Palladium-Catalyzed Synthesis of 2-Aryl-2H-Benzotriazoles from Azoarenes and TMSN3
摘要:
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.
The Wallach Rearrangement of Some 4,4′-Disubstituted Azoxybenzenes
作者:Ichiro Shimao、Shigeru Oae
DOI:10.1246/bcsj.56.643
日期:1983.2
treatment of azoxybenzenes bearing electron-withdrawing substituents at 4,4′-positions with sulfuric acid gave the corresponding 2-hydroxyazobenzenes, together with 4′-substituted 4-hydroxyazobenzenes. The treatment of 4,4′-dimethoxyazoxybenzene with p-toluenesulfonic acid and acetic anhydride afforded 4,4′-dimethoxy-3-acetoxyazobenzene and 4,4′-dimethoxy-2-tosyloxyazobenzene as the main rearrangement products