Département de chimie moléculaire

New chiral nitroxides based on the imidazolidin-4-one skeleton, and the corresponding hydroxylamines, were prepd. from cyclic nitrones by a straightforward reaction sequence. They were evaluated as catalysts in the aerobic oxidn. of benzyl alc. using different co-catalysts. Both the imidazolidinone nitroxides and hydroxylamines were shown to catalyze the reaction, with the ring substituent having an effect depending on the co-catalytic system. In some cases, rapid oxidn. to benzaldehyde was accomplished at room temp. under an oxygen atm. Moreover, atroposelective desymmetrization was achieved during the aerobic oxidn. of a diol catalyzed by an enantiopure imidazolidinone nitroxide. Finally, the electrochem. behavior of the new hydroxylamines and nitroxides was investigated by cyclic voltammetry, which gave insights into the obsd. catalytic properties. [on SciFinder(R)]