KA 2 Coupling, Catalyzed by Well‐Defined NHC‐Coordinated Copper(I): Straightforward and Efficient Construction of α‐Tertiary Propargylamines

A new, straightforward, highly efficient, and mild catalytic protocol for the synthesis of α‐tertiary propargylamines, via the multicomponent KA 2 reaction (Ketone‐Amine‐Alkyne), employing well‐defined, sustainable copper(I) complexes bearing N ‐heterocyclic carbene ligands, is reported herein. The methodology uses very low catalyst loading under moderate heating to achieve the construction of a wide range of propargylamines in good to excellent yields in very short reaction times. Challenging substrates, including acyclic linear ketones, aromatic ketones, and electron‐poor aromatic alkynes, as well as substrates bearing synthetically valuable functionalities, are well tolerated.