Hypervalent Iodine-Mediated Selective Monofunctionalization of Calix[4]arenes
Haoliang Hao1,2, Wei Zhang2, Wenjie Zhu2
1The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China.
Abstract:
The selective introduction of a single functionality on the upper rim of calix[4]arene is challenging due to the identical reactivity of its four aryl units. In this study, we introduce a novel strategy for monofunctional modification of calix[4]arenes using a hypervalent iodine-mediated C-H functionalization. This process yields a calix[4]arene-iodonium salt, which can be easily isolated due to its distinct solubility compared to the native calixarene. This versatile intermediate efficiently undergoes C-O, C-N, and C-S couplings with a variety of nucleophiles, including amines, phenols, thiols, and sulfinate salts under mild conditions. This strategy enables streamlined structural diversification of calix[4]arenes, opening new avenues for the design of supramolecular macrocycles with tailored functions.
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