59014-89-0Relevant articles and documents
Application of Bulky NHC-Rhodium Complexes in Efficient S-Si and S-S Bond Forming Reactions
Bo?t, Ma?gorzata,?ak, Patrycja
supporting information, p. 17579 - 17585 (2021/11/18)
The efficient and straightforward syntheses of silylthioethers and disulfides are presented. The synthetic methodologies are based on new rhodium complexes containing bulky N-heterocyclic carbene (NHC) ligands that turned out to be efficient catalysts in thiol and thiol-silane coupling reactions. These green protocols, which use easily accessible reagents, allow obtaining compounds containing S-Si and S-S bonds in solvent-free conditions. Additionally, preliminary tests on coupling of mono- and octahydro-substituted spherosilicates with selected thiols have proved to be very promising and showed that these catalytic systems can be used for the synthesis of a novel class of functionalized silsesquioxane derivatives.
Extended Pummerer fragmentation mediated by carbon dioxide and cyanide
Liu, Jian,Kragh, Rasmus R.,Kamounah, Fadhil S.,Lee, Ji-Woong
supporting information, (2020/10/30)
Pummerer rearrangement reactions generate sulfur (II) oxidation state from sulfur (IV) starting materials in the presence of activating reagents. We found unprecedented transformation of vinyl sulfoxide; disulfide formation reactions mediated by atmospheric pressure of carbon dioxide in extended Pummerer rearrangement reactions. Only under CO2 atmosphere, we observed moderate to high yields of disulfide starting from sulfur (IV) starting materials. Investigations on the reaction mechanism revealed that the degradation of the starting materials and the products was significant in the absence of CO2. Further evidence for the suggested reaction mechanism was obtained by a cross-over experiment and a radical trapping reagent.
TEMPO visible light photocatalysis: The selective aerobic oxidation of thiols to disulfides
Xu, Hui,Zhang, Yu-Fei,Lang, Xianjun
supporting information, p. 1520 - 1524 (2019/12/09)
TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) is well-established in orangocatalysis that usually work in synergy with transition-metal catalysis or semiconductor photocatalysis. Here, TEMPO was turned into a visible light photocatalyst to conduct the selective aerobic oxidation of thiols into disulfides. With O2 as an oxidant, a mild and efficient protocol for the selective oxidation of thiols into disulfides including symmetrical and unsymmetrical ones with 5 molpercent of TEPMO as a photocatalyst was developed at room temperature under the irradiation of 460 nm blue LEDs. It was found that a complex formed between TEMPO and thiols underpinned the visible light activity and disulfides were obtained in very high isolated yields. This work suggests that TEMPO takes diverse roles in for photocatalytic selective oxidative transformations with O2 as the oxidant.