Kangkan Pradhan, Sourav Mandal, Kartic Manna, Ranjan Jana
We disclose herein an expedient protocol for the photoinduced, metal-free reductive C–N coupling of these challenging substrates, accessing a series of diarylamine-based and N-alkylated medicinal scaffolds.
Despite significant progress, metal-free reductive C–N coupling with ortho -substituted nitroarenes and alkyl boronic acids as coupling partners remains unknown. We disclose herein an expedient protocol for the photoinduced, metal-free reductive C–N coupling of these challenging substrates, accessing a series of diarylamine-based and N-alkylated medicinal scaffolds. Remarkably, the alkyl boronic acids, which were inefficient in earlier reports due to sluggish 1,2-migratory aptitude, also furnished excellent yields (up to 98%). In addition, DFT studies show that ortho -substituted nitroarenes require higher energy for n → π* photoexcitation to initiate the reaction, demanding a longer reaction time compared to those of electron-rich nitroarenes. The reaction is scalable and proceeds smoothly under renewable sunlight irradiation.