Rh(III)-Catalyzed [4 + 1]-Annulation of Azoxy Compounds with Alkynes: A Regioselective Approach to 2<i>H</i>-Indazoles
作者:Zhen Long、Yudong Yang、Jingsong You
DOI:10.1021/acs.orglett.7b00982
日期:2017.6.2
A rhodium-catalyzed regioselective C–H activation/cyclization of azoxycompounds 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
Transition metal catalyzed synthesis of 2H-indazoles
申请人:HALLAND Nis
公开号:US20100234601A1
公开(公告)日:2010-09-16
The present invention relates to a process for the regioselective synthesis of compounds of the formula I,
wherein R0; R1; R2; R3; R4; R5; A1; A2; A3; A4, Q and J have the meanings indicated in the claims. The present invention provides a direct transition metal catalyzed process to a wide variety of multifunctional 2H-indazoles or 2H-azaindazoles of the formula (I) from 2-halo-phenylacetylenes or (2-sulfonato)phenylacetylenes and monosubstituted hydrazines.
Cyclization of Azobenzenes Via Electrochemical Oxidation Induced Benzylic Radical Generation
作者:Anni Li、Xiangyi Li、Fang Ma、Hui Gao、Hongji Li
DOI:10.1021/acs.orglett.3c02099
日期:2023.8.18
An electrochemical oxidation-induced cyclization of ortho-alkyl-substituted azobenzenes has been developed. The direct electrochemical benzylic C–H functionalization with respect to azobenzenes could proceed in the absence of any catalyst or external chemical oxidant to afford a number of 2H-indazole derivatives in moderate to good yields. This protocol enables the reuse of the byproduct to the same