Iodonium salts in organic synthesis

Abstract

Hypervalent iodine compounds have found wide practical application as versatile, efficient, and sustainable reagents for organic synthesis. The preparation and reactions of diaryliodonium, alkenyl(aryl)iodonium, alkynyl(aryl)iodonium, and alkyl(aryl)iodonium salts are overviewed. Application of these reagents allows mild and highly selective arylations, alkenylations, alkynylations, and alkylations of various organic and inorganic substrates in a facile and environmentally friendly manner. The lecture also summarizes the chemistry of iodonium ylides with emphasis on their synthetic applications. Iodonium ylides have found synthetic application as efficient carbene precursors, especially useful as reagents for cyclopropanation of alkenes and preparation of heterocyclic compounds. Recently iodonium ylides have been utilized as efficient reagents in the thiotrifluoromethylation and nucleophilic fluorination reactions. Also summarizes the applications of iodonium compounds in the rapidly developing field of Positron Emission Tomography (PET). Reactions ofdiaryliodonium salts with fluoride anion have found wide practical application in PET as a fast and convenient method for the introduction of the radioactive [18F]-fluoride into radiotracer molecules. The best synthetic methods for the preparation of iodonium precursors for PET are described, the mechanistic aspects of nucleophilic fluorination reaction are discussed, and specific examples of the preparation of PET radioligands are provided.