The development of photochemistry in water is rapidly advancing, and the demand for water-soluble photocatalysts is increasing. Accordingly, anthraquinone sulfonates are interesting options for the activation of organic molecules through H-atom transfer, proton-coupled electron transfer, or the generation of reactive oxygen species. This work provides an overview of their synthetic applications and discusses future perspectives.

Anthraquinone sulfonates are water-soluble and cost-effective photocatalysts that have been attracting increasing interest due to their unique features. Their sulfonate groups unlock the application of the photoactive anthraquinone core in aqueous solution. Moreover, these readily available catalysts can engage with substrates through different activation modes, such as hydrogen atom transfer and proton-coupled electron transfer events. However, to date, their reactivity has not been fully explored and further applications are expected to emerge. Herein, the existing synthetic applications are outlined and the future perspectives are discussed.