Fabrication of a new heterogeneous tungstate-based on the amino-functionalized metal-organic framework as an efficient catalyst towards sonochemical oxidation of alcohols under green condition

Ultrasonic-assisted reactions, as a green technique, are often more efficient compared to those traditional protocols. To this end, the selective and solvent-free oxidation of aromatic alcohols to the corresponding aldehydes and ketones were investigated in the presence of Co-ABDC/W at room temperature under ultrasonic irradiation conditions for the first time in this paper. The structure, particle size, thermal stability, and morphology of the fabricated heterogeneous catalyst and the products were characterized by FT-IR, EDS, FE-SEM, XRD, TGA, and GC analyses. In this regard, immobilization of tungstate had a significant effect on thermal stability (around 450 degrees C for 40% weight loss) and catalytic performance. Moreover, the efficiency of two different oxidation methods, including ultrasound irradiations and reflux, were comparatively investigated by GC spectrometry. Obtained sonoxidation results presented higher conversions ranging (84 to 100%) than reflux condition via shorter reaction times. The influences of the reaction parameters, such as hydrogen peroxide concentration, and catalyst loading, were also investigated. The proposed method offers several advantages, such as excellent conversions, selective oxidations, environmentally-benign procedure, short reaction times, and easy workup. Notably, this is the first report that focuses on using amino-functionalized MOFs with ultrasonic irradiation for selective oxidation reactions. (C) 2020 Elsevier B.V. All rights reserved.