Iodanyl Radical Catalysis Enables Ring‐Opening and δ‐C─H Functionalization of Aliphatic Alcohols

Iodanyl radical catalysis offers distinct reactivity beyond conventional two‐electron hypervalent iodine manifolds. However, existing catalytic protocols rely predominantly on complex bis‐iodoarene platforms to stabilize radical intermediates, whereas simple monodentate aryl iodides remain poorly developed due to off‐cycle pathways. Herein, we report that 2‐iodopyridine serves as a highly efficient organo‐iodine catalyst for photocatalytic iodanyl radical catalysis under mild, redox‐neutral, and metal‐free conditions. Integrated within a visible‐light photoredox cycle, this protocol achieves direct single‐electron activation of unfunctionalized aliphatic alcohols to generate reactive alkoxy radical intermediates. This dual catalytic manifold facilitates both ring‐opening functionalization of cyclic alcohols via β‐scission and site‐selective δ‐C─H functionalization of linear alcohols through 1,5‐hydrogen atom transfer. Mechanistic investigations and radical trapping experiments support the proposed one‐electron catalytic pathway. This strategy provides an accessible and low‐cost platform for iodanyl radical catalysis, expanding the synthetic utility of native aliphatic alcohols.