Synthesis and structure of chiral macrocycles containing 2,2′-bipyridine subunits
✍ Scribed by R.Bruce Hopkins; Jeffrey S Albert; Donna Van Engen; Andrew D Hamilton
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 656 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0968-0896
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✦ Synopsis
A series of macrocyclic receptors has been prepared containing bipyridine groups linked to two amino acids. Variations in both the amino acid and the linking spacer have been made. The structure of the resulting macrocycles has been investigated using 1H NMR spectroscopy and X-ray crystallography. The use of L-valine leads to an open conformation for the macrocycle in which the 2-propyl substituents are directed perpendicular to the plane of the ring leaving the bipyridine and amide groups accessible for binding to a metal or complementary substrate. Proline-based macrocycles take up a twisted arrangement with the linking chain stretched across the face of the bipyridine which takes up a trans conformation. The metal ion binding properties of these derivatives have been investigated and shown to occur only to the valine macrocyles which have the two pyridine rings preorganized for complexation. These macrocycles have also been shown to bind to phenolic hydroxyl groups by using hydrogen-bond donors and acceptors from the amide groups in the linking chain.
📜 SIMILAR VOLUMES
## Abstract A series of polyimides containing 2,2′‐bipyridine, 7, were synthesized by reaction of 4,4′‐diamino‐2,2′‐bipyridine (4) with various aromatic dianhydrides, followed by imidization upon heating. These polyimides are fairly thermostable, and 5% weight loss occurs in the range of 484°C‐580°
## Abstract The new macrocyclic di‐ and tetralactams **__9__**, **__15__**, and **__16__** were obtained in 16–24% yields by heating the appropriate bis‐amines **__7__** or **__8__** with the corresponding bisaldehyde **__5__** or **__14__** in refluxing acetic acid under high‐dilution conditions.