Light-Promoted C-N Coupling of Aryl Halides with Nitroarenes

A photochemical C-N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a Ni-II complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald-Hartwig C-N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a Ni-I/Ni-III cycle, to a nitrosoarene intermediate.

Automated summary

This study demonstrates a photochemical C-N coupling of aryl halides with nitroarenes for the first time, catalyzed by a Ni-II complex in the absence of any external photosensitizer. The method provides a step-economic extension to the widely used Buchwald-Hartwig C-N coupling reaction and tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest the reaction proceeds via the addition of an aryl radical, generated from a Ni-I/Ni-III cycle, to a nitrosoarene intermediate.