Molecular oxygen, the most environmentally friendly oxidant, was used as the terminal oxidant for palladium-catalyzed radical oxidative acylation of arenes.
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
Palladium-Catalyzed Synthesis of 2-Aryl-<i>2H</i>-Benzotriazoles from Azoarenes and TMSN<sub>3</sub>
作者:Nilufa Khatun、Anju Modi、Wajid Ali、Bhisma K. Patel
DOI:10.1021/acs.joc.5b01706
日期:2015.10.2
Substrate-directed ortho C-H amination of azoarenes using TMSN3 as the source of nitrogen leading to the synthesis of 2-aryl-2H-benzotriazoles has been accomplished with the help of Pd/TBHP combinations. An intermolecular o-azidation (C-N bond formation) followed by an intramolecular N-N bond formation via nucleophilic attack of one of the azo nitrogen onto the o-azide nitrogen leads to cyclization with the expulsion of N-2.
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.
Atmaram, Shiravanate; Forrester, Alexander R.; Gill, Melvyn, Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry, 1982, vol. 36, # 9, p. 641 - 648
作者:Atmaram, Shiravanate、Forrester, Alexander R.、Gill, Melvyn、Napier, Russell J.、Thomson, Ronald H.