Scalable electrochemical oxidant-and metal-free dehydrogenative coupling of S–H/N–H

Abstract

The synthesis of sulfenamides via the oxidant- and metal-free electrochemical dehydrogenative coupling reaction of thiols and amines.

Efficient Synthesis of Sulfenamides through Mitsunobu‐type Coupling Reaction of Thiols with Amines using Dibenzyl Azodicarboxylate

“…dibenzyl azodicarboxylate (DBAD) with 3 equiv. thiomorpholine 2 a in DMF (0.06 M) at r.t. for 3 h to obtain 2‐(thiomorpholinothio)benzo[ d ]thiazole 3 a (Table , entry 1). Despite obtaining the mixture of 3 a and disulfide 4 a , the desired product 3 a was afforded and its structure was confirmed using 1 H NMR spectroscopy.…”

“…We explored the suitability of the reaction for synthesizing various sulfenamides starting with the appropriate thiols (Scheme ). Similarly, utilizing morpholine, 1‐methylpiperazine, and piperidine as coupling partners, the corresponding products 3 b , 3 c , and 3 d were obtained in yields of 87%, 66%, and 68%, respectively. Different ring‐sized secondary amines such as pyrrolidine, and azepane, were reacted with thiol 1 a to produce the adducts 3 e and 3 f in good yields (47% and 42%, respectively).…”

“…Similarly, utilizing morpholine, 1‐methylpiperazine, and piperidine as coupling partners, the corresponding products 3 b , 3 c , and 3 d were obtained in yields of 87%, 66%, and 68%, respectively. Different ring‐sized secondary amines such as pyrrolidine, and azepane, were reacted with thiol 1 a to produce the adducts 3 e and 3 f in good yields (47% and 42%, respectively). As well as secondary amines, primary amines bearing ethyl or benzyl moieties were used to form the desired products 3 g and 3 h in excellent yields (96% and 88%, respectively).…”

“…Different ring‐sized secondary amines such as pyrrolidine, and azepane, were reacted with thiol 1 a to produce the adducts 3 e and 3 f in good yields (47% and 42%, respectively). As well as secondary amines, primary amines bearing ethyl or benzyl moieties were used to form the desired products 3 g and 3 h in excellent yields (96% and 88%, respectively). In the case of less sterically hindered amines possessing cyclopropyl, cyclopentyl or cyclohexyl groups, 3 i , 3 j , and 3 k were generated in excellent yields (88% to 96%).…”

Electrochemical Synthesis of 1,2,4‐Thiadiazoles through Intermolecular Dehydrogenative S‐N Coupling

“…The S−N moiety exists in a series of bioactive compounds, such as sulfonamides, thiadiazoles. The recent decade has witnessed great progress made on oxidative S−N bond formation . However, the use of stoichiometric oxidants or transition metals is usually required.…”