Nickel/aluminium oxide as a sustainable and cost-effective catalyst for the Sonogashira coupling reaction

In our study, we report a cost-effective and sustainable Sonogashira coupling reaction with Nickel supported on alumina (Ni/Al 2 O 3 ) as a palladium-free catalyst. The procedure effectively couples phenylacetylene and 2-ethynylpyridine with various aryl iodides under optimized conditions and provides a greener route by reducing hazardous waste , cost-effectiveness, and eliminating toxic palladium catalysts. The simplicity of catalyst preparation and reusability of the catalyst make the procedure amenable to large-scale applications in keeping with green chemistry principles. • A straightforward and efficient method for synthesizing Ni/Al 2 O 3 catalysts under mild conditions. • Demonstration of high catalytic activity and excellent yields (up to 90 %) with low catalyst loading (5 mol%). • Recyclability of the catalyst over multiple cycles with minimal loss of efficiency. • A broad substrate scope, including heteroaryl and functionalized aryl halides, under optimized green reaction conditions.