Sulfur-containing molecules participate in many essential biological processes. Of utmost importance is the methylthioether moiety, present in the proteinogenic amino acid methionine and installed in tRNA by radical-S-adenosylmethionine methylthiotransferases. Although the thiol–ene reaction for carbon–sulfur bond formation has found widespread applications in materials or medicinal science, a biocompatible chemo- and regioselective hydrothiolation of unactivated alkenes and alkynes remains elusive. Here, we describe the design of a general chemoselective anti-Markovnikov hydroalkyl/aryl thiolation of alkenes and alkynes—also allowing the biologically important hydromethylthiolation—by triplet–triplet energy transfer activation of disulfides. This fast disulfide–ene reaction shows extraordinary functional group tolerance and biocompatibility. Transient absorption spectroscopy was used to study the sensitization process in detail. The hereby gained mechanistic insights were successfully employed for optimization of the catalytic system. This photosensitized transformation should stimulate bioimaging applications and carbon–sulfur bond-forming late-stage functionalization chemistry, especially in the context of metabolic labelling.

含硫分子参与许多必不可少的生物学过程。最重要的是甲硫基醚部分，其存在于蛋白氨基酸甲硫氨酸中，并通过自由基-S-腺苷甲硫氨酸甲硫基转移酶安装在tRNA中。尽管用于碳-硫键形成的硫醇-烯反应已在材料或医学科学中得到广泛应用，但未活化的烯烃和炔烃的生物相容性化学和区域选择性氢硫醇化作用仍然难以捉摸。在这里，我们描述了一种普通的化学选择性抗氧化剂的设计。-Markovnikov烯烃和炔烃的加氢烷基/芳基硫醇化反应（也使生物学上重要的加氢甲基硫醇化反应）通过三重态-三重态能量转移激活二硫化物。这种快速的二硫键反应显示出非凡的官能团耐受性和生物相容性。瞬态吸收光谱用于详细研究敏化过程。由此获得的机械见解已成功地用于优化催化系统。这种光敏化的转化应刺激生物成像的应用和碳硫键形成的后期功能化化学反应，特别是在代谢标记的背景下。