Iron(II)-Catalyzed Azidotrifluoromethylation of Olefins and N‑Heterocycles for Expedient Vicinal Trifluoromethyl Amine Synthesis

We
report herein an iron-catalyzed azidotrifluoromethylation method
for expedient vicinal trifluoromethyl primary-amine synthesis. This
method is effective for a broad range of olefins and N-heterocycles,
and it facilitates efficient synthesis of a wide variety of vicinal
trifluoromethyl primary amines, including those that prove difficult
to synthesize with existing approaches. Our preliminary mechanistic
studies revealed that the catalyst-promoted azido-group transfer proceeds
through a carbo-radical instead of a carbocation species. Characterization
of an active iron catalyst through X-ray crystallographic studies
suggests that in situ generated, structurally novel iron-azide complexes
promote the oxidant activation and selective azido-group transfer.