Substrate scope for copper-catalyzed synthesis of dihydro-6H-indolo[2,3-b]quinolines (3)^a.

3 (time, yieldb)

^aReaction conditions: under nitrogen atmosphere, 3-alkyl-1-alkylindolin-2-imine hydrochloride (1) (0.33 mmol, 1.1 equiv.), substituted 2-iodobenzyl bromide (2) (0.3 mmol, 1.0 equiv.), CuCl (30 μmol, 10 mol%), K₂CO₃ (1.2 mmol, 4.0 equiv.), ^tBuOH (3.0 mL), temperature (100 °C), time (20 h) in a sealed Schlenk tube.

^bIsolated yield.