Copper-Mediated Hydroxylation of Arenes and Heteroarenes Directed by a Removable Bidentate Auxiliary

A copper-mediated
C–H hydroxylation of arenes and heteroarenes
using our newly developed PIP directing group has been developed.
This procedure is scalable and compatible with a wide range of functional
groups and heteroarenes, providing an operationally simple protocol
for the synthesis of o-hydroxybenzamides. The hydroxylation
of nicotinamides gave 4-oxo-1,4-dihydropyridine-3-carboxamides selectively.
Preliminary mechanistic studies implicate that a basic ligand-enabled,
irreversible, rate-determining CMD step is most likely involved in
this process.