Chemo- and Enantioselective Oxidative α-Azidation of Carbonyl Compounds.

We report a high-performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α-azidation of carbonyl compounds by using sodium azide under biphasic neutral phase transfer conditions.   To induce higher reactivity especially for the α-azidation of 1,3-dicarbonyls, we designed a structurally compact isoindoline-derived quaternary ammonium iodide catalyst bearing electron-withdrawing groups.   In addition, the non-productive decomposition pathways of I+/H2O2 catalysis could be suppressed by the use of a catalytic amount of a radical trapping agent.   This oxidative coupling tolerates a variety of functional groups and could be easily applied to the late-stage α-azidation of structurally diverse complex molecules.   Moreover, we achieved the enantioselective α-azidation of 1,3-dicarbonyls, as the first successful example of enantioselective intermolecular oxidative coupling using chiral hypoiodite catalysis.