Metal-Free Activation of a C(sp)−H Bond of Aryl Acetylenes

Abstract

C(sp)−H Bond activation of acetylene molecule still remains a challenge for synthetic organic chemists. In practice, acetylenes are activated by strong bases and metals. The first example for activating acetylenic protons under base and metal‐free conditions is reported here. It involves a general method for synthesizing propargylic derivatives of cotarnine. An array of tetrahydroisoquinolines alkaloids was synthesized by C(sp)−H bond activation of aromatic acetylenes with cotarnine at room temperature. A DFT‐based mechanism is proposed for the reaction.