Rotaxanes amide

Figure 13.28 The electrochemically induced shuttling in the benzylic amide rotaxane 30.

Scheme 10 Synthesis of amide rotaxanes by a template effect based on the formation of...

Another approach to test a template mechanism is to use appropriate control compounds that can be expected to fail to yield the rotaxanes or catenanes, if the tentative mechanism is indeed operative. In order to gain further support for the template mechanism of amide rotaxane formation (Scheme 10), it is desirable to have additional evidence for the... 

SCHEME 14 AXLE CENTERPIECES 30 AND 31 THAT WERE USED AS CONTROL COMPOUNDS FOR A MORE DETAILED INVESTIGATION OF THE MECHANISM OF AMIDE ROTAXANE FORMATION. 

Schalley, C.A, Reckien, W., Peyerimhoff, S., Vogtle, F. Theory and experiment in concert templated synthesis of amide rotaxanes, catenanes and knots, Chem. Eur. J. in press. 

Fig. 4 Two enantiomers of an amide rotaxane. showing their overall structures. Note that the sulfonamide group in the wheel defines an atom sequence (indicated by the arrows in the bottom drawings). The sulfonamide incorporated in the axle permits the two stoppers to be distinguished. Such rotaxanes can be separated into the two enantiomers by HPLC on chiral stationary phases, and their CD spectra were measured.

Heim. C. Affeld, A. Nieger, M. Vogtle, F. Size 29. complementarity of macrocyclic cavities and stoppers in amide-rotaxanes. Helv. Chim. Acta 1999. 82, 746. 

Kaufmann L, Traulsen NL, Springer A, et al. Evaluation of multivalency as an organization principle for the efficient synthesis of doubly and triply threaded amide rotaxanes. Org Chem Front. 2014 1 521-531. 

Benzyhc amide rotaxanes A versatile architecture 12COS199. [2]Catenanes on surfaces as candidates for nanoelectronic devices 12COS188. 

Box 1 Structural Characterization of the Threaded Topology of Amide Rotaxanes in the Gas Phase... 

Figure 51 An electrochemically driven molecular shuttle based on an amide rotaxane...

Nonionic template synthesis of amide-linked catenanes and rotaxanes with macroheterocyclic fragments 97AG(E)930. 

R. Jager, F. Vogtle, A New Synthetic Strategy towards Molecules with Mechanical Bonds Nonionic Template Synthesis of Amide-Linked Catenanes and Rotaxanes , Angew. Chem Int. Ed. Engl. 1997,36,930-944. 

The templated syntheses of amide-based rotaxanes discussed until now have made use of the threading-followed-by-capping method. However there are also examples in which the clipping approach has been employed. Leigh, for example, has used a five-component clipping method to prepare [2]rotaxanes. Isophthalamide and peptide-based threads were shown to template the formation of benzylic amide macrocycles about them in non-polar solvents [69, 70]. When the peptide-based threads (49) contain bulky stoppers at their ends, the [2]rotaxanes (50) can be prepared in high yields (see Scheme 24) [71]. 

Leigh DA, Venturini A, Wilson AJ, Wong JKY, Zerbetto F (2004) The mechanism of formation of amide-based interlocked compounds prediction of a new rotaxane-forming motif. Chem Eur J 10 4960 -969... 

Scheme 15.9 Reversible shuttling of the benzylic amide macrocycle in [2]rotaxane 53 by redox reactions.

Catenaries and Rotaxanes Incorporating Amide Recognition Sites... 

The corresponding macrocycle, intended to be a host for carbon dioxide, was not detected, but was synthesized in 1996 by an elegant strategy via rotaxane formation (see Section 8.3, Amide-Based Rotaxanes) [25]. 

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