1334951-11-9Relevant academic research and scientific papers
Metal-free, regioselective, visible light activation of 4CzIPN for the arylation of 2H-indazole derivatives
Saritha, Rajendhiran,Annes, Sesuraj Babiola,Ramesh, Subburethinam
, p. 14079 - 14084 (2021/04/22)
Highly regioselective organo photocatalysis of 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) for the arylation of 2H-indazole is demonstrated. The present synthetic route provides a highly safe and easily accessible aniline precursor as an arylation reagent. The photoactivated 4CzIPN organocatalyst is found to be more efficient for single electron transfer without any organic base for the radical reaction. The carbazole-based photocatalyst (4CzIPN) with wide redox potential is stable and recyclable for further reaction transformations. Many indazole and aniline derivatives were used in the reaction and provided the arylated indazole derivatives in good to excellent yield.
Rh(III)-Catalyzed [4 + 1]-Annulation of Azoxy Compounds with Alkynes: A Regioselective Approach to 2H-Indazoles
Long, Zhen,Yang, Yudong,You, Jingsong
, p. 2781 - 2784 (2017/06/07)
A rhodium-catalyzed regioselective C-H activation/cyclization of azoxy compounds with alkynes has been disclosed to construct a variety of 2H-indazoles. A [4 + 1]-cycloaddition rather than a normal [4 + 2] mode is observed in the process of cyclative capture along with an oxygen-atom transfer and a C≡C triple bond cleavage. This protocol features a broad substrate scope, a good functional group tolerance, and an exclusive regioselectivity.
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.
A general and efficient approach to 2H-indazoles and 1H-pyrazoles through copper-catalyzed intramolecular N-N bond formation under mild conditions
Hu, Jiantao,Cheng, Yongfeng,Yang, Yiqing,Rao, Yu
, p. 10133 - 10135 (2011/10/09)
A new efficient copper-catalyzed intramolecular amination reaction has been developed to readily synthesise a wide variety of multi-substituted 2H-indazole and 1H-pyrazole derivatives from easily accessible starting materials under mild conditions. A highly selective ligand for estrogen receptor β was prepared in three steps by employing this method. The Royal Society of Chemistry 2011.
