Making Carbon–Chlorine Bonds by Dipalladium Electrocatalysis

Abstract

[(Benzo[h]quinolinyl)Pd^(II)(μ-OAc)]_2 and [(2-phenylpyridinyl)PdII(μ-OAc)]_2 undergo one-electron oxidation to afford mixed-valent (Pd^(II)–Pd^(III)) species. Electrochemical oxidation of the Pd^(II)–Pd^(II) complexes in the presence of chloride at the Pd^(III)–Pd^(II)/Pd^(II)–Pd^(II) potential results in a two-electron loss with addition of two chlorides to form [(benzo[h]quinolinyl)Pd^(III)Cl(μ-OAc)]_2 and [(2-phenylpyridinyl)Pd^(III)Cl(μ-OAc)]_2, respectively. When both excess benzo[h]quinoline and chloride are present, [(benzo[h]quinolinyl)Pd^(II)(μ-OAc)]2 electrocatalyzes the chlorination of the substrate to afford 10-chlorobenzo[h]quinoline with high chemical and Faradaic yields.

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