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

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.