6533b855fe1ef96bd12b090a
RESEARCH PRODUCT
Calixarenes as Stoppers in Rotaxanes
Fritz VögtleOliver MogckClaudia FischerMartin NiegerRocco UngaroVolker Böhmersubject
chemistry.chemical_compoundRotaxaneStereochemistryChemistryAmideOrganic ChemistryPolymer chemistryCalixareneAmine gas treatingPhysical and Theoretical ChemistryTemplate synthesisdescription
The synthesis of the amide-based rotaxane 7a bearing calix[4]arene blocking groups is described for the first time. While rotaxane formation fails if a calix[4]arene is functionalized at the upper rim with only an amino or methylamino group lacking any spacer, the prolonged amine 5a works successfully as stopper unit preventing dethreading of the dimeric wheel 1a by its size. Rotaxane formation of 8b was observed only by MALDI-TOF mass spectrometry of the reaction mixture of the amine 5b, the axle 6 and 1a. With the larger trimeric wheel 1b no stable rotaxane could be obtained. It either does not act as a concave template or its opening is too wide, even for the bulky calixarene stoppers.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1998-01-01 | European Journal of Organic Chemistry |