One-Pot Oxidative C–H Activation/Aza-Prins-Type Reaction of Tertiary Alkynylamines: A Counter Ion-Induced Iminium Ion–Alkyne Cyclization

Herein, the design and development of a new one-pot and metal-free oxidative C–H activation/aza-Prins type cyclization of alkynylamines is reported. The scope of this method was demonstrated by the preparation of ten new pyrido­[2,1-a]­isoquinolines in moderate to high yields (38–92%). Furthermore, a mechanistic proposal for the alkyne aza-Prins cyclization is described based on DFT calculations.