A convenient nitroxyl radical catalyst for the selective oxidation of primary and secondary alcohols to aldehydes and ketones by O-2 and H2O2 under mild conditions

A new macrocyclic tetrafunctional nitroxyl radical, I, developed by Ciba Specialty Chemicals, is a particularly effective catalyst in combination with Mn(II) and Co(II) or Cu(II) nitrates for the selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones by air or O-2 under mild conditions (ambient temperature and pressure) or H2O2. A distinctive feature of I is the possibility of easy recovery and recycles, due to its low solubility, particularly as ammonium salt, in most organic solvents, which makes it especially useful for practical applications.