Evaluation of the transannular interaction of 5-substituted [2.2]metacyclophanes carrying a diazonio group on their outer position

Abstract

A diazonio group has been introduced into the outer (13-)position of 5-substituted [2.2]metacyclophanes (MCPs) (3). The absorption maxima of the substituted [2.2]MCP diazonium salts are bathochromically shifted from those of unsubstituted reference compounds. Stability constants (log K_s) of the complexation between the [2.2]MCP diazonium salts have been measured in order to estimate their cationic character. When log K_s for [2.2]MCP diazonium salts which carry the functional groups are plotted against Brown–Okamoto’s substituent constant (σ_p⁺) for them, a linear relationship is obtained. This result establishes that the electronic effect of the functional group is transmittable between two aromatic rings in [2.2]MCPs through a transannular interaction.

References

1. Cyclophanes, ed. P. M. Keehn and S. M. Rosenfeld, Academic Press, New York, 1983, vols. 1 and 2; V. Boekelheide, in Topics in Current Chemistry, ed. F. L. Boschke, Springer-Verlag, Berlin, 1987; F. Diederich, in Cyclophanes, ed. J. F. Stoddart, Monographs in Supramolecular Chemistry, The Royal Society of Chemistry, Cambridge, 1989, vol. 1.
2. (a) A. Tsuge, T. Moriguchi, S. Mataka and M. Tashiro, Chem. Lett., 1992, 579; (b) J. Chem. Soc., Perkin Trans. 1, 1993, 2211; (c) J. Org. Chem., 1995, 60, 4930.
3. A. Tsuge, T. Moriguchi, S. Mataka and M. Tashiro, Bull. Chem. Soc. Jpn., 1994, 67, 277.
4. M. Tashiro, S. Mataka, Y. Takezaki, M. Takeshita, T. Arimura, A. Tsuge and T. Yamato, J. Org. Chem., 1989, 54, 451.
5. A. Tsuge, T. Moriguchi, S. Mataka and M. Tashiro, Liebigs Ann., 1996, 769.
6. J. P. Idoux, J. Chem. Soc. (C), 1970, 435.
7. H. C. Brown and Y. Okamoto, J. Am. Chem. Soc., 1958, 80, 4979; E. N. Peters, M. Ravindranathan and H. C. Brown, in Aspects of Organic and Organometallic Chemistry, ed. J. H. Brewster, Plenum Press, New York, 1978.
8. Y. Hashida and K. Matsui, Bull. Chem. Soc. Jpn., 1980, 53, 551.