it is still not known with certainty whether the required four electrons are transferred between the last few members of the electron-transporting chain in pairs or singly, nor is it known precisely how molecular oxygen accepts the electrons from the last member of this chain (the cytochrome c oxidase). 1

Keywords

Molecular Oxygen Active Copper Cupric Oxide Basic Copper Cuprous Chloride 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References and Notes

  1. 1.
    For a general discussion of the metabolic and respiratory mechanisms see A. L. Lehninger, “Biochemistry”, Worth, New York, NY, 1975.Google Scholar
  2. 2.
    For a general review of monooxygenases and dioxygenases see “Molecular Mechanisms of Oxygen Activation”, O. Hayaishi, Ed., Academic Press, New York, NY, 1974.Google Scholar
  3. 3.
    a) G. A. Hamilton, “Molecular Mechanisms of Oxygen Activation”, O. Hayaishi, Ed., Academic Press, New York, NY, 1974, p. 405;Google Scholar
  4. 3.
    b) G. A. Hamilton, “Advances in Enzymology”, F. F. Nord, Ed., John Wiley and Sons, New York, NY, 1969, p. 55;Google Scholar
  5. 3.
    c) M. M. T. Khan and A. E. Martell, “Homogeneous Catalysis by Metal Complexes”, Vol. 1, Academic Press, New York, NY, 1974;Google Scholar
  6. 3.
    d) W. Ullrich, Angew. Chem. Int. Ed. Engl., 11, 701 (1972);CrossRefGoogle Scholar
  7. 3.
    e) J. H. Olive and S. Olive, ibid., 13, 29 (1974);Google Scholar
  8. 3.
    f) J. H. Fuhnhop, ibid., 15, 618 (1976);Google Scholar
  9. 3.
    g) J. H. Wang, Acc. Chem. Res., 3, 90 (1970).CrossRefGoogle Scholar
  10. 4.
    O. Hayaishi in ref. 2, chapter 1.Google Scholar
  11. 5.
    M. M. Rogic, J. Vitrone and M. D. Swerdloff, J. Am. Chem. Soc., 97, 3848 (1975); 99, 1156 (1977).CrossRefGoogle Scholar
  12. 6.
    M. M. Rogic, K. P. Klein, J. M. Balquist, and B. C. Oxenrider, J. Org. Chem., 41, 482 (1976).CrossRefGoogle Scholar
  13. 7.
    M. M. Rogic, M. T. Tetenbaum and M. D. Swerdloff, J. Org. Chem., 42, 2748 (1977).CrossRefGoogle Scholar
  14. 8.
    M. M. Rogic, K. P. Klein, T. R. Demmin and B. C. Oxenrider, J. Am. Chem. Soc., submitted for publication.Google Scholar
  15. 9.
    For a preliminary report see M. M. Rogic, T. R. Demmin and W. B. Hammond, J. Am. Chem. Soc., 98, 7441 (1976).Google Scholar
  16. 10.
    M. M. Rogic and T. R. Demmin, J. Am. Chem. Soc., 100, 0000 (1978).CrossRefGoogle Scholar
  17. 11.
    W. Brackman and E. Havinga, Rec. Trav. Chim., 74, 937, 1021, 1070, 1100, 1107 (1955).Google Scholar
  18. 12.
    A. P. Terentiev and Ya. D. Magilyanskii, Doklady Acad. Nauk S.S.S.R., 103, 91 (1955); C. A., 50, 4807 (1956).Google Scholar
  19. 13.
    K. Kinoshita, Bull. Chem. Soc., Jpn.: 32, 777, 780, 783 (1959); K. Kinoshita, J. Chem. Soc. Jpn., Pure Chem. Sect., 75, 48 (1954).Google Scholar
  20. 14.
    A. S. Hay, H. S. Blanchard, G. F. Endres and J. W. Eustance, J. Am. Chem. Soc., 81, 6335 (1959).CrossRefGoogle Scholar
  21. 15.
    a) A. S. Hay, J. Polym. Chem., 58, 581 (1962);Google Scholar
  22. 15.
    b) G. F. Endres and J. Kwiatek, ibid., 58., 593 (1962);Google Scholar
  23. 15.
    c) G. F. Endres, A. S. Hay and J. W. Eustance, J. Org. Chem., 28, 1300 (1963);CrossRefGoogle Scholar
  24. 15.
    d) A. S. Hay and G. F. Endres, Polym. Lett., 3, 887 (1965);CrossRefGoogle Scholar
  25. 15.
    e) H. Finkbeiner, A. S. Hay, H. S. Blanchard and G. F. Endres, J. Org. Chem., 31, 549 (1966).CrossRefGoogle Scholar
