Concentrated Aqueous Peroxodicarbonate: Efficient Electrosyn- thesis and Use as Oxidizer in Epoxidations, S-, and N-Oxidations

Peroxodicarbonates are of substantial interest as potentially powerful and sustainable oxidizers but have so far been accessible only in low concentrations with unsatisfactory energy efficiency. Concentrated (> 0.9 mol L^-1 ) peroxodicarbonate solutions have now been made accessible by the electrolysis of aqueous K₂ CO₃ /Na₂ CO₃ /KHCO₃ solutions at high current density of 3.33 A cm^-2 in an efficiently cooled circular flow reactor equipped with a boron-doped diamond anode and a stainless-steel cathode. Their synthetic potential as platform oxidizers was clearly demonstrated in transformations including sulfoxidation, N-oxidation, and epoxidation.