- Photoredox Catalyzed Sulfonylation of Multisubstituted Allenes with Ru(bpy)3Cl2 or Rhodamine B
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A highly regio- and stereoselective sulfonylation of allenes was developed that provided direct access to α, β-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)3Cl2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds.
- Chen, Jingyun,Chen, Shufang,Jiang, Jun,Lu, Qianqian,Shi, Liyang,Xu, Zekun,Yimei, Zhao
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supporting information
(2021/11/09)
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- Functionalized styrene synthesis via palladium-catalyzed C[sbnd]C cleavage of aryl ketones
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We report herein the synthesis of functionalized styrenes via palladium-catalyzed Suzuki–Miyaura cross-coupling reaction between aryl ketone derivatives and potassium vinyltrifluoroborate. The employment of pyridine-oxazoline ligand was the key to the cleavage of unstrained C[sbnd]C bond. A variety of functional groups and biologically important moleculars were well tolerated. The orthogonal Suzuki–Miyaura coupling demonstrated the synthetic practicability.
- Dai, Hui-Xiong,Wang, Xing,Wang, Zhen-Yu,Xu, Hui,Zhang, Xu
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supporting information
(2022/03/31)
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- A simple and efficientin situgenerated copper nanocatalyst for stereoselective semihydrogenation of alkynes
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Development of a simple, effective, and practical method for (Z)-selective semihydrogenation of alkynes has been considered necessary for easy-to-access applications at organic laboratory scales. Herein, (Z)-selective semihydrogenation of alkynes was achieved using a copper nanocatalyst which was generatedin situsimply by adding ammonia borane to an ethanol solution of copper sulfate. Different types of alkynes including aryl-aryl, aryl-alkyl, and aliphatic alkynes were selectively reduced to (Z)-alkenes affording up to 99% isolated yield. The semihydrogenation of terminal alkynes to alkenes and gram-scale applications were also reported. In addition to eliminating catalyst preparation, the proposed approach is simple and practical and serves as a suitable alternative method to the conventional Lindlar catalyst.
- Park, Byoung Yong,Lim, Taeho,Han, Min Su
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supporting information
p. 6891 - 6894
(2021/07/19)
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- Electrochemical Proton Reduction over Nickel Foam for Z-Stereoselective Semihydrogenation/deuteration of Functionalized Alkynes
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Selective reduction strategies based on abundant-metal catalysts are very important in the production of chemicals. In this paper, a method for the electrochemical semihydrogenation and semideuteration of alkynes to form Z-alkenes was developed, using a simple nickel foam as catalyst and H3O+ or D3O+ as sources of hydrogen or deuterium. Good yields and excellent stereoselectivities (Z/E up to 20 : 1) were obtained under very mild reaction conditions. The reaction proceeded with terminal and nonterminal alkynes, and also with alkynes containing easily reducible functional groups, such as carbonyl groups, as well as aryl chlorides, bromides, and even iodides. The nickel-foam electrocatalyst could be recycled up to 14 times without any change in its catalytic properties.
- Johansson, Magnus J.,Kaur, Gurpreet,Martín-Matute, Belén,Martínez-Pardo, Pablo,Valiente, Alejandro
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- Phenylacetylene semihydrogenation over a palladium pyrazolate hydrogen-bonded network
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The palladium azolate/carboxylate network (Pd-dmpzc) catalyses the selective hydrogenation of phenylacetylene to styrene in water. Under optimised conditions, at a Pd:NaBH4 ratio of 1:100 at 40 °C, Pd-dmpzc provided much better results than Pd(OAc)2 or PdCl2(CH3CN)2. Analysis of the recovered catalyst revealed the presence of different Pd2+ species and Pd0 NPs which contributed in the catalytic reaction.
- Augustyniak, Adam W.,Trzeciak, Anna M.
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- Selective reduction of alkynes to alkenes with hydrogen or formic acid catalyzed by cis,mer-[IrH2Cl(mtppms)3]
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In this work we have found, that the water-soluble cis,mer-[IrH2Cl(mtppms)3] (mtppms = monosulfonated triphenylphosphine Na-salt) was an excellent catalyst for reduction of terminal alkynes by hydrogen transfer from aqueous HCOOH/HCOONa mixtures. The conversions strongly depended on the pH of the reaction mixtures, and the highest rate of phenylacetylene transfer hydrogenation was observed at pH 3. The same dihydrido-Ir(III) complex actively catalyzed also the hydrogenation of terminal alkynes under mild conditions (T = 50 °C; P(H2) = 2–10 bar). Importantly, both the hydrogenation and hydrogen transfer reductions afforded exclusively the corresponding alkenes as products. Phenylacetylene and its substituted derivatives reacted smoothly, while benzylic and aliphatic alkynes were less reactive or did not react at all. It was also found, that an excess of the mtppms ligand inhibited the reaction. This was rationalized by formation of cisz-[IrH2(mtppms)4]+ which was also confirmed with multinuclear NMR spectroscopy. On the basis of the experimental results, a joint mechanism was suggested for both the hydrogenation and transfer hydrogenation pathways. The mechanism of hydrogenation and transfer hydrogenation of phenylacetylene was also studied by DFT calculations, which revealed several possibilities for protonation of a vinyl intermediate as the crucial step in formation of the styrene product.
- Hankó, Gy?rgy,Márton, Richárd,Udvardy, Antal,Purgel, Mihály,Kathó, ágnes,Joó, Ferenc,Papp, Gábor
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supporting information
(2021/04/09)
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- Seed-mediated Growth of Alloyed Ag-Pd Shells toward Alkyne Semi-hydrogenation Reactions under Mild Conditions?
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Ag@Ag-Pdx core-shell nanocomposites with various Ag/Pd ratio were deposited on Ag nanoplates using a seed growth method. When physically loaded on C3N4, Ag@Ag-Pd0.077/C3N4 with optimized Ag/Pd ratio could accomplish high catalytic performance for the semi-hydrogenation of phenylacetylene as well as other aliphatic (both terminal and internal alkynes) alkynes and phenylcycloalkynes containing functional groups (such as ester, hydroxyl, ethyl groups) under room temperature and 1 atm H2. The alloying and ensemble effects are used to interpret such catalytic performance.
