Functionalized [3]Catenanes
COMMUNICATION
11 as a red solid in 65–70% yield. Demetalation was carried out by vigo-
rously stirring a solution of the copper complex (0.100 g, 0.033 mmol) 11
in CH2Cl2 (10 mL) with a large excess of KCN (~0.200 g, 3.0 mmol) in
water (10 mL) at RT for 3 h. The reddish-brown color disappeared. The
organic phase was separated, washed with water (5ꢁ10 mL), dried over
Na2SO4, filtered through paper and finally concentrated to dryness. Final
purification was achieved by flash chromatography (SiO2) using CH2Cl2/
CH3OH 99:1, quantitatively affording 13 as a yellow solid.
Synthesis of 10: A similar procedure was used as in the case of 11.[9]
Acknowledgements
The authors are deeply grateful to Prof. Jean-Pierre Sauvage for his help-
ful suggestions. This work was supported by the National Science Foun-
dation (Grant CHE-0647334).
Figure 3. MALDI-TOF mass-spectrum of triazole-linked Cu-free non-
symmetric acid-ester functionalized [3]catenane 13. A=carboxyl group
and E=carbomethoxy ester group.[9]
Keywords: click chemistry
· catenanes · cyclization ·
supramolecular chemistry · template synthesis
mild conditions, this methodology seems to be well adapted
to the synthesis of large interlocked structures, whose pre-
cursors are relatively unstable or are sensitive to the final
macrocyclization “click” reaction. The possibility of intro-
ducing different peripheral functional groups into the [3]cat-
enane structures allows the preparation of structurally ela-
borated materials, such as nanoscale interlocked donor-ac-
ceptor systems. For example, we are currently converting
[3]catenanes 11 and 13 into porphyrin–fullerene functional-
ized [3]catenanes for study of long-range photoinduced elec-
tron transfer reactions.[13] The easy access to such structures
will facilitate photochemical and photophysical studies of
even more extended interlocked electron donor-acceptor
systems and other interesting concatenated materials.[14]
[1] For examples of synthesis of [3]catenanes, see: a) G. Schill, C.
1378; e) C. O. Dietrich-Buchecker, C. Hemmert, A. K. Khemiss, J.-P.
C. L. Brown, E. J. T. Chrystal, T. T. Goodnow, A. E. Kaifer, K. P.
Parry, A. M. Z. Slawin, N. Spencer, J. F. Stoddart, D. J. Williams,
miya, Y. Fukuzawa, Tetrahedron Lett. 2003, 44, 5733–5776.
Experimental Section
[2] a) V. Serreli, C.-F. Lee, E. R. Kay, D. A. Leigh, Nature 2005, 445,
523–527; b) J. E. Green, J. W. Choi, A. Boukai, Y. Bunimovich, E.
Johnston-Halperin, E. Delonno, Y. Luo, B. A. Scheriff, K. Xu, Y. S.
417; c) D. A. Leigh, J. K. Y. Wong, F. Dehez, F. Zerbetto, Nature
e) J. D. Badijic, V. Credi, S. Silvi, J. F. Stoddart, Science 2004, 303,
1845–1849; f) A. Livoreil, J.-P. Sauvage, N. Armaroli, V. Balzani, L.
24, 5095–5098; b) C. O. Dietrich-Buchecker, J.-P. Sauvage, J. M. J.
e) J.-L. Weidmann, J.-M. Kern, J.-P. Sauvage, D. Muscat, S. Mullins,
W. Kçhler, C. Rosenauer, H. J. Rꢃder, K. Martin, Y. Geerts, Chem.
Synthesis of 11: In flask A,[9] carboxymethyl-macrocycle
0.0618 mmol) was dissolved in degassed CH2Cl2/CH3CN 7:3 (1 mL), to
which [Cu(CH3CN)4PF6] (0.023 g, 0.0618 mmol) was added under N2 at
RT. In flask B, carboxy-macrocycle 6 (0.046 g, 0.0618 mmol) was dis-
solved in degassed CH2Cl2/CH3CN 7:3 (1 mL), to which [Cu-
5 (0.047 g,
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG(CH3CN)4PF6] (0.023 g, 0.0618 mmol) was added under N2 at RT. Both
dark orange solutions were stirred for 30 min at RT. The azidophenan-
throline ligand 3 (0.042 g, 0.0618 mmol) was then added to flask A, while
the alkynylphenanthroline ligand 4 (0.044 g, 0.0618 mmol) was added to
flask B. Both deep red solutions were stirred at RT for 3 h. Meanwhile,
in the reaction flask C, CuI (0.024 g, 0.123 mmol), SA (0.195 g,
0.988 mmol) and SBP (0.146 g, 0.247 mmol) were dissolved in degassed
H2O/EtOH 1:1 (20 mL). The pink suspension was heated at reflux for
5 min and then cooled to RT. The deep red solutions in the flasks A and
B were diluted to degassed CH2Cl2 (10 mL) and then added by cannula
to flask C. Finally, DBU (0.146 g, 0.247 mmol) was added and the red
mixture was stirred under N2 for 12 h at RT. The crude mixture was neu-
tralized by addition of 10% aqueous HCl (10 mL) and extracted with
CH2Cl2 (3ꢁ50 mL). The organic phase was washed with water (2ꢁ
100 mL) and stirred for 2 h with a saturated MeOH solution of KPF6 to
effect the anion exchange. The solvents were evaporated, the remaining
insoluble white solid was extracted with CH2Cl2 (3ꢁ100 mL) and the so-
lution was filtered through paper. The solvent was evaporated under re-
duced pressure and the crude product was purified by column chroma-
tography (SiO2) using CH2Cl2/CH3OH 99:1 as eluent, affording metalated
[4] F. Bitsch, C. O. Dietrich-Bucheker, A. K. Khemiss, J.-P. Sauvage,
Ed. 1968, 7, 321–328; b) H. C. Kolb, M. G. Finn, K. B. Sharpless,
Chem. Eur. J. 2009, 15, 5444 – 5448
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5447