Synthesis, Optical Resolution and Complexation Properties of Inherently Chiral Monoalkylated p-tert-Butyl-(1,2)-calix[4]crown Ethers
- 1 November 1997
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 62 (23), 8041-8048
- https://doi.org/10.1021/jo970934e
Abstract
Reaction of mono-O-alkylated calix[4]arenes 2 with tri- to pentaethylene glycol ditosylates and K(2)CO(3) affords asymmetrical (1,2)-calix[4]crown ether derivatives 3 as the main product, along with minor amounts of calix[4]arene dimers 4 and mixed syn-distal di-O-alkylated calix[4]arenes 5. A reaction mechanism for the formation of 3-5 is proposed, and the NMR spectral features of these products are briefly discussed. Evidence of the chirality of 3 was provided by diastereomeric interaction with enantiopure alkylammonium salts. The enantiomeric resolution of racemates 3 was achieved by direct HPLC separation, using chiral stationary phases. A screening of the complexing abilities of pyridino-(1,2)-calix[4]crown ethers 3a-c by extraction studies from water into CH(2)Cl(2) showed a low extraction level of alkali, alkaline earth, and heavy metal picrates, while up to 25% extraction was found for Ag(+). UV and pH-metric measurements of 3a-c with silver picrate in THF indicate the formation of 1:1:1 (metal:ligand:picrate) species, with log K's in the range 3.1-3.7.Keywords
This publication has 25 references indexed in Scilit:
- A PC compatible computer program for the calculation of equilibrium constants by the simultaneous processing of different sets of experimental resultsTalanta, 1994
- Synthetic strategies to inherently chiral calix[4]arenes with mixed ligating functionalities at the lower rimThe Journal of Organic Chemistry, 1994
- Syntheses and optical resolution of calix[4]arenes with molecular asymmetry. Systematic classification of all possible chiral isomers derivable from calix[4]areneJournal of the American Chemical Society, 1993
- Direct separation of cone‐shaped tri‐O‐alkylated chiral calix[4]arenes by enantioselective HPLCChirality, 1993
- SELECTIVE FUNCTIONALIZATION AND CONFORMATIONAL PROPERTIES OF CALIX[4]ARENES, A REVIEWOrganic Preparations and Procedures International, 1992
- A Convenient Void Volume Marker for Several Chiral HPLC ColumnsJournal of Liquid Chromatography, 1991
- Formation of Solvent-Separated Ion Pairs in Calixarene Ester–Alkali Picrate ComplexesBulletin of the Chemical Society of Japan, 1989
- Supramolecular Chemistry—Scope and Perspectives Molecules, Supermolecules, and Molecular Devices (Nobel Lecture)Angewandte Chemie-International Edition, 1988
- Calixarenes. 3. Preparation of the 2,4-dinitrophenyl and camphorsulfonyl derivatives of the calix[8]arene from p-tert-butylphenolThe Journal of Organic Chemistry, 1979
- Interactions of macrobicyclic polyethers with ions and ion pairs of picrate saltsJournal of the American Chemical Society, 1975