A Highly Recyclable Magnetic Core‐Shell Nanoparticle‐Supported TEMPO catalyst for Efficient Metal‐ and Halogen‐Free Aerobic Oxidation of Alcohols in Water

Upping the tempo! A new, stable, TEMPO‐based organocatalyst, supported on magnetic iron nanoparticles, provides a highly efficient heterogeneous catalyst 1 for the metal‐ and halogen‐free aerobic oxidation of a wide range of primary, secondary, allylic, and even sterically hindered alcohols in water. After use, the catalyst was magnetically separated (see image) and reused for 20 consecutive rounds of reaction, without any significant loss in catalytic activity.