Light-fuelled nitro-reduction via cascaded electron donor–acceptor complexes in aqueous media

Abstract

The photochemistry of EDA complexes is initiated from a ground-state associate with a biomolecule capable of intermolecular electron transfer by channelling chemical synthesis via a specific radical-based mechanistic pathway. Herein, we activate the innovative cascade mode of EDA complex photoexcitation for nitro-reduction in aqueous media using charge transfer interactions between a sole donor and multiple acceptors (ArNO₂, ArNO, and ArNHOH·glycine adduct). A triplet-state quenching experiment, UV-vis analysis, NMR titration, and preliminary kinetic investigation verified the rationality and feasibility of the mechanism. With successful applications of this cascaded system in arylamine compounds and commercially available drug synthesis (61 examples), these achievements highlight the attractiveness, usefulness, and effectiveness of this protocol.