The tetrahydroquinoline unit is important in synthetic chemistry because of its presence in many biologically active natural products1 and pharmaceuticals.2 In organic synthesis, some tetrahydroquinolines have been used as ligands.3 The preparation of 1,2,3,4-tetrahydroquinolines has been accomplished by several methods such as an intramolecular aza-Michael addition,4 an imino-Diels–Alder reaction,5 an intramolecular hydroamination,6 the reduction of quinolines,7 and other ...
