Chemoselective Reduction of Nitro and Nitrile Compounds with Magnetic Carbon Nanotubes-Supported Pt(II) Catalyst under Mild Conditions

Multi-walled carbon nanotubes (MWNTs) decorated with Fe3O4 nanoparticles have been prepared using a coprecipitation technique and were surface modified using poly(citric acid) (PC) dendrimer. These PC-functionalized magnetic carbon nanotubes (MWCNT/MA@PC) have been used as a novel support for Pt(II) complex immobilized as magnetic nanocatalyst (MWCNT/MA@PC/Pt(II)). The morphology and structural features of the magnetic nanocatalyst were characterized using different microscopic and spectroscopic techniques, including FT-IR, TEM, EDX, BET, XRD, TGA, ICP, and VSM. The nitro and nitrile groups in aromatic and aliphatic compounds containing various reducible substituents, such as carboxylic acid, ketone, aldehyde, and halogen, are selectively reduced to the corresponding amines in water as a eco-friendly solvent with excellent yields by employing NaBH4 in the presence of MWCNT/MA@PC/Pt(II). In addition, the Pt(II) magnetic nanocatalyst can be simply separated from the mixture of reactants by using an external magnetic field and could be reused up to five runs continuously without considerable loss of catalytic activity.