Robust Aerobic Alcohol Oxidation Catalyst Derived from Metal-Organic Frameworks

A new catalyst system based on Cu-3(BTC)(2) (BTC: 1,3,5-benzenetricarboxylate) and TEMPO and NMI (TEMPO: 2,2,6,6-tetramethylpiperidine-N-oxyl; NMI: N-methylimidazole) was developed for aerobic alcohol oxidation. Various primary alcohol substrates were converted to the corresponding aldehyde in excellent yield over the Cu-3(BTC)(2)/TEMPO/NMI catalyst system. However, the reusability and stability of the new catalyst system were poor due to the relatively weak coordination bond between the metal and the organic ligand in Cu-3(BTC)(2). Simple pyrolysis of Cu-3(BTC)(2) afforded a robust and chemically inert copper-carbon nanocomposite (Cu@C). A new catalyst based on Cu@C exhibited outstanding performance for the aerobic oxidation of alcohols with the assistance of TEMPO and NMI. Furthermore, the Cu@C/TEMPO/NMI catalyst system revealed a broad scope for the substrate and excellent reusability for the aerobic oxidation of alcohols. Robust and reusable heterogeneous catalyst for aerobic oxidation of alcohol have been prepared by simple pyrolysis of iconic MOF, Cu-3(BTC)(2) (BTC: 1,3,5-benzenetricarboxylate).