A supramolecular dimer strategy for enhancing the selective generation of sulfides and sulfoxides by visible-light induced photoredox thiol–ene cross-coupling reactions of anthraquinone

Abstract

Enhancing the photocatalytic efficiency of organic photocatalysts and increasing the generation capacity of reactive oxygen species (ROS) have consistently been substantial obstacles. In this study, we designed and synthesized a supramolecular dimer based on anthraquinone (Amvp-CB[8]) between the methylated vinylpyridinium substituted anthraquinone derivative (Amvp) and cucurbit[8]uril (CB[8]) through host–guest interactions in the aqueous solution. Compared to the monomer Amvp, the supramolecular dimer Amvp-CB[8] exhibited significantly enhanced fluorescence and demonstrated remarkable capabilities in generating singlet oxygen (¹O₂) and superoxide anion radicals (O₂˙⁻) in water. Importantly, Amvp-CB[8] displayed superior photocatalytic activity under visible light, facilitating efficient photoredox thiol–ene cross-coupling reactions between phenthiol and styrene, which selectively enabled rapid synthesis of sulfides within 0.5 h and sulfoxides within 12 h, showcasing high efficiency, low catalyst loading, and excellent functional group tolerance. This study introduces a novel supramolecular dimer strategy that enhances the design of efficient photocatalysts for organic conversions in photocatalysis.