Reduction of N-arylporphyrins to N-arylphlorins: opposite stereochemical courses as a function of the reducing agent

Abstract

Electrochemical or Na₂S₂O₄ reduction of N-arylporphyrins gives stable phlorins epimeric to those obtained by tosylhydrazine or NaBH₄ reduction.

References

1. R. B. Woodward, Angew. Chem., 1960, 72, 651.
2. H. H. Inhoffen, P. Jäger, R. Mählhop and C.-D. Mengler, Liebigs Ann., 1967, 704, 188; T. Ema, M. O. Senge, N. Y. Nelson, H. Ogoshi and K. M. Smith, Angew. Chem., Int. Ed. Engl., 1994, 33, 1879.
3. H. Sugimoto, J. Chem. Soc., Dalton Trans., 1982, 1169; H. Segawa, R. Azumi and T. Shimidzu, J. Am. Chem. Soc., 1992, 114, 7564.
4. J. Setsune, T. Ikeda, T. Iida and T. Kitao, J. Am. Chem. Soc., 1988, 110, 6572; J. Setsune, Y. Ishimaru and T. Kitao, Chem. Lett., 1990, 1351; J. Setsune, H. Yamaji and T. Kitao, Tetrahedron Lett., 1990, 31, 5057; J. Setsune, K. Wada and H. Higashino, Chem. Lett., 1994, 213.
5. B. Krattinger and H. J. Callot, Chem. Commun., 1996, 1341.
6. B. Krattinger and H. J. Callot, Tetrahedron Lett., 1996, 37, 7699.
7. B. Krattinger and H. J. Callot, Eur. J. Org. Chem., 1999, 1857.
8. D. M. Arciero and A. B. Hooper, Biochem. Soc. Trans., 1998, 26, 385; D. M. Arciero, M. Hendrich, T. Iverson, D. Rees and A. B. Hooper, ACS National Meeting, Anaheim, March 21–25, 1999, abster INOR 333see also: D. M. Arciero, A. B. Hooper, M. Cai and R. Timkovich, Biochemistry, 1993, 32, 9371.
9. S. Aizawa, Y. Tsuda, K. Hatano and S. Funahashi, Inorg. Chem., 1993, 32, 1119.
10. A mechanistic dichotomy was also observed during the reductive demetallation of silver copper porphyrins: J. A. Cowan and J. K. M. Sanders, Tetrahedron Lett., 1986, 27, 1201.