Silyl-Triflate-Catalyzed Divergent Annulation of Isoquinolines with Ynamides: Direct Access to 2-Aminonaphthalenes and 2-Amino-1-naphthonitriles

Metal-free, silyl-triflate-catalyzed formal inverse-electron-demand Diels–Alder annulation of isoquinolines with ynamides enables the divergent synthesis of 2-aminonaphthalenes and 2-amino-1-naphthonitriles. The 3-substituent on isoquinoline dictates product selectivity: H or Me leads to nitrile extrusion, whereas Cl or Br triggers HX elimination. The transformation features a broad substrate scope, good scalability, and unified catalytic cycle involving substituent-directed bifurcation from a common bicyclic imine intermediate. This work offers a practical, metal-free route to functionalized naphthalenes and new insights into Lewis-acid-catalyzed annulations.