Visible-light-induced radical cascade sulfonylation/cyclization towards indole-fused pyridine derivatives

Abstract

Indole-fused pyridines are an important motif in pharmaceuticals and functional molecules. A visible-light induced Ru(bpy)₃Cl₂·6H₂O catalyzed radical cascade sulfonylation/cyclization strategy for the synthesis of indole-fused pyridine derivatives was developed. Diverse indole-fused pyridines bearing different functional groups were obtained in moderate to good yields. Compared with previous work, the easily accessible starting materials, molecular nitrogen as byproduct, and eco-friendly visible light as an energy source all make this transformation more sustainable and practical.