University of Chicago scientists devise light‑driven carbon‑to‑nitrogen swap for drug molecules

Chemists at the University of Chicago have created a mild, light‑driven reaction that swaps a carbon atom for a nitrogen atom in molecules commonly used in medical research and industry. The method uses a triplet‑state nitrene generated from aryl azides, blue light and oxygen to open a ring, rearrange atoms and close the ring with nitrogen in place of carbon. When applied to a stubborn indole substrate, the reaction gave a 73% yield of the nitrogen‑containing product. The team also modified a Vinca alkaloid cancer drug, producing a version with improved metabolic stability and reduced inhibition of the hERG potassium channel, a key safety marker. Nitrogen versions of the natural compounds yohimbine and catharanthine were also obtained, opening new routes for synthesising the chemotherapy precursor vinblastine. The authors note the technique is not universal and relies on toxic aryl azides, but claim the mild conditions and broad skeletal diversity give the method unexpected generality and potential value for medicinal chemistry. The findings were reported in Science on September 23, 2026.