Photoredox catalysis for oxygenation/deoxygenation between sulfides and sulfoxides by visible-light-responsive polyoxometalates
Photoredox catalysis for oxygenation/deoxygenation between sulfides and sulfoxides by visible-light-responsive polyoxometalates
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DOI：
10.1039/c5nj01045d
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发表时间：
2016-01-01
影响因子：
3.3
通讯作者：
Mizuno, Noritaka
中科院分区：
文献类型：
--
作者：
Suzuki, Kosuke;Jeong, Jinu;Mizuno, Noritaka
在本文中，我们报告了独特的可见光响应的光氧化还原催化的双空位缺位硅钨酸盐TBA（4）H（4）[γ-SiW 10 O 36]（SiW 10）的含硫化合物的官能团转化，即（i）氧氧化的硫化物亚砜和（ii）脱氧的亚砜硫化物。在合适的添加剂，如Ce 3+（电子转移介体氧化）和醇（电子和质子供体脱氧）的存在下，SiW 10显示可见光诱导的电荷转移，通过使用新形成的最高占据的分子轨道来自协调Ce 3+或醇在SiW 10的空位。因此，硫化物的氧化和亚砜的脱氧可以通过用可见光（λ> 400 nm）照射来选择性地进行，以高产率提供相应的所需产物。SiW 10光催化剂可以很容易地回收和重复使用这些转换。根据几个实验的证据，添加剂的作用，以及这些转变的反应机理进行了讨论。
In this paper, we report the unique visible-light-responsive photoredox catalysis of a divacant lacunary silicotungstate TBA(4)H(4)[gamma-SiW10O36] (SiW10) for functional group transformations of sulfur-containing compounds; namely, (i) aerobic oxygenation of sulfides to sulfoxides and (ii) deoxygenation of sulfoxides to sulfides. In the presence of suitable additives, such as Ce3+ (electron transfer mediator for oxygenation) and an alcohol (electron and proton donor for deoxygenation), SiW10 shows visible-light-induced charge transfers by using the newly formed highest occupied molecular orbitals derived from the coordinating Ce3+ or alcohol at the vacant site of SiW10. Consequently, oxygenation of sulfides and deoxygenation of sulfoxides can selectively proceed by irradiation with visible light (lambda > 400 nm) to afford the corresponding desired products in high yields. The SiW10 photocatalysts can readily be recovered and reused for these transformations. Based on evidence from several experiments, the roles of the additives as well as the reaction mechanisms for these transformations are also discussed.