  26. 16.
    However, a direct cleavage of phenol to cis, cis-muconic acid ester aldehyde, followed by rapid oxidation of the latter to the acid ester 1, cannot be completely ruled out at this point.Google Scholar
  27. 17.
    J. Tsuji and H. Takayanagi, J. Am. Chem. Soc., 96, 7349 (1974).CrossRefGoogle Scholar
  28. 18.
    J. Tsuji, H. Takayanagi and I. Sakai, Tetrahedron Letters., 1245 (1975).Google Scholar
  29. 19.
    As early as in 1937, F. Kubowitz proposed [Biochem. Z., 292 221 (1937); 299, 32 (1939] that in oxidation of catechol to o-benzoquinone, catalyzed by copper oxidases, the function of oxygen was to regenerate copper(I)-enzyme to copper(II)-enzyme, which was the actual oxidizing reagent. Similarly, in their studies of copper(Il)-catalyzed polymerization of phenols, Hay, Endres and their co-workers15 felt that the role of oxygen was to reoxidize the copper(I)-back to the copper(II)- species which was the actual oxidizing reagent.Google Scholar
  30. 20.
    It is assumed at this point, for the sake of simplicity, that the oxidation of cuprous chloride in pyridine in the presence of methanol leads to pyridine cupric methoxy chloride complex A and two equivalents of water, a reagent equivalent to that formed in Method A. However, as it will become apparent later in the text, the actual oxidizing reagent is a mixture of several species (vide infra).Google Scholar
  31. 21.
    C. E. Kramer, G. Davies, R. B. Davis and R. W. Slaven, J. Chem. Soc., Chem. Comm., 606 (1975).Google Scholar
  32. 22.
    Y. Ogata and T. Morimoto, Tetrahedron, 21, 2791 (1965).CrossRefGoogle Scholar
  33. 23.
    H. Praliand, Y. Kodrafoff, G. Condurier and M. V. Mathieu, Spectrochimica Acta, 30A, 1389 (1974); E. Ochiai, Tetrahedron, 20, 1831 (1964).CrossRefGoogle Scholar
  34. 24.
    G. Condurier, H. Praliand and M. V. Mathieu, ibid., 30A, 1399 (1974).Google Scholar
  35. 25.
    M. Berthelot, Ann. Chim. Phys., [5] 20, 503 (1880).Google Scholar
  36. 26.
    M. Groger, Z. Anorg. Chem., 28, 154 (1901).CrossRefGoogle Scholar
  37. 27.
    We have also prepared copper-oxygen species by a direct oxidation of copper metal in the presence of catalytic amounts of cuprous chloride.Google Scholar
  38. 28.
    For example see W. E. Hatfield, ACS Symp. Ser., 5, (1974), and references therein.Google Scholar
  39. 29.
    P. Jeffrey Hay, J. C. Thibeault and R. Hoffman, J. Am. Chem. Soc., 97, 4884 (1975).CrossRefGoogle Scholar
  40. 30.
    The EPR spectra of either of the three reagents in pyridine clearly showed the presence of approximately 50% of the total amount of copper in a paramagnetic state. The spectrum is consistent with that of bispyridine cupric chloride in pyridine and exhibits general features very similar to that described earlier.23Google Scholar
  41. 31.
    C. H. Brubaker, Jr. and M. Wicholas, J. Inorg. Nucl. Chem., 27, 59 (1965).CrossRefGoogle Scholar
  42. 32.
    R. W. Adams, E. Bishop, R. L. Martin and G. Winter, Aust. J. Chem., 19, 207 (1966).CrossRefGoogle Scholar
  43. 33.
    It should be remembered, however, that cupric oxide, once isolated and “aged”, is insoluble in either of these solvents. Consequently, if present at all in these solutions, cupric oxide must be stabilized in monomeric or oligomeric form by pyridine/methanol, as it is being formed in situ.Google Scholar
