110-88-3Relevant articles and documents
The salt effect on the yields of trioxane in reaction solution and in distillate
Yin, Liuyi,Hu, Yufeng,Zhang, Xianming,Qi, Jianguang,Ma, Weiting
, p. 37697 - 37702 (2015)
Batch reaction experiments were performed to investigate the salt effect on the yield of trioxane in the reaction solution. The salts considered include NaHSO4, Na2SO4, NaH2PO4, Na2HPO4, KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3. The effects of the anionic structure and the cation charge density on the yield of trioxane in the reaction solution were elucidated and the mechanisms that govern such effects were established. It is shown that the first four salts exerted a negative effect on the yield of trioxane in the reaction solution and such an effect increased progressively from left to right. This trend is due to the formation of NaHSO4, H3PO4, or (H3PO4 and NaH2PO4), which decreased the concentration of H+ in the solution. The latter six salts showed a positive effect on the yield of trioxane in the reaction solution. The salt effect paralleled the ability of the salt to decrease the water activity of the reaction solution and followed the order KCl 2 2 3. Continuous production experiments were performed to investigate the salt effect on the concentration of trioxane in the distillate. The salts considered were KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3, and the salt effect increased progressively from left to right. Such an effect was shown to be determined by the ability of the salt to increase the yield of trioxane in the reaction solution and to increase the relative volatilities of trioxane and water and of trioxane and oligomers.
Study of trioxane production process with super- or subcritical fluid as solvent and extractant
Tanaka, Michio,Ogino, Kenji
, p. 1927 - 1932 (2006)
A super- or subcritical fluid was used as a reaction solvent for nonaqueous trioxane synthesis instead of common organic solvents. The generation of trioxane from paraformaldehyde was observed in the presence of the catalyst when carbon dioxide reached a supercritical region, suggesting that the supercritical carbon dioxide acted as the reaction solvent. In the case of Freon 12, the trioxane was effectively produced even in a subcritical state. Copyright Taylor & Francis Group, LLC.
Selective Reduction of CO2 to CH4 by Tandem Hydrosilylation with Mixed Al/B Catalysts
Chen, Jiawei,Falivene, Laura,Caporaso, Lucia,Cavallo, Luigi,Chen, Eugene Y.-X.
, p. 5321 - 5333 (2016)
This contribution reports the first example of highly selective reduction of CO2 into CH4 via tandem hydrosilylation with mixed main-group organo-Lewis acid (LA) catalysts [Al(C6F5)3 + B(C6F5)3] {[Al] + [B]}. As shown by this comprehensive experimental and computational study, in this unique tandem catalytic process, [Al] effectively mediates the first step of the overall reduction cycle, namely the fixation of CO2 into HCOOSiEt3 (1) via the LA-mediated C - O activation, while [B] is incapable of promoting the same transformation. On the other hand, [B] is shown to be an excellent catalyst for the subsequent reduction steps 2-4, namely the hydrosilylation of the more basic intermediates [1 to H2C(OSiEt3)2 (2) to H3COSiEt3 (3) and finally to CH4] through the frustrated Lewis pair (FLP)-type Si-H activation. Hence, with the required combination of [Al] and [B], a highly selective hydrosilylative reduction of CO2 system has been developed, achieving high CH4 production yield up to 94%. The remarkably different catalytic behaviors between [Al] and [B] are attributed to the higher overall Lewis acidity of [Al] derived from two conflicting factors (electronic and steric effects), which renders the higher tendency of [Al] to form stable [Al]-substrate (intermediate) adducts with CO2 as well as subsequent intermediates 1, 2, and 3. Overall, the roles of [Al] and [B] are not only complementary but also synergistic in the total reduction of CO2, which render both [Al]-mediated first reduction step and [B]-mediated subsequent steps catalytic.
Methanesulfinylation of Benzyl Halides with Dimethyl Sulfoxide
Fu, Duo,Dong, Jun,Du, Hongguang,Xu, Jiaxi
, p. 2752 - 2758 (2020/01/31)
A phenyltrimethylammonium tribromide-mediated nucleophilic substitution/oxygen transformation reaction of benzyl halides with DMSO has been developed. In this transition-metal-free reaction, DMSO acts as not only a solvent but also a "S(O)Me" source, thus providing a convenient method for the efficient and direct synthesis of various benzyl methyl sulfoxides.
(V)/Hydrotalcite, (V)/Al2O3, (V)/TiO2 and (V)/SBA-15 catalysts for the partial oxidation of ethanol to acetaldehyde
Hidalgo,Ti?ler,Kubi?ka,Raabova,Bulanek
, p. 178 - 189 (2016/05/19)
Vanadium-based catalysts have been investigated in the partial oxidation of ethanol to acetaldehyde with the aim of understanding relationship between vanadium structure and acetaldehyde productivity. Hydrotalcite, Al2O3, TiO2 and SBA-15 with and without a 5% of vanadium content were prepared to study the oxidative dehydrogenation of ethanol. They were characterized by XRF, TPR (H2), NH3-TPD, CO2-TPD, RAMAN, UV-vis, Nitrogen physisorption, XRD and SEM. The most easily reducible catalysts (as determined by TPR) were the most active ones. In the low temperature region (150 °C), the most active catalyst was the V/TiO2 which presented stable activity in the production of acetaldehyde up to TOS = 200 h. On the contrary, in the high temperature region (250 °C), the most active catalyst was the V/Al2O3catalyst. The most promising result was obtained over V/TiO2 catalyst that afforded a total ethanol conversion of 60.4%wt. and a selectivity to acetaldehyde of 76.2%wt. at TOS = 164 h and T = 150 °C. Also, hydrotalcite was tested for the first time for this type of reaction providing a conversion lower than 7%wt. with a selectivity of 100%wt. to acetaldehyde at T = 150-225 °C.