Calixarenes as Stoppers in Rotaxanes

Nieger, Martin; Mogck, O.; Böhmer, Volker; Ungaro, Rocco; Vögtle, Fritz

doi:10.1002/(sici)1099-0690(199801)1998:1<155::aid-ejoc155>3.0.co;2-e

Cited by 41 publications

(48 citation statements)

References 23 publications

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“…In view of these examples, it is astonishing that the larger calix[8]arene was not yet used as a macrocyclic component in rotaxanes or catenanes. Calix [4] arenes have been used, however, as stoppers in rotaxanes [76], where they can contribute to the binding of guests [77].…”

Section: Discussionmentioning

confidence: 99%

Tetra‐Urea Calix[4]arenes — From Dimeric Capsules to Novel Catenanes and Rotaxanes

Podoprygorina

Böhmer

2008

Modern Supramolecular Chemistry

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The preparation of topologically interesting molecules and supramolecular structures such as catenanes, knots [1], or Möbius strips [2] is primarily an intellectual challenge, although more and more applications [3] have been proposed during the last decade(s). The synthesis of structures consisting of interlocked rings usually requires the formation of cyclic molecules from linear precursors while they are penetrating already existing rings. Similarly to the macroscopic example (the fabrication of a chain [Latin: catena]), an efficient synthesis of catenanes 1) requires a perfect prearrangement of the respective building blocks. On the molecular level, such a preorganization can be achieved by an appropriate covalent linkage which has to be cleaved after the intended ring-closure reaction(s). However, the desired mutual arrangement of the precursors can also be obtained via reversible links, such as coordination to metal cations, hydrogen bonding, or interactions of the donoracceptor type. This has the advantage that wrong connections can be corrected during the assembly process. The rapid progress in the synthesis of topologically more and more demanding molecules and complex structures in reasonable yields, for which Borromean rings [4] represent an impressive example, is therefore strongly connected with the development of supramolecular chemistry in general [5].The first rational synthesis of a [2]catenane was reported by Schill and Lüttrin-ghaus [6], who successfully used a covalent attachment to a template. This covalent approach was recently applied by Godt and coworkers for the preparation of a series of [2]catenanes consisting of really large and thus mutually mobile chain rings (non-rusty catenanes) [7]. In this case a prefabricated macrocycle and a precursor for the second ring were linked via a carbonate group. The oxidative coupling of the alkyne residues formed the second cycle, which has to be threaded through the first one (Scheme 5.1). Hydrolysis of the carbonate linkage disconnected the two rings, producing a [2]catenane.

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Section: Discussionmentioning

confidence: 99%

Tetra‐Urea Calix[4]arenes — From Dimeric Capsules to Novel Catenanes and Rotaxanes

Podoprygorina

Böhmer

2008

Modern Supramolecular Chemistry

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“…19 Amide catenanes of the Leigh type and their derivatives thiophene, and sulfonamide derivatives [145], and it is possible to use olefinic and aliphatic building blocks instead [146]. Also, the stoppers have been exchanged against porphyrins [147] and calixarenes [148]. While all rotaxanes mentioned so far have been synthesized from acid chloride center pieces and amine stopper groups, it is also possible to use isocyanates together with trityl aniline or trityl phenol stoppers providing access to urea and urethane groups in the axle [149,150].…”

Section: Synthesis and Structural Variability Of Amide Catenanes And mentioning

confidence: 99%

Hydrogen-Bond-Mediated Template Synthesis of Rotaxanes, Catenanes, and Knotanes

Schalley

Weilandt

Brüggemann

et al. 2005

Topics in Current Chemistry

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139

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“…This approach has led to the preparation of rotaxanes by either threading-followedby-stoppering [152,[182][183][184] or slippage [135][136][137][138][139][140][141][142][143][144][145][146][147][148] protocols. However, in 2001, the Stoddart group [185] reported a simple and highly effective dynamic procedure (Scheme 10) for the formation of a [2]rotaxane by the clipping of a diamine with a dialdehyde, as the precursor components of a [24]crown-8-like macrocycle, around a dialkylammonium center that also acts as a template.…”

Section: Ammonium Ion Templated Synthesesmentioning

confidence: 99%

“…Clipping of isophthalaldehyde 64 occurs at an intermediate rate. This reactivity scale is consistent [183][184][185][186][187][188][189][190][191][192][193][194][195] with the electrophilicities of the different formyl groups.As expected, the dialdehyde 57 exhibits the most electrophilic behavior, while 65 exhibits the least. The donor-acceptor nature of the dumbbell-shaped dialkylammonium ion also affects the rates of clipping.…”

Section: Ammonium Ion Templated Synthesesmentioning

confidence: 99%