a,b
a Reaction conditions: Carbon rod anode (Ø = 6 mm), carbon rod cathode (Ø = 6 mm), constant current = 10 mA, undivided cell, 1a (0.5 mmol), 2 (0.8 mmol), Se (0.6 mmol), TBAI (0.5 mmol), MeCN (4 mL), H2O (2 mL), room temperature, N2, 12 h. b Isolated yield.
To showcase the application of this methodology, the electrocatalytic three-component reaction was examined by using indoles 1 , sulfinic acid sodium salts 2 and sulfur powder as substrates under the standard conditions to prepare thiosulfonates (Scheme 5). Notably, indoles 1 bearing functional groups at the aryl ring (4aa ), such as OMe (4ab and 4ac ), Me (4ad ), or F (4ae ), efficiently participated in the reaction. In addition, benzothiophen was also well compatible with this methodology (4af ). Notably, cyclohexyl-substituted sodium sulfinate was well-suited for this transformation (4ag ).
Scheme 5 Synthesis of thiosulfonates