Hexagonal Mesoporous Silica Supported Ultrasmall Copper Oxides for Oxidative Amidation of Carboxylic Acids

Hexagonal mesoporous silica (HMS) supported copper oxide nanoparticles were prepared by a one-pot sol–gel synthesis, and their physicochemical properties were determined by XRD, ICP-MS, SEM, TEM, and N2 physisorption, HR-TEM, and elemental mapping. A series of CuO/HMS catalysts was prepared with different Cu loadings (1, 1.5, 2, 2.5, 3, and 5 wt %). The catalytic performance of the prepared catalysts was investigated for the oxidative amidation of carboxylic acids. Notably, under mild reaction conditions the CuO/HMS catalysts exhibited excellent activity in terms of conversions (70–95%) and selectivity (80–86%). The improved catalytic performance of CuO/HMS catalysts may be attributed to the homogeneous dispersion and uniformity of the active copper species on the HMS support with a large surface area. Having investigated the functional group tolerance, the developed protocol can also be extended for the synthesis of insect repellent molecules such as N,N-diethyl phenylacetamide (DEPA), N,N-diethylbenzami...