Visible-Light- and PPh3-Mediated Direct C-N Coupling of Nitroarenes and Boronic Acids at Ambient Temperature

We present here a metal- free, visible- light- and triphenylphosphine-mediated intermolecular, reductive amination between nitroarenes and boronic acids at ambient temperature without any photocatalyst. Mechanistically, a slow reduction of nitroarenes to a nitroso and, finally, a nitrene intermediate occurs that leads to the amination product with concomitant 1,2-aryl/-alkyl migration from a boronate complex. A wide range of nitroarenes underwent C-N coupling with aryl-/alkylboronic acids providing high yields.

Automated summary

This method enables a metal-free, visible-light- and triphenylphosphine-mediated intermolecular reductive amination between nitroarenes and boronic acids at ambient temperature without any photocatalyst. Mechanistically, a slow reduction of nitroarenes to a nitroso and, finally, a nitrene intermediate occurs that leads to the amination product with concomitant 1,2-aryl/alkyl migration from a boronate complex. A wide range of nitroarenes underwent C-N coupling with aryl/alkylboronic acids providing high yields.