[Synthesis and reaction of hypervalent λ3-iodane-crown ether complexes]

In this review, we show that intermolecular hypervalent I(III)…O interactions play an essential role in the complexation of organo-λ(3)-iodanes with crown ethers. In addition to the well-known driving force for the complexation of crown ethers, ion-dipole interaction, and hydrogen bonding interaction, our result provides a new class of interaction in supramolecular chemistry of crown ethers. Both solid state structure analysis and solution chemistry indicate that diaryl-, 1-alkenyl(phenyl)-, 1-alkynyl(phenyl)-, and hydroxy(phenyl)-λ(3)-iodanes form stable complexes with 18-crown-6 through hypervalent I(III)…O interactions. The complexation not only increases the stability of these hypervalent λ(3)-iodanes but also holds its high reactivity toward nucleophiles. The complex of hydroxy(phenyl)-λ(3)-iodanes with 18-crown-6 serve as versatile oxidizing agents, especially in water.