Direct Access to Acylated Azobenzenes via Pd-Catalyzed C–H Functionalization and Further Transformation into an Indazole Backbone
摘要:
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.
Tosyl Hydrazine-Promoted Tandem Condensation and Cyclization of Acyl Azobenzenes Enabling Access to 2<i>H</i>
-Indazoles under Metal-Free Aerobic Conditions
作者:Jeong-Yu Son、Hyunseok Kim、Yonghyeon Baek、Kyusik Um、Gi Hoon Ko、Gi Uk Han、Sang Hoon Han、Kooyeon Lee、Phil Ho Lee
DOI:10.1002/adsc.201801055
日期:2018.11.16
Tosyl hydrazine‐promoted tandem condensation and cyclization of 2‐acyl azobenzenes under metal‐free aerobic conditions was demonstrated to give 2‐aryl‐2H‐indazoles having alkyl‐ or aryl groups at the 3‐position in quantitative yields through the release of water, molecular nitrogen, and sulfinic acid. All of the examples produced the corresponding 2H‐indazoles in quantitative yields. The present reaction