Copper-mediated hydroxylation of arenes and heteroarenes directed by a removable bidentate auxiliary

Abstract

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.