Cu-Catalyzed tandem N-arylation of phthalhydrazides with cyclic iodoniums to yield dihydrobenzo[c]cinnolines

Abstract

Dihydrocinnolines have significant pharmacological properties. Herein, we investigate a Cu-catalyzed tandem N-arylation reaction of phthalhydrazides with cyclic iodonium salts to construct dihydrobenzo[c]cinnoline derivatives. Various iodonium salts, such as symmetrical, unsymmetrical, aryl–aryl, and aryl–heteroaryl ones, could react with phthalhydrazides smoothly and give the title products in moderate to high yields. Moreover, the –NH₂ group, which has been diarylated by cyclic iodonium salts to form carbazoles in previous reports, is also well tolerated in this work.