Facile and Rapid Synthesis of 5-Substituted 1H-Tetrazoles VIA a Multicomponent Domino Reaction Using Nickel(II) Oxide Nanoparticles as Catalyst

2-(1H-Tetrazol-5-yl)acrylonitrile derivatives were synthesized through multicomponent domino Knoevenagel condensation/1,3-dipolar cycloaddition reaction of carbonyl compounds, malononitrile, and sodium azide in the presence of NiO nanoparticles as a highly efficient catalyst. This method has the advantage of very short reaction times, high yields, simple methodology, and easy work-up. The catalyst can be recovered and reused while maintaining good yields.