Design of a Copper(II) Complex with Tetradentate Bis‐Benzotriazole‐Appended Bipyridine Ligand and its Catalytic Application in A3 Coupling Reaction

In this report, a Cu(II) complex Cu‐L4 containing a new tetradentate benzotriazole‐appended bipyridine ligand was synthesized and characterized fully via spectroscopic and crystallographic techniques. The crystal structure of the complex revealed that the ligand is bound to copper in a tetradentate fashion in a plane and the axial positions are occupied by an anion and a solvent molecule, resulting in a distorted octahedral geometry of the complex in solid‐state. This air‐stable complex was utilized as homogeneous precatalyst for the synthesis of several propargylamine derivatives by 3‐component A 3 coupling reactions of aldehydes, amines, and alkynes under aerial atmosphere.