Redox-Neutral Imination of Alcohol with Azide: A Sustainable Alternative to the Staudinger/Aza-Wittig Reaction

The traditional Staudinger/aza-Wittig
reaction represents one of
the most powerful tools for imine formation. However, for this multistep
procedure, the sacrificial phosphine has to be used, resulting in
difficulties in the purification process and waste disposal at the
same time. Here, we report a redox-neutral azide–alcohol imination
methodology enabled by a base-metal nickel PN3 pincer catalyst.
The one-step, waste-free, and high atom-economical features highlight
its advantages further. Moreover, mechanistic insight suggests a non-metal–ligand
cooperation pathway based on the observation of an intermediate and
density functional theory calculations.