Mechanochemical activation for sustainable oxidation of benzylic alcohols

This study focuses on developing a new sustainable synthesis method for oxidizing alcohols into carbonyl compounds using a mechanochemical protocol. Oxidation reactions are widely employed in the chemical industry; however, they generate large amounts of waste and score poorly on green chemistry metrics.¹ As reported in the literature, mechanochemistry has proven to be a valuable tool for chemists to achieve more sustainable reactions² and to activate catalytic processes.³ Preliminary studies in this work have shown that the use of copper-supported catalysts in combination with TEMPO can effectively oxidize p-hydroxybenzyl alcohol into its corresponding carbonyl compound. After three hours of reaction a conversion about 80% is achieved (Figure 1). The solid reagents are placed in the mixing vial and then subjected to ball milling. The green assessment4,5,6 indicates that this method presents greener parameters compared to the equivalent solution synthesis. Additionally, it is less energy and time intensive and offer better selectivity.