51112-92-6Relevant academic research and scientific papers
Divergent Synthesis of 1H-Indazoles and 1H-Pyrazoles from Hydrazones via Iodine-Mediated Intramolecular Aryl and sp3 C–H Amination
Wei, Wei,Wang, Zhen,Yang, Xikang,Yu, Wenquan,Chang, Junbiao
, p. 3378 - 3387 (2017/10/09)
A divergent intramolecular C–H amination of hydrazones has been developed employing molecular iodine (I2) as the sole oxidant. The required hydrazone substrates were readily obtained by condensation of hydrazines with the corresponding ketones.
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.
Copper-catalyzed aerobic C(sp2)-H functionalization for C-N bond formation: Synthesis of pyrazoles and indazoles
Li, Xianwei,He, Li,Chen, Huoji,Wu, Wanqing,Jiang, Huanfeng
, p. 3636 - 3646 (2013/06/04)
A simple, practical, and highly efficient synthesis of pyrazoles and indazoles via copper-catalyzed direct aerobic oxidative C(sp2)-H amination has been reported herein. This process tolerated a variety of functional groups under mild conditions. Further diversification of pyrazoles was also investigated, which provided its potential for drug discovery.
Direct C-3-arylations of 1H-indazoles
Ben-Yahia, Ali,Naas, Mohammed,El Kazzouli, Said,Essassi, El Mokhtar,Guillaumet, Gerald
, p. 7075 - 7081 (2013/02/22)
The first example of intermolecular C-H arylation of substituted 1H-indazoles is reported. Various 1-substituted indazoles were used as starting materials, and (hetero)aryl bromides and iodides were investigated as coupling partners. Different reaction co
Pd- and Cu-catalyzed C-H arylation of indazoles
Hattori, Keika,Yamaguchi, Kazuya,Yamaguchi, Junichiro,Itami, Kenichiro
experimental part, p. 7605 - 7612 (2012/09/07)
The palladium- and copper-catalyzed C-H arylation reactions of 1H- and 2H-indazoles with haloarenes are described. A PdCl2/phen/Ag 2CO3/K3PO4 catalytic system is effective for the C-H arylation of 1H- and 2H-indazoles with haloarenes, whereas a less expensive CuI/phen/LiOt-Bu catalytic system is applicable to the C-H coupling of substituted 2H-indazoles and iodoarenes. The utility of newly developed catalyst was demonstrated in the rapid synthesis of YC-1 (an antitumor agent) and YD-3 (platelet anti-aggregating agent). These new reactions represent important direct functionalization tools of indazoles, well-known bioisosteres of pharmaceutically important indole core.
