Halogen and Chalcogen Transfer Chemistry

Abstract

AbstractAtom transfer reactions have become an indispensable tool for carbon–carbon bond formations. Atom transfer radical addition (ATRA) reactions were first discovered by Kharasch and coworkers in the year 1945. This type of transformations did not receive much attention until the mid‐1980s when Curranet al.first demonstrated the atom transfer radical cyclization (ATRC) reactions and their application in the synthesis of (±)‐hirsutene. Enormous progress has been made since then. Reactions involving transfer of halogens (I, Br, Cl) and chalcogens (SePh and TeAr) have been developed, providing a powerful, atom‐economic, and nonreductive complement to the tin hydride method for conducting radical addition reactions. The introduction of Lewis acids increases the efficiency and regio‐ and stereoselectivity in many cases. Transition‐metal catalysis, in combination with reducing agents, makes the ATRA and ATRC reactions more efficient and environmentally friendly. In this article, the versatile chemistry of halogen (I, Br, Cl) and chalcogen (PhSe and ArTe) transfer involving carbon–carbon bond formation is discussed.