ORGANIC
LETTERS
2003
Vol. 5, No. 23
4381-4384
Furan-Containing Oligoaryl
Cyclophanene
Jui-Chang Tseng,†,‡ Shou-Ling Huang,† Cheng-Lan Lin,‡ Hsin-Chieh Lin,†,‡
,†,‡
Bih-Yaw Jin,† Chun-Yan Chen,† Jen-Kan Yu,† Pi-Tai Chou,† and Tien-Yau Luh*
Department of Chemistry and Institute of Polymer Science and Engineering,
National Taiwan UniVersity, Taipei 106, Taiwan, and Institute of Chemistry,
Academia Sinica, Nangang, Taipei 115, Taiwan
Received September 1, 2003
ABSTRACT
Furan-containing oligoaryl cyclophanene 1 and the corresponding cyclophane 2 were synthesized from propargylic dithioacetal 3. The
electrochemical and photophysical properties and the fluxional behavior of these molecules have been examined. The emission of 1 appeared
at 499 nm whereas that of 2 appeared at 389 nm.
Cyclophanes have provided useful models for the investiga-
tion of through-space interactions between chromophores.1-5
Several factors are known to dictate the nature of such
interactions. Recently, Bazan and co-workers have shown
that the conjugation length and the orientation of the
chromophores in paracyclophanes may play an important role
in this respect.1 Five-membered heteroaromatic ring(s) in
cyclophanes are well documented.2 These compounds may
demonstrate a unique structural feature because the stereo-
chemistry of these molecules is very different from those
constituted of only para-substituted benzene derivatives.2-4
It is noteworthy that oligoaryl cyclophanes whose backbone
contains five-membered heteroaromatic ring(s) have been
sporadically studied.2 Incorporation of double bond(s) in the
tethering aliphatic chain(s) such as cyclophanenes may alter
the geometry of the molecules.5 An extreme case can be seen
in planar and annulene-like porphycenes and related ana-
logues, although they can be considered structurally as
cyclophanes.4 Other than porphycene and related compounds,
study on the influence of the double bond in nonplanar
cyclophanenes on the photophysical properties of these
molecules has been rare.
† National Taiwan University.
‡ Academia Sinica.
(1) (a) Bazan, G. C.; Oldham, W. J., Jr.; Lachicotte, R. J.; Tretiak, S.;
Chernyak, V.; Mukamel, S. J. Am. Chem. Soc. 1998, 120, 9188 and
references therein. (b) Batholomew, G. P.; Bazan, G. C. J. Am. Chem. Soc.
2002, 124, 5183 and references therein. (c) Bartholomew G. P.; Ledoux I.;
Mukamel S.; Bazan G. C.; Zyss, J. J. Am. Chem. Soc. 2002, 124, 13480.
(2) (a) Kaikawa, T.; Takimiya, K.; Aso, Y.; Otsubo, T. Org. Lett. 2000,
2, 4197. (b) Vo¨gtle, F.; Staab, A. Chem. Ber. 1968, 101, 2709. (c) Hart,
H.; Rajakumar, P. Tetrahedron 1995, 51, 1313. (d) Vo¨gtle, F. Cyclophane
Chemistry; Wiley: New York, 1993.
(3) For examples, see: (a) Pahor, N. B.; Calligaris, M.; Randaccio, L.
J. Chem. Soc., Perkin Trans. 2 1978, 42. (b) Haley, J. F.; Rosenfeld, S.
M.; Keehn, P. M. J. Org. Chem. 1977, 42, 1379. (c) Cooke, M. P. J. Org.
Chem. 1981, 46, 1747.
(4) Vogel, E.; Jux, N.; Do¨rr, J.; Pelster, T.; Berg, T.; Bo¨hm, H.-S.;
Behrens, F.; Lex, J.; Bremm, D.; Hohlneicher, G. Angew. Chem., Int. Ed.
2000, 39, 1101 and references therein.
(5) (a) Cram, D. J.; Cram, J. M. Acc. Chem. Res. 1971, 4, 204. (b)
Mitchell, R. H.; Boekelheide, V. J. Am. Chem. Soc. 1974, 96, 1547 and
references therein. (c) Sto¨bbe, M.; Reiser, O.; Na¨der, R.; de Meijere, A.
Chem. Ber. 1987, 120, 1667.
We recently reported a new annulation procedure for the
synthesis of trisubstituted furans from the corresponding
propargylic dithioacetals.6 The strategy has been employed
for the iterative construction of a variety of soluble furan-
and pyrrole-containing oligoaryls leading to molecular wires.
We now wish to report the synthesis and unusual properties
10.1021/ol0356688 CCC: $25.00 © 2003 American Chemical Society
Published on Web 10/18/2003