2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) was reacted with ethylbenzene (1a), 1-bromo-4-ethylbenzene (1b), and 4-ethylphenyl acetate (1c), respectively, using tert-BuOOH/Co(OAc).4H(2)O in acetonitrile at room temperature. The reactions produced the respective TEMPO-adducts (2a, 2b, and 2c) in the yields of 37, 44, and 45 %, which were based on TEMPO. Similarly, TEMPO was reacted with 4-ethylphenyl 2,3,6,2',3',4',6'-hepta-O-acetyl-beta-D-cellobioside (1d) to afford the glycoconjugated TEMPO-adduct (2d) in 45 % yield, which was based on 1d. These results indicated that the reaction has the potential to become an easy and also safe strategy, which provided various functionalized alkoxylamines.