- Zheng, Yuqin,Tan, Taixing,Wang, Cheng
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p. 3071 - 3078
(2021/09/13)
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- In-situ facile synthesis novel N-doped thin graphene layer encapsulated Pd@N/C catalyst for semi-hydrogenation of alkynes
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Transition metal-catalyzed semi-hydrogenation of alkynes has become one of the most popular methods for alkene synthesis. Specifically, the noble metal Pd, Rh, and Ru-based heterogeneous catalysts have been widely studied and utilized in both academia and industry. But the supported noble metal catalysts are generally suffering from leaching or aggregation during harsh reaction conditions, which resulting low catalytic reactivity and stability. Herein, we reported the facile synthesis of nitrogen doped graphene encapsulated Pd catalyst and its application in the chemo-selective semi-hydrogenation of alkynes. The graphene layer served as “bulletproof” over the active Pd Nano metal species, which was confirmed by X-ray and TEM analysis, enhanced the catalytic stability during the reaction conditions. The optimized prepared Pd@N/C catalyst showed excellent efficiency in semi-hydrogenation of phenylacetylene and other types of alkynes with un-functionalized or functionalized substituents, including the hydrogenation sensitive functional groups (NO2, ester, and halogen).
- Lin, Shanshan,Liu, Jianguo,Ma, Longlong,Sun, Jiangming
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- Polymerization of Allenes by Using an Iron(II) β-Diketiminate Pre-Catalyst to Generate High Mn Polymers
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Herein, we report an iron(II)-catalyzed polymerization of arylallenes. This reaction proceeds rapidly at room temperature in the presence of a hydride co-catalyst to generate polymers of weight up to Mn=189 000 Da. We have determined the polymer structure and chain length for a range of monomers through a combination of NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. Mechanistically, we postulate that the co-catalyst does not react to form an iron(II) hydride in situ, but instead the chain growth is proceeding via a reactive Fe(III) species. We have also performed kinetic and isotopic experiments to further our understanding. The formation of a highly unusual 1,3-substituted cyclobutane side-product is also investigated.
- Durand, Derek J.,Webster, Ruth L.,Woof, Callum R.
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supporting information
p. 12335 - 12340
(2021/07/19)
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- Controlling the Lewis Acidity and Polymerizing Effectively Prevent Frustrated Lewis Pairs from Deactivation in the Hydrogenation of Terminal Alkynes
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Two strategies were reported to prevent the deactivation of Frustrated Lewis pairs (FLPs) in the hydrogenation of terminal alkynes: reducing the Lewis acidity and polymerizing the Lewis acid. A polymeric Lewis acid (P-BPh3) with high stability was designed and synthesized. Excellent conversion (up to 99%) and selectivity can be achieved in the hydrogenation of terminal alkynes catalyzed by P-BPh3. This catalytic system works quite well for different substrates. In addition, the P-BPh3 can be easily recycled.
- Geng, Jiao,Hu, Xingbang,Liu, Qiang,Wu, Youting,Yang, Liu,Yao, Chenfei
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p. 3685 - 3690
(2021/05/31)
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- Rapid synthesis method of biomass-based olefin
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The invention discloses a rapid synthesis method of biomass-based olefin, which comprises the following steps: by taking a biomass ketone compound as a substrate and 2-pentanol as a hydrogen source and a solvent at the same time, under the action of hafnium/zirconium-based catalysts such as hafnium phenylphosphonate and Zirconium phenylphosphonate, hafnium phytate andzirconium phytate and hafnium polydivinylphenylphosphonate and zirconium polydivinylphenylphosphonate, selectively converting a biomass-based ketone compound into a corresponding alcohol compound, and continuously dehydrating to prepare olefin. According to the present invention, the time required by the system reaction is substantially shortened and is at least 2 h, the target product selectivity is significantly improved, the conversion rate of the representative reaction 4 '-methoxypropiophenone can at least achieve 99.8%, and the anethole yield can achieve 98.1%.
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Paragraph 0020; 0041-0046; 0049-0050
(2021/07/31)
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- Electrochemistry enabled selective vicinal fluorosulfenylation and fluorosulfoxidation of alkenes
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Both sulfur and fluorine play important roles in organic synthesis, the life science, and materials science. The direct incorporation of these elements into organic scaffolds with precise control of the oxidation states of sulfur moieties is of great significance. Herein, we report the highly selective electrochemical vicinal fluorosulfenylation and fluorosulfoxidation reactions of alkenes, which were enabled by the unique ability of electrochemistry to dial in the potentials on demand. Preliminary mechanistic investigations revealed that the fluorosulfenylation reaction proceeded through a radical-polar crossover mechanism involving a key episulfonium ion intermediate. Subsequent electrochemical oxidation of fluorosulfides to fluorosulfoxides were readily achieved under a higher applied potential with the adventitious H2O in the reaction mixture.
- Jiang, Yimin,Shi, Zhaojiang,Wu, Jinnan,Wu, Shaofen,Ye, Keyin,Yu, Yi,Yuan, Yaofeng
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supporting information
(2021/11/17)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Wittig Olefination Using Phosphonium Ion-Pair Reagents Incorporating an Endogenous Base
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Despite common perception, the use of strong bases in Wittig chemistry is utterly unnecessary: we report a series of novel ion-pair phosphonium carboxylate reagents which are essentially "storable ylides". These reagents are straightforwardly prepared in excellent yields, and their fluxional nature permits clean olefination of a broad range of aldehydes and even hemiacetals.
