ORGANIC
LETTERS
2001
Vol. 3, No. 22
3519-3522
Change of Connectivity on Catenane
Ring: Ring Expansion by
Annulation−Ring Scission Sequence
Nobuhiro Watanabe, Nobuhiro Kihara, and Toshikazu Takata*
Department of Applied Chemistry, Graduate School of Engineering,
Osaka Prefecture UniVersity, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
Received August 15, 2001
ABSTRACT
Ring expansion of a catenane without destruction of the interlocked structure was attained by Diels−Alder reaction followed by ozonolysis.
Annulation by Diels−Alder reaction introduced a C4 fragment onto the ring, and the ozonolysis scissored the resulting double bond to expand
the catenane ring. The annulation−ring scission sequence provides a general approach for changing the connectivity on a catenane ring
without destroying the interlocked structure.
Recent advances in the chemistry of noncovalent bonding
systems have increased the expectancy for a molecular device
based on interlocked molecules such as rotaxane, catenane,
and trefoil knot.1 A number of chemical modifications of
the interlocked molecules are often necessary to turn an
original molecule into a sophisticated molecular system or
device. So far, however, only a few simple chemical reactions
of interlocked molecules have been reported. Introduction,2
redox reaction,3 conversion,4 and interconnection5 of the
functional groups have been reported, especially for cat-
enanes, where the connectivity on the ring component is
preserved throughout the transformation. At present, the only
successful technique for the modification of an interlocked
compound with change of connectivity is the “unlock-lock
approach”.6,7 In this approach, the bond-scission-formation
process is thermodynamically well-controlled, since one
component is readily released from the other during ring
Credi, A.; Mattersteig, G.; Matthews, O. A.; Raymo, F. M.; Stoddart, J. F.;
Venturi, M.; White, A. J. P.; Williams, D. J. J. Org. Chem. 2000, 65, 1924.
(e) Collier, C. P.; Mattersteig, G.; Wong, E. W.; Lio, Y.; Beverly, K.;
Sampaio, J.; Raymo, F. M.; Stoddart, J. F.; Heath, J. R. Science 2000, 289,
1172.
(4) (a) Muscat, D.; Ko¨hler, W.; Ra¨der, H. J.; Martin, K.; Mullins, S.;
Mu¨ller, B.; Greets, Y.; Macromolecules 1999, 32, 1737. (b) Watanabe, N.;
Furusho, Y.; Kihara, N,; Takata, T.; Kinbara, K.; Saigo, K. Chem Lett.
1999, 915.
(5) (a) Ashton, P. R.; Reader, J. A.; Spencer, N.; Stoddart, J. F. J. Am.
Chem. Soc. 1993, 115, 5286. (b) Weidmann, J. L.; Kern, J.-M.; Sauvage,
J.-P.; Greets, Y.; Muscat, D.; Mu¨llen, K. Chem. Commun. 1996, 1243. (c)
Menzer, S.; White, A. J. P.; Williams, D. J.; Belohradsky, M.; Hamers, C.;
Raymo, F. M.; Shipway, A. N.; Stoddart, J. F. Macromolecules 1998, 31,
295. (d) Hamers, C.; Raymo, F. M.; Stoddart, J. F. Eur. J. Org, Chem.
1998, 2109.
(6) (a) Cantrill, S. J.; Rowan, S. J.; Stoddart, J. F. Org. Lett. 1999, 1,
1363. (b) Roman, S. J.; Stoddart, J. F. Org. Lett. 2000, 2, 1913. (c) Furusho,
Y.; Hasegawa, T.; Tsuboi, A.; Kihara, N.; Takata, T. Chem Lett. 2000, 18.
(1) Recent reviews: (a) Chambron, J.-C.; Sauvage, J.-P. Chem. Eur. J.
1998, 4, 1362. (b) Nepogodiev, S. A.; Stoddart, J. F. Chem. ReV. 1998, 98,
1959. (c) Harada, A. Acta Polym. 1998, 49, 3. (d) Molecular Catenanes,
Rotaxanes and Knots; Sauvage, J.-P., Dietrich-Buchecker, C., Eds.; Wiley-
VCH: Weinheim, 1999. (e) Balzani, V.; Credi, A.; Raymo, F. M.; Stoddart,
J. F. Angew. Chem., Int. Ed. 2000, 39, 3349. (f) Hubin, T. J.; Busch, A. D.
H. Coord. Chem. ReV. 2000, 200, 5.
(2) (a) Ja¨ger, R.; Schmidt, T.; Karbach, D.; Vo¨gtle, F. Synlett 1996, 723.
(b) Baumann, S.; Ja¨ger, R.; Ahuis, F.; Kray, B.; Vo¨gtle, F. Liebigs Ann.
1997, 761.
(3) (a) Balzani, V.; Go´mez-Lo´pez, M.; Stoddart, J. F. Acc. Chem. Res.
1998, 31, 405, and references therein. (b) Hamilton, D. G.; Montalti, M.;
Prodi, L.; Fontani, M.; Zanello, P.; Sanders, J. K. M. Chem. Eur. J. 2000,
6, 608. (c) Balzani, V.; Credi, A.; Langford, S. J.; Raymo, F. M.; Stoddart,
J. F.; Venturi, M. J. Am. Chem. Soc. 2000, 122, 3542. (d) Balzani, V.;
10.1021/ol016586r CCC: $20.00 © 2001 American Chemical Society
Published on Web 10/09/2001