Oxidation of arylamidoximes by various chemical and biomimetic systems: comparison with their oxidations by hemeproteins

Oxidation of 4-chlorobenzamidoxime by various chemical systems leads to the corresponding amide and nitrile, and to three dimeric compounds in greatly variable amounts as a function of the oxidizing agent. Monoelectronic oxid ants, such as Pb(OAc)(4) and Ag2CO3, selectively led to 4-chlorobenzonitril e, whereas hydroperoxides such as H2O2 and tBuOOH only led to 4-chlorobenza mide. Other oxidants like m-chloroperbenzoic acid and Br-2 gave more comple x mixtures. Introduction of an iron-porphyrin catalyst in the oxidation per formed by tBuOOH and m-chloroperbenzoic acid resulted in a spectacular incr ease of the formation of 4-chlorobenzonitrile. These results suggest that h igh-valent porphyrin iron-ore species preferentially oxidize arylamidoximes in a manner similar to monoelectronic oxidants. (C) 2000 Academie des Scie nces/Editions scientifiques et medicales Elsevier SAS.