A waste-minimized protocol for electrochemical reductive amination and its environmental assessment

Abstract

The environmental impact linked to the use of solvents is a recurring criticism of the development of sustainable chemical processes. The possibility of recovering the reaction medium is a key aspect to simplify the isolation of the desired target material. At the same time, it may also allow the minimization of additional solvents necessary for the purification and ultimately minimize all the contributions to the waste generated. Electrochemical processes are of high interest in modern organic synthesis. Anyway, most electrochemical processes nowadays feature the use of unrecoverable solvents or solvent mixtures in high amounts (dilution). The consequent high environmental impact of such procedures is easily understood. Aiming at the definition of effective waste-minimized synthetic protocols, herein, we report our study towards the development of an electrochemical reductive amination protocol employing an acetonitrile-water azeotrope as the recoverable reaction medium. Through the use of gram-scale synthesis and comprehensive sustainability and environmental assessments, we present an efficient management of solvents and electrolytes in an electrochemical methodology for a widely useful chemical transformation.