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Updated: Jul 11, 2025
Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Chemical Site-Differentiation of Calix[4]arenes through Enforced Conformations by Confinement in a Cage
Kenta Iizuka1, Hiroki Takezawa1, Makoto Fujita1,2,3
1Department of Applied Chemistry, School of Engineering, The University of Tokyo, Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan.
Abstract:
Desymmetrization of a symmetric skeleton enables late-stage functionalization of molecules. However, reagent-controlled desymmetrization by site-selective reactions of symmetric molecules remains a difficult synthetic strategy. Here, we found that complete confinement of a symmetric molecule within a coordination cage can desymmetrize the guest conformation, making it possible to site-selectively activate or protect the otherwise equivalent reaction sites of calix[4]arene derivatives. Multistep, one-cage reactions also demonstrated the transformation of an AAAA-type calix[4]arene into a lower symmetry ABAC-type one.
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