ISSN:
1573-1111
Keywords:
Chiral calixarene crown ethers
;
separation of enantiomers
;
molecular recognition
;
RNH3 + inclusion complexes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Alkylation of p-tert-butylcalix[5]arene (1) with 2,2'-bis(5-tosyloxy-3-oxa-1-pentyloxy)-1,1'-binaphthalene ((±)-2) in the presence of CsF affords selectively racemic 1,3-bridged calix[5] [5]crown-6-triol 3, along with very small amounts of the (1,2)-bridged regioisomer 4. Compound 3 has been converted into tri-methoxy and tri-α-picolyloxy derivatives 5 and 6, respectively, by exhaustive alkylation with the appropriate electrophile and base. The direct separation of the enantiomers of racemates 3 and 6 was achieved by HPLC, using a chiral stationary phase (Chiralpak AD). Hosts 5 and 6 are able to selectively form 1 : 1 endo-cavity complexes with the linear RNH3 + ions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008062428030
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