9-Azanoradamantane N-oxyl, Nor-AZADO
9-Azanoradamantane N-oxyl (Nor-AZADO) is a less hindered nitroxyl radical, that exhibits an enhanced reactivity compared with TEMPO.
The use of tert-butyl nitrite as the co-catalyst in a 2-azaadamantane-N-oxyl (AZADO)- and 9-azanoradamantane-N-oxyl (nor-AZADO)-catalyzed efficient aerobic oxidation of primary alcohols in MeCN instead of the previously reported AcOH provides the corresponding aldehydes selectively. The addition of saturated aqueous NaHCO3 after the completion of the reaction suppresses the overoxidation of the product during the workup.
M. Shibuya, K. Furukawa, Y. Yamamoto, Synlett, 2017, 28, 1554-1557.
A nitroxyl-radical-catalyzed oxidation using diisopropyl azodicarboxylate (DIAD) allows the conversion of various primary and secondary alcohols to their corresponding aldehydes and ketones without overoxidation to carboxylic acids. 1,2-Diols are oxidized to hydroxyl ketones or diketones depending on the amount of DIAD used.
M. Hayashi, M. Shibuay, Y. Iwabuchi, J. Org. Chem., 2012, 77, 3005-3009.
A series of α-diketones were readily prepared by the nitroxyl-radical-catalyzed oxidation of silyl enol ethers using magnesium monoperoxyphthalate hexahydrate (MMPP • 6 H2O) as the co-oxidant.
M. Hayashi, M. Shibuya, Y. Iwabuchi, Synlett, 2012, 23, 1025-1030.