g-C3N4 catalysed sustainable synthesis of (hetero)aryl acids and regioselective α-bromo ketones in one pot under visible light catalysis

Abstract

Heterogeneous metal-free 2D semiconductor g-C₃N₄ with outstanding electronic characteristics is an emerging alternative redox catalyst to conventional thermochemical catalysts, where it functions as a high-performance photocatalyst towards a sustainable synthesis of high-value organic molecules. Herein, we reported the excellent activity of g-C₃N₄ toward the selective oxidation of (hetero)aryl methyl halides to (hetero)aryl carboxylic acids under sunlight with oxygen molecules in air as a benign oxidant. To ensure maximum atom efficiency, the generated by-product HBr can be reutilized for the synthesis of α-bromo ketones with zero effluent discharge, signifying an eco-friendly process. g-C₃N₄ features a remarkable enhancement in performance for the selective photocatalytic oxidation of (hetero)aryl methyl halide with subsequent generation of α-bromo ketones in one pot with an excellent isolated yield of 90–97%.