Buchwald-Hartwig C-N cross coupling reactions catalyzed by palladium nanoparticles immobilized on thio modified-multi walled carbon nanotubes as heterogeneous and recyclable nanocatalyst

摘要

In current research, the multi walled carbon nanotubes was functionalized with mercapto-melamine groups by covalent grafting of f-CNT with ethylenediamine, cyanuric chloride and 2-mercaptoethanol for introducing mercapto functional groups on the surface of nanotube. Consequently, the thiolated MWCNTs were applied to deposing Pd nanoparticles. The results of FTIR, Raman spectroscopy, powder XRD, energy dispersive spectroscopy (EDS), wavelength-dispersive X-ray spectroscopy (WDX) and CHN analysis showed the successful synthesis of nanocatalyst. The scanning and transmission electron microscopes (SEM and TEM) were used to study the morphologies of the nanocatalyst. Moreover, the (MWCNTs/CC-SH/Pd) nanocatalyst was effectively applied in Buchwald-Hartwig C-N cross coupling reaction with wide variety of functionalized substrates. A variety of aryl amines were prepared through reaction of aryl halides (chloride, bromide and iodide) and amines in high yields. Remarkably, the new catalyst could be reused for six recycles without change in its catalytic activity.