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Abstract：
Development of efficient, stable, and recyclable photocatalysts for organic synthesis is vital for transformation of traditional thermal organic chemistry into green sustainable organic chemistry. In this work, the study reports an electrostatic approach to assemble meso-tetra (4-sulfonate phenyl) porphyrin (TPPS)tetra (4-sulfonate phenyl) porphyrin (TPPS) as a donor and benzyl viologen (BV) as an acceptor into stable and recyclable photocatalyst for an efficient organic transformation reaction - aryl sulfide oxidation. By use of the electrostatic TPPS-BV photocatalysts, 0.1 mmol aryl sulfide with electron-donating group can be completely transformed into aryl sulfoxide in 60 min without overoxidation into sulfone, rendering near 100% yield and selectivity. The photocatalyst can be recycled up to 95% when 10 mg amount is used. Mechanistic study reveals that efficient charge separation between TPPS and BV results in sufficient formation of superoxide which further reacts with the oxidized sulfide by the photocatalyst to produce the sulfoxide. This mechanistic pathway differs significantly from the previously proposed singlet oxygen-dominated process in homogeneous TPPS photocatalysis.
摘要：
高效发展,稳定,和有机合成的可回收光催化剂对于将传统的热有机化学转变为绿色可持续有机化学至关重要。在这项工作中,该研究报告了一种静电方法，将meso-tetra-（4-磺酸苯基）卟啉（TPPS）四（4-磺酸苯基）卟啉（TPPS）作为供体和苄基紫精（BV）作为受体组装成稳定且可回收的光催化剂，以进行有效的有机转化反应-芳基硫化物氧化。通过使用静电TPPS-BV光催化剂，0.1mmol带有给电子基团的芳基硫醚可以在60分钟内完全转化为芳基亚砜，而不会过度氧化为砜，呈现接近100%的产率和选择性。当使用10mg的量时,光催化剂可以再循环高达95%。机理研究表明，TPPS和BV之间的有效电荷分离导致超氧化物的充分形成，超氧化物进一步通过光催化剂与氧化的硫化物反应生成亚砜。该机制途径与先前提出的在均相TPPS光催化中单线态氧主导的过程明显不同。
