112-53-8Relevant articles and documents
Kinetics of the Acid-catalysed Hydrolysis of Dodecylsulphate and Dodecyldiethoxysulphate Surfactants in Concentrated Micellar Solutions. Part 1. - Effects of Acid and Surfactant Concentrations and of the Nature and Concentration of Counterions
Garnett, Christopher J.,Lambie, Alan J.,Beck, William H.,Liler, Milica
, p. 953 - 964 (1983)
The rates of the acid-catalysed hydrolysis of sodium dodecylsulphate (SDS) and sodium dodecyldiethoxysulphate (SDE2S) have been investigated in concentrated surfactant solutions (0.035 - 0.6 mol dm-3).The acid concentration dependence of the initial rates shows a 'saturation' effect, whereas increasing surfactant concentrations above the c.m.c. lead to a maximum in the k2,obs values, beyond which they decrease sharply.These results are discussed in terms of the ion-exchange pseudophase model of the miceller reaction.The nature of the counterion has an effect on k2,obs, the values following the sequence NH4 > Li > Na >> Mg.This has been ascribed to differences in the ion-exchange constants, KH/X, of these cations in the Stern layer of the micelles with the hydrogen ion.Maintaining the total counterion concentration and the ratio of concentrations of surfactant counterion to the concentration of hydrogen ion constant (at 30, i.e. 0.6 : 0.02 mol dm-3) largely eliminates the decrease in the k2,obs values with increasing surfactant concentration, as expected from the pseudo-phase ion-exchange model.Quantitative agreement between theory and experiment is less good, however, owing at least partly to deviations from ideality in solutions of high ionic strength.
Acid-catalyzed hydrolysis of sodium dodecyl sulfate
Nakagaki,Yokoyama
, p. 1047 - 1052 (1985)
The acid-catalyzed hydrolysis of sodium dodecyl sulfate (1) and the effect of 1-dodecanol (2) on this hydrolysis were investigated. The rate of hydrolysis was followed by measuring the rate of production of HSO4- using a pH-stat. The rate constant (κ(H+)) below the critical micelle concentration (CMC) increased with increasing concentrations of 2, up to a mole ratio of 0.5 for 2 to 1, after which the hydrolysis rate was independent of the concentration of 2. These results suggest the possible formation of a complex between 1 and 2. A micellar solution of pure sodium dodecyl sulfate (20 mM) hydrolyzed 50 times faster than that of a premicellar solution at the same pH. Plots of log κ versus pH were linear with a slope of -1 at pH 4.3. At a constant pH, the addition of NaCl resulted in a decrease in the rate of hydrolysis of a micellar solution. This is probably due to the reduction of concentration of protons at the micelle surface. Furthermore, κ(H+) was also decreased by the addition of 2 in the region where 2 is solubilized in the micelle; again, this was probably due to the reduction of the charge density (σ) on the surface of the micelle.
An effective hydrolysis of crowded chiral esters
Vávra, Jan,Streinz, Ludvík,Vodi?ka, Petr,Budě?ínsky, Milo?,Koutek, Bohumír
, p. 1886 - 1888 (2002)
Trifluoromethanesulfonic acid-coated silica in the absence of solvents is an effective reagent for hydrolysis of sterically crowded chiral esters giving chiral acids in good chemical and optical yield. On the other hand, the method was unsuitable for the
Cleavage of protecting groups catalysed by π-acceptors
Tanemura, Kiyoshi,Nishida, Yoko,Suzuki, Tsuneo,Satsumabayashi, Koko,Horaguchi, Takaaki
, p. 40 - 41 (1999)
The cleavage of protecting groups is caused by the acidic adducts produced from the methanolysis of acceptors.
Selective conversion of coconut oil to fatty alcohols in methanol over a hydrothermally prepared Cu/SiO2 catalyst without extraneous hydrogen
Wu, Liubi,Li, Lulu,Li, Bolong,Zhao, Chen
, p. 6152 - 6155 (2017)
A novel one-pot approach selects a hydrothermally synthesized Cu/SiO2 catalyst (consisting of Cu2O·SiO2 and Cu0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity.
