Single Step Synthesis of Non-symmetric Azoarenes Using Buchwald-Hartwig Amination

Abstract

Aromatic azo compounds stand as a highly sought-after class of substances owing to their extensive array of applications across various fields. Despite their significance, their synthesis often presents challenges, requiring either multistep reactions or being restricted to specific substrate types. In this study, we are showing the universality and mechanistic aspects of a one-step approach for synthesis of nonsymmetrical azoarenes via the Buchwald-Hartwig amination reaction of (pseudo)haloaromatics with arylhydrazines, conducted in the presence of atmospheric oxygen. This reaction protocol yields products in up to 85% yield and is compatible with a wide class of substituents, making it highly adaptable. Notably, the inclusion of BINAP as a ligand plays a pivotal role in achieving favorable outcomes. This study not only offers a versatile solution to a long-standing synthetic challenge but also provides experimental and computational insights into the mechanisms driving the reaction.