Triiodide-Mediated δ-Amination of Secondary C-H Bonds

The C-delta-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.