A glucose-activatable trimodal glucometer self-assembled from glucose oxidase and MnO2 nanosheets for diabetes monitoring
Chen, Jin-Long,Li, Li,Wang, Shuo,Sun, Xiao-Yan,Xiao, Lu,Ren, Jia-Shu,Di, Bin,Gu, Ning
, p. 5336 - 5344 (2017)
Daily monitoring of blood glucose is of great importance for the treatment of diabetes mellitus. Herein, we present an ensemble glucometer with a sandwich structure formed by the spontaneous entrapment of glucose oxidase (GOD) onto manganese dioxide nanosheets (MnO2 NSs) via the hydrophobic effect and hydrogen bond interaction. Within the hybrid glucometer, the ultrathin MnO2 NSs act as an enzyme nanosupport and target-activated signal transducer. Trimodal self-indication by fluorescence (FL) and UV-absorbance (UV) and magnetic resonance signal (MRS) activation with glucose-specificity provides multiple response signals to glucose. Taking account of its operational simplicity and convenience, even being observable by the naked eye, a detection limit as low as 0.1 ;M was obtained by using the ensemble glucometer in a colorimetric assay, whilst the precision for 11 replicated detections of 10 M glucose was 3.5% (relative standard deviation, RSD). Notably, the value of the Michaelis-Menton constant of GOD involved the presented glucometer is estimated to be 0.051 mM, showing an exceptional enhanced enzymatic activity of free GOD measured by far. The designed glucometer, with its high sensitivity and simplicity highlighted, was capable of routine blood glucose monitoring for type-I diabetes mellitus in rats. Furthermore, the fully integrated platform can be readily generalized in principle for a number of biomarkers for point of care diagnostics in the future.
Benzimidazoline-dimethoxypyrene. An effective promoter system for photoinduced electron transfer promoted reductive transformations of organic compounds
Hasegawa, Eietsu,Hirose, Harumi,Sasaki, Kosuke,Takizawa, Shinya,Seida, Takayuki,Chiba, Naoki
, p. 1147 - 1161 (2009)
2-(p-Methoxyphenyl)-1,3-dimethylbenzimidazoline (ADMBI) and 2-(o-hydroxyphenyl)-1,3-dimethylbenzimidazoline (HPDMBI) are used as reducing reagents in 1,8-dimethoxypyrene (1,8-DMP) sensitized, photoinduced electron transfer (PET) reactions. This system was effectively used for PET induced, reductive transformations of various organic substrates, including α,β-epoxy ketones, the olefin tethered 2-bromomethyl-l-tetralone, and o-allyloxy-iodobenzene, as well as for the deprotection reactions of dodecyl-2-benzoylbenzoate and N-sulfonylindole. The results of studies show that 1,8-DMP is a more effective sensitizer than the previously used 9-methylcarbazole for deprotection of N-methyl-4-picolinium ester.
Transformation of methyl laurate into lauryl alcohol over a Ru-Sn-Mo/C catalyst by using zerovalent iron and water as an in situ hydrogen source
Sagata, Kunimasa,Hirose, Mina,Hirano, Yoshiaki,Kita, Yuichi
, p. 85 - 91 (2016)
Hydrogenation and hydrogenolysis reactions, which are used in the chemical industry for the synthesis of organic compounds, are very expensive operations because of the need for facilities that can liquefy, transport, and store the hydrogen produced through steam reforming of natural gas. We have therefore developed a novel approach for hydrogenation that does not require the use of high-cost facilities. Using this, zerovalent iron (Fe) and water (H2O) are introduced as an in situ hydrogen donor system for the transformation of methyl laurate into lauryl alcohol over a Ru-based catalyst. This combination of a Ru-Sn-Mo/C catalyst with a Fe/H2O system showed significantly higher transformation rates for the conversion of methyl laurate into lauryl alcohol than a conventional reaction system that uses pressurized hydrogen. The reason for this is that the new system produces lauric acid as an intermediate during the reaction, which is more efficiently hydrogenized into lauryl alcohol over the Ru-Sn-Mo/C catalyst. The Fe/H2O system played two important roles: a hydrogen source for the hydrogenation reaction and a catalyst for the generation of lauric acid by methyl laurate hydrolysis.
Riemschneider,R.,Hoyer,G.-A.
, p. 642 - 651 (1968)
Influence of Higher Alcohols on Acid-Catalyzed Hydrolysis of Sodium Dodecyl Sulfate. Effect of Complex Formation
Nakagaki, Masayuki,Yokoyama, Shoko
, p. 935 - 936 (1986)
The order of effectiveness of 1-alkanols for increasing the rate of acid-catalyzed hydrolysis of sodium dodecyl sulfate is 1-dodecanol>-tetradecanol>>1-decanol.The effect of 1-alkanols on this hydrolysis is discussed from the viewpoint of formation of complexes composed of SDS and 1-alkanol.
Preparation of cyclohexene-d10 by H/D-exchange reaction
Ishibashi, Kenichi,Matsubara, Seijiro
, p. 724 - 725 (2007)
Preparation of fully deuterium-labeled cyclohexene by H/D-exchange reaction was performed efficiently in the presence of ruthenium catalyst under irradiation of microwaves. The reaction proceeds via a repetition of hydroruthenation and β-elimination. Copyright
Adkins,Burgoyne,Schneider
, p. 2626 (1950)
Lithium amidotrihydroborate, a powerful new reductant. Transformation of tertiary amides to primary alcohols
Myers, Andrew G.,Yang, Bryant H.,Kopecky, David J.
