Environmentally friendly approach to α-acyloxy carboxamides via a chemoenzymatic cascade

Abstract

A new, green route for the synthesis of α-acyloxy carboxamides from an alcohol, a carboxylic acid and an isocyanide was developed. The reaction comprises the aerobic oxidation of an alcohol to the corresponding aldehyde, catalyzed by the Trametes versicolor laccase/TEMPO system, followed by a one pot Passerini reaction in an aqueous surfactant medium. The influence of different types of surfactants on the reaction efficiency was investigated. The best results were obtained by employing dioctadecyldimethylammonium bromide (DODAB), a known vesicle-forming cationic surfactant. Importantly, apart from the metalloenzyme used, the described procedure toward α-acyloxy carboxamides is metal-free and does not require hazardous organic solvents, what makes it environmentally friendly.