1369490-60-7Relevant academic research and scientific papers
Synthesis of indazoles and azaindazoles by intramolecular aerobic oxidative C-N coupling under transition-metal-free conditions
Hu, Jiantao,Xu, Huacheng,Nie, Pengju,Xie, Xiaobo,Nie, Zongxiu,Rao, Yu
supporting information, p. 3932 - 3938 (2014/04/17)
A transition-metal-free oxidative C-N coupling method has been developed for the synthesis of 1H-azaindazoles and 1H-indazoles from easily accessible hydrazones. The procedure uses TEMPO, a basic additive, and dioxygen gas as the terminal oxidant. This reaction demonstrates better reactivity, functional group tolerance, and broader scope than comparable metal catalyzed reactions. A transition-metal-free oxidative C-N coupling method has been developed for the synthesis of 1H-azaindazoles and 1H-indazoles from easily accessible hydrazones (see scheme). The procedure uses TEMPO, a basic additive, and dioxygen gas as the terminal oxidant. This reaction demonstrates better reactivity, functional group tolerance, and broader scope than comparable metal catalyzed reactions. TEMPO=2,2,6,6-tetramethyl-1-piperidinyloxy.
Synthesis of substituted 1 H-indazoles from arynes and hydrazones
Li, Pan,Wu, Chunrui,Zhao, Jingjing,Rogness, Donald C.,Shi, Feng
experimental part, p. 3149 - 3158 (2012/07/14)
The 1H-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 likely through an annulation/oxidation process. The reactions operate under mild conditions and can accommodate aryl, vinyl, and less satisfactorily, alkyl groups.
