Ammonium hypoiodite

Ammonium hypoiodites are a class of reactive intermediates used in certain organic oxidation reactions. They consist of either ammonium itself or an alkylammonium with various substituents as cation, paired with a hypoiodite anion as the active oxidant. The hypoiodite is generated in situ from the analogous iodide reagent using peroxides, oxone, peracids, or other strong oxidizing agents.^[1] The hypoiodite is then capable of oxidizing various organic substrates. The iodide is regenerated, meaning the reaction runs with the iodide/hypoiodite as a catalyst in the presence of excess of the original strong oxidizing agent.

Ammonium hypoiodites are capable of oxidizing benzylic methyl groups,^[2] initiating oxidative dearomatization,^[3] and oxidative decarboxylation of β-ketolactones.^[4] Similar to the β-ketolactone reaction, oxidative ether formation can be performed at the alpha position of various ketones. Using chiral ammonium cations can give high enantioselectivity of the alpha-etherification reaction, an example of an efficient chiral metal-free organocatalysis process.^[5][6]

Several guanidinium hypoiodites can also be used in the various oxidative-coupling reactions. The guanidinium cation has the added benefit of forming multiple ionic interactions or hydrogen bonds to the substrates.^[7] The conjugate acid of triazabicyclodecene is especially effective.