Oxidation of N,N-Benzylalkylamines to Nitrones by Mo(VI) and W(VI) Polyperoxo Complexes

Abstract Oxidation of N,N-benzylalkylamines in chloroform by Mo(VI) and W(VI) polyperoxo complexes (PPC) of general formula Q+3{PO4[MO(O2)2]4}3− (Q+ = onium ion) yield the corresponding nitrones as oxidized products quantitatively. Only in the case of N,N-benzylmethylamine the formation of nitrone is accompanied by 25% of benzaldoxime. Oxidation of N,N-benzyltertbutylamine and N,N-benzylisopropylamine follows second order kinetics. This finding does not disqualify the hypothesis that the reaction might occur by a rate determining nucleophilic attack of the amine onto the peroxide oxygens leading, through a Bartlett-type transition state, to the probable formation of the corresponding hydrox…