Aryne [3+ 2] cycloaddition with N-sulfonylpyridinium imides and in situ generated N-sulfonylisoquinolinium imides: a potential route to pyrido [1, 2-b] indazoles and …

J Zhao, P Li, C Wu, H Chen, W Ai, R Sun…

Index: Zhao, Jingjing; Li, Pan; Wu, Chunrui; Chen, Hongli; Ai, Wenying; Sun, Renhong; Ren, Hailong; Larock, Richard C.; Shi, Feng Organic and Biomolecular Chemistry, 2012 , vol. 10, # 9 p. 1922 - 1930

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Citation Number: 39

Abstract

The aryne [3+ 2] cycloaddition process with pyridinium imides breaks the aromaticity of the pyridine ring. By equipping the imide nitrogen with a sulfonyl group, the intermediate readily eliminates a sulfinate anion to restore the aromaticity, leading to the formation of pyrido [1, 2- b] indazoles. The scope and limitation of this reaction are discussed. As an extension of this chemistry, N-tosylisoquinolinium imides, generated in situ from N′-(2-alkynylbenzylidene ...