Synthesis of Quinolines from Allylic Alcohols via Iridium-Catalyzed Tandem Isomerization/Cyclization Combined with Potassium Hydroxide

A new tandem catalytic process has been established for the synthesis of quinolines. This process utilizes the [IrCp*Cl-2](2)/KOH catalyzed isomerization/cyclization of allylic alcohols with 2-aminobenzyl alcohol. Both the secondary and primary allylic alcohols were investigated in this catalytic system to afford different substituted quinoline derivatives in moderate to good yields. A mechanism study showed the reaction following a tandem process integrating isomerization of allylic alcohols and oxidative cyclization of 2-aminobenzyl alcohol.