- Vetter, Anna C.,Gilheany, Declan G.,Nikitin, Kirill
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supporting information
p. 1457 - 1462
(2021/03/08)
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- Efficient synthesis of styrene derivatives through ethenolysis of renewable propenylbenzenes
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Functionalized styrenes were obtained by the ethenolysis of renewable 1-propenylbenzenes in a very efficient synthetic pathway. Some of the products are valuable food & flavor ingredients (4-vinylguaiacol) or locust pheromone (4-vinylanisole). The catalysts employed were ruthenium-alkylidene complexes bearing a N-heterocyclic carbene as a ligand, which bulkiness proved to be important for the catalysis output. The judicious choice the reaction conditions was critical to enable near quantitative yields under mild conditions in short reaction times. More strikingly, the catalyst load could be reduced to 0.01 mol%, keeping good conversion and selectivity.
- Avenda?o Villarreal, Jesus A.,Delolo, Fábio G.,Granato, Artur V.,dos Santos, Eduardo N.
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- KO-t-Bu Catalyzed Thiolation of β-(Hetero)arylethyl Ethers via MeOH Elimination/hydrothiolation
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Herein, we describe a KO-t-Bu catalyzed thiolation of β-(hetero)arylethyl ethers through MeOH elimination to form (hetero)arylalkenes followed by anti-Markovnikov hydrothiolation to afford linear thioethers. The system works well with a variety of β-(hetero)arylethyl ethers, including electron-deficient, electron-neutral, electron-rich, and branched substrates and a range of aliphatic and aromatic thiols.
- Shigeno, Masanori,Shishido, Yoshiteru,Hayashi, Kazutoshi,Nozawa-Kumada, Kanako,Kondo, Yoshinori
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supporting information
p. 3932 - 3935
(2021/08/24)
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- Electro-mediated PhotoRedox Catalysis for Selective C(sp3)–O Cleavages of Phosphinated Alcohols to Carbanions
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We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)?O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)?O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
- Barham, Joshua P.,K?nig, Burkhard,Karl, Tobias A.,Reiter, Sebastian,Tian, Xianhai,Yakubov, Shahboz,de Vivie-Riedle, Regina
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p. 20817 - 20825
(2021/08/18)
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- Synthesis of Deuterated (E)-Alkene through Xanthate-Mediated Hydrogen-Deuterium Exchange Reactions
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Herein we have developed a reversible hydrogen-deuterium exchange reaction of nonactivated olefins. By using EtOCS2K as a mediator, the H/D exchange reaction was realized through repeated addition and elimination reactions, demonstrating reversible H/D exchange between ordinary olefins and deuterated olefins. Using the lowest cost D2O without precious metal catalysts and ligands, a broad spectrum of compatibility of functional groups was achieved.
- Li, Jiaming,Li, Jian,Ji, Xiaoliang,He, Runfa,Liu, Yang,Chen, Zebin,Huang, Yubing,Liu, Qiang,Li, Yibiao
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supporting information
p. 7412 - 7417
(2021/10/01)
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- Valorisation of urban waste to access low-cost heterogeneous palladium catalysts for cross-coupling reactions in biomass-derived γ-valerolactone
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Herein we report a simple protocol for the valorisation of a common urban biowaste. The lignocellulosic biomass obtained after the pre-treatment of pine needle urban waste is efficiently transformed into a low-cost support (PiNe) for the immobilization of Pd nanoparticles. The final Pd/PiNe heterogeneous catalyst features a small particle size (4.5 nm) and a metal loading (9.9 wt%) comparable with most commercially available and generally used counterparts. In this contribution, we tested the catalytic efficiency of the Pd/PiNe system in two representative cross-couplings, Heck and Hiyama reactions, and compared the results obtained with commercial Pd/C catalyst. The good reactivity in the biomass-derived solvent (GVL) confirms that the Pd/PiNe heterogeneous catalyst is a valid system that can be integrated into a waste valorization chain within a circular economy approach. In addition, the efficiency of the catalyst has also been extended to perform the challenging consecutive Hiyama-Heck reaction to afford differently substituted (E)-1,2-diarylethenes.
- Valentini, Federica,Ferlin, Francesco,Lilli, Simone,Marrocchi, Assunta,Ping, Liu,Gu, Yanlong,Vaccaro, Luigi
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supporting information
p. 5887 - 5895
(2021/08/23)
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- Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis
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The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.
- Zhou, Min-Jie,Zhang, Lei,Liu, Guixia,Xu, Chen,Huang, Zheng
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supporting information
p. 16470 - 16485
(2021/10/20)
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- Copper-Catalyzed Methoxylation of Aryl Bromides with 9-BBN-OMe
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A Cu-catalyzed cross-coupling reaction between aryl bromides and 9-BBN-OMe to provide aryl methyl ethers under mild conditions is reported. The oxalamide ligand BHMPO plays a key role in the transformation. Various functional groups on bromobenzenes are well tolerated, providing the desired anisole products in moderate to high yields.
- Li, Chen,Song, Zhi-Qiang,Wang, Dong-Hui,Wang, Jing-Ru
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supporting information
p. 8450 - 8454
(2021/11/17)
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- The first one-pot metathesis-hydroformylation procedure: a straight synthesis of 2-arylpropanals from renewable 1-propenylbenzenes
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Hydroformylation is a consolidated synthetic tool in the chemical industry, both in commodity and in the fine chemicals industry. Olefin metathesis has been largely employed in the petrochemical sector, and, more recently, in the synthesis of specialty chemicals. Although these reactions may be involved in the same synthetic route for various industrial chemicals, to the best of our knowledge, they have never been combined in a one-pot procedure. As a proof of concept, we have demonstrated in the present work that the ruthenium-catalyzed ethenolysis of renewable 1-propenylbenzenes followed by the rhodium-catalyzed hydroformylation of functionalized styrenes formed in the first step could be done in one pot. The integration of these reactions was not straightforward once the catalyst of the first step interfered with the catalyst of the second step. Under optimized conditions, it was possible to synthesize 2-arylpropanals, a class of compounds valuable as synthetic intermediates to access non-steroidal anti-inflammatory drugs, in overall yields of 85-90%, at low catalyst loadings.
