General procedure for the synthesis of 7-chloro-1,2,3,4-tetrahydroquinoline from 7-chloroquinoline: In a 10 mL Schlenk tube, Fe(OTf)2 (0.005 mmol, 1.8 mg), 7-chloroquinoline (0.5 mmol, 72 mg), Hantzsch ester A (1.25 mmol, 318 mg) and 1.0 mL of CHCl3. The reaction mixture was stirred at 40 °C for 2 hours. After completion of the reaction, the reaction solution was concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography to afford pure 7-chloro-1,2,3,4-tetrahydroquinoline (63.8 mg, 96% yield).
