Selective hydrogen isotope exchange on sulfonamides, sulfilimides and sulfoximines by electrochemically generated bases

We present a mild, metal-free electrochemical method to selec-
tively add deuterium to the position α of the sulfur atom in sulfo-
namides, sulfilimides, and sulfoximines using a simple two-elec-
trode setup under galvanostatic conditions. Our method is based
on readily available NMR solvent DMSO-d6 as the deuterium
source and reusable glassy carbon electrodes. A low current
density ensures functional group tolerance and enables selective
incorporation of deuterium into pharmaceutically relevant moi-
eties. With deuterium incorporation up to 97% the method stands
out as a new possibility to label molecules electrochemically
without the use of toxic and expensive transition-metal catalysts.