Remote C(sp3)-H Oxygenation of Protonated Aliphatic Amines with Potassium Persulfate.

This letter describes the development of a method for selective remote C(sp3)-H oxygenation of protonated aliphatic amines using aqueous potassium persulfate. Protonation serves to deactivate the proximal C(sp3)-H bonds of the amine substrates and also renders the amines soluble in the aqueous medium. These reactions proceed under relatively mild conditions (within 2 h at 80 °C with amine as limiting reagent) and do not require a transition metal catalyst. This method is applicable to a variety of types of C(sp3)-H bonds, including 3°, 2°, and benzylic C-H sites in primary, secondary, and tertiary amine substrates.