Hydroxylation of organoborons via uranyl photocatalysis

Aerobic oxidation of organoboron, via uranyl photocatalysis using the principle of indirect single electron transfer (i-SET), was established under mild ambient conditions, and afforded multifarious phenols and alcohols, including nine natural products/pharmaceuticals. The i-SET process between the uranyl catalyst and triethylamine (Et₃N), rather than through direct oxygen molecules (O₂), was determined through UV-visible absorption experiments, Stern-Volmer analysis, and density functional theory calculations. ¹⁸O labeling experiments showed unambiguously that the oxygen was derived from O₂. The hundred-fold efficiency of a flow operation further demonstrated the potential for scaling up the application.