ISMSC 2007 - Università degli Studi di Pavia

PSB 9
A Quantitative [2]Rotaxane Synthesis via “Active-Template” Pd-Catalyzed
Michael Addition
Stephen M. Goldup, David A. Leigh, Paul J. Lusby and Roy T. McBurney
School of Chemistry, University of Edinburgh, The King’s Buildings, West Mains Road,
Edinburgh, EH9 3JJ, United Kingdom (R.T.McBurney@sms.ed.ac.uk)
Recently we introduced the “active-template” approach for the synthesis of interlocked
structures, in which a metal atom both templates the assembly of the threaded architecture
AND catalyzes the key covalent bond forming reaction to form a rotaxane (Scheme 1). [1] The
first example of this strategy exploited the copper(I)-catalyzed cycloaddition of azide- and
alkyne-functionalized ‘stoppers’ such that in the presence of a metal-binding macrocycle, a
rotaxane was produced. [2]Rotaxanes were obtained in up to 94% yield using stoichiometric
amounts of copper and in up to 82% yield when using just 20 mol% loading of the metal in the
presence of excess pyridine. [1]
Scheme 1: Schematic representation of a general “active-template” route to [2]rotaxanes.
To expand on this “active-template” approach for synthesizing interlocked architectures, other
metal-mediated covalent bond forming reactions are being investigated in our group. Due to
success of palladium(II) as a classical “passive-template” for the formation of rotaxanes [2] and
catenanes [3] , and the widespread use of this metal as a catalyst for a variety of bond-forming
reactions, we have examined its use in various rotaxane-forming reactions. Here we report how
the Pd-catalyzed double Michael addition of an -cyano-ester to a “stopper” functionalized as a
,-unsaturated ketone [4] , in the presence of a Pd-coordinating macrocycle, results in
quantitative formation of a [2]rotaxane (Scheme 2).
Scheme 2: Rotaxane synthesis via an “active-template” Pd-catalyzed Michael addition.
[1] V. Aucagne, K. D. Hänni, D. A. Leigh, P. J. Lusby and D. B. Walker, J. Am. Chem. Soc.,
2006, 128, 2186-2187.
[2] A.-M. Fuller, D. A. Leigh, P. J. Lusby, I. D. H. Oswald, S. Parsons and D. B. Walker, Angew.
Chem. Int. Ed., 2004, 43, 3914-3918.
[3] A.-M. L. Fuller, D. A. Leigh, P. J. Lusby, A. M. Z. Slawin and D. B. Walker, J. Am. Chem.
Soc, 2005, 127, 12612-12619.
[4] K. Takenaka, M. Minakawa and Y. Uozumi, J. Am. Chem. Soc., 2005, 127, 12273-12281.
PSB 10
Binding properties of two amides derivatives of p-phenyl
tetrahomodioxacalix[4]arene towards alkali and alkaline-earth metal ions
B. Mellah, a,b R. Abidi, a H. Herschbach, c K. No, d F. Arnaud-Neu b
a Faculté des Sciences de Bizerte, Université 7 Novembre à Carthage, Bizerte, Tunisia;
b Laboratoire de Chimie-Physique, UMR 7512 (CNRS-ULP), ECPM, Strasbourg, France;
c Laboratoire de Spectrométrie de Masse, UMR 7512 (CNRS-ULP), ECPM, Strasbourg, France;
d Departement of Chemistry, Sookmyung Women’s University, Seoul, Korea;
Calix[n]arenes are known for their ability to complex selectively a large variety of metal ions [1].
Among this family of compounds, homooxacalix[n]arenes bearing extra oxygen atoms in the
macrocyclic ring are particularly interesting for their conformational flexibility [2-3].
We report here our most recent results concerning the binding of alkali, alkaline-earth metal
ions by two amides derivatives of p-phenyl tetrahomodioxacalix[4]arene differing by the nature
of the functional groups at the lower rim: phenyle (1) and diethylamide (2), blocked in the 1,2
alternate conformation [4].
Liquid-liquid and solid-liquid extraction of metal picrates
from water into dichloromethane or chloroform, and
stability constants determination in acetonitrile have
been performed using UV-absorption spectrophotometry,
ESI-MS and 1 N
N
NH
NH
O O
O O
O
O
O
O
O
O
H NMR techniques. The results show the
O
O
O
O
O
O formation of ML or M2L complexes, according to the
O O
cation and the ligand. They will be discussed in terms of
NH
NH
O O
N
N size and conformational effects.
(1) (2)
[1] M. A. McKervey, M. J.Schwing-Weill, F. Arnaud-Neu, in Comprehensive Supramolecular
Chemistry; J. M. Lehn, G. W. Eds.; 1996, 1, p 534.
[2] J. M. Harrowfield, M. I. Ogden, A. H. White, J. Chem. Soc., Dalton Trans., 1991, 979.
[3] C. Bavoux, F. Vocanson, M. Perrin, R. Lamartine, J. Incl. Phenom. Mol. Recogn. Chem.,
1995, 22, 119.
[4] a/ K. H. No, J. H. Lee, S. H. Yang, S. H. Yu, M. H. Cho, M. J. Kim, J. S. Kim; J. Org.
Chem. 2002, 67, 3165. b/ K. No, J. H. Lee, S. H. Yang, K. H. Noh, S. K. Kim, J. Seo, S. S. Lee,
J. S. Kim; J. of Inclusion Phenom. and Macrocyc. Chem., 2003, 47, 167.