6998-82-9Relevant articles and documents
Highly-efficient Ru/Al-SBA-15 catalysts with strong Lewis acid sites for the water-assisted hydrogenation of: P -phthalic acid
Ahamad, Tansir,Kankala, Ranjith Kumar,Mao, Cong,Matsagar, Babasaheb M.,Wu, Kevin C.-W.,Yang, Yucheng,Zhang, Xueqin,Zheng, Jingwei
, p. 2443 - 2451 (2020/05/14)
Ruthenium nanoparticles supported onto aluminum-doped mesoporous silica catalysts (Ru/Al-SBA-15) are fabricated using hydrothermal and impregnation methods for catalysis application. The Ru/Al-SBA-15-3 catalyst at a Si/Al molar ratio of 3 exhibited excellent catalytic performance for the hydrogenation of p-phthalic acid with high conversion efficiency (100.0%) and cis-isomer selectivity (84.0%) in water. Moreover, this system displays exceptional stability and recyclability through preserving the conversion efficiency, as well as a cis-isomer selectivity of 90.2 and 83.3%, respectively, after reusing it fourteen times. Such an exceptional system can also be ideal for the hydrogenation of aromatic dicarboxylic acids and their ester derivatives in water. Strong Lewis acid sites due to doped Al species play significant roles in the hydrogenation reaction. Moreover, isotope labeling studies indicated that water molecules effectively participated in the hydrogenation reaction. Hydrogen and water contributed half of the hydrogen atoms for this hydrogenation reaction. In the end, a plausible mechanistic pathway for the hydrogenation of p-phthalic acid using the Ru/Al-SBA-15-3 catalyst in water is proposed.
Cyclohexane Rings Reduce Membrane Permeability to Small Ions in Archaea-Inspired Tetraether Lipids
Koyanagi, Takaoki,Leriche, Geoffray,Onofrei, David,Holland, Gregory P.,Mayer, Michael,Yang, Jerry
supporting information, p. 1890 - 1893 (2016/02/03)
Extremophile archaeal organisms overcome problems of membrane permeability by producing lipids with structural elements that putatively improve membrane integrity compared to lipids from other life forms. Herein, we describe a series of lipids that mimic some key structural features of archaeal lipids, such as: 1) single tethering of lipid tails to create fully transmembrane tetraether lipids and 2) the incorporation of small rings into these tethered segments. We found that membranes formed from pure tetraether lipids leaked small ions at a rate that was about two orders of magnitude slower than common bilayer-forming lipids. Incorporation of cyclopentane rings into the tetraether lipids did not affect membrane leakage, whereas a cyclohexane ring reduced leakage by an additional 40 %. These results show that mimicking certain structural features of natural archaeal lipids results in improved membrane integrity, which may help overcome limitations of many current lipid-based technologies.
The 1,3-dimethoxytrimethylene bridge as two latent carboxyl groups: synthesis of cis-isoaposantenic and cis-apocamphoric acids
Camps, Pelayo,Jaime, Carlos
, p. 2848 - 2852 (2007/10/02)
The syntheses of cis-cyclopentane-1,3-dicarboxylic acid, cis-cyclohexane-1,3-dicarboxylic acid, cis-isoaposantenic acid, and cis-apochamphoric acid are described.The key step of each synthesis is the bromine oxidation of an appropiate bicyclic compound in which a 1,3-dimethoxytrimethylene bridge is converted into two cis-carboxyl groups.
