- The Silicon-Hydrogen Exchange Reaction: A Catalytic σ-Bond Metathesis Approach to the Enantioselective Synthesis of Enol Silanes
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The use of chiral enol silanes in fundamental transformations such as Mukaiyama aldol, Michael, and Mannich reactions as well as Saegusa-Ito dehydrogenations has enabled the chemical synthesis of enantiopure natural products and valuable pharmaceuticals. However, accessing these intermediates in high enantiopurity has generally required the use of either stoichiometric chiral precursors or stoichiometric chiral reagents. We now describe a catalytic approach in which strongly acidic and confined imidodiphosphorimidates (IDPi) catalyze highly enantioselective interconversions of ketones and enol silanes. These "silicon-hydrogen exchange reactions"enable access to enantiopure enol silanes via tautomerizing σ-bond metatheses, either in a deprotosilylative desymmetrization of ketones with allyl silanes as the silicon source or in a protodesilylative kinetic resolution of racemic enol silanes with a carboxylic acid as the silyl acceptor.
- Zhou, Hui,Bae, Han Yong,Leutzsch, Markus,Kennemur, Jennifer L.,Bécart, Diane,List, Benjamin
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p. 13695 - 13700
(2020/08/24)
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- NOVEL 5 or 8-SUBSTITUTED IMIDAZO [1, 5-a] PYRIDINES AS SELECTIVE INHIBITORS OF INDOLEAMINE AND/OR TRYPTOPHANE 2, 3-DIOXYGENASES
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Disclosed herein are 5 or 8-substituted imidazo [1, 5-a] pyridines and pharmaceutical compositions comprising at least one such 5 or 8-substituted imidazo [1, 5-a] pyridines, processes for the preparation thereof, and the use thereof in therapy. Disclosed herein are certain 5 or 8-substituted imidazo [1, 5-a] pyridines that can be useful for inhibiting indoleamine 2, 3-dioxygenase and/or tryptophane 2, 3-dioxygenase and for treating diseases or disorders mediated thereby.
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Paragraph 0801; 0805
(2018/04/20)
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- Method for synthesizing trans-4-alkylcyclohexyl benzene structure liquid crystal intermediates and monomers
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The invention discloses a method for synthesizing trans-4-alkylcyclohexyl benzene structure liquid crystal intermediates and monomers and belongs to the technical field of trans-cyclohexyl benzene liquid crystal. The method comprises the following steps:
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- Fluorinated compounds containing naphthalene structure
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PROBLEM TO BE SOLVED: To provide a compound concurrently having a large dielectric anisotropy (Δε), a high clear point (T) and a low viscosity (η), and to provide a liquid crystal composition and a liquid crystal display element including the above compou
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- Compound having 2-fluorophenyloxymethane structure
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There is provided a compound having a good miscibility with another liquid crystal compound and having a combination of a low viscosity (η), high storage stability, and high T?i even after being used to produce a liquid crystal composition. In
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- ORTHO ESTER DERIVATIVE, LIQUID CRYSTAL COMPOSITION, AND LIQUID CRYSTAL DISPLAY ELEMENT
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The invention is to provide a liquid crystal compound having a large dielectric anisotropy, a high voltage holding ratio and stability to heat, light and so forth, maintaining a nematic phase in a wide temperature range, having a suitable optical anisotropy and an excellent compatibility with other liquid crystal compounds, particularly, to provide a liquid crystal compound having a large dielectric anisotropy. The invention provides compound (1): In the formula, for example, R1 is alkyl and having 1 to 20 carbons; ring A1, ring A2, ring A3, ring A4, ring A5 and ring A6 are independently 1,4-cyclohexylene or 1,4-phenylene; Z1, Z2, Z3, Z4, Z5, Z6 and Z7 are independently a single bond, - (CH2) 2-, -COO-, -OCO-, CF2O-, -OCF2- or -CH=CH-; X1 is fluorine, -CF3 or -OCF3; and Y1 and Y2 are independently hydrogen or fluorine.
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- COMPOUND HAVING 2-FLUOROPHENYLOXYMETHANE STRUCTURE
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The present invention relates to a compound having a 2-fluorophenyloxymethane structure and useful for organic electronic materials and medical and agricultural chemicals, particularly materials for liquid crystal display elements. A problem to be solved
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- Discovery of pyrazolyl propionyl cyclohexenamide derivatives as full agonists for the high affinity niacin receptor GPR109A
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A series of pyrazolyl propionyl cyclohexenamides were discovered as full agonists for the high affinity niacin receptor GPR109A. The structure-activity relationship (SAR) studies were aimed to improve activity on GPR109A, reduce Cytochrome P450 2C8 (CYP2C
- Ding, Fa-Xiang,Shen, Hong C.,Wilsie, Larrisa C.,Krsmanovic, Mihajlo L.,Taggart, Andrew K.,Ren, Ning,Cai, Tian-Quan,Wang, Junying,Tong, Xinchun,Holt, Tom G.,Chen, Qing,Gerard Waters,Hammond, Milton L.,Tata, James R.,Colletti, Steven L.
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scheme or table
p. 3372 - 3375
(2010/08/06)
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- Niacin Receptor Agonists, Compositions Containing Such Compounds and Methods of Treatment
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The present invention encompasses compounds of Formula I: as well as pharmaceutically acceptable salts and hydrates thereof, that are useful for treating atherosclerosis, dyslipidemias and the like. Pharmaceutical compositions and methods of use are also included.
