Study On Visible-light Catalyzed Radical Cyclization Of Isocyanides With Aryldiazonium Salts

Phenanthroline derivatives and isoquinoline derivatives,as two kinds of compounds with biological activities and medicinal value,can be widely used in the field of drug synthesis and optoelectronic device materials.The main research includes two sections:visible light catalyzed cyclization of aryldiazonium in situ with biphenyl isonitrile compounds to synthesize phenanthroline derivatives and visible light induced cyclization of diazonium in situ with vinyl isonitrile compounds to synthesize isoquinoline derivatives.Phenanthroline derivatives are a kind of compounds with variety of drug activities and biological activities,and the core skeleton structure of phenanthroline also exists in many natural products with valuable applications.At the same time,it is also an important structural unit in organic synthesis,so it is of great significance to explore the synthetic method of phenanthroline derivatives.In section one,after screening solvents,bases and reaction times,and the optimal conditions are obtained:0.4 mmol biphenyl isonitrile,1.2 mmol aniline,1mol%Ru（bpy）₃（PF₆）₂,2.0 mmol t-BuONO,0.44 mmol NaOAc and dry MeCN at room temperature in the atmosphere of Ar under the irraditon of blue LED for 12 h.This method has the advantages of using cheap and stable raw materials,mild conditions,and good tolerance for functional groups.Section two focuses on the photocatalyzed arylative cyclization between vinyl isonitrile and diazonium in situ.Isoquinoline compounds are important skeleton structures in natural products.They have important medicinal value for analgesia and pain relief,and functional isoquinoline compounds are also excellent ligands for phosphorescence emitters in organic light-emitting diodes（OLEDs）.Therefore,the synthesis of isoquinoline compounds with mild conditions and environmental friendliness has important application value.After screening solvents,bases,and light,the optimal reaction conditions was obtained:0.2 mmol isonitrile,0.6 mmol aniline,5 mol%Eosin B,0.22 mmol Na₂HPO₄,dry DMSO,in the atmosphere of Ar for 12 h with the irraditon of green LED.With the optimal conditons in hand,we investigate the scope of substrate preliminarily.