- Ir(NHC)-Catalyzed Synthesis of β-Alkylated Alcohols via Borrowing Hydrogen Strategy: Influence of Bimetallic Structure
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Multi N-heterocyclic carbene(NHC)-modified iridium catalysts were employed in the β-alkylation of alcohols; dimerization of primary alcohols (Guerbet reaction), cross-coupling of secondary and primary alcohols, and intramolecular cyclization of alcohols. Mechanistic studies of Guerbet reaction, including kinetic experiments, mass analysis, and density functional theory (DFT) calculation, were employed to explain the fast reaction promoted by bimetallic catalysts, and the dramatic reactivity increase of monometallic catalysts at the late stage of the reaction. (Figure presented.).
- Sung, Kihyuk,Lee, Mi-hyun,Cheong, Yeon-Joo,Kim, Yu Kwon,Yu, Sungju,Jang, Hye-Young
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supporting information
p. 3090 - 3097
(2021/05/10)
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- Diastereoselective synthesis of functionally substituted alkene dimers and oligomers, catalysed by chiral zirconocenes
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The research addresses the reaction of terminal alkenes and propene with AlR3 (R = Me, Et) in the presence of chiral Zr complexes, rac-[Y(η5-C9H10)2]ZrCl2 (Y = C2H4, SiMe2) or (NMI)2ZrCl2 (NMI- η5–neomenthylindenyl), and methylaluminoxane. The effect of reaction conditions, catalyst and trialkylalane structure on the substrate conversion and the reaction chemo- and stereoselectivity has been studied. The reaction predominantly goes via the stage of alkene methyl(ethyl)zirconation with subsequent introduction of substrate molecules into the Zr-C bond. As a result, a diastereoselective one-pot method for the synthesis of functionally substituted linear terminal alkene dimers and propene oligomers was developed.
- Kovyazin, Pavel V.,Abdullin, Il'giz N.,Parfenova, Lyudmila V.
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p. 144 - 152
(2018/11/21)
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- Preparation method and application of bifurcated halogenated alkyl chain compounds
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The invention discloses a preparation method and an application of bifurcated halogenated alkyl chain compounds. The method comprises the following steps: reacting bromoalkane with dimethyl malonate to obtain single-branch dimethyl malonate; reacting bromoalkane with the obtained single-branch dimethyl malonate to obtain two-branch dimethyl malonate; carrying out selective hydrolysis decarboxylation on the two-branch dimethyl malonate to obtain a hydrolysate; reducing the hydrolysate to obtain primary alcohol; carrying out a bromination reaction on the primary alcohol to obtain a brominated product; reacting the brominated product with ethylene oxide to obtain carbon chain-extended primary alcohol compounds; and carrying out a halogenation reaction on the carbon chain-extended primary alcohol compounds to obtain the bifurcated halogenated alkyl chain compounds with R being a corresponding halogen atom. The method has the advantages of low cost, high yield, simplicity in operation, andeasiness in realization of industrialization. Alkyl chains with different bifurcated lengths are introduced to an organic conjugated polymer, so the pi-pi piling distance between polymers is effectively reduced, the mobility of the polymer is improved.
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- GUERBET CONDENSATION REACTION
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The invention relates to a process for the preparation of a Guerbet alcohol, comprising the steps of: (a) providing at least one alcohol, wherein said at least one alcohol has a carbon atom bearing at least one hydrogen atom adjacent to the hydroxyl group; (b) providing a catalyst composition, wherein said catalyst composition comprises an alkaline catalyst and a copper-nickel catalyst comprised in a hydrotalcite; (c) mixing alcohol (a) with catalyst composition (b), thereby obtaining a mixture; and, (d) heating said mixture; thereby obtaining a Guerbet alcohol.
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Page/Page column 17-18; 23-24
(2017/07/08)
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- Synthetic base stock based on Guerbet alcohols
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Guerbet (β branched) alcohols of varying chain length of even carbon numbers were synthesized by using single linear fatty alcohols ranging from 1-octanol to 1-dodecanol. All Guerbet alcohols having fewer than 28 carbon atoms and are liquid at 0 °C due to β branching. Synthetic base oils were prepared by reacting commonly available unsaturated fatty acids and dicarboxylic acids with Guerbet alcohols using p-toluenesulfonic acid as a catalyst. These base oils were characterized by physical and tribological properties like viscosity, viscosity index, pour point, flash point, wear scar, weld load, coefficient of friction etc. and compared with commercially available 150 and 500 N base oils.
