Sodium periodate/TEMPO as a selective and efficient system for amine oxidation.

A new metal-free protocol for promoting oxidation of amines in aqueous-organic medium was developed. NaIO and TEMPO as the catalyst emerged as the most efficient and selective system for oxidation of differently substituted benzyl amines to the corresponding benzaldehydes without overoxidation. Unsymmetrical secondary amines underwent selective oxidation only at the benzylic position thus realising an oxidative deprotection of a benzylic group with an easy amine recovery.