Visible Light‐Induced Radical‐Radical Coupling: One‐Pot Synthesis of 6‐Benzyl‐6‐hydroxyindolo[2,1‐b]quinazolin‐12(6H)‐ones from Isatins and Potassium Benzyl Trifluoroborates

Abstract A method for one‐pot synthesis of 6‐benzyl‐6‐hydroxyindolo[2,1‐ b ]quinazolin‐12(6 H )‐ones from isatins and potassium benzyl trifluoroborates was developed. Bioactive tryptanthrin skeleton can be constructed by visible light‐induced radical‐radical cross coupling, in which C−C and C−N bonds are formed in one pot. With this method, 31 products were synthesized directly from isatins in 22–86% yields. Notable features of this method include mild reaction conditions, metal‐ and external oxidant‐free, and direct construction of high‐value complex structures from inexpensive and readily available starting materials. magnified image