Enantioselective Recognition of Calix[4]arene Derivative Bearing Bicyclic Guanidinium for D/L Amino Acid Zwitterions
✍ Scribed by Fang Liu; Guo-Yuan Lu; Wei-Jiang He; Zhen-Sheng Wang; Long-Gca Zhu
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 233 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0256-7660
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✦ Synopsis
Abstract
The p‐tetra‐te__r__t‐butyl calix[4] arene derivatives (3 and 4) with (5,5) chiral bicyclic guanidinium, as the receptors of amino acid zwitterions, have been synthesized via a O‐alkylation reaction of p‐tetra‐tert‐butyl calix [4] arene with cbJoromethyl chiral bicyclic guanidinium 2 in the presence of anhydrous K~2~CO~3~ in acetonitrile. The results obtained from liquid‐liquid competitive extraction experiments indicate that the two receptors may selectively recognize L‐aromatic amino acids, and that the enantioselective recognizability of the receptor 4 with two chiral bicyclic guanidinium units reachs up to about 90% for __L‐Ph__e.