Cobalt-Catalyzed Cycloamination: Synthesis and Photophysical Properties of Polycyclic N-Heterocycles

The first earth-abundant cobalt-catalyzed cycloamination of indolylquinones and various (hetero)aromatic amine under ligand-free conditions for the synthesis of polycyclic N-heterocycles has been developed. The process allows facile access to polycyclic N-heterocycles with tolerance of chloride, bromide, amino, thio, etc. groups in moderate to high yields (up to 89%). In addition, The photophysical properties of the synthesized products were evaluated. These products exhibit interesting fluorescence properties, which is promising for fluorescent probes.