bridged aromatic azo compounds (AAzos) from aromatic amines was developed by using red copper as catalyst. Despite numerous efforts towards the catalytic synthesis of symmetric and asymmetric AAzos derivatives, most reactions present certain drawbacks inhibiting their industrial applications, such as laborious multi-step processes, harsh reaction conditions and expensive reagents. And the synthesis
Oxidative coupling of anilines to azobenzenes using heterogeneous manganese oxide catalysts
作者:Min Wang、Jiping Ma、Miao Yu、Zhe Zhang、Feng Wang
DOI:10.1039/c5cy01015b
日期:——
Cryptomelane-type manganese oxide shows high efficiency for the NN formation reaction in the oxidative coupling of anilines to azobenzenes. The difference of the Hammett constants (Δσ) of two substituted groups determines the selectivity to unsymmetric azobenzenes in cross-coupling reactions, which are favored at Δσ < 0.32.