Green Oxidative Synthesis of Azo, Diazo, and Azido Compounds

Organic azo, diazo, and azido compounds are valuable intermediates applied in the synthesis of various nitrogen-containing compounds. This chapter displays recent advances in the preparation of these compounds via green oxidative strategies. Besides, most synthetic methods of azo compounds focus on the symmetric reactions, and reports on the asymmetric version with high yield and selectivity are still rare. Thus, it is necessary to continue developing new and efficient methods for the synthesis of asymmetric azo compounds from simple anilines. In diazo synthesis, the unsatisfying atom economy and/or the low cost-effectiveness of several methods is still hard to eliminate. In the synthesis of azido compounds, the azidation of aryl C–H bond is not general. Moreover, azidation of non-activated aliphatic C–H bonds mainly rely on the use of hypervalent iodine reagents, the utilization of benign oxidants, particularly molecular oxygen, is still challenging.