The photoinduced deboronative generation of unstabilized radicals, including vinyl, methyl, heteroaryl, and cyclopropyl radicals, from commercially available and easy‐to‐handle boronic esters under mild conditions in a two‐molecule photoredox system was achieved. The generated unstabilized radicals readily added to electron‐deficient alkenes, resulting in new C─C bond formation without transition metals.
Herein, we present a photocatalytic route that exploits a redox‐neutral tandem hydrogen atom transfer (HAT) and oxidative radical polar crossover (RPC) manifold. This method enables the efficient synthesis of valuable allylic amides and ethers through the valorization of three classes of ubiquitous feedstock chemicals: carboxylic acids as precursors to hydrogen atom abstractors, amides or ethers as C(sp 3 )─H donors, and olefins as radical acceptors. The protocol operates under mild conditions, exhibits broad functional group tolerance, and is readily scalable. The redox‐neutral nature of this transformation mechanistically distinguishes it from traditional net‐oxidative approaches associated with exogenous stoichiometric oxidants. Crucially, it allows HAT substrates bearing “hydridic” C─H bonds (e.g., α ‐ to heteroatom: X─C H R 1 R 2 ) to be engaged in Giese‐type addition reactions and subsequent oxidative RPC/nucleophilic trapping, where traditional net‐oxidative approaches inevitably result in Shono‐type further oxidation of the HAT‐derived radical (e.g ., α ‐ to heteroatom: X + ═CR 1 R 2 ) and nucleophilic interception prior to intermolecular radical addition.
Iodanyl radical catalysis offers distinct reactivity beyond conventional two‐electron hypervalent iodine manifolds. However, existing catalytic protocols rely predominantly on complex bis‐iodoarene platforms to stabilize radical intermediates, whereas simple monodentate aryl iodides remain poorly developed due to off‐cycle pathways. Herein, we report that 2‐iodopyridine serves as a highly efficient organo‐iodine catalyst for photocatalytic iodanyl radical catalysis under mild, redox‐neutral, and metal‐free conditions. Integrated within a visible‐light photoredox cycle, this protocol achieves direct single‐electron activation of unfunctionalized aliphatic alcohols to generate reactive alkoxy radical intermediates. This dual catalytic manifold facilitates both ring‐opening functionalization of cyclic alcohols via β‐scission and site‐selective δ‐C─H functionalization of linear alcohols through 1,5‐hydrogen atom transfer. Mechanistic investigations and radical trapping experiments support the proposed one‐electron catalytic pathway. This strategy provides an accessible and low‐cost platform for iodanyl radical catalysis, expanding the synthetic utility of native aliphatic alcohols.
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.
