A decade of lessons in the activation of ArIL species.

Hypervalent iodine(iii) compounds of the general structure ArIL are widely used as oxidizing agents for a variety of applications across both organic and inorganic chemistry. Considerable work has been done on the activation of these compounds by tuning the ligands at the iodine centre. This perspective summarises the work of our and other groups on rectification of historically misidentified iodine(iii) reagents of this class, and the syntheses of activated species.

Electrophilic activation of molecular bromine mediated by I(III).

In pursuit of a genuine bromo-λ-iodane, it has been found that the combination of Br and electron deficient λ-iodanes can result in the delivery of both bromine atoms from Br to a range of aryl substrates, some highly deactivated. These brominations occur rapidly in common chlorinated solvents at room temperature and can be achieved with the catalytic activation of commercially available PhI(OAc) and PhI(OTFA). -NO substituted derivatives are employed to direct bromination towards more deactivated substrates.

C-H, Si-H and C-F abstraction with an extremely electron poor I(III) reagent.

The recently discovered I(III) reagent NO-CH-I(OTf) is found to rapidly react with hydride sources, including HSiEt and relatively hydridic C-H precursors. These represent the first distinct reactions involving direct hydride abstraction by I(III) under ambient conditions. Direct C-F abstraction is also demonstrated, as well as oxidation of cyclic alkenes to aromatic rings, all representing new reactions for I(III) demonstrating the very high reactivity of NO-CH-I(OTf).

Synthesis, structural characterization, reactivity and catalytic activity of mixed halo/triflate ArI(OTf)(X) species.

Both mixed λ-iodoarenes and λ-iodoarenes possessing -OTf ligands are coveted for their enhanced reactivities. Here we describe the synthesis, reactivity, and comprehensive characterisation of two new ArI(OTf)(X) species, a class of compound that were previously only invoked as reactive intermediates where X = Cl, F and their divergent reactivity with aryl substrates. A new catalytic system for electrophilic chlorination of deactivated arenes using Cl as the chlorine source and ArI/HOTf as the catalyst is also described.