70704-41-5Relevant academic research and scientific papers
Preparation method 2 - substituted - 222H-indazole compound
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Paragraph 0049-0051, (2020/10/19)
The invention provides a preparation method of a 2-substituent-2H-indazole compound. With a cuprous catalyst, a coupling reaction is carried out to substituted 1H-indazole and aryliodonium salt in a low-molecular polar organic solvent to obtain a corresponding 2-substituent-2H-indazole compound, wherein the molar ratio of the 1H-indazole to the aryliodonium salt is 1:1.2. According to the method,the reaction route starts from the 1H-indazole compound which is easy to obtain; with the low-cost cuprous compound as a catalyst, the reaction condition is gentle and yield of produced target compound is high. The method also has good compatibility with various functional groups and can be widely applied to synthesize 2-substituent-2H-indazole compounds having different substituent groups. The method has important application value.
Access to 2-substituted-2: H -indazoles via a copper-catalyzed regioselective cross-coupling reaction
Zhang, Rong,Liu, Zheng,Peng, Qiujun,Zhou, Yijun,Xu, Lanting,Pan, Xianhua
, p. 1816 - 1822 (2018/03/23)
A CuCl catalyzed C-N cross-coupling reaction using commercially available 1H-indazoles with diaryliodonium salts is described. The methodology features ample structural versatility, affording 2-substituted-2H-indazole in good yields and complete N(2)-regiocontrol. Furthermore, the utility of the reaction was demonstrated in the synthesis of a known estrogen receptor β agonist. Mechanistic studies using density functional theory calculations suggested that the complete regioselectivity can be attributed to the only weak base TfO- in our system which could not deprotonate indazoles, and the catalyst oxidation process would be the rate-determining step.
