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[Cu(bpdo)2·2H2O]2+/Montmorillonite was successfully prepared by impregnation method and characterized by XRD, FESEM, EDS, ICP, FT-IR, and TGA. The XRD patterns show swelling of montmorillonite layers, leading more absorption of the Cu (II) complexes. The catalytic activity of this novel nanocomposite was investigated in the efficient synthesis of 2-amino-4H-chromene and 2-amino-4H-benzopyran derivatives via Multicomponent Reactions (MCRs). A wide range of substituted benzaldehyde, malononitrile (or ethyl cyanoacetate), and diverse enolizable C–H activated acidic compounds were reacted in the presence of [Cu(bpdo)2·2H2O]2+/Mont, in EtOH/H2O under reflux conditions to afford the corresponding 2-amino-4H-chromene and 2-amino-4H-benzopyran derivatives. In addition, spirochromene and spiroacenaphthylene derivatives were synthesized successfully in the presence of [Cu(bpdo)2·2H2O]2+/Mont under reflux conditions in EtOH/H2O. Some advantages of this method involved efficiency and rapidness leading to short reaction times, easy workup procedure, high yields, and recyclable green catalyst and being performed under eco-friendly conditions. This novel nanocatalyst was easily separated, recovered, and reused at least for five times without noteworthy loss in its catalytic activity and performance. [ABSTRACT FROM AUTHOR]

In this article, palladated-magnetic nitrogen doped porous carbon was prepared from nano magnetic γ-Fe2O3 hollow sphere (h-Fe2O3) with high specific surface area and pore volume. To the purpose, initially h-Fe2O3 was prepared and covered with glucose via hydrothermal treatment with subsequent polymerization of organic shell. The polymerization of melamine-resorcinol–formaldehyde (MRF) was achieved in the presence of Cl-functionalized glucose coated h-Fe2O3 (h-Fe2O3@glu-MRF). Next, the prepared magnetic core–shell hollow sphere was palladated followed by carbonization to yield Pd@h-Fe2O3@C introducing more pores in its structure. The resulted compound, Pd@h-Fe2O3@C, was fully characterized, showing that carbonization process expressively increased the specific surface area. The resulted Pd@h-Fe2O3@C was successfully used for promoting C–C coupling reactions under mild reaction conditions as a heterogeneous catalyst and its activity was compared with some prepared control catalysts. This novel catalyst was magnetically separated simply by a magnet bar and recycled and reused at least in five consecutive runs, without considerable loss of its activity. It is note mentioning that, high recyclability with low Pd leaching are another gains of this protocol. [ABSTRACT FROM AUTHOR]