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Updated: Aug 14, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Synthesis and conformational studies on hexa-O-alkyl p-unsubstituted calix[6]arenes
José C Iglesias-Sánchez1, Beatriz Souto, César J Pastor
1Departamento de Química Orgánica and Servicio Interdepartamental de Investigación, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain.
Abstract:
[structure: see text] In this article we describe the selective O-benzylation of para-unsubstituted calix[6]arene 1 in rings 1 and 4 (2a-c) and the subsequent alkylation of phenol groups with alpha-haloesters (methyl esters 3a, 3c, and 3e; tert-butyl esters 3b, 3d, and 3f) to determine the effect of these groups on their conformational behavior. 2D NMR studies at 188 K reveal that compounds 2a-c, 3b, 3d, and 3f are less flexible, showing a 1,2,3-alternate conformation. The same conformation has been observed in the solid state.
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