In the fully optimized system, 5 mol% of preformed Ni(dtbpy)3Br2 complex was used as a catalyst, and a stock solution of SO2 in DMA was used as the S source. The stock solution can be conveniently prepared in-house by simply bubbling SO2 gas into the solvent, and can be stored in a sealed vessel at 4 °C. In fact, a 5.6 M solution still retained 84% of its SO2 content after repeated usage for 6 months. N,N-Diisopropylethylamine (DIPEA) and N-methylphthalimide (NMPI) (0.5 equiv each) were added to the reaction, and 3 equiv of tetra-n-butylammonium bromide (TBABr) was employed as the electrolyte. The electrolysis was performed in acetonitrile, using a standard ElectraSyn 2.0 potentiostat, with Zn anode and Ni foam cathode, at 4 mA (or 5 mA/cm 2 ) for 6 F/mol. The reaction was conducted over a nitrogen atmosphere without the need for a glovebox. To simplify the isolation and quantification of the e-sulfinylation reaction, sulfinates were converted in situ into the stable sulfonyl fluorides. Sulfonyl fluorides are a versatile functional group, capable of SuFEx Click chemistry, 58, 59 acting as a covalent warhead in protein inhibitors, 60-62 and as synthetic intermediates to other S(VI) derivatives. 42, 43, 63-69 The fluorination was optimized and performed in the same pot after sulfinylation, using inexpensive TBAF and N-chlorosuccinimide (NCS).