Cobalt‐Catalyzed Double C−H Activation of Imidazopyridines with Vinylene Carbonate for the Synthesis of Pyrido[1,2‐a]benzimidazoles

The synthesis of pyrido[1,2‐ a ]benzimidazole derivatives from the cobalt(III)‐catalyzed C−H activation and vinylene transfer of imidazo[1,2‐ a ]pyridines with vinylene carbonate has been proposed. Most products of pyrido[1,2‐ a ]benzimidazoles were achieved in good yields under simple and easy‐to‐operate conditions. Scale‐up preparation and several preliminary mechanistic studies involving C−H bond activation and electronic effects between different substrates were also performed. This protocol offers an alternative approach for the synthesis of diverse useful pyrido[1,2‐ a ]benzimidazole derivatives.