Electrosynthesis ofN-labeled amino acids fromN-nitrite and ketonic acids

15N isotope-labeled amino acids(15N-amino acids) are crucial in the fields of biology, medicine, and chemistry. 15N-amino acids are conventionally synthesized through microbial fermentation and chemical reductive amination of ketonic acids methodologies, which usually require complicated procedures, high temperatures, or toxic cyanide usage, causing energy and environmental concerns. Here, we report a sustainable pathway to synthesize 15N-amino acids from readily available 15N-nitrite(15NO2-)and biomass-derived ketonic acids under ambient conditions driven by renewable electricity. A mechanistic study demonstrates a 15N-nitrite→ 15NH2OH→ 15N-pyruvate oxime→ 15N-alanine reaction pathway for 15N-alanine synthesis. Moreover, this electrochemical strategy can synthesize six 15N-amino acids with 68%–95% yields. Furthermore, a 15N-labeled drug of 15N-tiopronin,the most commonly used hepatitis treatment drug, is fabricated using 15N-glycine as the building block. Impressively, 15N sources can be recycled by the electrooxidation of 15NH4+to 15NO2-with a method economy. This work opens an avenue for the green synthesis of 15N-labeled compounds or drugs.