Visible Light‐Induced Radical‐Radical Coupling: One‐Pot Synthesis of 6‐Benzyl‐6‐hydroxyindolo[2,1‐<i>b</i>]quinazolin‐12(6<i>H</i>)‐ones from Isatins and Potassium Benzyl Trifluoroborates
Lan‐Qian Huang, Chun‐Lin Dong, Yan‐Hong He, Zhi Guan
Abstract
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
Topics & Concepts
ChemistryPotassiumCombinatorial chemistryPhotochemistryMedicinal chemistryOrganic chemistryQuinazolinone synthesis and applicationsPhenothiazines and Benzothiazines Synthesis and ActivitiesRadical Photochemical Reactions