Catalyst-free photoarylation of 2-aryl-2H-indazoles by carbon–iodine bond activation
摘要:
A catalyst-free photoarylation of 2-aryl-2H-indazoles by carbon–iodine bond activation has been developed for the synthesis of C3-arylated indazoles in moderate to good yields.
Rhenium-Catalyzed [4 + 1] Annulation of Azobenzenes and Aldehydes via Isolable Cyclic Rhenium(I) Complexes
作者:Xiaoyu Geng、Congyang Wang
DOI:10.1021/acs.orglett.5b00938
日期:2015.5.15
The first Re-catalyzed [4 + 1] annulation of azobenzenes with aldehydes was developed to furnish 2H-indazoles via isolable and characterized cyclic ReI-complexes. For the first time, the acetate-acceleration effect is showcased in Re-catalyzed C–H activation reactions. Remarkably, mechanistic studies revealed an irreversible aldehyde-insertion step, which is in sharp contrast to those of previous Rh-
Visible-light-mediated direct C3-arylation of 2<i>H</i>-indazoles enabled by an electron-donor–acceptor complex
作者:Kim Christopher C. Aganda、Junyoung Kim、Anna Lee
DOI:10.1039/c9ob02074h
日期:——
A mild visible-light-mediated, photocatalyst-free arylation of 2H-indazoles was developed. The formation of an electron donor–acceptor complex by 2H-indazoles and aryl diazonium salts in the presence of pyridine allows the direct arylation of 2H-indazoles under visible-light irradiation. This process provides an efficient route for the synthesis of C3-arylated-2H-indazoles, which are important scaffolds
Direct Access to Acylated Azobenzenes via Pd-Catalyzed C–H Functionalization and Further Transformation into an Indazole Backbone
作者:Hongji Li、Pinhua Li、Lei Wang
DOI:10.1021/ol303434n
日期:2013.2.1
Azobenzenes were readily acylated at the 2-position through a Pd-catalyzed C-H functionalization from simple aromatic azo compounds and aldehydes in good yields. The obtained acylated azobenzenes could be efficiently converted into the corresponding indazole derivatives in nearly quantitative yields.