C-H bond activation is a fundamental challenge in organic synthesis, and various routes have been explored. Among them, halogenation has played an important role in producing valuable intermediates. We report a novel photoelectrochemical (PEC) tandem C-H chlorination using a Ti-doped Fe2O3 (Ti:Fe2O3) photoanode in a two-phase electrolyte system consisting of natural seawater and a chloroform organic phase. This system enables the in situ generation of Cl2 via the chlorine evolution reaction (CER) with near 100% Faradaic efficiency (FE) while suppressing the competing oxygen evolution reaction (OER). The generated Cl2 undergoes photolytic cleavage, forming chlorine radicals that selectively chlorinate sp3 C-H bonds in toluene, cyclohexane, and ethylbenzene with 100% regioselectivity. This work demonstrates the feasibility of seawater-based PEC halogenation and provides a sustainable strategy for selective C-H functionalization in organic synthesis.
This study was supported by the C1 Gas Refinery Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT, and Future Planning (2015M3D3A1A01064899). This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (RS-2023-00249042). This research was supported by Learning & Academic research institution for Master\u2019s\u00B7PhD students, and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (No. RS-2023-00285390).
