26153-41-3Relevant articles and documents
Efficient hydrogenation of levulinic acid catalysed by spherical NHC-Ir assemblies with atmospheric pressure of hydrogen
Liu, Yaoqi,Lu, Zeye,Shen, Lingyun,Tu, Tao,Wu, Jiajie,Zheng, Qingshu
supporting information, p. 5037 - 5042 (2021/07/29)
A practical, efficient, and mild hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) under 1 atm H2was realized by single-sited 3D porous self-supported N-heterocyclic carbene iridium catalysts. Quantitative yields and selectivities were achieved at 0.02 mol% catalyst loading, and the catalyst could be reused for 9 runs without obvious loss of selectivity or activity.
Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid
Brouwer, Albert M.,De Bruin, Bas,Van Leeuwen, Nicole S.,Van Vliet, Kaj M.
supporting information, p. 398 - 408 (2020/03/27)
Where monochloroacetic acid is widely used as a starting material for the synthesis of relevant groups of compounds, many of these synthetic procedures are based on nucleophilic substitution of the carbon chlorine bond. Oxidative or reductive activation of monochloroacetic acid results in radical intermediates, leading to reactivity different from the traditional reactivity of this compound. Here, we investigated the possibility of applying monochloroacetic acid as a substrate for photoredox catalysis with styrene to directly produce γ-phenyl-γ-butyrolactone. Instead of using nucleophilic substitution, we cleaved the carbon chlorine bond by single-electron reduction, creating a radical species. We observed that the reaction works best in nonpolar solvents. The reaction does not go to full conversion, but selectively forms γ-phenyl-γ-butyrolactone and 4-chloro-4-phenylbutanoic acid. Over time the catalyst precipitates from solution (perhaps in a decomposed form in case of fac-[Ir(ppy)3]), which was proven by mass spectrometry and EPR spectroscopy for one of the catalysts (N,N-5,10-di(2-naphthalene)-5,10-dihydrophenazine) used in this work. The generation of HCl resulting from lactone formation could be an additional problem for organometallic photoredox catalysts used in this reaction. In an attempt to trap one of the radical intermediates with TEMPO, we observed a compound indicating the generation of a chloromethyl radical.
Indium-Catalyzed Direct Conversion of Lactones into Thiolactones and Selenolactones in the Presence of Elemental Sulfur and Selenium
Sakai, Norio,Horikawa, Shuhei,Ogiwara, Yohei
, p. 565 - 574 (2017/12/26)
The direct conversion of lactones into thiolactones with elemental sulfur (S 8) catalyzed by InCl 3 /PhSiH 3 in a one-pot reaction is described. This catalytic system was successfully applied to the novel preparation of selenolactones from lactones and selenium.
