Synthesis of 3-Substituted Indazoles from Arynes and N-Tosylhydrazones
Pan Li, Jingjing Zhao, Chunrui Wu, Richard C. Larock and Feng Shi*
*Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province, Henan University, Jinming Campus, Kaifeng, 475004, PR China, Email: fshihenu.edu.cn
P. Li, J. Zhao, C. Wu, R. C. Larock, F. Shi, Org. Lett., 2011, 13, 3340-3343.
DOI: 10.1021/ol201086g (free Supporting Information)
Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in good yields. The reaction involves a 1,3-dipolar cycloaddition of in situ generated diazo compounds and arynes.
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P. Li, C. Wu, J. Zhao, D. C. Rogness, F. Shi, J. Org. Chem., 2012, 77, 3127-3133.
Z. Liu, F. Shi, P. D. G. Martinze, C. Raminelli, R. C. Larock, J. Org. Chem., 2008, 73, 219-226.