- Towards Sustainable Catalysis – Highly Efficient Olefin Metathesis in Protic Media Using Phase Labelled Cyclic Alkyl Amino Carbene (CAAC) Ruthenium Catalysts
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New generations of Hoveyda and bis-carbene type of ruthenium-based olefin metathesis catalysts (10 and 12), containing cationic cyclic alkyl amino carbene (CAAC) ligands, have been synthetized. The catalysts show exceptional stability and activity in environmentally benign, protic media. Various olefin metatheses reactions of OH functionalized feedstock (e. g. RCM, ROMP CM) can be carried out at as low as 0.05 mol % catalyst loading in methanol, isopropanol, water or methanol/water solvent mixture, accomplishing the lowest applied catalyst loading reported so far in these media. The facile olefin metathesis of renewable feedstocks including phospholipids (23) and vegetable oils (20) in protic media has also been demonstrated.
- Nagyházi, Márton,Turczel, Gábor,Balla, áron,Szálas, Gábor,Tóth, Imre,Gál, Gyula Tamás,Petra, Bombicz,Anastas, Paul T.,Tuba, Róbert
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- Ultra-Small Platinum Nanoparticles with High Catalytic Selectivity Synthesized by an Eco-friendly Method Supported on Natural Hydroxyapatite
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Abstract: The biosynthesis of Pt-nanoparticles (Pt NPs) supported on bovine bone powder was conducted by an environmentally friendly method that consists on immersing bovine bone powder into a Pt4+ metal ion solution at room temperature, atmospheric pressure and subsequent reduction by Heterotheca inuloides. It is worth pointing out that a calcination process is not required for the synthesis of this catalyst by the method reported herein. The nanocomposite was characterized by transmission electron microscopy (TEM), which revealed uniformly dispersed platinum nanoparticles with quasi-spherical form and average particle size of 7.1?nm. The XPS studies exhibited the presence of 47.62% Pt° and 51.84% PtO. The catalyst activity was tested in the selective hydrogenation of 2-butyne-1,4-diol towards 2-butene-1,4-diol. The nanocomposite exhibits a reasonable catalytic performance with nearly 100% conversion of the alkyne and 96% selectivity towards 2-butene-1,4-diol. Graphic Abstract: [Figure not available: see fulltext.].
- Gama-Lara,Natividad,Vilchis-Nestor,López-Casta?ares, Rafael,García-Orozco,Gonzalez-Pedroza, María G.,Morales-Luckie, Raúl A.
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- Continuous flow olefin metathesis using a multijet oscillating disk reactor as the reaction platform
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The multijet oscillating disk (MJOD) flow reactor is a relatively new technology for continuous flow synthesis. This technology is still under investigation as an all-round platform for flow synthesis. In this article, findings are disclosed from a project where a MJOD flow reactor rig (reactor volume of ≈50 mL) was investigated as the reaction platform for ring closing metathesis and cross (self) metathesis reaction, using reaction mixture volumes down to only ≈5 mL. The Hoveyda-Grubbs second-generation catalyst was used without an inert atmosphere. The results of the flow synthesis provided excellent selectivity and high yield. For comparison purposes, the syntheses conducted in the MJOD reactor were compared with similar literature experiments performed with other flow technologies and batch conditions.
- Bjorsvik, Hans-Ren,Liguori, Lucia
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- Ammonium-tagged ruthenium-based catalysts for olefin metathesis in aqueous media under ultrasound and microwave irradiation
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The influence of microwave and ultrasonic irradiation on the performance of ammonium-tagged Ru-based catalysts in olefin metathesis transformations in aqueous media was studied. Differences in the catalytic activity in correlation with the nature of the present counter ion and the size of the N-heterocyclic carbene (NHC) ligand were revealed. The presented methodology allows for preparation of a variety of polar and non-polar metathesis products under environmentally friendly conditions.
- Gu?ajski, ?ukasz,Tracz, Andrzej,Urbaniak, Katarzyna,Czarnocki, Stefan J.,Bieniek, Micha?,Olszewski, Tomasz K.
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- A solid-supported phosphine-free ruthenium alkylidene for olefin metathesis in methanol and water.
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The synthesis and olefin metathesis activity in protic solvents of 7, a phosphine-free ruthenium alkylidene bound to a hydrophilic solid support are reported. This heterogeneous catalyst promotes relatively efficient ring closing- and cross-metathesis reactions in both methanol and water. The potential utility of homogeneous catalyst 2 for olefin metathesis in methanol is also demonstrated.
- Connon, Stephen J,Blechert, Siegfried
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- Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions
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The combination of visible light, photovoltaics, and electrochemistry provides a convenient, inexpensive platform for conducting a wide variety of sustainable oxidation reactions. The approach presented in this article is compatible with both direct and indirect oxidation reactions, avoids the need for a stoichiometric oxidant, and leads to hydrogen gas as the only byproduct from the corresponding reduction reaction.
- Nguyen, Bichlien H.,Perkins, Robert J.,Smith, Jake A.,Moeller, Kevin D.
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- The influence of nickel loading on the structure and performance of a Ni-Al2O3 catalyst for the hydrogenation of 1,4-butynediol to produce 1,4-butenediol
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In combination with a planetary ball-milling machine, a Ni-Al2O3 catalyst was prepared by a mechanochemical method. The effect of Ni loading on the crystal structure, reduction characteristics, and hydrogenation performance of the Ni-Al2O3 catalyst was investigated. The prepared catalysts were characterized using EDX, XRD, H2-TPR, BET, TEM and NH3-TPD methods. The results of the XRD characterization showed that the peak intensity of the active Ni component increased with an increase in the Ni content. The ratio of the measured Ni content to the theoretical Ni content of the MC25percent and MC30percent samples exceeded 1.1. As the Ni addition was increased up to 10percent, the sample consisted of uniform spherical particles, which could provide more contact surfaces. The medium acid peak temperature shifts towards the high temperature direction as the Ni loading increased from 5percent to 20percent, and then (>20percent) decreased to a lower temperature. The corresponding peak area firstly increased and then decreased, presenting a visual representation of changes in the number of acid centers on the catalyst. Evaluation of the results showed that the MC20percent catalyst presented a large specific surface area of 279 m2 g-1, and it showed good hydrogenation performance, with a BYD conversion of 25.0percent, BED selectivity of 89.3percent, and BED yield of 22.3percent.