- Waykole, Chetan,Bhowmick, Diptinarayan,Pratap, Amit
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p. 1407 - 1416
(2014/08/18)
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- GRANULE COATED WITH URETHANE RESIN
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A coated granule obtained by coating a bioactive substance-containing granule with a urethane resin obtained by reaction of an aromatic polyisocyanate with an alcohol mixture comprising a polyesterpolyol having 15 wt % or more of an oxycarbonyl structure (—O—C(═O)—) part in the molecule and a C4-C30 alkanol optionally substituted by one or more aryl groups, wherein the molar ratio of the polyesterpolyol to the alkanol is 1:1 to 100:1, is capable of controlling elution of the bioactive substance appropriately, and, the urethane resin forming the coat film shows degradability in soil.
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- Lubricant Composition for Fluid Dynamic Bearing
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A lubricating oil composition for fluid dynamic bearings which comprises 50 to 100% by mass of an ether compound comprising at least one ether bond and having 11 to 34 carbon atoms as the base oil and has a kinematic viscosity of at least 2.2 mm2/s at 100° C. is provided. The composition has excellent viscosity characteristics such as excellent fluidity at low temperatures and a small decrease in the viscosity in a high temperature range, exhibits lower evaporability, excellent energy saving property and excellent heat stability and is advantageously used for compact fluid dynamic bearings used under rotation at a high speed.
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- Guerbet reaction of primary alcohols leading to β-alkylated dimer alcohols catalyzed by iridium complexes
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[IrCl(cod)]2 and [Cp*IrCl2]2 complexes catalyzed efficiently the Guerbet reaction of primary alcohols to β-alkylated dimer alcohols in good yields. For instance, the reaction of 1-butanol in the presence of [Cp*IrCl2]2 (1 mol %), t-BuOK (40 mol %), and 1,7-octadiene (10 mol %) produced 2-ethyl-1-hexanol in 93% yield. Various primary alcohols undergo the Guerbet reaction under the influence of Ir complexes to give the corresponding dimer alcohols in good yields. This method provides an alternative direct route to β-alkylated primary alcohols which are prepared by aldol condensation of aldehydes followed by hydrogenation.
- Matsu-Ura, Toyomi,Sakaguchi, Satoshi,Obora, Yasushi,Ishii, Yasutaka
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p. 8306 - 8308
(2007/10/03)
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- Pharmaceutical compositions for transdermal administration of anti-inflammatory agents
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The invention concerns a pharmaceutical composition for transdermal administration comprising: a polymeric release matrix capable of forming a soft film after drying, selected among cellulose polymers or copolymers, said matrix being present at a concentration not exceeding 6% of the composition weight; an active principle selected among the group of non-steroid anti-inflammatory agents comprising at least a metal carboxylic or carboxitate group; a transcutaneous absorption promoter of the active principle; water; and at least a physiologically acceptable non-aqueous solvent capable of dissolving the release matrix, the active principle and transcutaneous absorption promoter and to be rapidly eliminated by evaporation in contact with the skin.
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- Propoxylated guerbet alcohols and esters thereof
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The present invention relates to propoxylated guerbet alcohols and esters having an iodine number less than 7 and defined by the general formula: STR1 which alcohols and esters are useful, individually or in admixture, as lubricants in the working of metals.
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- Method for the production of guerbet alcohols utilizing insoluble lead catalysts
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An improvement in the production of Guerbet alcohols by the condensation of alcohols in the presence of a catalyst and an alkali consisting of utilizing from 0.05 to 3.0 gm per mol of total alcohol of an insoluble lead salt of an oxyacid of a group IV element having a molecular weight greater than 27, such as oxyacids selected from the group consisting of the silicate, the titanate, the zirconate, the germanate and the hafnate, as said catalyst.
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