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Page/Page column 60-61
(2009/04/24)
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- Discovery of novel orally active ureido NPY Y5 receptor antagonists
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We have derived a novel series of neuropeptide Y (NPY) Y5 receptor antagonists from the biphenylurea 3. Cyclohexylurea 21c, a member of the series, is a potent NPY Y5 receptor antagonist that exhibits excellent pharmacokinetic parameters in rats and dogs. On chronic oral administration to diet-induced obese rats, 21c displayed an anti-obesity profile, causing a modest reduction in food intake, a significant decrease in body weight gain, a decrease in adipose mass, and an increase in lean tissue mass.
- Li, Guoqing,Stamford, Andrew W.,Huang, Ying,Cheng, Kuo-Chi,Cook, John,Farley, Constance,Gao, Jun,Ghibaudi, Lorraine,Greenlee, William J.,Guzzi, Mario,van Heek, Margaret,Hwa, Joyce J.,Kelly, Joe,Mullins, Deborra,Parker, Eric M.,Wainhaus, Sam,Zhang, Xiaoping
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p. 1146 - 1150
(2008/09/18)
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- NIACIN RECEPTOR AGONISTS, COMPOSITIONS CONTAINING SUCH COMPOUNDS AND METHODS OF TREATMENT
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The present invention encompasses compounds of Formula (I): as well as pharmaceutically acceptable salts and hydrates thereof, that are useful for treating atherosclerosis, dyslipidemias and the like. Pharmaceutical compositions and methods of use are also included.
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Page/Page column 31; 52-54
(2008/06/13)
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- Fluoro-substituted alkenyl compounds, liquid crystal compositions, and liquid crystal display elements
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The invention relates to a fluoro-substituted alkenyl compound represented by formula (1) 1wherein Y1, Y2, Y3 and Y4 are each independently H or F, provided that at least one of Y1 and Y2 is F; Q1 is a single bond or an alkylene group of 1-20 carbon atoms, at least one —CH2— being optionally substituted by —O—, provided that two or more —O— are not adjacent to each other; Q2 is a single bond or —C≡C—; Rings A1, A2 and A3 are each independently a cyclohexane ring, a dioxane ring, a cyclohexene ring, a pyrimidine ring, a pyridine ring, or a benzene ring, or a benzene ring having at least one hydrogen atom substituted by F; Z1, Z2 and Z3 are each independently a single bond, —CH2CH2—, —CH2O—, —OCH2—, —COO—, —OCO—, —CH=CH—, —C≡C—, —CF2O—, or —OCF2; and m and n are each independently 0 or 1; provided that Y3 is F when Ring A3 is a cyclohexane ring and Z3 is a single bond. The liquid crystal composition comprising the compound, when used in liquid crystal display elements for various modes, excels in driving voltage and contrast.
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- Dioxane derivatives, liquid-crystal compositions containing the same, and liquid-crystal display devices made by using the same
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The present invention provides liquid crystalline compounds having a high voltage holding ratio and a remarkably high Δε value, electric and chemical stability, and having good compatibility with known liquid crystalline compounds, liquid crystal compositions containing the compound, and liquid crystal display devices constituted by using the compounds. The liquid crystalline compounds of the present invention are particular dioxane derivatives represented by general formula (1). Further, the present invention relates to liquid crystal compositions characterized in that the compositions comprise at least one of the derivatives, and liquid crystal display devices constituted by using the compositions.
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- Highly birefringent nematic liquid crystals for reflective STN applications
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An important parameter of any LCD containing portable electronic device is a low power requirement. The reflective STN display mode offers a moderate to high information content display with low power consumption. One method to realise colour in this mode is to use a large retardation (dΔn) value in the cell. For a cell gap of 6 μm, and a retardation of ~1.5, a birefringence (Δn) of greater than +0.2 is necessary. To achieve such a value in an STN LC mixture, materials with broad nematic range, good solubility and a Δn value of +0.25 are required. A study of the trans-cyclohexyldifluorophenyltolane core structure was made and a large number of dialkyl, alkenyl-alkyl and alkoxy materials were synthesised and characterised. These materials possess low to moderate melting points, broad purely nematic mesophases, a high An and very good solubility in nematic LC hosts. They are suitable materials for inclusion in mixtures for colour reflective STN displays.
- Goulding, Mark,Reiffenrath, Volker,Hirschmann, Harald
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p. 899 - 910
(2007/10/03)
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- A liquid crystalline compound containing fluorine atom substituted alkyl group(s) and a liquid crystal composition
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A liquid crystalline compound exhibiting a large Δ ε value, an electrical and chemical stability and a superior compatibility with existing liquid crystalline compounds, a liquid crystal composition containing the same, and a liquid crystal display element constructed by using the composition are provided,???which liquid crystalline compound is expressed by the formula (I), F-(CH2)n ―E-(CH2CH2) k―G-(CH2CH2)l―L-(CH2CH2) m―Z―Q―Y wherein n is an integer of 1 to 10; k, l and m each independently are an integer of 0 to 2; ring E is 1,4-cyclohexylene group or 1,4-phenylene group, wherein one or more H atoms on six-membered ring may be replaced by F atom(s); G and L each independently is a covalent bond or 1,4-cyclohexylene group or 1,4-phenylene group, wherein one or more H atoms on six-membered ring may be replaced by F atom(s); Q is covalent bond or -O-; Y is a fluoroalkyl group of 1 to 3C or F atom; but in the case where ring E is 1,4-cyclohexylene group and at least one of G and L is covalent bond, and in the case where Q is -O-, Y is not F atom.
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