Fabrication of self-assembled Co3O4 nano-flake for one-pot synthesis of tetrahydrobenzo[b]pyran and 1,3-benzothazole derivatives

Abstract

We report the fabrication of self-assembled Co3O4 nano-flake material by dissociation of CoCl2.6H2O under basic medium using co-precipitation method. The electronic/crystalline structure and morphology and elemental purity of Co3O4 material have been analyzed by UV–Vis, fluorescence, powder X-ray diffraction, field emission scanning electron microscopy, and energy dispersive X-ray measurement. The Co3O4 nano-flake has demonstrated excellent catalytic activity in the one-pot multicomponent synthesis of tetrahydrobenzo[b]pyran and 2-aryl-1,3-benzothazole derivatives under neat conditions in excellent yields. The Co3O4 nano-flake material was recovered from the reaction mixture and reused for at least ten runs without appreciable loss of catalytic activity.