CuI heterogenized on thiosemicarbazide modified-multi walled carbon nanotubes (thiosemicarbazide-MWCNTs-CuI): Novel heterogeneous and reusable nanocatalyst in the C-N Ullmann coupling reactions

Herein we described the synthesis of novel thiosemicarbazide-MWCNTs-CuI nanocatalyst by covalent grafting of thiosemicarbazide on carbon nanotubes surface and subsequent coordination with CuI catalyst. The formation of nanocatalyst was analyzed by Raman spectroscopy, energy dispersive spectroscopy (EDS), wavelength-dispersive X-ray spectroscopy (WDX) and ICP analysis. The morphology of the nanocatalyst was characterized using scanning and transmission electron microscopes (SEM and TEM). Additionally, the (thiosemicarbazide-MWCNTs-CuI) nanocatalyst was successfully employed in the N-arylation of indole, amines and imidazoles through intermolecular C(aryl)-N bond formation from the corresponding aryl halides (Ar–I, Ar–Br, Ar–Cl) with amines through Ullmann-type coupling reactions. Interestingly, the novel catalyst could be recovered and recycled five times.