- Avenda?o Villarreal, Jesus Alberto,Delolo, Fábio Godoy,Granato, Artur Vicari,Gusevskaya, Elena Vitalievna,dos Santos, Eduardo Nicolau
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p. 8007 - 8013
(2021/12/27)
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- An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- And Stereoselective Semihydrogenation of Internal and Terminal Alkynes
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The catalytic utility of [RuL1(CO)2I2] (1), containing an annelated π-conjugated imidazo-naphthyridine-based mesoionic carbene (MIC) ligand (L1), is evaluated for E-selective alkyne semihydrogenation. The precatalyst 1, in combination with 2 equiv of AgBArF, semihydrogenates a broad range of internal alkynes with molecular hydrogen (5 bar) in water. (E)-Alkenes are accessed in high yields, and a number of reducible functional groups are tolerated. A chelate MIC ligand and two cis carbonyls provide a well-defined platform at the Ru center for hydrogenation and isomerization. The loss of two iodides and the presence of two carbonyls render the Ru center electron deficient and thus the formation of metal vinylidenes with terminal alkynes is avoided. This is leveraged for the semihydrogenation of terminal alkynes by the same catalytic system in isopropyl alcohol. Reaction profile, isomerization, kinetic, and DFT studies reveal initial alkyne hydrogenation to a (Z)-alkene, which further isomerizes to an (E)-alkene via metal-catalyzed Z → E isomerization.
- Bera, Jitendra K.,Choudhury, Joyanta,Das, Shubhajit,Dutta, Indranil,Pati, Swapan K.,Saha, Sayantani,Yadav, Suman
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p. 3212 - 3223
(2020/10/02)
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- Piperazine-promoted gold-catalyzed hydrogenation: The influence of capping ligands
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Gold nanoparticles (NPs) combined with Lewis bases, such as piperazine, were found to perform selective hydrogenation reactions via the heterolytic cleavage of H2. Since gold nanoparticles can be prepared by many different methodologies and using different capping ligands, in this study, we investigated the influence of capping ligands adsorbed on gold surfaces on the formation of the gold-ligand interface. Citrate (Citr), poly(vinyl alcohol) (PVA), polyvinylpyrrolidone (PVP), and oleylamine (Oley)-stabilized Au NPs were not activated by piperazine for the hydrogenation of alkynes, but the catalytic activity was greatly enhanced after removing the capping ligands from the gold surface by calcination at 400 °C and the subsequent adsorption of piperazine. Therefore, the capping ligand can limit the catalytic activity if not carefully removed, demonstrating the need of a cleaner surface for a ligand-metal cooperative effect in the activation of H2 for selective semihydrogenation of various alkynes under mild reaction conditions.
- Barbosa, Eduardo C. M.,Camargo, Pedro H. C.,Fiorio, Jhonatan L.,Hashmi, A. Stephen K.,Kikuchi, Danielle K.,Rossi, Liane M.,Rudolph, Matthias
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p. 1996 - 2003
(2020/04/22)
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- Unexpectedly selective hydrogenation of phenylacetylene to styrene on titania supported platinum photocatalyst under 385 nm monochromatic light irradiation
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Conversion of alkynes to alkenes by photocatalysis has inspired extensive interest, but it is still challenging to obtain both high conversion and selectivity. Here we first demonstrate the photocatalytic conversion of phenylacetylene (PLE) to styrene (STE) with both high conversion and selectivity by using the titania (TiO2) supported platinum (Pt) as photocatalyst under 385 nm monochromatic light irradiation. It is demonstrated that the conversion rate of PLE is strongly dependent on the content of Pt cocatalyst loaded on the surface of TiO2. Based on our optimization, the conversion of PLE and the selectivity towards STE on the 1 wt% Pt/TiO2 photocatalyst can unexpectedly reach as high as 92.4% and 91.3%, respectively. The highly selective photocatalytic hydrogenation can well be extended to the conversion of other typical alkynes to alkenes, demonstrating the generality of selective hydrogenation of C≡C over the Pt/TiO2 photocatalyst.
- Lian, Juhong,Chai, Yuchao,Qi, Yu,Guo, Xiangyang,Guan, Naijia,Li, Landong,Zhang, Fuxiang
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p. 598 - 603
(2020/01/28)
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- Accelerating Chemo- And Regioselective Hydrogenation of Alkynes over Bimetallic Nanoparticles in a Metal-Organic Framework
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Selective semihydrogenation of alkynes has been a long-term and significant target, yet it remains a great challenge. Herein, bimetallic nanoparticles in a metal-organic framework (MOF), i.e., CuPd&at;ZIF-8 composite, featuring a cubic CuPd core and a porous ZIF-8 shell, have been rationally fabricated for this end. Given the unique physicochemical properties, the Cu nanocubes can not only convert solar energy into heat to accelerate the reaction but also serve as the seed for in situ formation of Pd nanoparticles (NPs) on their external surface to regulate the chemoselectivity of Pd active sites. The additional growth of the MOF shell is helpful to stabilize the CuPd core and offer regioselectivity via the steric hindrance effect. Ammonia borane provides active hydrogen species to significantly boost the hydrogenation and ensure the high selectivity. As a result, the CuPd&at;MOF exhibits high efficiency, featuring a turnover frequency (TOF, 6799 min-1) of 5-105 times higher than that in previous reports, and high chemo- and regioselectivity toward the semihydrogenation of alkynes, in the presence of NH3BH3 as a hydrogen source, under visible-light irradiation at ambient temperature.
