Efficient electrosynthesis of sulfinic esters via oxidative cross‐coupling between alcohols and thiophenols

Abstract

A new protocol for SO bond formation was developed by electrochemical oxidative cross‐coupling between alcohols and thiophenols. With this strategy, a series of valuable sulfinic ester derivatives were synthesized up to 96% yield from basic starting materials. A preliminary mechanistic investigation reveals that this reaction involves oxygen reduction reaction (ORR).

Strategies for the direct oxidative esterification of thiols with alcohols

“…Four decades later, Gong and Lu along with their co-workers developed a robust electrochemical oxidative cross-coupling between thiophenols 4 and aliphatic alcohols 5 for the synthesis of alkyl benzenesulnates 6. 21 In an undivided cell assembled with a graphite rod anode and platinum plate cathode, the best reaction conditions were achieved with tetrabutylammonium tetrauoroborate ( n Bu 4 NBF 4 ) as the electrolyte and acetonitrile as the solvent, with a constant current of 12 mA under air atmosphere at room temperature (Scheme 2b). A broad reaction scope was evaluated by testing different groups on the thiophenol ring (e.g., OMe, F, Cl, Br), as well as a variety of aliphatic (primary and secondary) alkyl/benzyl alcohols.…”

Electrochemical synthesis of sulfinic and sulfonic esters from sulfonyl hydrazides

“…Representative methods for synthesizing sulfinic esters include the condensation of sulfinic acids with alcohols, 5 substitution reactions involving alcohols and sulfinic acid derivatives (such as sulfinic acid chlorides, sulfoxides, and sulfonyl hydrazides), 6 the oxidation of disulfides in the presence of alcohols, 7 and the oxidative esterification of thiols and alcohols. 8…”

Electrochemical oxidative selective halogenation of pyrazolones for the synthesis of 4-halopyrazolones

“…Electro-organic synthesis has risen to become a favored and eco-friendly approach for assembling molecular complexity, eliminating the requirement for stoichiometric chemical redox agents. [21][22][23][24][25][26][27] In recent years, there have been significant breakthroughs in the field of electrochemical halogenation. [28][29][30][31][32][33][34][35][36] To our best knowledge, the electrochemical oxidative halogenation of pyrazolones remains uncharted territory.…”