Synthesis of a heterocyclic variant of the biphenylophanes, namely anti-[2.2](2-phenylthiazolophane) (1), is described via a sequence involving the pyrolysis of an intermediate bis-lactone (8). Dynamic 1H NMR analysis revealed both the bis-lactone 8 and the target heterophane 1 to be conformationally mobile on the NMR time scale at temperatures down to −55 °C.
See, for earlier works: (a) VogtleF., Liebigs Ann. Chem., 1969, 728; (b) F. Vogtle and P. Neumann, Tetrahedron., 1970, 26, 5299; (c) R. B. Du Vernet, T. Otsubo, J. A. Lawson and V. Boekelheide, J. Am. Chem. Soc., 1975, 97, 1629; (d) P. J. Jessup and J. A. Reiss, Aust. J. Chem., 1976, 29, 1267; (e) B. Thulin and O. Wennerstrom, Tetrahedron Lett., 1977, 929; (f) F. Vogtle, M. Atzmuller, W. Welmer and J. Crutze, Angew. Chem. Int. Ed. Engl., 1977, 16, 325; (g) R. B. Du Vernet, O. Wennerstrom, J. Lawson, T. Otsubo and V. Boekelheide, J. Am. Chem. Soc., 1978, 100, 2457; (h) D. N. Leach and J. A. Reiss, J. Org. Chem., 1978, 43, 2484; (i) D. N. Leach and J. A. Reiss, Tetrahedron Lett., 1979, 4501; (j) D. N. Leach and J. A. Reiss, Aust. J. Chem., 1980, 33, 823; (k) K. Bockmann and F. Vogtle, Chem. Ber., 1981, 114, 1048.
2.
For recent reports, see (a) LaiY.-H., and WongS.-Y., Tetrahedron., 1993, 49, 669; (b) Y.-H. Lai, S.-G. Ang and S.-Y. Wong, Tetrahedron Lett., 1997, 38, 2553; (c) K. Tani, H. Seo, M. Maeda, K. Imagawa, N. Nishwaki, M. Ariga, Y. Tohda, H. Higuchi and H. Kuma, Tetrahedron lett., 1995, 36, 1883; (d) S. Laufenberg, N. Feuerbacker, I. Pischel, O. Boersch, M. Nieger and F. Vogtle, Liebigs Ann. Recl., 1997, 1901.
See, for examples (a) MashraquiS.H., and NivalkarK. R., Tetrahedron Lett., 1997, 38, 4487; (b) S. H. Mashraqui, S. Kumar and K. R. Nivalkar, Heterocyclic Commun., 2001, 7, 74; (c) S. H. Mashraqui, M. M. Biswas and K. R. Nivalkar, Ind. J. Chem., 1996, 35B, 1031.
5.
This name, while sufficient for present purposes, does not, of course, describe the molecule completely. Using the Baeyer system, 1 would be 3,13-dithia-23,26-diazapentacyclo [16.2.2.28,11.12,5.112,15] hexaconta-1(20),2(23),4,8,10,12(26),14,18,21,-24-decaene.
6.
HassB.H., and BenderM. L., J. Am. Chem. Soc., 1949, 71, 1767.
7.
RegenS.L., and KimuraY., J. Am. Chem. Soc., 1982, 104, 2064.
8.
KaplanM.C., and TruesdaleE. A., Tetrahedron Lett., 1976, 3665.
9.
CramD.J., WechterW. J., and KiersteadR. W., J. Am. Chem. Soc., 1958, 80, 3126.
10.
(a) MashraquiS.H., and KeehnP. M., J. Org. Chem., 1983, 48, 1341; (b) I. D. Reingold, W. Schimdt, V. Boekelheide, J. Am. Chem. Soc., 1979, 101, 2121; (c) I. Gault, B. J. Price and I. O. Sutherland, J. Chem. Soc. Chem. Commun., 1967, 540; (d) R. H. Mitchell, in Cyclophanes, P.M. Keehn and S.M. Rosenfeld, eds, 1983, Vol 1, p. 240. Academic Press, New York, 1983.
11.
The thiazole nucleus is sufficiently basic (pKa is 2.52) to be able to undergo protonation in the presence of CF3CO2H. See J.V. Metzger, in Comprensive Heterocyclic Chemistry, 1984, Pergamon Press, New York, USA, Vol 6 (PottsK. T., ed.), p. 252.
12.
When 1H NMR of 1 was recorded in CDCl3 containing a drop of CF3CO2H, there was observed downfield shifts of the protons associated with both the phenyl (δ 7. 1 and 7. 43) as well as the thiazole ring (δ 7. 54) as a consequence of the presence of the positive charge on the thiazole rings. Furthermore, a single set of absorptions for these protons strongly indicated bis-protonation of heterophane 1 in the presence of CF3CO2H.
