Hypervalent Iodine Chemistry

Iodine is one of the heaviest non-radioactive elements in the Periodic Table classified as a non-metal, and it is the largest, the least electronegative, and the most polarizable of the halogens. Structural features and reactivity pattern of hypervalent iodine compounds in many aspects are similar to the derivatives of transition metals, and the reactions of hypervalent iodine reagents are commonly discussed in terms of oxidative addition, ligand exchange, reductive elimination, and ligand coupling, which are typical of the transition metal chemistry. Hypervalent iodine compounds are now widely used in organic synthesis as efficient and environmentally sustainable reagents for various oxidative transformations of organic substrates.

The lecture will summarize our research on the development of new hypervalent iodine reagents with improved physical properties and reactivity by changing coordination sphere at the iodine center. In particular, we have developed several powerful oxidants and atom-transfer reagents based on the hypervalent iodine system of benziodoxole. We have also designed the soluble and highly reactive pseudocyclic hypervalent organoiodine imides and ylides, which are efficient nitrene and carbene precursors and can be used as reagents for aziridination and cyclopropanation of alkenes and for the preparation of oxazole derivatives. Our studies on the development of recyclable hypervalent iodine reagents and catalytic systems based on hypervalent iodine compounds will also be presented.