Aryl-Alkenylation and Aryl-Iodination of Strained C–C σ Bonds via Palladium Photoredox Catalysis

Here, we present a Pd/blue-light-catalyzed strategy for the redox-neutral difunctionalization of bicyclo[1.1.0]butanes (BCBs). This mild protocol enables the rapid construction of iodinated and alkenylated 3-spirocyclobutyl oxindoles through strained C–C σ bond activation. Sensitive functional groups were tolerated, including hydroxyl, Bpin, and pyridine, as well as some drug structures. In our approach, C–I bond reductive elimination was more favored than β-H elimination due to the ring strain. The further derivatization of iodinated products proved its synthetic utility. This methodology complements avenues for hybrid palladium catalysis as well as the construction of functionalized spirocyclobutyl molecules.