NaI‐Catalyzed Oxidative Amination of Aromatic Sodium Sulfinates: Synergetic Effect of Ethylene Dibromide and Air as Oxidants

Abstract

A novel NaI‐catalyzed oxidative amination of sodium sulfinates, employing both ethylene dibromide (EDB) and air as the oxidants, is described. EDB was first demonstrated to be a promising mild organic oxidant that in air, converted NaI into molecular iodine to promote the cross‐coupling reactions of aromatic sodium sulfinates with amines to produce arylsulfonamides. Mechanistic studies indicated that a radical pathway might be involved in the reaction process.

Bond-Forming and -Breaking Reactions at Sulfur(IV): Sulfoxides, Sulfonium Salts, Sulfur Ylides, and Sulfinate Salts

“…In addition to the methods mentioned above, several further protocols for sulfonamide formation from sodium sulfinates have been reported in recent years. Common to these approaches, relying either on molecular iodine, − or the oxidation of iodide, − is the putative formation of a sulfonyl iodide intermediate.…”

Aerobic α‐Sulfonylation of Ketones with Zinc Sulfinates in Aqueous Micellar Media: Highly Selective Access to β‐Keto Sulfones

“…Based on these experimental results and our previous results, we propose the catalytic cycles as shown in Scheme . The key steps include (i) EDB and oxygen oxidized iodide ions into elemental iodine which then converted chlorozinc sulfinate ( III ) into sulfonyl iodide ( IV ).…”

“…Previously, we reported a reductive sulfonylation of alkyl chlorides with sulfonyl chlorides whereby various type of sulfones were prepared in good to high yields . Recently, We reported a convenient NaI‐catalyze oxidative amination of aromatic sodium sulfinates employing both air and ethylene dibromide (EDB) as the oxidants . Our previous findings led us to investigate the more challenging reaction of sulfonylation of ketones with chlorozinc sulfinates, which could be easily obtained from corresponding sulfonyl chlorides in nearly quantitative yields in our laboratory, for the synthesis of β‐ketosulfones…”

Direct C(sp3)−H Sulfonylation and Sulfuration Reactions of Isoquinoline‐1,3(2H,4H)‐diones under Metal‐free Conditions

“…Based on the experiments and literature, [3,8,9] we proposed a plausible mechanism for the oxidative direct C(sp 3 )−H sulfonylation reaction of isoquinolone. Sulfinate 2 a is converted into radical D via a single electron transfer (SET) process under the oxidation of iodide, which is captured by enol A to form radical intermediate B .…”