- Gao, Xianlong,Mo, Wenlong,Ma, Fengyun,Fan, Xing
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- The stereochemistry of solvolysis of an acyclic allylic epoxide
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In contrast to solvolysis of cyclic allylic epoxides, the acid-catalyzed solvolyses of optically pure 1,2-epoxy-3-butene using water or alcohols show a high degree of inversion stereoselectivity.
- Boaz
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- Sunlight, electrochemistry, and sustainable oxidation reactions
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Inexpensive, readily available photovoltaic cells have been used to conduct indirect electrochemical oxidation reactions. The reactions retain the efficiency of the solar-electrochemical method while capitalizing on the unique opportunities for selectivity afforded by a chemical oxidant. The versatility of the electrochemical method allowed for the recycling of Os(viii)-, TEMPO-, Ce(iv)-, Pd(ii)-, Ru(viii)-, and Mn(v)-oxidants all with the same very simple reaction apparatus.
- Nguyen, Bichlien H.,Redden, Alison,Moeller, Kevin D.
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- Highly selective semi-hydrogenation of alkynes with a Pd nanocatalyst modified with sulfide-based solid-phase ligands
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Soluble small molecular/polymeric ligands are often used in Pd-catalyzed semi-hydrogenation of alkynes as an efficient strategy to improve the selectivity of targeted alkene products. The use of soluble ligands requires their thorough removal from the reaction products, which adds significant extra costs. In the paper, commercially available, inexpensive, metallic sulfide-based solid-phase ligands (SPL8-4 and SPL8-6) are demonstrated as simple yet high-performance insoluble ligands for a heterogeneous Pd nanocatalyst (Pd@CaCO3) toward the semi-hydrogenation of alkynes. Based on the reactions with a range of terminal and internal alkyne substrates, the use of the solid-phase ligands has been shown to markedly enhance the selectivity of the desired alkene products by efficiently suppressing over-hydrogenation and isomerization side reactions, even during the long extension of the reactions following full substrate conversion. A proper increase in the dosage or a reduction in the average size of the solid-phase ligands enhances such effects. With their insoluble nature, the solid-phase ligands have the distinct advantage in their simple, convenient recycling and reuse while without contaminating the products. A ten-cycle reusability test with the SPL8-4/Pd@CaCO3 catalyst system confirms its well-maintained activity and selectivity over repeated uses. A mechanistic study with x-ray photoelectron spectroscopy indicates that the solid-phase ligands have electronic interactions with Pd in the supported catalyst, contributing to inhibit the binding and further reaction of the alkene products. This is the first demonstration of solid-phase ligands for highly selective semi-hydrogenation of alkynes, which show strong promise for commercial applications.
- Huang, Lingqi,Hu, Kecheng,Ye, Ganggang,Ye, Zhibin
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- A simple and practical preparation of an efficient water soluble olefin metathesis catalyst
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This study details homogeneous olefin metathesis in water catalysed by a di-ammonium functionalised Ru-alkylidene complex. A facile gram scale synthesis of an air stable catalyst precursor which can be readily converted to its water soluble derivative is described. The di-ammonium functionalised Ru-alkylidene complex facilitates a range of ring-closing metathesis (RCM) and cross-metathesis (CM) reactions in water.
- Wang, Zhen J.,Jackson, W. Roy,Robinson, Andrea J.
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- Highly Efficient Catalytic Formation of (Z)-1,4-But-2-ene Diols Using Water as a Nucleophile
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The first general catalytic and highly stereoselective formation of (Z)-1,4-but-2-ene diols is described from readily available and modular vinyl-substituted cyclic carbonate precursors using water as a nucleophilic reagent. These 1,4-diol scaffolds can be generally prepared in high yields and with ample scope in reaction partners using a simple synthetic method that does not require the presence of any additive or any special precaution unlike the stoichiometric approaches reported to date. Control experiments support the mechanistic view that hyperconjugation within the catalytic intermediate after decarboxylation plays an imperative role to control the stereoselective outcome of these reactions.
- Guo, Wusheng,Martínez-Rodríguez, Luis,Martin, Eddy,Escudero-Adán, Eduardo C.,Kleij, Arjan W.
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- Synthesis of diols from 1,2-epoxy-3-butene
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The catalytic hydration of 1,2-epoxy-3-butene was studied. The products of the reaction are 3-butenediol-1,2(BD-1,2) and 2-butenediol-1,4 (BD-1,4). It was shown that the formation of 2-butenediol-1,4 proceeds predominantly in a polar solvent medium in the presence of the catalytic system "nickel iodide (bromide)-tetraethylammonium iodide" at a temperature of 80°C. In the presence of inorganic acids, the main product is 3-butenediol-1,2. Nauka/Interperiodica 2007.
- Mel'nik,Srednev,Rybina,Meshechkina,Shevchuk,Danilova
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- Continuous Flow Z-Stereoselective Olefin Metathesis: Development and Applications in the Synthesis of Pheromones and Macrocyclic Odorant Molecules**
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The first continuous flow Z-selective olefin metathesis process is reported. Key to realizing this process was the adequate choice of stereoselective catalysts combined with the design of an appropriate continuous reactor setup. The designed continuous process permits various self-, cross- and macro-ring-closing-metathesis reactions, delivering products in high selectivity and short residence times. This technique is exemplified by direct application to the preparation of a range of pheromones and macrocyclic odorant molecules and culminates in a telescoped Z-selective cross-metathesis/ Dieckmann cyclisation sequence to access (Z)-Civetone, incorporating a serial array of continually stirred tank reactors.