  44. 34.
    Cupric methoxide was prepared according to the published procedure of ref. 31.Google Scholar
  45. 35.
    T. Tsuda, T. Hashimoto and T. Saegusa, J. Am. Chem. Soc., 94, 658 (1972).CrossRefGoogle Scholar
  46. 36.
    A reaction of cuprous tert-butoxide with water in pyridine does take place. While a solution of the cuprous tert-butoxide in pyridine is stable, the resulting reaction mixture, after treatment with water, does not undergo appreciable disproportionation over several hours. However, an overnight reaction produced appreciable amounts of what appears to be a polymeric cuprous oxide and small amount of copper(O) and cupric oxide. Presumably, after addition of water, the copper(I)-species in pyridine is either cuprous hydroxide or cuprous oxide hydrate, present in oligomeric form.Google Scholar
  47. 37.
    The reaction mixture, before hydrolysis, appears homogeneous and does not deposit cupric oxide on standing. Consequently, it is possible that in solution the copper(II)-catecholate complex and cupric hydroxide exist as a mixture of the isomeric copper (II)-catecholate/cupric hydroxide complexes (vide infra).Google Scholar
  48. 38.
    While cuprous hydroxide undergoes ready reaction with cupric chloride, cuprous chloride does not react with cupric meth-oxide/water in pyridine.Google Scholar
  49. 39.
    D. G. Brown, J. T. Reinprecht and G. C. Vogel, Inorg. Nucl. Chem. Letters, 12, 399 (1976).CrossRefGoogle Scholar
  50. 40.
    The molecular weight of the 4-tert-butylcatecholate pyridine- copper(II)-complex in benzene solution was found to be 918.0, indicating that it exists as a trimer. We assume that in pyridine solution the trimer either completely dissociates to the corresponding monomer containing two pyridine ligands, or, at least, that it exists under the reaction conditions in equilibrium with such a monomer. We will discuss the structure and EPR spectra of this and other related copper(II)-catecholate complexes elsewhere.Google Scholar
  51. 41.
    Brown and coworkers42 have shown that 3,5-di-tert-butylcatecholate-1,10-phenanthrolinecopper(II), and 3,5-di-tert-butylcatecholate-2,2’-dipyridylcopper(II) undergo a reaction with oxygen in solution to give a mixture of a cleavage product and unidentified copper complexes.Google Scholar
  52. 42.
    D. G. Brown, Z. Beckmann, C. H. Ashby, G. C. Vogel and J. T. Reimprecht, Tetrahedron Lett., 1363 (1977).Google Scholar
  53. 43.
    Presumably, all, “Cu-Reagents” should behave in the same way.Google Scholar
  54. 44.
    a) For a review of oxidation by copper(II), see W. G. Nigh, “Oxidation by Cupric Ion,” in “Oxidation in Organic Chemistry”, W. S. Trahanovsky, Ed., Academic Press, New York, NY, 1973;Google Scholar
  55. 44.
    b) R. A. Sheldon and J. K. Kochi, Advances in Catalysis, 25, 272 (1976);CrossRefGoogle Scholar
  56. 44.
    c) J. K. Kochi, “Free Radicals”, Vol. 1, J. K. Kochi, Ed., John Wiley and Sons, New York, NY, 1973, p. 591 and references therein.Google Scholar
  57. 45.
    F. A. Cotton and G. Wilkinson, “Advanced Inorganic Chemistry”, 3rd ed., John Wiley and Sons, New York, NY, 1972, p. 905.Google Scholar
  58. 46.
    H. Hashimoto, T. Noma and T. Kawaki, Tetrahedron Lett., 3411 (1968).Google Scholar
  59. 47.