- Guan, Qiaoqiao,Jiang, Hai-Long,Li, Luyan,Lu, Junling,Yang, Qihao,Yang, Weijie,Yu, Shu-Hong
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p. 7753 - 7762
(2020/08/21)
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- Selective Transfer Semihydrogenation of Alkynes with H2O (D2O) as the H (D) Source over a Pd-P Cathode
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We reported a selective semihydrogenation (deuteration) of numerous terminal and internal alkynes using H2O (D2O) as the H (D) source over a Pd-P alloy cathode at a lower potential. P-doping caused the enhanced specific adsorption of alkynes and the promoted intrinsic activity for producing adsorbed atomic hydrogen (H*ads) from water electrolysis. The semihydrogenation of alkynes could be accomplished at a lower potential with up to 99 % selectivity and 78 % Faraday efficiency of alkene products, outperforming pure Pd and commercial Pd/C. This electrochemical semihydrogenation of alkynes might proceed via a H*ads addition pathway rather than a proton-coupled electron transfer process. The decreased amount of H*ads at a lower potential and the more preferential adsorption of the Pd-P to C≡C π bond than C=C moiety resulted in the excellent alkene selectivity. This method was capable of producing mono-, di-, and tri-deuterated alkenes with up to 99 % deuterium incorporation.
- Liu, Cuibo,Lu, Siyu,Wang, Changhong,Wu, Yongmeng,Zhang, Bin
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supporting information
p. 21170 - 21175
(2020/09/11)
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- Palladium-catalyzed proaromatic C(Alkenyl)-H olefination: Synthesis of densely functionalized 1,3-dienes
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An example of proaromatic C(alkenyl)-H olefination is reported. This protocol utilized a free carboxylic acid as a directing group for C(alkenyl)-H activation of 1,4-cyclohexadiene and coupled with various alkenes. Direct and sequential bisolefinations of proaromatic acids were achieved. The synthetic applicability has been exhibited by [4 + 2] cycloaddition and decarboxylative aromatization of the resulting proaromatic 1,3-dienes. Additionally, several kinetic studies also have been carried out to elucidate the reaction mechanism.
- Wang, Yu-Chun,Huang, Yen-Hsiang,Tsai, Hung-Chang,Sidick Basha,Chou, Chih-Ming
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supporting information
p. 6765 - 6770
(2020/09/15)
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- Synthesis method of monosubstituted styrene
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The invention discloses a synthetic method of monosubstituted styrene. According to the method, monosubstituted benzaldehyde and methyltriphenylphosphonium bromide are used as initial raw materials, tetrahydrofuran is used as a solvent, strong base without nitrogen protection and low-temperature reaction conditions is used for reaction at normal temperature and normal pressure, and after the reaction is finished, a flash column chromatography method is used for post-treatment to obtain monosubstituted styrene. According to the method, water-free and oxygen-free harsh operation conditions are avoided, and the synthesis cost is reduced; the post-treatment process is simplified, quenching and extraction operations are not needed, the post-treatment time is shortened, a large amount of eluentdoes not need to be used, and the product loss is reduced.
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Paragraph 0038-0040; 0049-0050; 0055-0064; 0065-0068
(2020/05/05)
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- Efficient palladium-catalyzed synthesis of 2-aryl propionic acids
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A flexible two-step, one-pot procedure was developed to synthesize 2-aryl propionic acids including the anti-inflammatory drugs naproxen and flurbiprofen. Optimal results were obtained in the presence of the novel ligand neoisopinocampheyldiphenylphosphine (NISPCPP) (9) which enabled the efficient sequential palladium-catalyzed Heck coupling of aryl bromides with ethylene and hydroxycarbonylation of the resulting styrenes to 2-aryl propionic acids. This cascade transformation leads with high regioselectivity to the desired products in good yields and avoids the need for additional purification steps.
- Neumann, Helfried,Sergeev, Alexey G.,Spannenberg, Anke,Beller, Matthias
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supporting information
(2020/09/16)
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- Novel nickel nanoparticles stabilized by imidazolium-amidinate ligands for selective hydrogenation of alkynes
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The main challenge in the hydrogenation of alkynes into (E)- or (Z)-alkenes is to control the selective formation of the alkene, avoiding the over-reduction to the corresponding alkane. In addition, the preparation of recoverable and reusable catalysts is of high interest. In this work, we report novel nickel nanoparticles (Ni NPs) stabilized by three different imidazolium-amidinate ligands (ICy·(Ar)NCN; L1: Ar = p-tol, L2: Ar = p-anisyl and L3: Ar = p-ClC6H4). The as-prepared Ni NPs were fully characterized by (HR)-TEM, XRD, WASX, XPS and VSM. The nanocatalysts are active in the hydrogenation of various substrates. They present a remarkable selectivity in the hydrogenation of alkynes towards (Z)-alkenes, particularly in the hydrogenation of 3-hexyne into (Z)-3-hexene under mild reaction conditions (room temperature, 3% mol Ni and 1 bar H2). The catalytic behaviour of Ni NPs was influenced by the electron donor/acceptor groups (-Me, -OMe, -Cl) in the N-aryl substituents of the amidinate moiety of the ligands. Due to the magnetic character of the Ni NPs, recycling experiments were successfully performed after decantation in the presence of an external magnet, which allowed us to recover and reuse these catalysts at least 3 times preserving both activity and chemoselectivity.
- López-Vinasco, Angela M.,Martínez-Prieto, Luis M.,Asensio, Juan M.,Lecante, Pierre,Chaudret, Bruno,Cámpora, Juan,Van Leeuwen, Piet W. N. M.
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p. 342 - 350
(2020/02/04)
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- Methoxy-enriched cationic stilbenes as anticancer therapeutics
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Stilbene-based compounds are largely described for their antioxidant activity. But their use as anticancer chemotherapeutics is hampered by poor pharmacokinetic properties and non-selectivity towards cancer and non-cancer potency. To overcome these drawbacks, twin chain cationic lipid conjugated, methoxy-enriched stilbene derivatives were designed, synthesized and evaluated for their anticancer potency. Our findings reveal that HMSC16, a molecule with the highest number of methoxy groups and with C16-twin chain lipid, is the most potent as well as the most selective anticancer agent when compared to the other synthesized derivatives and commercially available stilbene-based drug, tamoxifen, and resveratrol. To justify these results, we have conducted a series of mechanistic experiments where we found that HMSC16 induced ROS generation, apoptosis, and autophagy by affecting the mitochondrial, lysosomal and nuclear pathways. Further cell cycle analysis data reveals that HMSC16 not only induces cell death but is also involved in the arrest of the cell cycle at the sub-G1 phase. Moreover, HMSC16 showed self-aggregation property owing to a possibly favorable hydrophilic-lipophilic balance. The self-aggregation property of HMSC16 allowed it to entrap hydrophobic drugs, withaferin. With entrapped withaferin, HMSC16 showed additive if not synergistic cell killing effect in HeLa cells. From the above results, we concluded that HMSC16 can be used not just as a drug but also as a drug delivery agent.
