Intramolecular H-bond stabilization of a primary hydroxylamine in salen-type metal complexes.

Primary hydroxylamines, RNHOH, decompose readily in the presence of transition metal ions. We show that this reactivity can be arrested by ligand design via an intramolecular hydrogen bond. Six metal complexes with an intact NHOH group were synthesized and crystallographically characterized. The Cu-hydroxylamine complexes can catalyze the aerobic oxidation of benzylic alcohols.