The partial anodic oxidation of n-alkanes in acetonitrile and trifluoroacetic acid

Abstract

The partial anodic oxidation of several n-alkanes at a smooth platinum electrode in acetonitrile or trifluoroacetic acid containing a tetra-alkylammonium tetrafluoroborate as the electrolyte have been studied. In both media these hydrocarbons give well-formed oxidation waves and a detailed investigation of the oxidation of n-octane in acetonitrile showed that at high potentials the electrode reaction is a diffusion-controlled two electron process while on the rising portion of the i–E curve, electron transfer is rate determining. Preparative electrolyses showed that in both acetonitrile and trifluoroacetic acid, the initial products of the electrode reaction are secondary carbonium ions which then react rapidly with the solvents to give mixtures of isomeric N-s-alkylacetamides (total yield 35–40%) and isomeric s-alkyl trifluoroacetates (total yields 50–80%) respectively.