Evolution of N‐Heterocycle‐Substituted Iodoarenes (NHIAs) to Efficient Organocatalysts in Iodine(I/III)‐Mediated Oxidative Transformations

Abstract The reactivity of ortho ‐functionalized N ‐heterocycle‐substituted iodoarenes (NHIAs) as organocatalysts in iodine(I/III)‐mediated oxidations was systematically investigated in the α ‐tosyloxylation of ketones as the model reaction. During a systematic catalyst evolution, it was found that NH‐triazoles and benzoxazoles have the most significant positive influence on the reactivity of the central iodine atom. A further catalyst improvement which focused on the substitution pattern of the arene revealed a remarkable ortho ‐effect. By introduction of an o ‐OMe group we were able to generate a novel NHIA with a so far unseen catalytic efficiency. This new catalyst is not only easy to synthesize but also enabled the α ‐tosyloxylation of carbonyl compounds at the lowest reported catalyst loading of only 1 mol%. Finally, the performance of this iodine(I) catalyst was successfully demonstrated in intramolecular oxidative couplings of biphenyls and oxidative rearrangements. magnified image