- Synthesis of Branched Biolubricant Base Oil from Oleic Acid
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The mature manufacturing of synthetic lubricants (poly-α-olefins, PAO) proceeds through oligomerization, polymerization, and hydrogenation reactions of petrochemical ethylene. In this work, we utilize the inexpensive bio-derived oleic acid as raw material to synthesize a crotch-type C45 biolubricant base oil via a full-carbon chain synthesis without carbon loss. It contains several cascade chemical processes: oxidation of oleic acid to azelaic acid (further esterification to dimethyl azelate) and nonanoic acid (both C9 chains). The latter is then selectively hydrogenated to nonanol and brominated to the bromo-Grignard reagent. In a next step, a C45 biolubricant base oil is formed by nucleophilic addition (NPA) of excessive C9 bromo-Grignard reagent with dimethyl azelate, followed by subsequent hydrodeoxygenation. The specific properties of the prepared biolubricant base oil are almost equivalent to those of the commercial lubricant PAO6 (ExxonMobil). This process provides a new promising route for the production of value-added biolubricant base oils.
- Chen, Shuang,Wu, Tingting,Zhao, Chen
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p. 5516 - 5522
(2020/09/07)
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- Synthesis and characterization of anaerobic degradation biomarkers of n-alkanes via hydroxylation/carboxylation pathways
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Metabolite profiling is a powerful method in research on anaerobic biodegradation of hydrocarbons. Hydroxylation and carboxylation are proposed pathways in anaerobic degradation but very little direct evidence is available about metabolites and signature biomarkers. 2-Acetylalkanoic acid is a potential signature metabolite because of its unique and specific structure among possible intermediates. A procedure for the synthesis of four homologues with various carbon chain lengths was proposed and the characteristics of 2-acetyl-alkanoic acid esters were investigated using four derivatization processes, namely methyl, ethyl, n-butyl and trimethylsilyl esterification. Four intermediate fragments observed were at m/z 73 + 14n, 87 + 14n, 102 + 14n (n = 1, 2 and 4 for methyl, ethyl and n-butyl ester, respectively) and [M - 42]+ for three of the derivatization methods. For silylation, characteristic ions were observed at m/z 73, 117, [M - 42]+ and [M - 55]+ . These are basic and significant data for the future identification of potential intermediates of the hydroxylation and carboxylation pathways in hydrocarbon degradation.
- Zhou, Jing,Bian, Xin-Yu,Zhou, Lei,Mbadinga, Serge Maurice,Yang, Shi-Zhong,Liu, Jin-Feng,Gub, Ji-Dong,Mua, Bo-Zhong
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- Visible-light photoredox catalysis using a macromolecular ruthenium complex: Reactivity and recovery by size-exclusion nanofiltration in continuous flow
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A novel macromolecular photoredox catalyst based on [Ru(bpy)3]2+ anchored to a 2nd-generation PAMAM dendrimer has been developed. Its catalytic activity under visible light irradiation and recyclability using organic solvent nanofiltration with a size-exclusion membrane have been explored under continuous flow conditions.
- Guerra, Javier,Cantillo, David,Kappe, C. Oliver
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p. 4695 - 4699
(2016/07/11)
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- A practical method for O-acylation of N -hydroxythiazole-2(3 H)-thiones
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O-Acylation of 4- and 4,5-substituted N-hydroxythiazole-2(3H)-thiones occurred in solutions of acetone upon treatment with solid K2CO3 and a variety of neat acyl chlorides (primary, secondary, and tertiary alkyl, aryl; 60-87% yield; ~10 g scale).
- Schur, Christine,Gross, Andreas,Hartung, Jens
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experimental part
p. 538 - 542
(2010/06/13)
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- Calamitic organometallic liquid crystals with terminal metal. Syntheses and liquid crystal properties of dicarbonylrhodium(I) β-diketonate complexes
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A series of novel organometallic complexes based on γ-substituted β-diketone ligands with terminal metal Rh(I) have been prepared by reaction of the ligands with [Rh(CO)2(μ-Cl)]2. The mesomorphism of the ligands and complexes has been investigated using DSC and polarizing microscope. It is found that non-mesogenic ligands with n=7, 8, 9, 10, 11 can form liquid crystalline phase by direct coordination to metal. The effect of the terminal carbon number on the mesomorphism has also been discussed.
