Metal-Free Synthesis of 2-Substituted 3-(2-Hydroxyaryl)quinolines and 4-(2-Hydroxyaryl)acridines via Benzyne Chemistry

A metal-free approach for the synthesis of 3-aryl-2-substituted quinolines and 4-arylacridines has been developed via the 1,3-dipolar cycloaddition reactions of arynes with N-oxides. Reactions of various 2-substitued quinoline N-oxides with ortho-(trimethylsilyl)aryltriflates in the presence of KF gave 3-(2-hydroxyaryl)quinoline derivatives in good yields. Acridine N-oxides also reacted with arynes to furnish 4-(2-hydroxyaryl)acridines, albeit in moderate yields.