Electrochemical Amination of Less‐Activated Alkylated Arenes Using Boron‐Doped Diamond Anodes

Abstract

The anodic C–H amination of aromatic compounds is a powerful and versatile method for the synthesis of aniline derivatives. By using boron‐doped diamond (BDD) anodes, a method initially described by Yoshida et al. for electron‐rich arenes was expanded to less‐activated aromatic systems e.g., simple alkylated benzene derivatives. Anodes based on sp3 carbon seem to be the key for the electrochemical amination reaction. The corresponding primary anilines are obtained in good yields. Despite the cationic intermediates of the electrolytic reaction tert‐butyl moieties are tolerated.

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…While Yoshida’s original condition works most effectively for electron-rich arenes such as anisole derivatives, Waldvogel expanded the scope to include electron-neutral substrates with the use of a BDD anode—even diamination has been demonstrated on some substrates. 319,320 In Waldvogel’s study, it was also noted that amination of the arene nucleus trumps benzylic functionalization for substrates substituted with alkyl appendages. An intramolecular variant of this method allowed access to 2-aminobenzoxazoles and benzothiazoles (Figure 19C).…”

Electrochemically Enabled, Nickel‐Catalyzed Amination

“…[20] From ah olistic standpoint, this study is reminiscent of the electrochemically assisted Heck reaction using simple unmodified electrodes as reported by Tian and Moeller [21] ,apioneering contribution which has largely been overlooked by the community.T he work of Little and co-workers work on electroreductive coupling provides another instructive example where electrochemistry opens up new dimensions in nickel catalysis. [20] From ah olistic standpoint, this study is reminiscent of the electrochemically assisted Heck reaction using simple unmodified electrodes as reported by Tian and Moeller [21] ,apioneering contribution which has largely been overlooked by the community.T he work of Little and co-workers work on electroreductive coupling provides another instructive example where electrochemistry opens up new dimensions in nickel catalysis.…”

“…Amines substituted with hydroxy,p yridinyl, cyano,a nd ester substituents (8)(9)(10)(11)h ave also been successfully coupled with 1,thus underscoring the functional-group compatibility of the reaction. Va rious electronwithdrawing functional groups were tolerated, such as amide (18), ester (19), nitrile (20,25), and sulfonamide (21). Additionally,c ross-couplings using acyclic secondary amines have been demonstrated.…”

Elektrifizierung der organischen Synthese

“…By employing boron-doped diamond (BDD) anodes, Waldvogel and co-workers were able to overcome the limitation to electron-rich substrates, [44] and the method was successfully expanded to less activated 1,3-dialkylarenes (Scheme 6). Other anode materials including Pt showed strong fouling behavior as electropolymerization and carbonization is promoted at such positive potentials.…”

“…Electrochemical CÀHamination of less activated alkylated arenes at BDD anodes. [44] Scheme 7. Twofold electrochemical CÀHa mination of naphthalene.…”