- Adhikari, Susanta Sekhar,Banerjee, Rajkumar,Jinka, Sudhakar,Yousuf, Md
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- Fast and Regioselective Polymerization of para-Alkoxystyrene by Palladium Catalysts for Precision Production of High-Molecular-Weight Polystyrene Derivatives
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Polymerization of polar vinyl monomers by a coordination-insertion approach is a topic of fundamental importance to the field of polymer synthesis. Herein, we initially report the coordination-insertion polymerization of para-alkoxystyrene (pAOS) monomers by the dibenzobarrelene-based α-diimine palladium catalysts. The unprecedented polymerization characteristics including rapid initiation, fast chain growth, controlled chain transfer, and high-molecular-weight polymer with a narrow distribution (Mw > 1000 kg/mol, PDI 1.32) reflected previously unrecognized aspects of palladium-catalyzed pAOS polymerization. Chain-end analysis and characterization of palladium intermediates showed that the pAOS monomer was rapidly inserted into the primary palladium species in a full 1,2-regioselectivity, and the chain transfer took place by monomer-assisted β-H abstraction at high monomer concentrations. The resultant polymers showed improved mechanical properties and thermal stabilities and were also attractive candidates of hydrophilic styrenic resin.
- Liao, Guangfu,Xiao, Zefan,Chen, Xiaolin,Du, Cheng,Zhong, Liu,Cheung, Chi Shing,Gao, Haiyang
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p. 256 - 266
(2020/01/09)
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- 6MNEP: A molecular cation with large hyperpolarizability and promise for nonlinear optical applications
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Molecular organic crystals are strategically designed for nonlinear optical applications using push-pull chromophores as the core feature. In this approach, electron-donating and accepting groups are connected through a π-conjugated bridge to obtain planar molecules with high hyperpolarizability. However, the non-centrosymmetric packing that is required for nonlinear optical (NLO) applications is a critical challenge that must be addressed to design useful materials. In this article, we present the new organic cation 6MNEP that shows a large hyperpolarizability and can be crystallized in ideal non-centrosymmetric structures for NLO applications, when paired with T and 4NBS anions. The 6MNEP cation was obtained by extending the conjugation length of already existing chromophores. We compare the 6MNEP crystals with other crystals that also have cations with extended conjugation lengths, but result in centrosymmetric crystal structures. Using the effective hyperpolarizability, we found 6MNEP-T and 6MNEP-4NBS to have 1.6 to 2.5 times larger macroscopic nonlinearities than benchmark NLO organic crystals. Additionally, the significantly lower absorption wavelength compared with other state-of-the-art crystals make 6MNEP-T and 6MNEP-4NBS promising materials for NLO applications like intense terahertz generation.
- Bloxham, Joseph C.,Brock, Daniel J.,Jackson, Erika W.,Johnson, Jeremy A.,Kenney, Karissa C.,Michaelis, David J.,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.,Wayment, Adam X.
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supporting information
p. 11079 - 11087
(2020/09/09)
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- Sequential Cleavage of Lignin Systems by Nitrogen Monoxide and Hydrazine
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The cleavage of representative lignin systems has been achieved in a metal-free two-step sequence first employing nitrogen monoxide for oxidation followed by hydrazine for reductive C?O bond scission. In combining nitrogen monoxide and lignin, the newly developed valorization strategy shows the particular feature of starting from two waste materials, and it further exploits the attractive conditions of a Wolff-Kishner reduction for C?O bond cleavage for the first time. (Figure presented.).
- Altmann, Lisa-Marie,Heinrich, Markus R.,Hofmann, Dagmar,Hofmann, Laura Elena,Prusko, Lea
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supporting information
(2020/03/27)
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- Reductive Deamination with Hydrosilanes Catalyzed by B(C6F5)3
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The strong boron Lewis acid tris(pentafluorophenyl)borane B(C6F5)3 is known to catalyze the dehydrogenative coupling of certain amines and hydrosilanes at elevated temperatures. At higher temperature, the dehydrogenation pathway competes with cleavage of the C?N bond and defunctionalization is obtained. This can be turned into a useful methodology for the transition-metal-free reductive deamination of a broad range of amines as well as heterocumulenes such as an isocyanate and an isothiocyanate.
- Fang, Huaquan,Oestreich, Martin
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supporting information
p. 11394 - 11398
(2020/05/25)
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- Site-selective aromatic C-H λ3-iodanation with a cyclic iodine(iii) electrophile in solution and solid phases
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An efficient and site-selective aromatic C-H λ3-iodanation reaction is achieved using benziodoxole triflate (BXT) as an electrophile under room temperature conditions. The reaction tolerates a variety of electron-rich arenes and heteroarenes to afford the corresponding arylbenziodoxoles in moderate to good yields. The reaction can also be performed mechanochemically by grinding a mixture of solid arenes and BXT under solvent-free conditions. The arylbenziodoxoles can be used for various C-C and C-heteroatom bond formations, and are also amenable to further modification by electrophilic halogenation. DFT calculations suggested that the present reaction proceeds via a concerted λ3-iodanation-deprotonation transition state, where the triflate anion acts as an internal base. This journal is
- Ding, Wei,García, Felipe,Ho, Chang Chin,León, Felix,Tan, Jie Ren,Wang, Chen,Yoshikai, Naohiko
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p. 7356 - 7361
(2020/08/03)
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- Iron-Catalyzed Direct Julia-Type Olefination of Alcohols
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Herein, we report an iron-catalyzed, convenient, and expedient strategy for the synthesis of styrene and naphthalene derivatives with the liberation of dihydrogen. The use of a catalyst derived from an earth-abundant metal provides a sustainable strategy to olefins. This method exhibits wide substrate scope (primary and secondary alcohols) functional group tolerance (amino, nitro, halo, alkoxy, thiomethoxy, and S- A nd N-heterocyclic compounds) that can be scaled up. The unprecedented synthesis of 1-methyl naphthalenes proceeds via tandem methenylation/double dehydrogenation. Mechanistic study shows that the cleavage of the C-H bond of alcohol is the rate-determining step.
