Palladium‐Catalyzed Selective CH Activation: A Simple Method to Synthesize C‐3 Site Arylated Quinoline Derivatives

Abstract A novel protocol for the synthesis of 3‐arylated quinoline derivatives has been developed using silver carbonate (Ag 2 CO 3 ) and dioxygen (O 2 ) as the oxidants. In this method, quinolines acting as the parent reagent react with arenes under palladium acetate [Pd(OAc) 2 ] catalysis along with 1‐adamantanecarboxylic acid (Adm). The combination of the 1‐adamantanecarboxylic acid ligand and the palladium catalyst is found to be an essential factor for achieving high activity and selectivity, and allows a wide range of 3‐arylquinoline derivatives to be obtained in high yields. Moreover, a relevant mechanism is proposed, revealing that un der the palladium(II) catalysis a migratory insertion to C‐3H of quinolines and insertion to the CH of arenes are key steps in this reaction. Mild reaction conditions and high selectivity of the reactive site provide potential for promising applications in drug discovery and functional materials. magnified image