Synthesis of Substituted 1 H-Indazoles from Arynes and Hydrazones

P Li, C Wu, J Zhao, DC Rogness…

Index: Li, Pan; Wu, Chunrui; Zhao, Jingjing; Rogness, Donald C.; Shi, Feng Journal of Organic Chemistry, 2012 , vol. 77, # 7 p. 3149 - 3158

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Citation Number: 41

Abstract

The 1 H-indazole skeleton can be constructed by a [3+ 2] annulation approach from arynes and hydrazones. Under different reaction conditions, both N-tosylhydrazones and N- aryl/alkylhydrazones can be used to afford a variety of indazoles. The former reaction affords 3-substituted indazoles either via in situ generated diazo compounds or through an annulation/elimination process. The latter reaction leads to 1, 3-disubstituted indazoles ...