Synthesis and Application of Cyclic Diaryliodonium Salts: A Platform for Bifunctionalization in a Single Step

In recent years the chemistry of cyclic iodonium salts has experienced ever-growing development. The advantages of using cyclic iodonium salts over acyclic iodonium salts are that the reactions between cyclic iodonium salts and various nucleophiles lead, under suitable reaction conditions, to dual arylations in a one-pot manner and to the formation of new heterocycles. Variously functionalized thiophenes, carbazoles, fluorenes, phenanthrenes and triazolophenanthridines have been synthesized by utilizing cyclic diaryliodonium salts. Various new ladder-type p-conjugated systems have also been synthesized by employing cyclic iodonium salts. In this microreview, the recent advancements in the synthesis and application of cyclic diaryliodonium salts are discussed in a systematic and concise manner.