- Browne, Duncan L.,Colombel-Rouen, Sophie,Crévisy, Christophe,Curbet, Idriss,Mauduit, Marc,McBride, Tom,Morvan, Jennifer,Roisnel, Thierry
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supporting information
p. 19685 - 19690
(2021/08/06)
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- Fourth subgroup metal complex with rigid annular bridging structure and application of fourth subgroup metal complex
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The invention belongs to the technical field of olefin polymerization catalysts, and particularly relates to a fourth subgroup metal complex with a rigid annular bridging structure and an application of the fourth subgroup metal complex. The fourth subgroup metal complex provided by the invention has a structure represented by a formula (A) or a formula (B), X is halogen or alkyl; and M is titanium, zirconium or hafnium. On the basis of a non-metallocene catalyst, a bridging structure in catalyst molecules is improved and upgraded, and a brand-new metal complex with excellent catalytic performance and good high-temperature tolerance is designed; when the fourth subgroup metal complex is used as a main catalyst to catalyze olefin polymerization reaction, under the activation action of a small amount of mixed cocatalyst, the fourth subgroup metal complex can efficiently catalyze the copolymerization reaction of ethylene and alpha-olefin to obtain polyolefin with high molecular weight and high comonomer insertion rate.
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Paragraph 0058; 0061; 0066
(2021/06/23)
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- Preparation method of N-(4-methylpyridine-3-yl) methyl carbamate
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The invention relates to the technical field of preparation methods of N-(4-methylpyridine-3-yl) methyl carbamate, and discloses preparation of potassium tert-butoxide and preparation of the potassium tert-butoxide by using potassium methoxide. According to the preparation method of the N-(4-methylpyridine-3-yl) methyl carbamate, a user uses the potassium methoxide to prepare the potassium tert-butoxide, so that the content of the potassium tert-butoxide is higher, the potassium tert-butoxide and the potassium methoxide are very similar in properties and functions, so that the cost is saved, the method for extracting a THT solvent by using 1, 4-dichlorobutene as a raw material is simple, and the method has the advantages that the use amount of the catalyst is small, the condition is mild, the extraction purity is high, so that the cost is reduced again; and the N-(4-methylpyridine-3-yl) methyl carbamate is obtained by catalyzing two high-purity raw materials through the catalyst carbonic acid diester and stirring, so that the preparation efficiency is improved, the purity of the prepared N-(4-methylpyridine-3-yl) methyl carbamate is improved, the over-high preparation cost of the N-(4-methylpyridine-3-yl) methyl carbamate is avoided, and the use of the user is facilitated.
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Paragraph 0020; 0022; 0025; 0030; 0032; 0035; 0040; 0042
(2021/06/02)
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- Dehydrogenative alcohol coupling and one-pot cross metathesis/dehydrogenative coupling reactions of alcohols using Hoveyda-Grubbs catalysts
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In this study,in situformed ruthenium hydride species that were generated from Grubbs type catalysts are used as efficient catalysts for dehydrogenative alcohol coupling and sequential cross-metathesis/dehydrogenative coupling reactions. The selectivity of Grubbs first generation catalysts (G1) in dehydrogenative alcohol coupling reactions can be tuned for the ester formation in the presence of weak bases, while the selectivity can be switched to the β-alkylated alcohol formation using strong bases. The performance of Hoveyda-Grubbs 2nd generation catalyst (HG2) was improved in the presence of tricyclohexylphosphine for the selective synthesis of ester derivatives with weak and strong bases in quantitative yields. Allyl alcohol was used as self and cross-metathesis substrate for the HG2 catalyzed sequential cross-metathesis/dehydrogenative alcohol coupling reactions to obtain γ-butyrolactone and long-chain ester derivatives in quantitative yields.
- ?zer, Halenur,Arslan, Dilan,?ztürk, Bengi ?zgün
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p. 5992 - 6000
(2021/04/12)
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- Olefin reaction in the catalyst and the olefin production
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PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
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Paragraph 0145-0146; 0149
(2020/10/31)
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- A Schiff Base Modified Pd Catalyst for Selective Hydrogenation of 2-Butyne-1,4-diol to 2-Butene-1,4-diol
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Abstract: Schiff-base modified Pd nanoparticles (NPs) supported on silica with an average size of ca. 2?nm have been synthesized via a one-pot aldimine condensation followed by impregnation-reduction of a palladium precursor, and the sample exhibits an excellent catalytic activity and selectivity in hydrogenation of 2-butyne-1,4-diol (BYD) to 2-butene-1,4-diol (BED). Under the mild reaction conditions (50?°C, 2?MPa H2, and 4?h) and additive-free, 95.2% BYD conversion has been achieved with ca. 100% BED selectivity over the Pd/SiO2–Schiff catalyst, and the Pd/SiO2–Schiff catalyst presents an excellent catalytic stability. The above results are much better than that of commercial Lindlar catalyst, and the improved catalytic performance is attributed to the strong metal–support interaction derived from the coordination of nitrogen sites (Schiff-base) to Pd NPs, based on catalyst characterization results. Graphic Abstract: Featured by additive-free and high selectivity, hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol over the Pd/SiO2–Schiff catalyst has been developed, aiming for green production of fine chemicals.[Figure not available: see fulltext.]