- Wan, Wen,Guang, Wen-Jie,Zhao, Ke-Qin,Zheng, Wei-Zhong,Zhang, Liang-Fu
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p. 157 - 161
(2007/10/03)
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- Hydroalumination of alkenes by the LiAlH4*3AlBr3 system
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The hydroalumination of a series of alkenes and some fused aromatic hydrocarbons by the LiAlH4*3AlBr3 system in low-polar solvents was studied.Alkenes with mono-, di-, tri-, and tetraalkyl substituted, mono- and diaryl substituted double bonds and anthracene react at room temperature to give the corresponding dibromoaluminoalkanes in high yields.Benzylidenefluorene, tetraphenylethylene, naphthalene, and phenanthrene do not undergo hydroalumination under these conditions.Camphene, bicyclooct-2-ene, and norbornene afford the corresponding organoaluminum compounds with high stereoselectivity.Oxidation and halo- and acyldemetallation of the resulting alkyl- and arylalanes were carried out.
- Gorobets, E. V.,Shitikova, O. V.,Lomakina, S. I.,Tolstikov, G. A.,Kuchin, A. V.
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p. 1573 - 1578
(2007/10/02)
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- Liquid crystal compounds and compositions
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Smetic C liquid crystal compounds, represented by the following formula (1) or (2) are disclosed. R1-O-A1-C≡C-A2-CO-(O)P-R2 (2)wherein R1and R2are C1-18 alkyl groups; A is a cyclic group, such as aubstituted or unsubstituted 1,4-phenylene group, X is direct bond, O or C#IDW#C; Y is -C#IDW#C- or -CH2CH2-; one of A1and A2is 1,4-phenylene group and the other is, 2,3-difluoro-1,4-phenylene group; and p is 0 or 1. These compounds can provide ferroelectric liquid crystal composition of low viscosity, and are useful as a component giving negative dielectric anisotropy and enlarging a temperature range showing smetic C phase.
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- Selectivity of Radical Formation in the Reaction of Carbonyl Compounds with Manganese(III) Acetate
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The selectivity of radical generation in the oxidation of carbonyl compounds by manganese(III) has been studied in two ways.Competitive reaction of acetic and propionic acids under conditions in which the resultant radicals are trapped efficiently by an alkene suggests that propionic acid reacts some 3.8 times more readily than does acetic acid.Oxidation of butanone under similar conditions gives products in the formation of which reaction has occurred 2.9 times more readily at C-3 of butanone than at C-1.However, this ratio reflects a combination of chain propagation and of initiation by manganese(III) oxidation.When propagation is effectively eliminated, the C-1 position is the more reactive.The significance of these observations on the mechanism of oxidation of carbonyl compounds by manganese(III) is discussed.It is suggested that enol radical-cations can be formed in the reaction but that these do not give carbonyl-stabilised radicals by deprotonation.
- Midgley, Gary,Thomas, C. Barry
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p. 1103 - 1108
(2007/10/02)
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- Method of improved pest control
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The disclosure describes a method for improved plant pest control comprising contacting a plant or plant pest with a composition comprising an effective amount of a plant pesticide and an effective delivery enhancing amount of compound having the structural formula STR1 wherein R' is H or a lower alkyl group having 1-4 carbon atoms, m is 3-7, n is 0-17 and R is --CH3, STR2 where R" is H or halogen, with the proviso that if m is 3 and R is CH3, then n is 5-17. Typical plant pesticides include insecticides, fungicides, herbicides, rodenticides, nematicides molluscicides and acaricides. The preferred penetration enhancing compound is 1-n-dodecylaza cycloheptan-2-one.
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- LIQUID CRYSTALLINE PROPERTIES OF 4-N-ALKOXYPHENYL 4-NITROBENZOATES.
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Twelve 4-alkoxyphenyl esters of 4-nitrobenzoic acid were synthesized. The mesophases were identified and the transition temperatures and enthalpies determined. The above series shows considerable similarity to the reverse analogues, i. e. , the 4-nitro-phenyl 4-n-alkoxybenzoates.
- Galewski,Sobczyk
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- Chlorotrimethylsilane/Lithium Bromide and Hexamethyldisilane/Pyridinium Bromide Perbromide: Effective and Selective Reagents for the Conversion of Alkyl (Cycloalkyl and Aralkyl) Alcohols into Bromides
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Alkyl bromides were obtained in high yield in the reaction of the corresponding alcohols with chlorotrimethylsilane/lithium bromide.The reaction was equally applicable to primary, secondary, and tertiary alcohols as well as to allylic and benzylic alcohols.High regioselectivity was observed in related conversions in which hexamethyldisilane/pyridinium bromide perbromide was used.Tertiary alcohols, for example, were converted selectively into the corresponding tertiary bromides in the presence of primary and secondary hydroxylic functions.The reactions were also highly steroselective.
- Olah, George A.,Gupta, B. G. Balaram,Malhotra, Ripudaman,Narang, Subhash C.
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p. 1638 - 1639
(2007/10/02)
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