Recent Advances in the Chemical Synthesis of [ 14 C]‐labeled Compounds

ABSTRACT Carbon‐14 ( 14 C), which shares the chemical properties of carbon‐12 ( 12 C) but possesses unique radioactivity, is an indispensable tool for probing metabolic pathways and molecular structures in drug research. It plays a crucial role in drug discovery. This review highlights the synthesis of diverse [ 14 C]‐labeled compounds from reactor‐produced [ 14 C]barium carbonate and its derivatives, including [ 14 C]carbon dioxide, [ 14 C]acetylene, and [ 14 C]cyanide. We discuss strategies for precise labeling of complex drug molecules, emphasizing the integration of carbon isotope exchange, photocatalysis, transition‐metal catalysis, and other late‐stage labeling methods with classical synthetic routes. These approaches streamline synthesis and improve labeling efficiency, offering significant potential for the labeling of complex molecules. By systematically summarizing these advances, this review provides a comprehensive overview of current 14 C labeling strategies and serves as a practical guide for designing efficient, accurate, and safe radiolabeling protocols to support drug discovery, development, and metabolism studies.