- Synthesis of 1,2-phenylenedimethanols by base-promoted reduction of isobenzofuran-1(3H)-ones with silane
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An efficient method for preparation of substituted 1,2-phenylenedimethanols and aliphatic 1,4-diols that are valuable intermediates in organic synthesis, has been developed by the base-promoted reduction of isobenzofuran-1(3H)-ones and γ-lactones with silane under mild conditions. Compared with traditional procedures using stoichiometric amounts of metal hydrides and alkyl reductants, the present method avoids the use of sensitive reagents and is operationally simple and a broad variety of functional groups are tolerated.
- Liu, Bin,Zhou, Xigeng
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supporting information
p. 725 - 728
(2018/12/11)
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- BROAD-SPECTRUM CARBAPENEMS
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The present disclosure provides broad-spectrum carbapenem derivatives and pharmaceutical compositions useful in the treatment of bacterial infections and methods for treating such infections using such derivatives and/or compositions.
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Paragraph 00315-00316; 00320
(2019/12/25)
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- The effect of the oxidation state of molybdenum complexes on the catalytic transformation of terminal alkynes: Cyclotrimerization vs. polymerization
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Reactions of monosubstituted alkynes (PhC≡CH, tBuC≡ CH, nBuC≡CH, HOCH2C≡CH, HO(CH 3)2CC≡CH) in the presence of molybdenum(0) and molybdenum(II) carbonyl complexes (Mo(CO)6/hv, [Mo(CO) 4(pip)2] (pip = piperidine), [Mo(CO)4(pip) 2]/SnCl4, [Rpip]2[{(μ-Cl)Mo(μ-Cl) (SnCl3)(CO)3}2] (R = C3H 5, H)) lead to the formation of cyclotrimerization and polymerization products, which were characterized by chromatography (GC-MS, GPC) and by 1H and 13C NMR spectroscopy. The effect of the oxidation state of the molybdenum catalyst on the transformation of the terminal alkynes was observed: cyclotrimerization vs. polymerization. Only molybdenum(II) complexes lead to the formation of polyenic polymers. Moreover, reaction of prop-2-yn-1-ol initiated by [Mo(CO)4(pip)2] in dichloromethane leads to the formation of oligomers containing the vinylidene unit. Mechanistic NMR studies show that η2-alkyne complex formation is the principal feature of all transformations of alkynes catalyzed by molybdenum complexes.
- Czelu?niak, Izabela,Kociecka, Paulina,Szymańska-Buzar, Teresa
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- Cyclotrimerization of alkynes catalyzed by the naphthalene ruthenium complex [CpRu(10H8)] +
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The naphthalene ruthenium complex [CpRu(10H8)] + (in the presence of Cl- ions) catalyzes the cyclotrimerization of 2,2-dimethyl-5,5-dipropargyl-1,3-dioxane-4,6-dione with alkynes (acetylene, hex-1-yne, hex-3-yne, oct-1-yne, phenylacetylene, trimetylsilylacetylene, octa-1,7-diyne, pent-1-yn-5-ol, methyl propargyl ether, and propargyl acetate) giving tricyclic aromatic compounds in 55-85% yields.
- Perekalin,Trifonova,Petrovskii,Kudinov
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experimental part
p. 2110 - 2113
(2012/09/22)
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- The first cobalt catalyzed [2 + 2 + 2] alkyne cyclotrimerization in aqueous medium at room temperature
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Chelate complex 1 (5 mol%) was found to catalyze the [2 + 2 + 2] cyclization of terminal alkynes in good yields in a 80/20 mixture of water and ethanol at room temperature without further activation.
- Yong, Li,Butenschoen, Holger
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p. 2852 - 2853
(2007/10/03)
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- CpCo(CO)2-catalysed cyclotrimerisation of alkynes in supercritical carbon dioxide
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The reactivity of mono-substituted HCCR (R=Ph, a; CH2OH, b; CH2CH2CH2CH3, c) and di-substituted RCCR (R=CH2CH3, d; CO2CH3, e; Ph, f) acetylenes was studied in supercritical carbon dioxide (scCO2) using the easily available complex CpCo(CO)2 as catalyst. The reaction of phenylacetylene produced a mixture of the isomeric cyclotrimers 1,3,5- (2a) and 1,2,4-triphenylbenzene (2a′), in a 1:5 ratio, and traces of cobaltcyclopentadienone complexes CpCo(η4-C4H2[Ph]2CO) (6a, mixture of isomers). The possible product formed by the incorporation of CO2 to alkynes, i.e. diphenylpyrone (7a) was not observed. The reaction of the cobaltacyclopentadiene complex CpCo(1.4-σ-C4[Ph]4)(PPh)3 (8f), in scCO2, was performed. No insertion of CO2 into the Co-C σ-bond to form tetraphenylpyrone (7f) by reductive elimination was observed, instead the cobaltcyclobutadiene complex CpCo(η4-C4[Ph]4) (9f) was formed. In the reactions with other alkynes, lower yields were obtained in general, except in the cyclotrimerisation of the highly activated alkyne, propargyl alcohol (b). Reaction of the non-activated alkynes, 1-hexyne (c) and 3-hexyne (d), produced complex mixtures of cobalt complexes in low yield in which the alkyne was coordinated to cobalt. Finally, the highly hindered diphenylacetylene (f) gave a mixture of the known complexes CpCo(η4-C4[Ph]4) (9f) and CpCo(η4-C4[Ph]4CO) (6f) in agreement with the results observed in conventional organic solvents.
- Montilla, Francisco,Avilés, Teresa,Casimiro, Teresa,Ricardo, Ana Aguiar,Nunes Da Ponte, Manuel
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p. 113 - 118
(2007/10/03)
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- Fused imidazopyridine derivatives as antihyperlipidemic agents
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A novel compound of the formula: wherein ring Q is an optionally substituted pyridine ring; One of R0, R1and R2is —Y0—Z0, and the other tow groups are a hydrogen, a halogen, an optionally substituted hydroxy group, a hydrocarbon group that may be an optionally substituted hydrocarbon group or an acyl group; Y0is a bond or an optionally substituted bivalent hydrocarbon group; Z0is a basic group which may be bonded via oxygen, nitrogen, —CO—, —CS—, —SO2N(R3)— (where R3is hydrogen or an optionally substituted hydrocarbon group), or S(O)n(wherein n is to 0, 1 or 2); .........is a single bond or a double bond, or a salt thereof, which has an excellent LDL receptor up-regulating, blood-lipids lowering, blood-sugar lowering and diabetic complication-ameliorating activity.
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- Arylmethylphosphonates and phosphonic acids useful as anti-inflammatory agents
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This invention provides a new use of acids, esters, and salts of arylmethylphosphonates of Formula I, STR1 or phosphonic acid derivatives of Formula II STR2 as anti-inflammatory and anti-arthritic agents. Representative compounds include 4-dodecyloxybenzylphosphonic acid dimethyl ester, (2-naphthalenylmethyl)phosphonic acid dimethyl ester, and ([1,1 '-biphenyl]-2-ylmethyl)phosphonic acid dimethyl ester. The invention also provides novel acids, esters, and salts of arylmethylphosphonic acid, phosphonic acid and derivatives.
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