- Li, Haomeng,Wang, Xinkui,Chen, Xiao,Li, Chuang,Wang, Min,Yi, Yanhui,Ji, Min,Wang, Huilong,Shao, Zhengfeng,Liang, Changhai
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p. 2150 - 2157
(2020/02/13)
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- An efficient approach for the synthesis of novel methyl sulfones in acetic acid medium and evaluation of antimicrobial activity
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A series of nine methyl sulphones (3a-3i) starting from the aldehydes (1a-1i) were synthesized in two consecutive steps. In the first step, preparation of allyl alcohols (2a-2i) from their corresponding aldehydes by the reaction of sodium borohydride in methanol at room temperature is reported. Finally, methyl sulphones are synthesized by condensing sodium methyl sulfinates with allyl alcohols in the presence of BF3.Et2O in acetic acid medium at room temperature for about 2-3 h. The reaction conditions are simple, yields are high (85%-95%), and the products were obtained with good purity. All the synthesized compounds were characterized by their 1H, 13C NMR, and mass spectral analysis. All the title compounds were screened for antimicrobial activity. Among the compounds tested, the compound 3f has inhibited both Gram positive and Gram negative bacteria effectively and compound 3i has shown potent antifungal activity. These promising components may help to develop more potent drugs in the near future for the treatment of bacterial and fungal infections.
- Bollikolla, Hari Babu,Dasireddy, Chandra Rao,Kotra, Vijay,Ravi Kumar, Gollapudi,Varala, Ravi
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p. 1386 - 1394
(2020/11/20)
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- Method for preparing olefin by catalyzing dehydration and deoxidation of polyhydroxy compound with organic molybdenum
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The invention discloses a method for preparing olefin by catalyzing dehydration and deoxidation of a polyhydroxy compound with organic molybdenum. The method comprises the following steps: reacting apolyhydroxy compound-containing raw material in the presence of an organic molybdenum-based catalyst to obtain olefin. According to the method, compounds containing nitrogen, sulfur, oxygen, phosphorus and other monodentate and polydentate coordination groups are used as organic ligands, and a series of organic molybdenum catalysts are prepared and used for catalyzing a deoxidation and dehydrationreaction of vicinal diol. The invention provides a cheap non-noble metal molybdenum-based catalyst, wherein the cost is greatly reduced.
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Paragraph 0122; 0124; 0129; 0131; 0134-0135
(2020/07/02)
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- Bimetallic Synergy Effects of Phyllosilicate-Derived NiCu@SiO2 Catalysts for 1,4-Butynediol Direct Hydrogenation to 1,4-Butanediol
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Hydrogenation of 1,4-butynediol (BYD) to 1,4-butanediol (BDO) is a two-step process, with an initial hydrogenation of BYD to 1,4-butenediol (BED) and the subsequent hydrogenation of BED to BDO. However, the BYD hydrogenation also involves many side reactions originated from the isomerization of BED. In order to inhibit the isomerization pathways, phyllosilicate-derived bimetallic NiCu@SiO2 catalysts have been developed for efficient C≡C/C=C hydrogenation in this work. Due to the formation of phyllosilicate matrix and highly dispersed metal nanoparticles, NiCu@SiO2 showed total BYD conversion with extremely high BDO selectivity compared to a conventional impregnated Ni/SiO2 catalyst. A remarkable result of NiCu@SiO2 catalysts is that a new type of bimetallic catalytic sites responsible for the high hydrogenation activity can be differentiated from the Ni phyllosilicate matrix by the induction of Cu species, and these neighboring bimetallic sites with the help of weak acid phyllosilicate interface, can realize to stabilize the activated BED species (allyl alcohol form) adsorbed on the cooperative active sites, thus to avoid its isomerization to aldehyde form and unexpected C=O hydrogenolysis. Consequently, it enhanced the selectivity to the diol products BDO significantly. Owing to the benign improvement of three center synergy effect, 9Ni1Cu@SiO2 possesses the optimum BYD direct hydrogenation ability with a rarely reported high selectivity of 90.5–94.5 % at 50 °C and 1 MPa.
- Wang, Changzhen,Tian, Yani,Wu, Ruifang,Li, Haitao,Yao, Benzhen,Zhao, Yongxiang,Xiao, Tiancun
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p. 4777 - 4787
(2019/08/26)
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- Acid-Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water
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The ability to use unprotected carbohydrates in olefin metathesis reactions in aqueous media is demonstrated. By using water-soluble, amine-functionalized Hoveyda–Grubbs catalysts under mildly acidic aqueous conditions, the self-metathesis of unprotected alkene-functionalized α-d-manno- and α-d-galactopyranosides could be achieved through minimization of nonproductive chelation and isomerization. Cross-metathesis with allyl alcohol could also be achieved with reasonable selectivity. The presence of small quantities (2.5 vol %) of acetic acid increased the formation of the self-metathesis product while significantly reducing the alkene isomerization process. The catalytic activity was furthermore retained in the presence of large amounts (0.01 mm) of protein, underlining the potential of this carbon–carbon bond-forming reaction under biological conditions. These results demonstrate the potential of directly using unprotected carbohydrate structures in olefin metathesis reactions under mild conditions compatible with biological systems, and thereby enabling their use in, for example, drug discovery and protein derivatization.
- Timmer, Brian J. J.,Ramstr?m, Olof
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supporting information
p. 14408 - 14413
(2019/11/11)
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- Method for preparing enol by semi-hydrogenating alkynol
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The invention provides a method for preparing 1,4-butenediol by semi-hydrogenating 1,4-butynediol. The method comprises the following steps: pre-treating raw materials by utilizing an alkaline solution; and realizing the controllability of a hydrogenating step by adopting a gradient stirring method in the presence of a catalyst. According to the method, the liquid-solid ratio of 1,4-alkynediol to the catalyst is (80-200) to 1, and the operation temperature (30 DEG C-115 DEG C) and the pressure (0.3MP-1MPa) are relatively low; and the conversion ratio of the 1,4-butynediol reaches 99.9% and the selectivity and yield of the 1,4-butenediol reach 98.2% and 95.87%. According to the method provided by the invention, the charge density of the raw material is changed and the controllability of a hydrogenating process is realized in the presence of the catalyst through adjusting a stirring speed by gradient, and a relatively good semi-hydrogenating performance is represented; and the method has a good industrial application value.
