54449-01-3Relevant academic research and scientific papers
Direct C3-Arylation of 2 H-Indazole Derivatives with Aryl Bromides by using Low Loading of a Phosphine-free Palladium Catalyst
Belkessam, Fatma,Aidene, Mohand,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 2239 - 2249 (2017)
The palladium-catalyzed direct arylation of 2 H-indazoles with aryl bromides for the preparation of 3-aryl-2 H-indazoles was found to proceed in high yields when using only 0.5–0.1 mol % Pd(OAc)2 catalyst and KOAc as inexpensive base. A wide variety of electron-deficient and electron-rich aryl bromides and also heteroaryl bromides has been successfully employed. Both electron-withdrawing and electron-donating substituents on the 2 H-indazoles are also tolerated. Moreover, the reaction can be performed in the “green” solvent cyclopentyl methyl ether.
Pd- and Cu-catalyzed C-H arylation of indazoles
Hattori, Keika,Yamaguchi, Kazuya,Yamaguchi, Junichiro,Itami, Kenichiro
, 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.
