Reaction of Azides with Dichloroindium Hydride:  Very Mild Production of Amines and Pyrrolidin-2-imines through Possible Indium−Aminyl Radicals

Organic azides are easily reduced to the corresponding amines by reaction with dichloroindium hydride under very mild conditions and in a highly chemoselective fashion. γ-Azidonitriles give rise to outstanding five-membered cyclizations affording pyrrolidin-2-imines. A rationalization of the overall experimental data cannot exclude the occurrence of competitive radical and nonradical pathways, but certain results are, however, soundly consistent with the intermediacy of indium-bound nitrogen-centered radicals.