ORGANIC
LETTERS
2013
Vol. 15, No. 1
116–119
Catenation of Calixarene Annulus
Carmine Gaeta,*,† Carmen Talotta,† Silvia Mirra,† Luigi Margarucci,‡
Agostino Casapullo,† and Placido Neri*,†
Dipartimento di Chimica e Biologia and NANO_MATES Research Center, and
ꢀ
Dipartimento di Scienze Farmaceutiche e Biomediche, Universita di Salerno, Via Ponte
don Melillo, I-84084 Fisciano (Salerno), Italy
cgaeta@unisa.it; neri@unisa.it
Received November 14, 2012
ABSTRACT
Through-the-annulus-catenated calixarenes have been obtained, for the first time, by exploiting the “superweak anion” approach that allows the
threading of the calix cavity with functionalized dialkylammonium axles. In addition, the first example of a stereoprogrammed synthesis of a catenane
orientational isomer (an oriented calix[2]catenane) has been obtained, after macrocyclization, by using a directional alkylbenzylammonium axle.
In the last two decades, research interest in mechanically
interlocked molecules (MIMs),1 such as rotaxanes, cate-
nanes, and knots, has increased dramatically thanks to
their applications in nanotechnology2 and as molecular
machines3 and sensors.4 Among them, the catenanes, con-
stituted by two or more mechanically interlocked rings, have
attracted considerable attention as the basic component of
switches,5 unidirectional motors,6 and electronic displays.2
Various kinds of macrocycles, including crown-ethers,2,7
azacyclophanes,2,7 cyclodextrins,8 cucurbiturils,9 and macro-
lactams,6,10 have been used as the basic macroring under-
going catenation, after threading with a complementary
component and exploiting various preorganizing supramo-
lecular interactions.
Regarding calixarene11 macrocycles, only a few exam-
ples of catenanes have been reported in which the calixar-
ene annulus is not catenated but simply acts as an “inert”
scaffold on which a different kind of macrocycle is con-
structed, leaving the calix cavity completely unexploited
(Figure 1A).12 Consequently, to the best of our knowledge,
no examples of through-the-annulus-catenated calixarene
systems (calix-catenane, Figure 1B) are currently known.
Here we describe the first examples of catenation through a
calixarene annulus (i.e., a calix[6]arene) to give either a
symmetrical system or a nonsymmetrical catenane with a
stereoprogrammed orientation of the calix wheel.
† Dipartimento di Chimica e Biologia and NANO_MATES Center.
‡ Dipartimento di Scienze Farmaceutiche e Biomediche.
(1) Molecular Catenanes, Rotaxanes and Knots: A Journey through
the World of Molecular Topology; Sauvage, J. P., Dietrich-Buchecker, C.,
Eds.; Wiley-VCH: Weinheim, Germany, 1999.
(2) (a) Ikeda, T.; Saha, S.; Aprahan, I.; Leung, K. C.-F.; Williams, A.;
Deng, W.-Q.; Flood, A. H.; Goddard, W. A.; Stoddart, J. F. Chem.
Asian J. 2007, 2, 76. (b) Collier, C. P.; Mattersteig, G.; Wong, E. W.;
Luo, Y.; Beverly, K.; Sampaio, J.; Raymo, F. M.; Stoddart, J. F.; Heath,
J. R. Science 2000, 289, 1172.
(3) (a) Balzani, V.; Credi, A.; Venturi, M. Molecular Devices and
Machines, 2nd ed.; Wiley-VCH: Weinheim, Germany, 2008. (b) Saha, S.;
Stoddart, J. F. Chem. Soc. Rev. 2007, 36, 77.
The synthetic strategy undertaken to catenate the
calix[6]arene macrocycle 1a was based on the so-called
(4) Caballero, A.; Zapata, F.; White, G. N.; Costa, P. J.; Felix, V.;
Beer, P. D. Angew. Chem., Int. Ed. 2012, 51, 1876.
(5) For a recent review, see: Fahrenbach, A. C.; Bruns, C. J.; Cao, D.;
Stoddart, J. F. Acc. Chem. Res. 2012, 45, 1581.
(6) (a) Leigh, D. A.; Wong, J. K. Y.; Dehez, F.; Zerbetto, F. Nature
2003, 424, 174. (b) Hernandez, J. V.; Kay, E. R.; Leigh, D. A. Science
2004, 306, 1532.
(7) For a recent report, see: Fahrenbach, A. C.; Hartlieb, K. J.; Sue,
C.-H.; Bruns, C. J.; Barin, G.; Basu, S.; Olson, M. A.; Botros, Y. Y.;
Bagabas, A.; Khdary, N. H.; Stoddart, J. F. Chem. Commun. 2012, 48,
9141.
(8) (a) Lim, C. W.; Sakamoto, S.; Yamaguchi, K.; Hong, J.-I. Org.
Lett. 2004, 6, 1079. (b) Armspach, D.; Ashton, P. R.; Ballardini, R.;
Balzani, V.; Godi, A.; Moore, C. P.; Prodi, L.; Spencer, N.; Stoddart,
J. F.; Tolley, M. S.; Wear, T. J.; Williams, D. J. Chem.;Eur. J. 1995, 1, 3.
(9) Park, K.-M.; Kim, S.-Y.; Heo, J.; Whang, D.; Sakamoto, S.;
Yamaguchi, K.; Kim, K. J. Am. Chem. Soc. 2002, 124, 2140.
(10) (a) White, N. G.; Beer, P. D. Chem. Commun. 2012, 48, 8499.
(b) Leigh, D. A.; Lusby, P. J.; Slawin, A. M. Z.; Walker, D. B. Chem.
Commun. 2012, 48, 5826.
(11) Gutsche, C. D. Calixarenes, An Introduction; Royal Society of
Chemistry: Cambridge, UK, 2008.
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10.1021/ol303142c
Published on Web 12/18/2012
2012 American Chemical Society