Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes
Yao Liu, Jilin Li, Xu‐Ge Liu, Jia‐Qiang Wu, Zhi‐Shu Huang, Qingjiang Li, Honggen Wang
Abstract
Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.
Topics & Concepts
ChemistryCarbeneBoraneCombinatorial chemistryFunctional groupMedicinal chemistryOrganic chemistryCatalysisPolymerCatalytic C–H Functionalization MethodsOrganoboron and organosilicon chemistryRadical Photochemical Reactions