First Synthesis of Upper Rim Mono and Dinitrone Calix[4]arene Derivatives
A new class of calix[4]arene derivatives bearing one or two nitrone groups on the upper rim has been synthesized using the oxidation of chiral imines with hydrogen peroxide. The imine intermediates were obtained via amination of the diformyl derivative. The 1H NMR spectra and X-ray data indicated a 1,3-disubstituted cone conformation for the imine derivatives and the existence of a single (E,E) isomer. The structural identity of the nitrone derivatives was confirmed from NMR, IR and ES-MS data. Both mono and dinitrone calix[4]arenes were in E configuration. [image omitted]
Keywords: Calixarene; Chiral ligands; Nitrone derivatives; Synthesis; X-ray structure
Document Type: Research Article
Affiliations: Equipe Chimie Supramoléculaire Appliquée, CNRS UMR 5634, Université Claude Bernard Lyon 1, 43 bd du 11 Novembre 1918, Villeurbanne cedex, France
Publication date: 01 September 2007
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