Visible-Light-Induced Site-Selective C(sp2/sp3)-H Functionalization toward Epoxides

Abstract

This work presents the first practical and modular strategy for visible-light-induced, site-selective C(sp²/sp³)-H functionalization of inert C–H bonds in feedstock chemicals. Utilizing tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer photocatalyst, a broad range of substrates, including ethers, thioethers, amides, alkanes, aldehydes, and complex bio-related molecules, undergo efficient epoxidation with allylic peroxides under mild, oxidant-free, and operationally simple conditions. The protocol affords diverse, highly functionalized oxiranes with excellent site-selectivity and wide functional group tolerance at room temperature under 390 nm light irradiation. Its synthetic utility is further demonstrated by gram-scale synthesis and versatile post-transformations, such as ring-opening, reduction, halogenation, azidation, and one-pot cyclizations. Molecular docking studies reveal that the resulting epoxides exhibit favorable binding interactions with kinase proteins, highlighting potential applications in biochemical research and drug development. This visible-light-mediated C–H epoxidation offers a green, efficient, and modular route to high-value oxiranes, expanding the toolkit for organic synthesis and medicinal chemistry.