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Paragraph 0097; 0098; 0099; 0100; 0101; 0102; 0103-0127
(2017/07/21)
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- Efficient Pd@MIL-101(Cr) hetero-catalysts for 2-butyne-1,4-diol hydrogenation exhibiting high selectivity
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Pd@MIL-101(Cr) hetero-catalysts have been successfully prepared using the metal-organic chemical vapour deposition (MOCVD) approach, by choosing [Pd(η3-C3H5)(η5-C5H5)] as a volatile precursor, and the hydrothermally stable metal-organic framework, MIL-101(Cr) as a support. The prepared Pd@MIL-101(Cr) hetero-catalysts characterized with various analytical techniques, exhibited highly monodispersed immobilized Pd nanoparticles in the MIL-101(Cr) cavities, while retaining the pristine crystallinity and porosity. The intact hybrid Pd@MIL-101(Cr) has been demonstrated to be an efficient catalyst for 2-butyne-1,4-diol hydrogenation with excellent activity, stability and selectivity (2-butene-1,4-diol (>94%)).
- Yin, Dongdong,Li, Chuang,Ren, Hangxing,Shekhah, Osama,Liu, Jinxuan,Liang, Changhai
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p. 1626 - 1633
(2017/01/18)
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- BiCl3: A versatile catalyst for the tetrahydropyranylation and depyranylation of 1°,2°,3°, allylic, benzylic alcohols, and symmetric diols
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Bismuth trichloride as mild reagent, has been found to be a worthful catalyst for tetrahydropyranylation of 1°,2°,3°, allylic, benzylic alcohols, and symmetric di-ols. At room temperature the reagent THP(3,4-dihydro-2H-pyran) was successfully employed as pyranylating agent in presence of BiCl3catalyst without the use of a solvent and the yields of the products were found to be 90-96%. Further, the depyranylation of alcohols was achieved in quantitative yield by simple addition of MeOH using the same catalyst. The developed method was showed good chemo-selectivity in symmetrical diols for mono THP protection.
- Vijaya Durga,Balamurali Krishna,Baby Ramana,Santha Kumari,Vijay,Hari Babu
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p. 1030 - 1034
(2017/05/26)
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- METHOD FOR PRODUCING ALLYL ALCOHOLS
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PROBLEM TO BE SOLVED: To provide a method for producing allyl alcohols by direct addition of water to a raw material olefin which can achieve both high selectivity of compounds and high yield. SOLUTION: In a method for producing allyl alcohols by direct addition of water to a raw material olefin, the raw material olefin and water are brought into contact with a solid catalyst, where a catalytically active component containing at least one transition metal element selected from groups 8-10 of the periodic table is carried on an oxide carrier, in the presence of oxygen to convert the raw material olefin to allyl alcohols. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0078
(2017/05/27)
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- Versatile PdTe/C catalyst for liquid-phase oxidations of 1,3-butadiene
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A commercial Pd catalyst based on Sibunit carbon support was treated with H6TeO6 in a reducing media to obtain a Te coating on the surface of Pd particles. The PdTe/C catalyst prepared in this way showed the ability to control the radical chain oxidation of 1,3-butadiene by promoting the selective formation of 2-butene-1,4-diol, 4-hydroxybut-2-enal and furan in DMA (total selectivity of 61% and yield of 7%). At the same time, the catalyst induced oxidation of 1,3-butadiene by a non-radical heterolytic mechanism involving the formation of two groups of primary products: (1) crotonaldehyde and methyl vinyl ketone and (2) the products of oxygenation at the 1,4-positions. The compounds of the second group including 1,4-dimethoxy-2-butene and maleic acid dimethyl ester were formed on PdTe centers in MeOH. Increasing the Te concentration in the PdTe/C catalyst forced the conversion of 1,3-butadiene toward 1,4-oxygenation and simultaneously decreased the intensity of secondary oxidation, resulting in the selective formation of derivatives of the 1,4-oxygenation - 1,4-dimethoxy-2-butene and allenic alcohol methyl ether (total selectivity of 84% and yield of 48%).
- Kuznetsova,Zudin,Kuznetsova,Zaikovskii,Kajitani,Utsunomiya,Takahashi
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- Structured catalyst
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The present invention relates to novel structured catalysts based on sintered metal fibers (SMF) coated by a basic oxide layer with Pd-nanoparticles, to reactions of organic compounds with hydrogen in the presence of said catalyst and an organic base as well as to vitamins, carotinoids, perfume ingredients, and/or food or feed ingredients prepared by using this reaction.
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Page/Page column 9
(2015/09/22)
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- Pd-Pb Alloy Nanocrystals with Tailored Composition for Semihydrogenation: Taking Advantage of Catalyst Poisoning
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Metallic nanocrystals (NCs) with well-defined sizes and shapes represent a new family of model systems for establishing structure-function relationships in heterogeneous catalysis. Here in this study, we show that catalyst poisoning can be utilized as an efficient strategy for nanocrystals shape and composition control, as well as a way to tune the catalytic activity of catalysts. Lead species, a well-known poison for noble-metal catalysts, was investigated in the growth of Pd NCs. We discovered that Pb atoms can be incorporated into the lattice of Pd NCs and form Pd-Pb alloy NCs with tunable composition and crystal facets. As model catalysts, the alloy NCs with different compositions showed different selectivity in the semihydrogenation of phenylacetylene. Pd-Pb alloy NCs with better selectivity than that of the commercial Lindlar catalyst were discovered. This study exemplified that the poisoning effect in catalysis can be explored as efficient shape-directing reagents in NC growth, and more importantly, as a strategy to tailor the performance of catalysts with high selectivity.
