Straightforward Electrochemical Sulfonylation of Arenes and Aniline Derivatives using Sodium Sulfinates

Abstract

We present a general electrochemical synthesis of sulfones from arenes and aniline derivatives with sodium sulfinates. A wide range of C−S cross‐coupling products is available by this oxidant‐ and transition metal‐free method. Both aryl and diaryl sulfones can be readily obtained, using this scalable and inherently safe one‐step protocol. Since the synthesis excludes the need for additional supporting electrolyte and occurs in an aqueous electrolyte system that is easily recovered and recycled, this strategy represents a sustainable and green alternative to existing sulfonylation reactions.

Electrochemical Oxidative Sulfonylation of N‐Arylamides/Amine with Sodium Sulfinates

“…Finally, desired product 3 aa was obtained via intramolecular hydrogen transfer. Undoubtedly, the addition of sulfonyl radicals to 8‐aminoquinolines as suggested by Waldvogel and others cannot be completely excluded [14b,c] . On the other hand, 8‐aminoquinolins 4 may be oxidized at the anode to form a radical cation and then generate C−S bond through radical/radical cross‐coupling with intermediate E [14d,f,15] …”

Electrochemical Nitration with Nitrite

“…This could be explained by the N-directing effect of the dimethylamino moiety and the electron-rich nature of the substrate. [31] The postulated reaction mechanism is displayed in Scheme 5. Cyclic voltammetry confirms the initial anodic oxidation of nitrite to NO 2 , which is in equilibrium to N 2 O 4 .…”

Oxidative Sulfonylation of Multiple Carbon‐Carbon bonds with Sulfonyl Hydrazides, Sulfinic Acids and their Salts

“…The reaction of A with B gives the final product 324 (Scheme 140). A similar process applying anilines [167] and other arenes with electron-donating substituents [168] as starting reagents was conducted electrochemically. A number of approaches to the sulfonylation of benzamides containing different directing groups at the amide nitrogen atom have been developed.…”

“…The reaction of A with B gives the final product 324 (Scheme 140). A similar process applying anilines [167] and other arenes with electron‐donating substituents [168] as starting reagents was conducted electrochemically.…”