Eco-friendly cyanation strategies of aryl halides using recyclable nickel nanocatalysts with promising antibacterial and antioxidant activities

Abstract

Recyclable nickel nanoparticles have been utilized as an efficient, stable, heterogeneous catalyst for the synthesis of aryl nitriles using commercially available and less toxic K₄[Fe(CN)₆]·3H₂O as an environmentally benign cyanide source. The reactions are not dependent on an inert atmosphere or a ligand. Several aryl chlorides, aryl bromides, and aryl iodides survived well and were associated with high yield in the aforesaid method. The synthesized Ni-γAl₂O₃ nanocatalysts could be recovered and recycled again without significantly reducing their efficacy. Moreover, “Sheldon's test (hot filtration method)” was carried out to establish the heterogeneity of the catalyst. The significant benefits of this catalytic methodology align with green chemistry principles, making this process potentially applicable in industrial chemistry. The synthesized Ni-γAl₂O₃ nanocatalysts exhibited moderate antioxidant activity, with maximum antioxidant activity (68.17%) at 200 mg mL⁻¹ concentration. Ni-γAl₂O₃ nanocatalysts were found to be effective against Staphylococcus aureus ATCC25923 (Gram-positive) and Escherichia coli (Gram-negative) with zones of inhibition of 10 ± 0.25 mm and 12 ± 0, respectively. MIC values against Escherichia coli (Gram-negative) and Staphylococcus aureus ATCC25923 (Gram-positive) were 200 mg mL⁻¹ and 205 mg mL⁻¹, respectively, while MBC values were 220 and 230 mg mL⁻¹ for Staphylococcus aureus ATCC25923 and Escherichia coli, respectively. This study is provided to demonstrate the dual applicability of the recyclable Ni-γAl₂O₃ nanocatalyst for a green synthetic route to aryl nitriles, and to exhibit potential antibacterial and antioxidant activity.