Copper(II)-Schiff Base Complex Embedded on Multi-Walled Carbon Nanotubes (APTMS@MWCNTs/Schiff Base/Cu): A Novel Versatile Nanostructure to Promote Four-Component Preparation of Dihydro-spiro[cycloalkane-1,4′-quinoline]-2′,5′-diones

In this paper, a novel air/moisture stable copper(II)-Schiff base complex supported on multi-walled carbon nanotubes (APTMS@MWCNTs/Schiff base/Cu) has been prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDAX), and scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Its catalytic activity has been examined in the synthesis of some important dihydro-spiro[cycloalkane-1,4 '-quinoline]-2 ',5 '-diones via a one-pot, one-step four-component reaction of various cyclic ketones, dimedone, Meldrum's acid, and amines/ammonia in refluxing ethanol. A wide range of desired products has been obtained through creating new C-C and C-N bonds in good yields. The recovery and reusability of the nanocatalyst has also been checked through three runs without activity loss. [GRAPHICS] .

Automated summary

A novel air/moisture stable copper(II)-Schiff base complex supported on multi-walled carbon nanotubes has been prepared and characterized. The catalytic activity of this nanocatalyst in the synthesis of dihydro-spiro[cycloalkane-1,4 '-quinoline]-2 ',5 '-diones has been demonstrated, showing high yields of desired products through creating new C-C and C-N bonds. The recovery and reusability of the nanocatalyst has also been confirmed through three runs without activity loss.