- Niu, Wenxin,Gao, Yongjun,Zhang, Weiqing,Yan, Ning,Lu, Xianmao
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supporting information
p. 8271 - 8274
(2015/07/07)
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- Allyl sulphides in olefin metathesis: Catalyst considerations and traceless promotion of ring-closing metathesis
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Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions. This journal is
- Edwards, Grant A.,Culp, Phillip A.,Chalker, Justin M.
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supporting information
p. 515 - 518
(2015/02/19)
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- Divergent Approach to a Family of Tyrosine-Derived Ru-Alkylidene Olefin Metathesis Catalysts
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A simple and generic approach to access a new family of Ru-alkylidene olefin metathesis catalysts with specialized properties is reported. This strategy utilizes a late stage, utilitarian Hoveyda-type ligand derived from tyrosine, which can be accessed via a multigram-scale synthesis. Further functionalization allows the catalyst properties to be tuned, giving access to modified second-generation Hoveyda-Grubbs-type catalysts. This divergent synthetic approach can be used to access solid-supported catalysts and catalysts that function under solvent-free and aqueous conditions.
- Gleeson, Ellen C.,Wang, Zhen J.,Jackson, W. Roy,Robinson, Andrea J.
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p. 7205 - 7211
(2015/07/28)
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- Raney Ni-Si catalysts for selective hydrogenation of highly concentrated 2-butyne-1,4-diol to 2-butene-1,4-diol
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Raney Ni-Si catalysts were synthesized by treating Raney Ni with silane in a fluidized bed reactor and tested in the selective hydrogenation of 2-butyne-1,4-diol (BYD) at high concentration. Structural characterizations including XRD patterns, TEM images, and X-ray photoelectron spectroscopy show that Raney Ni-Si catalysts are composed of a Ni core surrounded by nickel silicides. These species transform from Ni-rich silicide (Ni2Si) to Si-rich silicide (NiSi2) with increasing silicification temperature from 250 °C to 450 °C. The insertion of Si atoms into Raney Ni catalysts decreased the catalytic activity, but significantly improved the selectivity to 2-butene-1,4-diol (BED). The beneficial effect of Si on the selectivity hydrogenation of BYD may be caused by the presence of Si at Ni-defect sites, and the formation of the surface nickel silicide that suppress the further hydrogenation of BED. Compared with the traditional Lindlar-type catalysts, such Raney Ni-Si materials can be used extensively in organic synthesis for selective hydrogenation of alkynes, avoiding the associated hazards of toxic additives.
- Chen, Xiao,Zhang, Mingming,Yang, Kaixuan,Williams, Christopher T.,Liang, Changhai
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p. 1118 - 1126
(2014/07/21)
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- Cyclopentanoids by uncatalyzed intramolecular carbonyl ene (ICE) reaction of α-keto esters
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The uncatalyzed intramolecular carbonyl ene (ICE) reaction of substituted ε,ζ-unsaturated α-keto esters to terpenoid-related building blocks has been studied. We found a beneficial effect of a silyl substituent at the ene segment on the kinetics of the ICE reaction. A generalizable and scalable synthesis of ε,ζ-unsaturated α-keto esters from allylic alcohols was developed.
- Tymann, David,Klueppel, Andre,Hiller, Wolf,Hiersemann, Martin
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supporting information
p. 4062 - 4065
(2014/11/07)
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- Liquid-phase catalytic hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol at atmospheric pressure on suspended catalysts
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The optimum parameters of hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol on the suspended palladium and Ni-Raney catalysts at atmospheric pressure were found. In selected conditions a yield up to 90% of 1,4-butanediol was reached.
- Pyatnitsyna,El'Chaninov
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p. 394 - 397
(2013/06/27)
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- Catalytic properties of heteropoly compounds in 1,3-butadiene oxidation with hydrogen peroxide
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The homogeneous oxidation of 1,3-butadiene (BD) in H2O 2-HPC-CH3CN (HPC = heteropoly compound) solutions has been investigated. The route of the reaction depends on the nature of the metal capable of coordinating with active oxygen in the HPC. The products of radical BD oxidation (acrolein, 3-butene-1,2-diol, 2-butene-1,4-diol, furan) form in the presence of H3+n PMo12 - n V n O40 (n = 1, 2) acids. 3,4-Epoxy-1-butene (EB) and acrolein + furan, which form in equal amounts in the presence of the (n-Bu4N)5PW 11O39Fe(OH) salt, result, respectively, from the electrophilic addition of hydrogen peroxide to BD and from radical BD oxidation on iron-oxygen complexes in the HPC composition. The reaction carried out in the presence of (n-Bu4N)3{PO4[WO(O 2)2]4}, (n-Bu4N)5Na 0.6H1.4PW11O39, or (EMIm) 5NaHPW11O39 yields EB with high selectivity on the reacted BD basis (up to 97%) and H2O2 (about 100%). The formation and conversion of the phosphotungstate peroxo complexes PW n O m α- (n = 2, 3, 4) that are active in BD epoxidation have been investigated by 31PNMR spectroscopy. The role of the tetrabutylammonium and ethylmethylimidazolium cations in the formation of these complexes has been demonstrated.
