Structural regulation of CuOx/CeO2 and its application in α-<i>tert</i>-propylamine synthesis

Four cerium dioxide (CeO 2 ) powders with different particle sizes and shapes were prepared via regulating the amount of alkali and hydrothermal temperature. Then twelve 20 wt.% [Formula: see text]/[Formula: see text] materials were provided by loading the corresponding quantity cupric acetate in the cerium oxide carriers by impregnation method and changing the calcination temperature and atmosphere. These loaded [Formula: see text]/[Formula: see text] catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), displaying different valence state of copper on the support surface. The catalytic properties of these new materials were examined by using the coupling reaction of cyclohexanone, morpholine and phenylacetylene as a template reaction. It showed that the small-sized rod-like 20wt.% [Formula: see text]/[Formula: see text]-r-8.4-200 material has the best catalytic effect, and the isolation yield of [Formula: see text]-tert-propargylamine product could reach 75% under the conditions of 10 mg cat, 110[Formula: see text]C, 12 h and no solvent. Notably, the catalyst yield was still above 62% after four cycles of experiments, confirming the practical recoverability of the catalyst. Moreover, some examples of [Formula: see text]-tert-propargylamine derivatives can be obtained in medium isolated yields by replacing morpholine, and/or phenylacetylene. The synthesis mechanisms were discussed. The present results provide a three-component coupling reaction method for synthesizing [Formula: see text]-tert-propargylamine, which has the advantages of simple post-treatment, solvent-free and reusable catalyst.