Visible-Light-Driven C(sp ³ )–H bond Carboxylation of N -Arylbenzylamines with CO ₂ for the Synthesis of N -Aryl α-Amino Acids

A visible-light-driven direct α-C(sp3)–H carboxylation of N-aryl benzylamines with CO2. High-value N-aryl α-amino acids can be synthesized efficiently and economically under mild conditions. Various substituted N-aryl benzylamines containing different functional groups, including highly reactive groups such as halogens, trifluoromethyl, ester, and acyl groups, can be successfully converted into carboxylation products. Mechanistic studies indicate that a single-electron transfer (SET) occurs between the α-carbon radical intermediate generated from N-aryl benzylamine and the photocatalyst to produce a stabilized α-carbanion, which then undergoes carboxylation to form N-aryl α-amino acids.