Hypervalent Iodine Reagents Enable C-H Alkynylation with Iminophenylacetic Acids via Alkoxyl Radicals
Zhengyi Liu1, Yue Pan1,2, Peng Zou1
1State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Abstract:
Here we report δ-C-H alkynylation to synthesize various δ-alkynols from iminophenylacetic acids. The hypervalent iodine-coordinated benziodoxole-alkoxyl-iminophenylacetic acid complex was the key intermediate and was characterized by X-ray crystallography for the first time. δ-C-H alkynylation is compatible with sensitive functional groups, including azides, aldehydes, and free alcohols, for the synthesis of δ-alkynols with diversified substituents in excellent regioselectivity. This reaction extends to δ-hydroxylalkene and δ-hydroxylnitrile synthesis, and the δ-alkynol products are easily derivatized to other valuable bifunctional building blocks.
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