New methods to obtain 1,2-bridged calix[4]arene-biscrowns in the 1,2-alternate conformation are described. The stereochemistry of the proximal double functionalization reaction is mainly governed by the solvent, the length of the polyether units and the base used to deprotonate the calix[4]arene.
Water-soluble para-sulfonated 1,2;3,4-calix[4]arene-biscrowns in the cone conformation
β Scribed by Alexandre Mathieu; Zouhair Asfari; Jacques Vicens
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- French
- Weight
- 132 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
Water-soluble 1,2;3,4-calix[4]arene-biscrowns ( 14)-( 18) have been synthesized in two or three steps via chlorosulfonation. Cs + -ligand interactions were studied in aqueous media by 1 H NMR.
π SIMILAR VOLUMES
The title compound, C 54 H 66 N 2 O 4 , crystallizes with two molecules in the asymmetric unit. Both adopt the typical partial cone conformation which was also found for 26,28-diallyloxy-5,17-di-tert-butyl-25,27-bis(cyanomethoxy)-11,23-dinitrocalix[4]arene [Danila, Bo Β¨hmer & Bolte (2005). Org. Biom
A previously known imidazole-initiated intramolecular ester migration was modified by replacing the imidazole with Cs 2 CO 3 to effect the efficient conversion of 25, 27-bis-p-methoxy-, 25,27-bis-p-fluoro and 25, 27-bisbenzoyloxycalix[4]arene in the flattened cone conformation to the corresponding 2