Photochemical Efficient Radical Normalized Transformation of N ‐nitrosamines Triggered by Energy Transfer Process

N ‑nitrosamines are potent carcinogenic contaminants widely present in food, pharmaceutical products, and environmental matrices, posing considerable risks to human health. The accurate detection of these compounds calls for the urgent development of an efficient and chemoselective transformation capable of converting diverse N ‑nitrosamines into a single, stable product. Herein, we report a photochemical radical normalization strategy that achieves this goal via an energy‑transfer process. This methodology enables the synthesis of structurally diverse perfluoroalkyl oximes from N ‑nitrosamines, alkenes, and perfluoroalkyl iodides with up to 99% yields. The protocol exhibits broad functional‑group tolerance, rendering it particularly attractive for the late‑stage functionalization of complex molecules. Mechanistic studies reveal that energy transfer from photoexcited N ‑nitrosamines to perfluoroalkyl iodides concurrently suppresses undesired amino radical formation and promotes perfluoroalkyl radical generation, ensuring high reaction selectivity. Furthermore, this strategy proves applicable to the analysis of various N ‑nitrosamine impurities. Validation experiments using irbesartan active pharmaceutical ingredient batches confirmed the robust quantification of total N ‑nitrosamine content, demonstrating its practical utility in pharmaceutical quality control.