Modification of magnetic mesoporous N-doped silica nanospheres by CuO NPs: a highly efficient catalyst for the multicomponent synthesis of some propellane indeno indole derivatives

Herein, magnetic mesoporous N-doped silica nanospheres decorated by CuO nanoparticles (M-MNS/CuO) were prepared and used for the green and efficient synthesis of some [3.3.3] propellane indeno[1,2-b] indole derivatives. In order to prepare N-doped silica nanoparticles, tetraethyl orthosilicate (TEOS) was used as the silica source, and diethanolamine (DEA) as a nitrogen precursor. Immobilization of CuO nanoparticles on the mesoporous N-doped silica nanosphere surfaces increases the surface area of catalyst and provides Lewis acidic sites in addition to nitrogen atoms as active basic sites. The presence of nitrogen atoms and copper oxide nanoparticles in the catalyst structure, give dual acidic and basic properties. The synthesized catalyst was characterized by FESEM, EDS, HRTEM, XRD, VSM, FTIR, and BET techniques which proved its magnetic core shell structure.