Hypervalent Halogans and Their Reactions in Organic Synthesis

This review provides an overview of the chemistry of hypervalent organohalogans, organoiodanes and organobromanes, developed recently in Tokushima. Vinylic S(N)2 reactions, cyclopentene syntheses via 1,5 C-H insertion of alkylidene carbenes, reductive Claisen rearrangements, oxidations with peroxy-lambda(3)-iodanes, iodobenzene-catalyzed oxidations, oxidative cleavage of double bonds, oxidative coupling of alcohols with alkynes, Michael additions, and transylidations are involved. These reactions mostly rely on the hyperleaving group ability of aryl-lambda(3)-iodanyl, -bromanyl, and -chloranyl groups.