- Kuznetsova,Kuznetsova,Maksimovskaya,Koshcheeva,Utkin
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p. 420 - 430
(2013/12/04)
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- Selectivity in the addition reactions of organometallic reagents to aziridine-2-carboxaldehydes: The effects of protecting groups and substitution patterns
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Good to excellent stereoselectivity has been found in the addition reactions of Grignard and organozinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycarbonyl-protected trans, and tosyl-protected 2,3-disubstituted aziridine-2-carboxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziridines' substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6-31G* level of theory with the SM8 solvation model to account for solvent effects. Grignard and bear it: Good to excellent stereoselectivity is reported for the addition reactions of Grignard and organozinc reagents to N-protected aziridine-2-carboxaldehydes (see scheme). High syn selectivity was obtained with benzyl-protected cis, tert-butyloxycarbonyl-protected trans, and tosyl-protected 2,3-disubstituted aziridine-2-carboxaldehydes. Copyright
- Kulshrestha, Aman,Schomaker, Jennifer M.,Holmes, Daniel,Staples, Richard J.,Jackson, James E.,Borhan, Babak
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supporting information; experimental part
p. 12326 - 12339
(2011/12/15)
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- Olefin cross-metathesis on proteins: Investigation of allylic chalcogen effects and guiding principles in metathesis partner selection
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Olefin metathesis has recently emerged as a viable reaction for chemical protein modification. The scope and limitations of olefin metathesis in bioconjugation, however, remain unclear. Herein we report an assessment of various factors that contribute to productive cross-metathesis on protein substrates. Sterics, substrate scope, and linker selection are all considered. It was discovered during this investigation that allyl chalcogenides generally enhance the rate of alkene metathesis reactions. Allyl selenides were found to be exceptionally reactive olefin metathesis substrates, enabling a broad range of protein modifications not previously possible. The principles considered in this report are important not only for expanding the repertoire of bioconjugation but also for the application of olefin metathesis in general synthetic endeavors.
- Lin, Yuya A.,Chalker, Justin M.,Davis, Benjamin G.
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supporting information; experimental part
p. 16805 - 16811
(2011/02/17)
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- PROCESS FOR SELECTIVE HYDROGENATION OF ALKYNES TO ALKENES OVER SINGLE METAL SUPPORTED CATALYSTS WITH HIGH ACTIVITY
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The present invention relates to a process for selectively hydrogenating alkynes to alkenes over suitably supported single metal catalysts with high activity per unit of metal contents. It further elaborates selective hydrogenation of technical grades of 2-Butyne-1,4 diol produced from Reppe synthesis to 2-Butene-1,4 diol, with substantially lower Pd containing catalyst, amongst various commercially available Pd/ Al2Q3 catalysts, under lower hydrogen pressures ranging from 1 to 20 bar, at lower temperatures between 15 to 250 °C, with GHSV 1 to 10,000 h 1 and LHSV 0.001 to 10 h-1, which can be scaled up more than 10 times in a continuous single tube or multi tubular reactor.
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Page/Page column 17
(2010/04/30)
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- Batchwise and continuous organophilic nanofiltration of Grubbs-type olefin metathesis catalysts
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A mass-tagged N-mesityl imidazolinium salt with four additional -CH 2NCy2 substituents was synthesized, leading to a molecular mass of nearly 1100 g mol-1 in the corresponding carbene ligand. This mass-tagged ligand was used to generate the respective Grubbs II and Grubbs-Hoveyda type complexes. The catalytic activity of the latter complex was tested in several olefin metathesis reactions and found to be slightly superior to that of the related N-mesityl based complex. In batchwise solvent resistant nanofiltration experiments the ruthenium complex dissolved in toluene and following a metathesis reactions was efficiently retained (>99.8%) by a single nanofiltration; the permeate contained less than 4 ppm of Ru. Equally efficient catalyst retention was observed in a membrane reactor utilized for the continuous synthesis of a RCM product.
- Schoeps, Dirk,Buhr, Kristian,Dijkstra, Marga,Ebert, Katrin,Plenio, Herbert
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experimental part
p. 2960 - 2965
(2009/12/08)
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- Polyaniline supported Pd and Pt catalysts. Role of metal in hydrogenation of 2-butyne-1,4-diol
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Polyaniline (PANI), an electroactive polymer having amine (-NH-) and imine (-N=) groups in structure is used as the support for platinum and palladium catalysts. They are prepared, characterized by number of techniques (FTIR, XRD, XPS, SEM, TEM) and tested in the hydrogenation of alkyne, 2-butyne-1,4-diol (B3-D), reaction of industrial importance. Catalysts are prepared using aqueous solutions of PdCl2 and H2PtCl6 of pH = 2-3. In these conditions redox mechanism is involved resulting in partial reduction of Pd2+ to Pd0 and Pt4+ to Pt2+. In the as-prepared 2%Pd/PANI and additionally reduced 2%Pt/PANI catalysts the particles of Pd, Pt metal of size in nano-scale are formed. Performance of Pt and Pd-doped PANI in the hydrogenation of 2-butyne-l,4-diol (B3-D) strongly varies. In particular they differ in ability for selective hydrogenation of unsaturated C≡C bond in B3-D to 2-butene-1, 4-diol. Catalytic performance of 2%Pt/PANI is found to be similar to that observed for typical, inorganic carrier supported platinum catalysts. 2%Pd/PANI catalyst offers much higher activity and almost selectively reduces C=C bond in B3-D to C=C in B2-D. This advantageous performance of Pd/PANI catalyst can be related to an influence of electroactive matrix on properties of palladium centres.
- Drelinkiewicz,Zieba,Krol,Sobczak,Grzywa
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experimental part
p. 1717 - 1732
(2009/04/05)
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- Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
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Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
- Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
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supporting information; experimental part
p. 9642 - 9643
(2009/02/04)
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- Process for the Preparation of 22-Butene-1.4-Diol
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2-Butene-1.4-diol can be prepared by hydrogenating 2-butyne-1,4-diol in the presence of a structured catalyst in the absence of a solvent.