- Landge, Vinod G.,Babu, Reshma,Yadav, Vinita,Subaramanian, Murugan,Gupta, Virendrakumar,Balaraman, Ekambaram
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p. 9876 - 9886
(2020/09/03)
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- Aminopotassiation by Mixed Potassium/Lithium Amides: A Synthetic Path to Difficult to Access Phenethylamine Derivates
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Insights gained from a comparison of aminometalation reactions with lithium amides, potassium amides and mixed lithium/potassium amides are presented. A combination of structural characterization, DFT calculations and electrophile reactions of aminometalated intermediates has shown the advantages of using a mixed metal strategy. While potassium amides fail to add, the lithium amides are uncontrollable and eliminated, yet the mixed K/Li amides deliver the best of both systems. Aminopotassiation proceeds to form the alkylpotassium species which has enhanced stability over its lithium counterpart allowing for its isolation and thereby its further characterization.
- Brieger, Lukas,O'Shea, Donal F.,Opper, Ulrike,Otte, Felix,Seymen, Andreas,Strohmann, Carsten,Unkelbach, Christian,Vo?, Andreas
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supporting information
p. 22500 - 22504
(2020/10/15)
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- Semihydrogenation of phenylacetylene over nonprecious Ni-based catalysts supported on AlSBA-15
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A series of nonprecious monometallic Ni/AlSBA-15 and bimetallic Ni–M (M = Zn, Ga, Cu, or Fe)/AlSBA-15 catalysts were prepared using a urea precipitation method and applied to the semihydrogenation of phenylacetylene. The catalysts were characterized by various techniques, showing that the Ni particle size of catalyst can be tuned by adjusting the Al content, and NiZn and NiGa supported catalysts exhibited geometric and electronic effects that originated from the bimetallic alloy. Among all the catalysts studied, NiZn3/AlSBA-15, with a turnover frequency of 10.89 s?1 comparable to that of precious Pd-based catalysts, presented the highest selectivity to styrene (90.3%) at nearly 100% conversion of phenylacetylene in semibatch operation. This catalyst was further evaluated in a continuous fixed-bed reactor for semihydrogenation of a model C8 aromatic fraction of pyrolysis gasoline (a mixture of phenylacetylene, styrene, ethylbenzene and xylene), which aimed at assessing its practical application of recovering styrene from pyrolysis gasoline. The results showed that at complete conversion of phenylacetylene, the styrene concentration in the product was always kept at a stable level and higher than its initial concentration over 100 h of time on stream, demonstrating high selectivity and good stability of NiZn3/AlSBA-15. Finally, the application of NiZn3/AlSBA-15 was extended to other phenylacetylene derivatives.
- Yang, Lei,Yu, Shiyi,Peng, Chong,Fang, Xiangchen,Cheng, Zhenmin,Zhou, Zhiming
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p. 310 - 320
(2019/01/24)
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- PdCx nanocrystals with tunable compositions for alkyne semihydrogenation
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The palladium carbide (PdCx) material has shown great promise as an efficient catalyst for alkyne semihydrogenation. Difficulties in preparing stable PdCx catalysts have been recognized as the main obstacle. Here, we synthesized a highly stable and durable class of PdCx nanocrystals by treating pre-formed Pd nanocrystals with glucose under hydrothermal conditions. The C/Pd atomic ratios in the resultant PdCx nanocrystals can be varied from 0.04 to 0.18, simply by changing the reaction time. The catalytic results for semihydrogenation of 4-ethynyl-1,1′-biphenyl show that PdC0.18 nanocrystals exhibit an activity with a turnover frequency as high as 7896 h-1, ~7.6 and ~38 times higher than that of commercial Pd/C and Lindlar catalysts, respectively, as well as a selectivity of >99%.
- Guo, Ruiyun,Chen, Qiang,Li, Xiang,Liu, Yaming,Wang, Chaoqi,Bi, Wei,Zhao, Caiyang,Guo, Yanjun,Jin, Mingshang
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supporting information
p. 4714 - 4720
(2019/03/07)
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- Bimetallic Co/Al nanoparticles in an ionic liquid: Synthesis and application in alkyne hydrogenation
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Herein, we report the microwave-induced decomposition of various organometallic cobalt and aluminum precursors in an ionic liquid (IL), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIm]NTf2), resulting in Co/Al nanoalloys with different molar Co/Al ratios. The dual-source precursor system of dicobalt octacarbonyl (Co2(CO)8) and pentamethylcyclopentadienyl aluminum ([AlCp?]4) in [BMIm]NTf2 afforded CoAl nanoparticles (CoAl-NPs) with a molar Co/Al ratio of 1?:?1. Their size and size distribution were determined via transmission electron microscopy (TEM) to be an average diameter of 3.0 ± 0.5 nm. Furthermore, the dual-source precursor system of cobalt amidinate ([Co(iPr2-MeAMD)2]) and aluminum amidinate [Me2Al(iPr2-MeAMD)] in molar ratios of 1?:?1 and 3?:?1 resulted in CoAl-and Co3Al-NPs with an average diameter of 3 ± 1 and 2.0 ± 0.2 nm, respectively. All the obtained materials were characterized via TEM, energy dispersive X-ray spectroscopy (EDX), selected area electron diffraction (SAED), together with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and (high-resolution) X-ray photoelectron spectroscopy ((HR-)XPS). Phase-pure Co/Al-NPs were not obtained since the concomitant formation of Co-NPs and Al2O3 occurred in this wet-chemical synthesis. The as-prepared Co/Al nanoalloys were evaluated as catalysts in the hydrogenation of phenylacetylene under mild conditions (2 bar H2, 30 °C in THF). In comparison to the monometallic Co-NPs, the Co/Al-NPs showed a significantly higher catalytic hydrogenation activity. The Co-and Co/Al-NPs were also active under harsher reaction conditions (80 bar H2, 80 °C) without the addition of the activating co-catalyst DIBAL-H.
