10.1002/chem.201702525
Chemistry - A European Journal
COMMUNICATION
the distance restraint. The resulting model reveals that [1·Na]+
could simultaneously accommodate both the enolate (Michael
donor) and a molecule of nitrostyrene (Michael acceptor) in
close proximity. Furthermore, the distance between the enolate
carbon atom and the -carbon atom of nitrostyrene was 4.89 Å,
making it highly likely that such bond formation could further
occur to give the experimentally observed product.
c) V. Blanco, D. A. Leigh, V. Marcos, J. A. Morales-Serna, A. L.
Nussbaumer, J. Am. Chem. Soc. 2014, 136, 4905–4908; d) D. A. Leigh,
V. Marcos, M. R. Wilson, ACS Catal. 2014, 4, 4490–4497.
[3]
[4]
a) M. Pons, O. Millet, Prog. Nucl. Magn. Reson. Spectrosc. 2001, 38,
267–324; b) S. A. Vignon, J. F. Stoddart, Collect. Czech. Chem.
Commun. 2005, 70, 1493–1576; c) A. Mateo-Alonso, G. M. A. Rahman,
C. Ehli, D. M. Guldi, G. Fioravanti, M. Marcaccio, F. Paolucci, M. Prato,
Photochem. Photobiol. Sci. 2006, 5, 1173–1176.
a) L. Raehm, J.-M. Kern, J.-P. Sauvage, Chem. Eur. J. 1999, 5, 3310–
3317; b) L. M. Hancock, P. D. Beer, Chem. Commun. 2011, 47, 6012–
6014; c) I. Murgu, J. M. Baumes, J. Eberhard, J. J. Gassensmith, E.
Arunkumar, B. D. Smith, J. Org. Chem. 2011, 76, 688–691; d) P. Farràs,
E. C. Escudero-Adán, C. Viñas, F. Teixidor, Inorg. Chem. 2014, 53,
8654–8661; e) E. Coronado, P. Gavina, J. Ponce, S. Tatay, Chem. Eur.
J. 2014, 20, 6939–6950.
We have demonstrated that the [2]rotaxane 1 can be
operated reversibly between catalytically active Na+-complexed
and inactive Na+-free states through the addition and removal,
respectively, of Na+ ions. At least three sequential on/off cycles
of a Michael reaction can be performed in situ when using the
NaTFPB/[2.2.2]cryptand reagent pair to switch “on” and “off” the
catalytic ability of the [2]rotaxane. Our discovery of a pirouetting
[2]rotaxane displaying switchable catalytic activity is a step
toward the design of interlocked catalysts displaying more
complicated functions in organic synthesis.
[5]
a) P. R. Schreiner, Chem. Soc. Rev. 2003, 32, 289–296; b) T. Marcelli,
J. H. van Maarseveen, H. Hiemstra, Angew. Chem. 2006, 118, 7658–
7666; Angew. Chem. Int. Ed. 2006, 45, 7496–7504; c) A. G. Doyle, E.
N. Jacobsen, Chem. Rev. 2007, 107, 5713–5743; d) S. J. Connon,
Chem. Commun. 2008, 2499–2510; e) J. Wang, B. L. Feringa, Science
2011, 331, 1429–1432; f) C. Najera, J. M. Sansano, E. Gomez-Bengoa,
Pure Appl. Chem. 2016, 88, 561–578; g) L. Yang, L. Zhao, Z. Zhou, C.
He, H. Sun, C. Duan, Dalton Trans. 2017, 46, 4086-4092.
[6]
[7]
[8]
Y.-J. Lee, T.-H. Ho, C.-C. Lai, S.-H. Chiu, Org. Biomol. Chem. 2016, 14,
1153–1160.
Acknowledgements ((optional))
T.-H. Ho, C.-C. Lai, Y.-H. Liu, S.-M. Peng, S.-H. Chiu, Chem. Eur. J.
2014, 20, 4563–4567.
CCDC-1511677, -1539017 and -1539018 contain the supplementary
crystallographic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
We thank the Ministry of Science and Technology (Taiwan)
(MOST-105-2826-M-002-004 and MOST-103-2113-M-002-018-
MY3) and National Taiwan University (NTU-105R890913) for
financial support.
[9]
Because of the limited solubility of NaTFPB in toluene, the association
constant for the interaction of the [2]rotaxane 1 with Na+ (as TFPB salt)
was determined in a mixture of CH2Cl2 and CH3CN (97:3), using
isothermal titration calorimetry (ITC); the value obtained from the
means of three independent experiments was (1.3 ± 0.4) 105 M-1.
Keywords: alkali metal ion • catalysis • Michael addition •
molecular switch • pirouetting • rotaxane
[10] (a) T. Okino, Y. Hoashi, T. Furukawa, X. Xu, Y. Takemoto, J. Am.
Chem. Soc., 2005, 127, 119–125; b) A. Hamza, G. Schubert, T. Soós, I.
Pápai, J. Am. Chem. Soc., 2006, 128, 13151–13160; c) J.-L. Zhu, Y.
Zhang, C. Liu, A.-M. Zheng, W. Wang, J. Org. Chem. 2012, 77, 9813–
9825.
[1]
a) Y. Tachibana, N. Kihara, T. Takata, J. Am. Chem. Soc. 2004, 126,
3438–3439; b) G. Hattori, T. Hori, Y. Miyake, Y. Nishibayashi, J. Am.
Chem. Soc. 2007, 129, 12930–12931; c) J. Berná, M. Alajarín, R.-A.
Orenes, J. Am. Chem. Soc. 2010, 132, 10741–10747; d) Y. Suzaki, K.
Shimada, E. Chihara, T. Saito, Y. Tsuchido, K. Osakada, Org. Lett.
2011, 13, 3774–3777; e) C. B. Caputo, K. Zhu, V. N. Vukotic, S. J.
Loeb, D. W. Stephan, Angew. Chem. 2013, 125, 994–997; Angew.
Chem. Int. Ed. 2013, 52, 960–963; f) C.-S. Kwan, A. S. C. Chan, K. C.-
F. Leung, Org. Lett., 2016, 18, 976–979; g) M. Galli, J. E. M. Lewis, S.
M. Goldup, Angew. Chem. 2015, 127, 13749–13753; Angew. Chem. Int.
Ed. 2015, 54, 13545–13549.
[11] Although it is unlikely that the catalytic activity of the [2]rotaxane results
from an increase in the basicity of the tertiary amino groups after
undergoing the pirouetting motion, measuring the basicity of the tertiary
amino groups in the Na+-complexed [2]rotaxane is not straightforward
so we cannot dismiss such a possibility.
[12] The structure was minimized using the Merck Molecular Force Field
(MMFF) as implemented in Discovery Studio 2.1 (Accelrys, CA) by
steepest descent followed by conjugated gradient protocols. See
Supporting Information for the details.
[2]
a) V. Blanco, A. Carlone, K. D. Hänni, D. A. Leigh, B. Lewandowski,
Angew. Chem. 2012, 124, 5256–5259; Angew. Chem. Int. Ed. 2012, 51,
5166–5169; b) V. Blanco, D. A. Leigh, U. Lewandowska, B.
Lewandowski, V. Marcos, J. Am. Chem. Soc. 2014, 136, 15775–15780;
This article is protected by copyright. All rights reserved.