The nature-mimetic valorization of renewable biomass into value-added chemicals is a cornerstone to achieve a circular chemical economy. Here, an organophotoredox-catalyzed regioselective deaminative esterification of amino acids at the α-position under visible-light irradiation at room temperature is disclosed. The amino acid-derived Katritzky salt undergoes a homolytic cleavage to generate an alkyl radical, which combines with the carboxyl radical generated from an aromatic/aliphatic/amino acid through a single-electron oxidation of the corresponding cesium carboxylate, furnishing the α-ester product in high yields. Intriguingly, an EDA complex with the electron-deficient pyridinium salt and NaI is formed in situ to forge C–O bonds.
Rahaman et al. (Mon,) studied this question.