Copper-Catalyzed Skeletal Rearrangements of O-Propargylic Oximes via Cleavage of a Carbon-Oxygen Bond

In this account, we describe recent developments in copper-catalyzed skeletal 2,3-rearrangement reactions of O-propargylic oximes to form four-membered cyclic nitrones, pyridine N-oxides, and amidodienes via N-allenylnitrone intermediates. The sequence of events leading up to our encounter with O-propargylic oximes is also presented.