Visible light-mediated direct C8-H arylation of quinolines and C2-H arylation of quinoline-N-oxides and pyridines under organic photocatalysis

CH-arylated quinolines have found widespread applications in drug discovery as well as in the field of fine chemicals and material science. Herein, we report a general, transition-metal-free, environmentally friendly photocatalytic strategy for the direct C-H arylation of quinolines and quinoline N-oxides/pyridines selectively at the C-8 and C-2 positions, respectively, using chlorophyll as the organic photocatalyst. This method offers a simple, practical route for direct access to C8-aryl quinolines, C2-aryl pyridines, and quinoline N-oxides. The key advantages of the present protocol include operational simplicity, the use of clean energy sources, low reagent costs, and no requirement of pre-functionalized substrates.