NiO nanocomposites/rGO as heterogeneous catalysis for imidazole scaffolds with their applications in inhibiting DNA binding activity
Herein, we report a facile approach to synthesize a new highly versatile heterogeneous catalyst by spontaneous aerial oxidation based on nickel oxide nanocomposites immobilized over the surface-functionalized reduced graphene oxide sheet. Reduced graphene oxide/NiO nanocomposites (rGO-NiO-NCs) is used as highly efficient, cost-effective, reusable, selective, and eco-friendly nano-catalyst without losing any activity even after five reaction cycle. Nickel loading on the rGO/NiO nanocomposites is found to be 3.3 At% which contributes to the effective and efficient use of rGO-NiO-NCs as nano-catalyst for the synthesis of imidazole derivatives. Consequently, a series of imidazole derivatives were synthesized, catalyzed by rGO-NiO-NCs, in 60 min with high yields (86 to 96 %) under green conditions. Furthermore, the present synthetic methodology is used for the synthesis of highly aromatic imidazole derivatives (B1-B3) whose calf thymus-DNA binding affinity suggesting their superior inhibition ability to the displace of ethidium bromide (EB), which is further confirmed by molecular docking. Additionally, green chemistry matrix of the synthesized reaction is found to be very close to ideal values such as Carbon efficiency (82.32 %), E-factor (0.51), Atom economy (77.86 %), Process mass intensity (1.51), and Reaction mass efficiency (66.14 %).