Iron(II)‐Catalyzed Site‐Selective Functionalization of Unactivated C(sp3)−H Bonds Guided by Alkoxyl Radicals

: An alkoxyl radical guided strategy for site-selective functionalization of unactivated methylene and methine C-H bonds enabled by an FeII -catalyzed redox process is described. The mild, expeditious, and modular protocol allows efficient remote aliphatic fluorination, chlorination, amination, and alkynylation of structurally and electronically varied primary, secondary, and tertiary hydroperoxides with excellent functional-group tolerance. The application for one-pot 1,4-hydroxyl functionalization of non-oxygenated alkane substrates initiated by aerobic C-H oxygenation is also demonstrated.