Irradiation of benzene solutions containing 4-cyano- and 4-methoxycarbonyl-1-naphthylmethyl furfuryl ethers afforded the (4π+4π) photocycloadducts via intramolecular singlet exciplexes as reactive intermediates in excellent yields.
Review articles: WenderP. A., and DoreT. M., CRC Handbook of Organic Photochemistry and Photobiology, ed by HorspoolW.M., and SongP.-S., CRC Press, pp. 280–290 (1995); J.J. McCullough, Chem. Rev., 87, 811 (1987); A. Gilbert, Synthetic Organic Photochemistry, ed by W.M. Horspool, Plenum Press, New York, pp. 1–60 (1984); R.A. Caldwell and D. Creed, Acc. Chem. Res., 1980, 13, 45.
2.
MizunoK., MaedaH., InoueY., SugimotoA., VoL. P., and CaldwellR. A., Tetrahedron Lett., 2000, 41, 4913; K. Mizuno, S. Konishi, T. Takata, and H. Inoue, Tetrahedron Lett., 1996, 37, 7775; K. Mizuno, R.A. Caldwell, A. Tachibana, and Y. Otsuji, Tetrahedron Lett., 1992, 33, 5779 and references cited therein.
3.
PacC., SugiokaT., and SakuraiH., Chem. Lett., 1972, 39; T. Sugioka, C. Pac, and H. Sakurai, H. Chem. Lett., 1972, 791, 1972, 667; H. Sakurai and C. Pac, Mem. Inst. Sci. Ind. Res., Osaka Univ., 1980, 37, 59; C. Pac, M. Yasuda, K. Shima, and H. Sakurai, Bull. Chem. Soc. Jpn., 55, 1605 (1982).
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6.
BerridgeB., Bryce-SmithD., and GilbertA., J. Chem. Soc., Chem. Commun., 1974, 964.
7.
NohT., and KimD., Tetrahedron Lett., 1996, 37, 9329.
8.
SakamotoM., KinbaraA., YagiT., TakahashiM., YamaguchiK., MinoT., and WatanabeS., J. Chem. Soc., Perkin Trans. 1, 1999, 171.
9.
The quantum yield for the formation of 2a (1 × 10−3 mol dm−3) in cyclohexane was 0.2. The relative quantum yield for the disappearance of 1a (1 × 10−4 mol dm−3) was 20 times higher than that for the disappearance of 1-cyanonaphthalene (1 × 10−4 mol dm−3) in the presence of furan (3 × 10−1 mol dm−3). Cf. ref. 3.
10.
Crystal data for 2a: C17H13NO2, triclinic, a = 12.275(3) Å, b = 12.761(4) Å, c = 7.735 Å, α = 90.065(7)°, β = 90.815(9) °, γ = 89.50(1)°, V = 1211.4(5) Å3, space group P-1(#2), Dcalc = 1.444 g/cm3, Z = 4, μ(Mo-Kα) = 0.95 cm−1, 3836 (I > 3.00(I)) reflections were used in the structure determination with 387 parameters. Final refinements converged to R (Rw) = 0.093 (0.162). S = 1.60. Details will be published elsewhere.
11.
The fluorescence lifetime of 1a in cyclohexane was measured by single photon counting method to show two components. The lifetimes of the monomer and exciplex emission were 1 and 17 ns, respectively.