, p. 3623 - 3626 (1996)
Lithium amidotrihydroborate (LiH2NBH3, LAB) is a new and highly nucleophilic reducing agent that is easily prepared by deprotonation of the commercial reagent borane-ammonia complex (H2NBH3) with n-BuLi in tetrahydrofuran (THF) at 0°C. LAB is found to be a superior reagent for the transformation of tertiary amides into the corresponding primary alcohols.
Elucidation of the mechanism of titanocene-mediated epoxide opening by a combined experimental and theoretical approach
Daasbjerg, Kim,Svith, Heidi,Grimme, Stefan,Gerenkamp, Mareike,Mueck-Lichtenfeld, Christian,Gansaeuer, Andreas,Barchuk, Andriy,Keller, Florian
, p. 2041 - 2044 (2006)
(Figure Presented) Steric effects govern the catalytic reductive epoxide ring opening. This is the result of combined experimental and theoretical studies, which revealed interesting features of the catalyst structure, substrate binding, transition state (see picture), and reaction energies. In light of these, highly selective conditions for the ring opening can be proposed.
Deactivation mechanism of Cu/Zn catalyst poisoned by organic chlorides in hydrogenation of fatty methyl ester to fatty alcohol
Huang, Hui,Wang, Shaohong,Wang, Shujia,Cao, Guiping
, p. 351 - 357 (2010)
The mechanism of deactivation of Cu/Zn catalyst poisoned by organic chlorides in hydrogenation of methyl laurate to lauryl alcohol in a slurry phase was studied in a stirred autoclave. The catalystwas prepared by co-precipitation, and the un-poisoned and poisoned catalysts were characterized using XRD, BET, ICP-AES and SEM, respectively. The results indicated that both of catalytic activity and selectivity decreased with increasing amount of chlorides in methyl laurate. According to the characterization of the catalysts, the main causes for the chlorine deactivation of the Cu/Zn catalyst were that the chlorides could modify the valence state of active sites, decrease the BETsurface area, and promote the growth of crystal and catalyst agglomeration. Further investigation indicated that chlorine atom decomposed from the chlorides combined with ZnO to produce ZnCl2, which could be dissolved in the liquid and promote ester-exchange reaction to lauryl laurate as Lewis acid.
Manganese-Catalyzed Hydrogenation of Sclareolide to Ambradiol
Zubar, Viktoriia,Lichtenberger, Niels,Schelwies, Mathias,Oeser, Thomas,Hashmi, A. Stephen K.,Schaub, Thomas
, (2021/11/16)
The hydrogenation of (+)-Sclareolide to (?)-ambradiol catalyzed by a manganese pincer complex is reported. The hydrogenation reaction is performed with an air- and moisture-stable manganese catalyst and proceeds under relatively mild reaction conditions at low manganese and base loadings. A range of other esters could be successfully hydrogenated leading to the corresponding alcohols in good to quantitative yields using this easy-to-make catalyst. A scale-up experiment was performed leading to 99.3 % of the isolated yield of (?)-Ambradiol.
Hydrodeoxygenation of non-edible bio-lipids to renewable hydrocarbons over mesoporous SiO2-TiO2 supported NiMo bimetallic catalyst
Ba, Wenxia,Fu, Lin,Li, Xin,Li, Yongfei,Liu, Yuejin,Zhang, Simiao,Zhao, Jingxuan
, (2022/02/17)
Ni-catalysts are promising candidate for fatty acid hydrodeoxygenation (HDO), but are limited by their quite poor HDO selectivity. Herein, a mesoporous Ni-Mo/SiO2-TiO2 catalyst was prepared by precipitation and impregnation method and used for methyl laurate HDO, yielding 96.3% n-dodecane yield at full methyl laurate conversion. Non-edible bio-lipids such as jatropha oil and waste cooking oil also converted to n-C14+16+18 hydrocarbons with yields of 94.3% and 92.4%, respectively. Besides, Ni-Mo/SiO2-TiO2 shows strong chemoselectivity towards the HDO of ester groups. Experimental results showed that Mo-addition and Ti/Si molar ratio strongly influenced HDO selectivity. Oxygen vacancies formed on partial reduced TiO2 surface securely bond Ni NPs and activate C[dbnd]O/C–O bonds, improving Ni NPs dispersion and promoting R–COOCH3→R–CHO reduction. Additional, Mo-addition switches reactant adsorption configuration from η1(C)-acyl to η2(C,O)-aldehyde, promoting the formation of R–CH2OH intermediate. Moreover, abundant Br?nsted acidic sites (Mo4+–OH, Mo6+–OH, hydroxy groups) facilitate the HDO of R-CH2OH to R-CH3.
Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
supporting information, p. 12671 - 12674 (2021/12/04)
Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
