Integrated Flow Synthesis of α-Amino Acids by <i>In Situ</i> Generation of Aldimines and Subsequent Electrochemical Carboxylation

Abstract

The synthesis of α-amino acids was carried out in a continuous flow system. In this system, aldimines were efficiently generated <i>in situ</i> via the dehydration-condensation of aldehydes with anilines in a desiccant bed column filled with 4 Å molecular sieves desiccant, followed by reaction with CO₂ in an electrochemical flow microreactor to afford the α-amino acids in high to moderate yields. The present system can provide α-amino acids without using stoichiometric amounts of metal reagents or highly toxic cyanide reagents.