- Synthesis of α-Cyclooctyl- and α-Cyclopentadecylglycosides of N-Acetylmuramyl-L-Alanyl-D-Isoglutamine
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N-Acetylmuramyl-L-alanyl-D-isoglutamine α-cyclooctyl- and α-cyclopentadecylglycosides were synthesized. The starting peracetylated α-N-glucosaminides were synthesized by reacting the cycloalkanols with peracetyl α-D-glucosaminyl chloride in the presence of Hg(II) iodide in CH3NO2 with heating or by using ZnCl2/tetrabutylammonium bromide in CH2Cl2 at room temperature. Sequential deacetylation, isopropyl protection, and alkylation by (S)-2-bromopropanoic acid gave α-cycloalkyl-4,6-O-isopropylidene-N-acetyl-D-muramic acids, condensation of which with the benzyl ester of L-Ala-D-iGln using the HOSu/DCC method and deprotection afforded the target glycopeptides.
- Zemlyakov,Tsikalov,Tsikalova
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- Pincerlike molybdenum complex and preparation method thereof, catalytic composition and application thereof, and alcohol preparation method
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The invention discloses a clamp-type molybdenum complex, a preparation method, a corresponding catalyst composition and application. The method comprises the steps: obtaining 9 molybdenum complexes with different structures through coordination reaction of 2-(substituent ethyl)-(5, 6, 7, 8-tetrahydroquinolyl) amine and a corresponding carbonyl molybdenum metal precursor; and catalyzing a ketone compound transfer hydrogenation reaction through a molybdenum complex to generate 40 alcohol compounds. The preparation method of the molybdenum complex is simple, high in yield and good in stability. For a transfer hydrogenation reaction of ketone, the molybdenum-based catalytic system has high catalytic activity and small molybdenum loading capacity, is used for production of aromatic and aliphatic alcohols, and has the advantages of simple method, small environmental pollution and high yield.
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Paragraph 0134-0140
(2021/08/11)
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- Efficient Transfer Hydrogenation of Ketones using Methanol as Liquid Organic Hydrogen Carrier
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Herein, we demonstrate an efficient protocol for transfer hydrogenation of ketones using methanol as practical and useful liquid organic hydrogen carrier (LOHC) under Ir(III) catalysis. Various ketones, including electron-rich/electron-poor aromatic ketones, heteroaromatic and aliphatic ketones, have been efficiently reduced into their corresponding alcohols. Chemoselective reduction of ketones was established in the presence of various other reducible functional groups under mild conditions.
- Garg, Nidhi,Paira, Soumen,Sundararaju, Basker
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p. 3472 - 3476
(2020/05/29)
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- Synthesis of β-cycloalkylglycosides of Muramyl Dipeptide
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β-Cyclooctyl-, β-cyclodecyl-, and β-cyclopentadecylglycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine were prepared in yields of 39, 18, and 25%, respectively, (calculated for muramic acid) via the reaction of β-cycloalkyl-4,6-O-isopropylidene-N-acetyl-D-muramic acids with the benzyl ester of L-Ala-D-iGln using the HOSu/DCC method followed by deprotection.
- Zemlyakov,Tsikalova,Tsikalov
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p. 929 - 932
(2017/10/07)
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- CIRCULAR ECONOMY METHODS OF PREPARING UNSATURATED COMPOUNDS
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Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.
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Paragraph 0062
(2018/01/18)
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- Catalytic transfer hydrogenation of cycloalkanones on MgO. Vapour and liquid phase modes of reaction
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The reactivity of a series of cycloalkanones of the general formula (CH2)nCO, where n = 4, 5, 6, 7, 11 and 14 in the transfer hydrogenation reaction over magnesium oxide as the catalyst, either in vapour or liquid phase (VP or LP) has been studied. In the VP mode of reaction the activity of MgO treated with triethylamine, water, phenol or benzoic acid in the reduction of cyclopentanone by propan-2-ol has been determined. A strongly diminished or residual activity of MgO has been observed after the catalyst's treatment with phenol or benzoic acid, respectively. The occurrence of side reactions of cyclopentanone in the LP mode of reaction resulted in high conversions of the ketone (up to 91%), very low yields of cyclopentanol (I) (below 6%) and very high yields of 2-cyclopentyli- dene-cyclopentanone (II) (>80%).
- Glinski
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experimental part
p. 187 - 194
(2009/10/23)
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- Method for oxidizing hydrocarbons
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The invention relates to a method for oxidizing substrates such as hydrocarbons, waxes or soot. The method involves the use of a compound of formula (I) in which: R1 and R2 represent H, an aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, each having 1 to 20 hydrocarbon atoms, SO3H, NH2, OH, F, Cl, Br, I and/or NO2, whereby R1 and R2 designate identical or different radicals or R1 and R2 can be linked to one another via a covalent bonding; Q1 and Q2 represent C, CH, N, CR5, each being the same or different; X and Z represent C, S, CH2, each being the same or different; Y represents O and OH; k=0, 1, 2; l=0, 1, 2; m=1 to 3, and; R5 represents one of the meanings of R1. Said compound is used as a catalyst in the presence of a radical initiator, whereby the molar ratio of the catalyst to the hydrocarbon is less than 10 mol %. Peroxy compounds or azo compounds can be used as the radical initiator. Preferred substrates are aliphatic or aromatic hydrocarbons.
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- 213. The reductive Conversion of Some Cyclic and Acyclic vic-Epoxides to Alcohols by Means of Lithium Aluminium Hydride/Aluminium Trichloride
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Unsubstituted medium-ring 1,2-epoxycycloalkanes and certain vic-epoxyalkanes are reduced to the corresponding alcohols very slowly when LiAlH4 alone is used as reducing agent.However, the combination of LiAlH4 and AlCl3, in a 2:1 molar ratio (with respect to 1 mol-equiv. of epoxide) used in refluxing Et2O, greatly enhances these reductions, rendering them of interest for practical purposes.
- Andrejevic, Vladimir,Bjelakovic, Mira,Mihailovic, Milan M.,Mihailovic, Mihailo Lj.
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p. 2030 - 2032
(2007/10/02)
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