Synthesis of Tetrahydroisoquinolines

Using benzotriazole as auxiliary gives convenient access to a range of 1,2,3,4-tetrahydroisoquinolines with different aromatic substitution patterns. In the light of the well-known difficulties in the preparation of derivatives with electron-withdrawing aromatic substituents and the interesting pharmacological properties of these compounds, the simple procedures and conditions of the described reactions as well as the very high yields, which are frequently obtained, make this approach an important new route to the 1,2,3,4-tetrahydroisoquinoline skeleton.