1365828-05-2Relevant academic research and scientific papers
A robust protocol for Pd(ii)-catalyzed C-3 arylation of (1H) indazoles and pyrazoles: Total synthesis of nigellidine hydrobromide
Ye, Mengchun,Edmunds, Andrew J.F.,Morris, James A.,Sale, David,Zhang, Yejia,Yu, Jin-Quan
, p. 2374 - 2379 (2013)
C3-arylated indazole and pyrazoles are privileged structural motifs in agrochemicals and pharmaceuticals. C-3 C-H arylation of (1H) indazole and pyrazole has been a significant challenge due to the poor reactivity of the C-3 position. Herein, we report a practical Pd(ii)/Phen catalyst and conditions for the direct C-3 arylation of indazole and pyrazole with ArI or ArBr without using Ag additives as halide scavengers. The use of toluene, chlorobenzene, trifluoromethylbenzene and mesitylene as the solvent was found to be crucial for the selectivity and reactivity. We further demonstrate the robustness of this protocol through the first total synthesis of nigellidine hydrobromide as well as the expedient preparation of heterocycles structurally related to pesticides and drug molecules.
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
One-pot synthesis of 1-alkyl-1H-indazoles from 1,1-dialkylhydrazones via aryne annulation
Markina, Nataliya A.,Dubrovskiy, Anton V.,Larock, Richard C.
supporting information; experimental part, p. 2409 - 2412 (2012/04/11)
The reaction of readily accessible 1,1-dialkylhydrazones with commercially available o-(trimethylsilyl)aryl triflates provides a direct one-step route to pharmaceutically important 1-alkylindazoles. The products are obtained in high yields by one-pot NCS-
