Taguchi-Optimized Green Synthesis of a Novel Nickel-bis-thiazoline Complex: A Bifunctional Platform for Sustainable Ullmann-type N-Arylation and Antibacterial Applications

A novel bis-thiazoline ligand and its nickel(II) complex were synthesized via an environmentally benign and mild protocol.Synthesis parameters were systematically optimized using the Taguchi Design of Experiments (DoE), achieving high yields (> 98%) and ensuring a scalable, reproducible green process. The novel Ni(II) complex was shown to be an efficient catalyst for the Ullmann-type C-N coupling, which was further utilized to synthesize mefenamic acid and its derivatives. Biological studies showed that the complex significantly enhanced the antibacterial efficacy compared to the free ligand, demonstrating its bifunctional potential in sustainable catalysis and medicinal chemistry.