Iodine/Manganese Dual Catalysis for Oxidative Dehydrogenation Coupling of Amines with Thiols

Abstract

A novel dual catalytic system of iodine and manganese is used for the first time for oxidative dehydrogenation coupling of amines with thiols during aerobic oxidation. Sulfenamides are synthesized via this approach with moderate to high efficiencies. The mechanistic studies indicate that activated MnO2 is an electron transfer bridge for assisting iodine in completing the catalytic cycle.

Direct synthesis of sulfenamides, sulfinamides, and sulfonamides from thiols and amines

“…Following these works, Zhang and Qian along with their co-workers used the I 2 /KMnO 4 dual catalyst system for the oxidative dehydrogenation of thiols 15 and amines 16 to afford a wide range of sulfenamides 17 in moderate to high yields ( Scheme 7 ). 33 Although various aliphatic and (hetero)aromatic thiols with either electron-donating or electron-withdrawing substituents were well tolerated under the reaction conditions, the protocol was restricted to only secondary cyclic amines, however, the method was successfully explored for the synthesis of a drug-like sulfenamide with antihypertensive activity. It should be mentioned that under the identical conditions, due to their higher reactivity, the primary amines were converted to sulfinamides rather than sulfenamides.…”

Recent Advances in Sulfur‐Centered S–X (X = N, P, O) Bond Formation Catalyzed by Transition Metals

“…Recently, our group [40] reported Cu 2 O-catalyzed S-P bond coupling reaction by using aryl thioureas and dialkyl phosphonates as substrates [Eq. (24)]. It is easy to construct the sulfurphosphorus bond without adding base or acid and using air as oxidant.…”

“…Qian and co-workers [24] established a dual catalyst system (iodine/manganese-dual system) for the oxidative dehydrogenation of amines and thiols under mild reaction condition [Eq. (9)].…”

Iodine‐Mediated Cross‐Dehydrogenative Coupling of Heterocyclic Thiols with Amines: An Easy and Practical Formation of S−N Bond

“…So far, various synthetic methods have been developed to access such important skeletons (Scheme 1), which can be mainly divided into metal catalysis, [6–10] electrochemical synthesis [11–12] and metal‐free oxidative cross‐coupling [13–16] . Nevertheless, these methods still suffer from the involvement of metal catalyst, the addition of highly flammable/irritating oxidants, long reaction time, or the requirement of additional additives or bases.…”