    Alternatively, the carbon-carbon bond cleavage may involve two simultaneous one-electron oxidations to provide the muconic acid ester and copper(I)-hydroxide and methoxide, followed by reaction between the acid ester and the copper(I)-species to give the copper(I)-muconate and methanol (or water).Google Scholar
  60. 48.
    Recently, Fenton, Schroeder and Lintvedt described a bimolecular copper(II)-system capable of accepting two electrons simultaneously.49 Google Scholar
  61. 49.
    D. E. Fenton, R. R. Schroeder and R. L. Lintvedt, J. Am. Chem. Soc., 100, 1931 (1978).CrossRefGoogle Scholar
  62. 50.
    We do not have evidence that the copper(II)-catecholate indeed exists in solution as the suggested mixed complex with basic copper(II)-muconate. The structures of inorganic and simple aliphatic basic cupric salts are usually portrayed as combinations of normal salts, cupric hydroxide, cupric oxide and water. However, Kaeding and Shulgin51 have shown that various basic cupric salts exist as such.Google Scholar
  63. 51.
    W. W. Kaeding and A. T. Shulgin, J. Org. Chem., 27, 3551 (1962).CrossRefGoogle Scholar
  64. 52.
    For a brief review of the copper-containing oxidases, see R. Malkin, in “Inorganic Biochemistry”, G. L. Eichhorn, Ed., Elsevier, New York, NY, 1973, Chapter 21.Google Scholar
  65. 53.
    R. Malkin and B. G. Malmstrom, Adv. Enzymol., 33, 177 (1970).Google Scholar
  66. 54.
    J. A. Fee, R. Malkin, B. G. Malmstrom and T. Vanngard, J. Biol. Chem., 244, 4200 (1969).Google Scholar
  67. 55.
    It is well known44 that electron transfer oxidations occur mainly with oxy-salts of copper(II)-, whereas ligand transfer oxidations predominate with copper(II)-halides. Accordingly, the singlet state of copper(II) is unreactive in electron transfer reactions. However, the triplet state of the dimer copper(II)-species is largely unreactive and only paramagnetic monomeric copper(II)-species function as electron transfer oxidizing reagents.Google Scholar
  68. 56.
    E. I. Solomon, D. M. Dooley, R.-H. Wang, H. B. Gray, M. Cerdonio, F. Moguo and G. L. Romani, J. Am. Chem. Soc., 98, 1029 (1976).CrossRefGoogle Scholar
  69. 57.
    The exact nature of bonding in this intermediate is, of course, not known.Google Scholar
  70. 58.
    The catecholate C is present in solution, either as a mixed complex with cupric hydroxide or basic copper(II)-muconate, or as a mixture with these copper(II)-species (see Scheme IV).Google Scholar
  71. 59.
    Once formed, the copper(II)-catecholate complex C is stable because the reverse reaction would require that a relatively soft hydroxide or methoxide anion of cupric methoxy hydroxide replace a much harder catecholate bidentate ligand in the copper(II)-catecholate complex C.Google Scholar
  72. 60.
    Presumably, the harder chloride anion from cupric chloride can replace the relatively softer catecholate anion from the copper catecholate in C’, but reverse reaction, the replacement of one of the harder chloride anions in the intermediate B’ to produce copper(II)-catecholate and cupric chloride as in C’, either does not take place readily, or if it does, the ensuing equilibrium favors the intermediate B’.Google Scholar

Copyright information

© Plenum Press, New York 1978

Authors and Affiliations

  • Milorad M. Rogić
    • 1
  • Timothy R. Demmin
    • 1
  1. 1.Corporate Research CenterAllied Chemical CorporationMorristownUSA

Personalised recommendations