Experimental and density functional theory investigation of nickel curcumin catalyzed Suzuki Miyaura cross coupling

Abstract The development of sustainable and cost-effective catalysts for carbon–carbon bond formation remains an important goal in modern organic synthesis. In the present study, a nickel–curcumin complex was investigated towards catalytic applications on Suzuki–Miyaura cross-coupling reactions between aryl halides and arylboronic acids. The catalytic system showed good performance under mild reaction conditions using methanol as the solvent and a low catalyst loading. Reaction parameters such as solvent, base, temperature, and catalyst concentration were systematically optimized using a model reaction. Under the optimized conditions, a variety of substituted aryl iodides, bromides, and chlorides were successfully coupled to give the corresponding biaryl products in moderate to excellent yields. The catalyst exhibited good functional group tolerance and consistent catalytic efficiency across different substrates. Mercury poisoning and radical trapping experiments suggested that the reaction proceeds mainly through a homogeneous catalytic pathway. The combination of naturally derived curcumin as a ligand with earth-abundant and low-cost nickel highlights the sustainable nature of this catalytic system. To the best of our knowledge, this is the first report describing the catalytic application of a nickel–curcumin complex in Suzuki–Miyaura cross-coupling reactions, which may provide opportunities for the further development of curcumin-based catalysts in organic synthesis.