853994-46-4Relevant academic research and scientific papers
Effects of cations, anions and H+ concentration of acidic ionic liquids on the valorization of polysaccharides into furfural
Matsagar, Babasaheb M.,Dhepe, Paresh L.
, p. 6137 - 6144 (2017)
The valorization of hemicellulose into valuable chemicals, such as C5 sugars and furfural, in a one-pot fashion is crucial. In this work, acidic ionic liquids in the presence of water showed high yields of C5 sugars (>80%) with >99% conversion of hemicelluloses at 160 °C. With a water + toluene biphasic solvent system, within 4 h, an 85% furfural yield was obtained directly from hemicellulose in a one-pot fashion using a catalytic amount of 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate. It was seen that Br?nsted acidic ionic liquids (BAILs) perform better than solid acid [Faujasite and Mordenite zeolites; ion exchange resin, Amberlyst-15] and mineral catalysts [HCl and H2SO4]. The higher activity of BAILs compared to solid acids and mineral acids was correlated to the Hammett acidity function (Ho) and ion-dipole type of interactions. The catalysts were characterized using NMR (1H and 13C), elemental analysis and TGA to confirm that they were stable under reaction conditions and were thus recyclable.
Synthesis of alkyl polyglycosides using SO3H-functionalized ionic liquids as catalysts
Wu, Wenliang,Gao, Hongshuai,Hai, Bin,Wang, Binqi,Yu, Min,Nie, Yi
, p. 14710 - 14716 (2021)
An effective process for synthesis of alkyl polyglycosides (APG) was developed using SO3H-functionalized ionic liquids (SFILs) as catalysts. Four SFILs, [PSmim][HSO4], [PSmim][pTSA], [PSPy][HSO4] and [PSPy][pTSA], were designed and synthesized for APG synthesis. The results indicated that [PSmim][HSO4] shows the best catalytic performance among these four SFILs, which has a great agreement with the order of their acidities. When the [PSmim][HSO4] was used as catalyst, the reaction time could be decreased from 24 h to 8 h, and molar ration of n-octanol to glucose could be decreased from 5?:?1 to 3?:?1 under the optimization reaction conditions. In addition, the [PSmim][HSO4] could be easily regenerated and recycled at least 5 times with slight decrease in catalytic activity. Moreover, the catalytic mechanism of [PSmim][HSO4] was further investigated by molecular simulation. The high catalytic activity of [PSmim][HSO4] is attributed to hydrogen bonds between [PSmim][HSO4] and glucose and n-octanol, which could accelerate the protonation of glucose and removal of hydrogen ions from the hydroxyl in n-octanol. This journal is
Condensation of 9-fluorenone and phenol using an ionic liquid and a mercapto compound synergistic catalyst
Lei, Yan,Yu, Limei,Shen, Maochang,Luo, Shikang,Gao, Zhanxian
, p. 15700 - 15705 (2019/10/19)
A series of ionic liquids (ILs) were synthesized and their Hammett acidities (H0) were determined using 4-nitroaniline as the indicator. The relationship among IL's structure, the acid strength, and the catalytic performance in the condensation reaction of 9-fluorenone with phenol was discussed. The effective H0 range of ionic liquids that can catalyse the condensation reaction was obtained. Moreover, the catalysis of the mercapto compound co-catalyst was also systematically studied. According to the analysis of how the structure of the sulfydryl co-catalyst affects the percent conversion of 9-fluorenone and the selectivity of BHPF, a mechanism for the reaction in the IL-thiol cooperative catalytic system was proposed. The present work gave a clear clue to design novel IL catalysts for the synthesis of BHPF.
