Mechanistic Study of a Photocatalyzed CS Bond Formation Involving Alkyl/Aryl Thiosulfate
作者:Yiming Li、Weisi Xie、Xuefeng Jiang
DOI:10.1002/chem.201502951
日期:2015.11.2
This study presents thioether construction involving alkyl/aryl thiosulfates and diazonium salt catalyzed by visible‐light‐excited [Ru(bpy)3Cl2] at room temperature in 44–86 % yield. Electron paramagnetic resonance studies found that thiosulfate radical formation was promoted by K2CO3. Conversely, radicals generated from BnSH or BnSSBn (Bn=benzyl) were clearly suppressed, demonstrating the special
这项研究提出了在室温下可见光激发[Ru(bpy)3 Cl 2 ]催化的含烷基/芳基硫代硫酸盐和重氮盐的硫醚结构,产率为44-86%。电子顺磁共振研究发现,K 2 CO 3促进了硫代硫酸根的形成。相反,从BnSH或BnSSBn(Bn =苄基)生成的自由基被明显抑制,证明了该系统中硫代硫酸盐的特殊性质。瞬态吸收光谱证实了[Ru(bpy)3 Cl 2 ]与4-MeO-苯基重氮盐之间的电子转移过程,其速率常数为1.69×10 9 M -1 s -1。通过X射线衍射确认了相应的自由基捕获产物。确定了完整的反应机理以及发射猝灭数据。此外,该系统有效地避免了在含有Ru 2+的光激发体系中H 2 O引起的硫化物过氧化。研究了具有各种电子性质的芳基和杂芳基重氮盐的合成兼容性。烷基和芳基取代的硫代硫酸盐都可用作底物。值得注意的是,药物衍生物在温和的条件下能够平稳地进行后期硫化。
Controllable Sulfoxidation and Sulfenylation with Organic Thiosulfate Salts via Dual Electron- and Energy-Transfer Photocatalysis
作者:Yiming Li、Ming Wang、Xuefeng Jiang
DOI:10.1021/acscatal.7b02735
日期:2017.11.3
Sulfoxides and sulfides are two important functional groups in organic molecules, containing different valence states of sulfur. Both sulfoxidation and sulfenylation with common sulfurating reagents were successfully tuned via a facile variation of the atmosphere under photocatalyzed conditions. The sulfoxidation and sulfenylation transformations involved tandem electron-/energy-transfer and single-electron-transfer
Synthesis and thermal transformation of stable monocyclic λ4-thiabenzenes
作者:Hiroshi Shimizu、Noriaki Kudo、Tadashi Kataoka、Mikio Hori
DOI:10.1039/b102806p
日期:——
The stable monocyclic λ4-thiabenzenes 6aâe, which are stabilized with electron-withdrawing substituents such as benzoyl, cyano and alkoxycarbonyl groups, are synthesized in high yields by proton abstraction from the corresponding thiopyranium salts 5aâe with triethylamine in ethanol. The ylidic properties of the λ4-thiabenzenes are established based on spectral and chemical evidence. Thermal decomposition of the λ4-thiabenzenes affords alkyl-rearranged products 7, 8, and 9, thienofuran derivatives 10 (from benzoyl-substituted λ4-thiabenzenes), and thiophene derivatives 11. A plausible mechanism for the formation of those products is also discussed.
Electron transfer in the peroxytrifluoroacetic acid-assisted sulfoxidation and oxidative destruction of benzhydryl sulfides
作者:A. R. Akopova、A. S. Morkovnik、V. N. Khrustalev、A. V. Bicherov
DOI:10.1007/s11172-013-0159-1
日期:2013.5
The reactions of benzhydryl sulfides Ph2CHSCH2R (R = H, CONH2, COOH, CN) with peroxytrifluoroacetic acid in CF3COOH were studied experimentally and by the quantum chemical density functional theory (DFT) method and exhibited an unusual dependence on the substituent R. When R≠H, a complicated oxidative destruction of the substrates occurs to form 2,4,6-tribenzhydrylphenol as one of the products, while
通过实验和量子化学密度泛函理论 (DFT) 方法研究了二苯甲基硫化物 Ph2CHSCH2R (R = H, CONH2, COOH, CN) 与过氧三氟乙酸在 CF3COOH 中的反应,并表现出对取代基 R 的异常依赖性。 当 R≠ H,底物发生复杂的氧化破坏,形成 2,4,6-三二苯甲基苯酚作为产物之一,而在 R = H 的情况下,起始二苯甲基硫化物被顺利亚氧化。这一事实是由于在初始步骤中从底物到试剂的共同电子转移以及随后形成的物种转化的差异。