Reagent‐ and Metal‐Free Anodic C−C Cross‐Coupling of Aniline Derivatives

The dehydrogenative cross‐coupling of aniline derivatives to 2,2′‐diaminobiaryls is reported. The oxidation is carried out electrochemically, which avoids the use of metals and reagents. A large variety of biphenyldiamines were thus prepared. The best results were obtained when glassy carbon was used as the anode material. The electrosynthetic reaction is easily performed in an undivided cell at slightly elevated temperature. In addition, common amine protecting groups based on carboxylic acids were employed that can be selectively removed under mild conditions after the cross‐coupling, which provides quick and efficient access to important building blocks featuring free amine moieties. Cross‐couplings under electrochemical conditions selectively provide protected 2,2′‐diaminobiaryl derivatives. For clean conversion, 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) and glassy carbon should be used as the electrolyte and anode material, respectively. Easily removable protecting groups enable the stepwise and selective liberation of the amine functional groups.