Cooperative Copper(I) and Primary Amine Catalyzed Room‐Temperature Carbocyclization of Formyl Alkynes

An efficient Cu I /amine catalytic system is described for the carbocyclization of α‐disubstituted formylalkynes at room temperature. Merging aminocatalysis to the copper(I)‐catalyzed activation of alkynes led to clean carbocyclization of a wide range of functionalized substrates under mild conditions. This novel cooperative catalytic system allowed the formation of a variety of carbo‐ and heterocycles, including pyrrolidines, in good to excellent yields. Mechanistic aspects of this process are also discussed.