The electrochemistry of TEMPO-mediated oxidation of alcohols in ionic liquid

摘要: The detailed electrochemistry of TEMPO-mediated oxidation alcohols to carbonyl compounds in ionic liquid medium is presented. It shown that TEMPO diffusion currents are suppressed IL medium, relative acetonitrile solvent, due the high viscosity medium; however, presence substrate and base reagent significantly reduces viscosity, improving performances significantly. Cyclic voltametry shows kinetics reaction between electrooxidized alcohol similar both media. was also observed case where product non-enolizable, electrolyses (diaphragm cell) with catalytic quantities TEMPO, (2,6-lutidine), results close 100% Faradaic chemical efficiencies. In contrast, prolonged electrolysis yielding enolizable products catalyst deactivation irreversible active form product, which ultimately leads low yields loss. Under these circumstances, reasonable selectivities can only be obtained partial (to ≤1F/mol).