Iizuka Kenta, Takezawa Hiroki, Fujita Makoto
Department 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.
Tokyo College, Institutes for Advanced Study, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.
J Am Chem Soc. 2023 Dec 6;145(48):25971-25975. doi: 10.1021/jacs.3c10720. Epub 2023 Nov 17.
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.
对称骨架的去对称化能够实现分子的后期功能化。然而，通过对称分子的位点选择性反应进行试剂控制的去对称化仍然是一种困难的合成策略。在这里，我们发现将对称分子完全限制在配位笼中可以使客体构象去对称化，从而有可能位点选择性地激活或保护杯[4]芳烃衍生物原本等价的反应位点。多步单笼反应也证明了将AAAA型杯[4]芳烃转化为对称性较低的ABAC型杯[4]芳烃。
