From aryl chlorides to phenols: Photouranium-catalyzed hydroxylation via water splitting

The efficient conversion from aryl chlorides to phenols remains a long-standing challenge with a standard of mild reaction conditions, due to the high energy barrier for C(sp²)−Cl bond activation (Ph−Cl at ∼400 kJ/mol). Herein, we accomplished a facile hydroxylation reaction from unactivated aryl chlorides with water under ambient conditions. The photouranium-catalyzed cascade processes of single-electron transfer, hydrogen atom transfer, and oxygen atom transfer facilitated the synergistic steps of water splitting and cation-radical accelerated nucleophilic aromatic substitution, enabling the late-stage hydroxylation for pharmaceuticals with sensitive functional groups.