Highly efficient and chemoselective singlet oxygen oxidation of unprotected methionine was performed in water using a continuous mesofluidic reactor. Sustainable process engineering and conditions were combined to maximize process efficiency and atom economy, with virtually no waste generation and safe operating conditions. Three water-soluble metal-free photosensitizers [Rose Bengal, Methylene Blue, and tetrakis(4-carboxyphenyl)porphyrin] were assessed. The best results were obtained with Rose Bengal (0.1 mol %) at room temperature under white light irradiation and a slight excess of oxygen. Process and reaction parameters were monitored in real-time with in-line NMR. Other classical organic substrates (α-terpinene and citronellol) were oxidized under similar conditions with excellent performances.

中文翻译：

---

连续流动条件下甲硫氨酸的可扩展光催化氧化

使用连续的中流体反应器在水中进行未保护的甲硫氨酸的高效且化学选择性的单线态氧氧化。将可持续的工艺工程和条件结合在一起，以最大程度地提高工艺效率和原子经济性，几乎不产生废物，并且没有安全的操作条件。评估了三种水溶性无金属光敏剂[玫瑰红，亚甲基蓝和四（4-羧苯基）卟啉]。室温下在白光照射下使用玫瑰红（0.1 mol％）和略微过量的氧气可获得最佳结果。使用在线NMR实时监控过程和反应参数。其他经典有机底物（α-萜品烯和香茅醇）在相似条件下被氧化，具有出色的性能。