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Page/Page column 1-2
(2009/01/24)
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- METHOD FOR PRODUCING UNSATURATED VICINAL DIOL COMPOUND
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A method for producing an unsaturated vicinal diol compound represented by the formula (2): wherein R1, R2, R3 R4, R5 and R6 are the same or different and each independently represent a hydrogen atom; a C1-C20 alkyl group which may be substituted with a halogen atom or atoms, a C1-C6 alkoxy group or groups, a C2-C7 alkoxycabonyl group or groups, a C6-C10 aryl group or groups, or a carboxyl group or groups; or a C6-C10 aryl group which may be substituted with a halogen atom or atoms, a C1-C6 alkoxy group or groups, a C6-C10 aryl group or groups, or a carboxyl group or groups, which comprises reacting an unsaturated epoxy compound represented by the formula (1): wherein R1, R2, R3, R4, R5 and R6 are the same as defined above, with water in the presence of a silicate containing at least one element selected from a group 5 element and a group 6 element of the long periodic table as a constituent.
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Page/Page column 7; 8
(2008/06/13)
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- Small-molecule N-heterocyclic-carbene-containing olefin-metathesis catalysts for use in water
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(Chemical Equation Presented) ROMPing around in water: Two well-defined, small-molecule olefin-metathesis catalysts (1 and 2) are introduced. While they are insufficiently stable to mediate most cross-metathesis reactions in water, these catalysts competently mediate ring-opening metathesis polymerization (ROMP) and ring-closing metathesis reactions in an aqueous environment.
- Jordan, Jason P.,Grubbs, Robert H.
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p. 5152 - 5155
(2008/03/14)
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- Olefin metathesis in homogeneous aqueous media catalyzed by conventional ruthenium catalysts
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(Chemical Equation Presented) Olefin metathesis in aqueous solvents is sought for applications in green chemistry and with the hydrophilic substrates of chemical biology, such as proteins and polysaccharides. Most demonstrations of metathesis in water, however, utilize exotic complexes. We have examined the performance of conventional catalysts in homogeneous water/organic mixtures, finding that the second-generation Hoveyda-Grubbs catalyst has extraordinary efficiency in aqueous dimethoxyethane and aqueous acetone. High (71-95%) conversions are achieved for ring-closing and cross metathesis of a variety of substrates in these solvent systems.
- Binder, Joseph B.,Blank, Jacqueline J.,Raines, Ronald T.
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p. 4885 - 4888
(2008/03/14)
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- Continuous hydrogenation of 2-butyne-1,4-diol to 2-butene- and butane-1,4-diols
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Continuous catalytic hydrogenation of 2-butyne-1,4-diol (B3D) was carried out in a fixed-bed reactor over 1% Pt/CaCO3 catalyst to give 2-butene-1,4-diol (B2D) and butane-1,4-diol (B1D) without formation of any other side products. In case of continuous hydrogenation, higher selectivity (66%) to B2D could be obtained and the selectivity pattern was completely different from that found in case of batch slurry operation in which B1D selectivity was very much higher (83%) than the B2D selectivity (17%). Another interesting feature was that by varying the contact time, the selectivity to both B2D as well as B1D could be varied over a wide range which is an attractive option to obtain the desired products mix of B1D and B2D, depending on the fluctuation in the market demand. Further, a mathematical model for reactor performance was also developed on the basis of the kinetic data obtained previously in a batch slurry reactor. The predicted values of conversion, selectivity, and rate of hydrogenation were found to agree with the experimental data over a wide range of conditions.
- Rode,Tayade,Nadgeri,Jaganathan,Chaudhari
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p. 278 - 284
(2012/12/22)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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A 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented by the generalformula (1): [Chemical formula 1] (1) or a pharmaceutically acceptable saltthereof. They are useful as a therapeutic/preventive agent for diabetes, diabeticnephropathy, or glomerulosclerosis.
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Page/Page column 86
(2010/11/30)
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- Catalytic hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol at atmospheric pressure in the liquid phase
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Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol on suspended palladium and Raney nickel catalysts at atmospheric pressure was studied. The optimal parameters of this reaction were determined. Samples containing 90% 2-butene-1,4-diol were
- Pyatnitsyna,El'chaninov,Savost'yanov
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- Free-radical-5-exo-trig cyclization of chiral 3-silylhepta-1,6-dienes: Concise approach to the A-B-C ring core of hexacyclinic acid
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Free-radical-mediated 5-exo-trig cyclization of hepta-1,6-dienes 6a-c incorporating an allylsilane moiety was shown to provide at low temperature exclusively the trans-cis cyclopentanes 7a-c in good yield. In contrast, the same reaction with the alkyl analogue 9a led to the formation of all four possible stereoisomers. Interestingly, extension of this sequence of radical processes to alkoxy analogues 12-14 provided the complementary cis-cis stereoisomers with modest to excellent stereoselectivity. It is noteworthy that under such conditions allylsilanes were found to be much more reactive than their alkyl and alkoxy analogues. Beckwith-Houk-type models were proposed that rationalize the stereochemical course of these 5-exo-trig cyclizations. Finally, an illustration of the value of this methodology was proposed with the synthesis of the A-B-C tricyclic unit of polyketide hexacyclinic acid 3a.
- James, Philippe,Felpin, Francois-Xavier,Landais, Yannick,Schenk, Kurt
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p. 7985 - 7995
(2007/10/03)
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- Highly active phosphine-free carbene ruthenium catalyst for cross-metathesis of acrylonitrile with functionalized olefins
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The carbene ruthenium complex [1,3-bis(2,6-dimethylphenyl)-4,5- dihydroimidazol-2-ylidene](C5H5N)2(Cl) 2RuCHPh (8) was prepared by the reaction of [1,3-bis (2,6-dimethylphenyl)-4,5-dihydroimidazol-2-ylidene](PPh3)(Cl) 2RuCHPh (7) with pyridine and used as a highly effective catalyst for the cross-metathesis of acrylonitrile with various functionalized olefins.
- Bai, Chen-Xi,Zhang, Wen-Zhen,He, Ren,Lu, Xiao-Bing,Zhang, Zhi-Qiang
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p. 7225 - 7228
(2007/10/03)
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