- Schmolke, Laura,Gregori, Bernhard J.,Giesen, Beatriz,Schmitz, Alexa,Barthel, Juri,Staiger, Lena,Fischer, Roland A.,Jacobi Von Wangelin, Axel,Janiak, Christoph
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p. 16583 - 16594
(2019/11/11)
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- Normal Alpha Olefin Synthesis Using Dehydroformylation or Dehydroxymethylation
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The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, 1-decene, and 1-dodecene in a multistep synthesis scheme from another normal alpha olefin. Also disclosed are reactions for converting aldehydes, primary alcohols, and terminal vicinal diols into normal alpha olefins.
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Paragraph 0127; 0128; 0129
(2019/09/06)
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- Oxidative Dehydroxymethylation of Alcohols to Produce Olefins
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Catalyst compositions for the conversion of aldehyde compounds and primary alcohol compounds to olefins are disclosed herein. Reactions include oxidative dehydroxymethylation processes and oxidative dehydroformylation methods, which are beneficially conducted in the presence of a sacrificial acceptor of H2 gas, such as N,N-dimethylacrylamide.
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Paragraph 0057; 0058
(2019/09/06)
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- Substituted styrene preparation method
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The invention belongs to the technical field of synthesis of chemical and medical intermediates, and relates to a substituted styrene preparation method, in particular to a method for preparing substituted styrene by using an ionic solution. In the method, the ionic solution is used as a solvent, and the reaction catalyzing efficiency is high. The ionic solution can be repeatedly used, industrialproduction cost is saved, and environment problems caused by a traditional solvent are solved favorably.
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- Method for preparing styrene derivative from ionic liquid
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The invention belongs to the technical field of chemical engineering and pharmaceutical intermediate synthesis and relates to a method for preparing a styrene derivative from ionic liquid. The methodhas advantages that by adoption of the ionic liquid as a solvent, high reaction catalyzing efficiency is achieved; due to reusability of the ionic liquid, industrial production cost is saved, and theenvironment problem caused by traditional solvents can be solved helpfully.
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- A method for the preparation of substituted styrene ion solution method
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The invention belongs to chemical and pharmaceutical intermediate synthesis technology field, relates to a process for preparing a substituted styrene ion solution method. The method takes the ionic liquid as solvent, reaction of high catalytic efficiency. The ionic liquid can be used repeatedly, save the industrialized production cost, and to facilitate the solution of the environmental problem of traditional solvent.
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- Synthesis and Catalytic Applications of [N,N]-Pyrrole Ligands for the Regioselective Synthesis of Styrene Derivatives
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We report the synthesis of two [N,N]-donor ligands (5 a–b) containing a 2-chalcogenazoline as the structural motif. These compounds were synthesized from a common intermediate Fischer type aminocarbene complex (3). The palladium-complexes of these [N,N]-donor ligands were successfully used as catalytic precursors in the Mizoroki-Heck coupling reaction between aryl halides and methyl acrylate, styrene and ethylene. For methyl acrylates, high yields with TOF values between 0.6 and 5.5×105 h?1 were obtained. In the case of ethylene, we reached high regioselectivities to obtain a diversity of styrene derivatives under soft pressure conditions, with good values of TON and TOF. (Figure presented.).
- Hochberger-Roa, Frank,Cortés-Mendoza, Salvador,Gallardo-Rosas, David,Toscano, Ruben A.,Ortega-Alfaro, M. Carmen,López-Cortés, José G.
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p. 4055 - 4064
(2019/07/31)
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- Pd-Catalyzed Synthesis of Vinyl Arenes from Aryl Halides and Acrylic Acid
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Acrylic acid is presented as an inexpensive, non-volatile vinylating agent in a palladium-catalyzed decarboxylative vinylation of aryl halides. The reaction proceeds through a Heck reaction of acrylic acid, immediately followed by protodecarboxylation of the cinnamic acid intermediate. The use of the carboxylate group as a deciduous directing group ensures high selectivity for monoarylated products. The vinylation process is generally applicable to diversely substituted substrates. Its utility is shown by the synthesis of drug-like molecules and the gram-scale preparation of key intermediates in drug synthesis.
- Gao, Yang,Ou, Yang,Goo?en, Lukas J.
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supporting information
p. 8709 - 8712
(2019/06/17)
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- Efficient and Practical Transfer Hydrogenation of Ketones Catalyzed by a Simple Bidentate Mn?NHC Complex
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Catalytic reductions of carbonyl-containing compounds are highly important for the safe, sustainable, and economical production of alcohols. Herein, we report on the efficient transfer hydrogenation of ketones catalyzed by a highly potent Mn(I)?NHC complex. Mn?NHC 1 is practical at metal concentrations as low as 75 ppm, thus approaching loadings more conventionally reserved for noble metal based systems. With these low Mn concentrations, catalyst deactivation is found to be highly temperature dependent and becomes especially prominent at increased reaction temperature. Ultimately, understanding of deactivation pathways could help close the activity/stability-gap with Ru and Ir catalysts towards the practical implementation of sustainable earth-abundant Mn-complexes.
- van Putten, Robbert,Benschop, Joeri,de Munck, Vincent J.,Weber, Manuela,Müller, Christian,Filonenko, Georgy A.,Pidko, Evgeny A.
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p. 5232 - 5235
(2019/07/18)
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