N-Heterocycle-Stabilized Iodanes: From Structure to Reactivity

Chemistry. 2018 Dec 12;24(70):18653-18657. doi: 10.1002/chem.201804957. Epub 2018 Nov 9.

Abstract

Pseudocyclic aryl-λ3 -iodanes are superior reagents for a variety of oxidative transformations due to a well-balanced relation between stability, solubility and reactivity. Their properties are substantially influenced by a dative interaction between a Lewis base, in general the oxygen atom of a carboxylic acid or an amide, and the central hypervalent iodine atom. This work presents the first systematic investigation of pseudocyclic N-heterocycle-stabilized iodanes (NHIs). The synthesis of these throughout shelf-stable solids is robust and can be achieved on a large scale. Their reactivity is highly tunable, depending on the stabilizing heterocycle. Solid state structures of selected derivatives are reported and their reactivity in a model oxygen transfer reaction is compared. Further derivatization reactions to N-heterocycle-stabilized pseudocyclic diaryliodonium salts and cyclic iodoso species are presented as well.

Keywords: heterocycles; hypervalent iodine; molecular diversity; oxidation; substituent effects.