Triiodide‐Mediated δ‐Amination of Secondary C−H Bonds

The C δ −H amination of unactivated, secondary C−H bonds to form a broad range of functionalized pyrrolidines has been developed by a triiodide (I 3 − )‐mediated strategy. By in situ 1) oxidation of sodium iodide and 2) sequestration of the transiently generated iodine (I 2 ) as I 3 − , this approach precludes undesired I 2 ‐mediated decomposition which can otherwise limit synthetic utility to only weak C(sp 3 )−H bonds. The mechanism of this triiodide‐mediated cyclization of unbiased, secondary C(sp 3 )−H bonds, by either thermal or photolytic initiation, is supported by NMR and UV/Vis data, as well as intercepted intermediates.