Limits of the Inversion Phenomenon in Triazolyl‐Substituted β‐Cyclodextrin Dimers. Issue 7 (19th December 2013)

• Record Type: Journal Article
• Authors: Potier, Jonathan; Menuel, Stéphane; Azaroual, Nathalie; Monflier, Eric; Hapiot, Frédéric
• Is Part Of: European journal of organic chemistry. Issue 7(2014)
• Page Start: 1547
• Page End: 1556
• Publication Date: 2013-12-19
• Subjects: Host‐guest systems -- Cyclodextrins -- Macromolecules -- Conformation analysis -- Structure elucidation; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201301681
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: Six different β‐cyclodextrin (β‐CD) dimers have been synthesized by copper‐catalyzed azide alkyne cycloaddition. The nature of the spacer connecting the two β‐CDs has been varied in length and hydrophilicity. For each dimer, a detailed NMR study was carried out in D2 O. It was found that, whereas β‐CD dimers having short spacer exhibited only one conformation, β‐CD dimers having long and/or hydrophobic spacers showed two different conformations. Indeed, the latter underwent an inversion process leading to self‐inclusion of the spacer in one of the two CD cavities. The behavior of the six β‐CD dimers in water has thus been rationalized and this allowed the proportion of "free" cavities actually available for molecular recognition to be determined. Abstract : Six β‐cyclodextrin (β‐CD) dimers have been synthesized by CuAAC. Depending on the nature of the spacer connecting the CDs, one or two conformations could be detected by NMR spectroscopic analysis. An inversion process was observed for dimers with a long and/or hydrophilic spacer. The proportion of "free" β‐CD cavities actually available for molecular recognition could be determined.