5905-61-3Relevant academic research and scientific papers
A comparison between nitroxide and hydrazyl free radicals in selective alcohols oxidation
Shakir, Ahmed J.,Madalan, Augustin M.,Ionita, Gabriela,Lupu, Stelian,Lete, Cecilia,Ionita, Petre
, p. 7 - 11 (2017)
Literature data are abundant in oxidations catalyzed by nitroxides free radicals, while hydrazyls free radicals are very seldom encountered. In this work we made a comparison between some nitroxides and hydrazyl free radicals towards the ability to selectively oxidize activated alcohols to the corresponding carbonyl derivatives. As nitroxides we used 2,2,6,6-tetramethylpirrolidin-N-oxide (TEMPO) and phtalimide-N-oxyl (PINO) free radicals, while as hydrazyls were used 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-p-nitrophenyl-1-picrylhydrazyl (DN-DPPH). The differences in the physico-chemical properties between nitroxides and hydrazyls were evaluated by UV–vis, EPR and cyclic voltammetry. For DN-DPPH the X-ray crystal structure was resolved. It has been shown that a nitroxide radical is a far better catalyst in such aerobic oxidations comparatively with a hydrazyl one. The explanation of these results consists firstly in a different mechanism involved in the oxidation procedures and secondly in the variation of the oxidation potentials of nitroxides comparatively with hydrazyls.
Preparation of 2,2-diaryl-1-picrylhydrazyls using potassium permanganate
Brown, K. C.,Weil, J. A.
, p. 1836 - 1838 (2007/10/02)
Potessium permanganate is used as a reagent for the oxidation of various 2,2-diaryl-1-picrylhydrazines to their corresponding hydrazyls.Thin-layer chromatography indicates complete oxidation of the hydrazine to free radical, unlike the case with PbO2 (the most widely used oxidant for this purpose).Several other advantages over previous oxidants used to produce the hydrazyls are offered.
