- Charge Transport between Coupling Colloidal Perovskite Quantum Dots Assisted by Functional Conjugated Ligands
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Long alkyl-chain capping ligands are indispensable for preparing stable colloidal quantum dots. However, its insulating feature blocks efficient carrier transport among QDs, leading to inferior performance in light-emitting diodes (LEDs). The trade-off between conductivity and colloidal stability of QDs has now been overcome. Methylamine lead bromide (MAPbBr3) QDs with a conjugated alkyl-amine, 3-phenyl-2-propen-1-amine (PPA), as ligands were prepared. Owing to electron cloud overlapping and the delocalization effect of conjugated molecules, the conductivity and carrier mobility of PPA-QDs films increased almost 22 times over that of OA-QD films without compromising colloidal stability and photoluminescence. PPA-QDs LEDs exhibit a maximum current efficiency of 9.08 cd A?1, which is 8 times of that of OA-QDs LEDs (1.14 cd A?1). This work provides critical solution for the poor conductivity of QDs in applications of energy-related devices.
- Dai, Jinfei,Xi, Jun,Li, Lu,Zhao, JingFeng,Shi, Yifei,Zhang, Wenwen,Ran, Chenxin,Jiao, Bo,Hou, Xun,Duan, Xinhua,Wu, Zhaoxin
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Read Online
- Pd(II)-Catalyzed CC Bond Cleavage by a Formal Group-Exchange Reaction
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A chelation-assisted palladium-catalyzed CC bond cleavage of α, β-unsaturated ketone to form alkenyl nitrile in the presence of nitrile is disclosed on the basis of a formal group-exchange reaction formulated as C1C2 + C3 → C1C3 + C2, differing from normal alkene oxidative cleavage and metathesis type. The isolated key active Pd(II) complex as well as deuterium-labeled experiment revealed the necessity of the chelation group, and a plausible catalytic pathway was proposed.
- Ye, Runyou,Zhu, Maoshuai,Yan, Xufei,Long, Yang,Xia, Ying,Zhou, Xiangge
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p. 8678 - 8683
(2021/07/26)
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- PROTEIN LABELLING
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A process for labelling a target protein, such as a target enzyme, such as a deubiquitinating enzyme (DUB). The process comprises providing a probe-protein complex comprising a probe and the target protein. The probe comprises a recognition element and a
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Paragraph 0173-0174
(2021/09/26)
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- Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
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Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
- Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
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p. 2059 - 2067
(2021/09/02)
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- Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
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Monosubstituted ureas are important scaffolds in organic chemistry. They appear in various biologically active compounds and serve as versatile precursors in synthesis. Monosubstituted ureas were originally prepared using toxic and hazardous phosgene equivalents. Modern methods include transamidation of urea and nucleophilic addition to cyanate salts, both of which suffer from a narrow substrate scope due to the need for a strong acid and prolonged reaction times. We hereby report that ammonium chloride can promote the reaction between amines and potassium cyanate to generate monosubstituted ureas in water. This method proceeds rapidly under microwave irradiation and tolerates a broad range of functional groups. Unlike previous strategies, it is compatible with other nucleophiles, acid-labile moieties, and most of the common protecting groups. The products precipitate out of solution, allowing facile isolation without column chromatography.
- Lan, Chunling Blue,Auclair, Karine
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p. 5135 - 5146
(2021/10/19)
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- Conjugated molecule based 2D perovskites for high-performance perovskite solar cells
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Conjugated molecules have been typically utilized as either hole or electron extraction layers to boost the device performance of perovskite solar cells (PSCs), formed from three-dimensional (3D) perovskites, due to their high charge carrier mobility and electrical conductivity. However, the passivating role of conjugated molecules in creating two-dimensional (2D) perovskites has rarely been reported. In this study, we report novel conjugated aniline 3-phenyl-2-propen-1-amine (PPA) based 2D perovskites and further demonstrate efficient and stable PSCs containing a (PPA)x(MAPbI3)1?x/MAPbI3bilayer thin film (where MA is CH3NH3+). The (PPA)x(MAPbI3)1?x/MAPbI3bilayer thin film possesses superior crystallinity and passivated trap states, resulting in enhanced charge transport and suppressed charge carrier recombination compared to those of a 3D MAPbI3thin film. As a result, PSCs containing the (PPA)x(MAPbI3)1?x/MAPbI3bilayer thin film exhibit a power conversion efficiency (PCE) of 21.98%, which is approximately a 25% enhancement compared to that of the MAPbI3thin film. Moreover, un-encapsulated PSCs containing the (PPA)x(MAPbI3)1?x/MAPbI3bilayer thin film retain 50% of their initial PCE after 1200 hours in an ambient atmosphere (25 °C, and 30 ± 10 humidity), whereas PSCs with the 3D MAPbI3thin film show significant degradation after 100 hours and a degradation of more than 50% of their original PCE after 500 hours. These results demonstrate that the incorporation of conjugated molecules as organic spacer cations to create 2D perovskites on top of 3D perovskites is an effective way to approach high-performance PSCs.
- Chen, Hanlin,Chen, Rui,Gong, Xiong,Shen, Lening,Wang, Junpeng,Yang, Yongrui,Zheng, Jie,Zheng, Luyao,Zhu, Tao
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supporting information
p. 21910 - 21917
(2021/10/12)
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- Copper catalyzed reduction of azides with diboron under mild conditions
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We report herein the first Cu catalyzed reduction of azides with B2pin2 (pin = pinacolato) as the reductant under very mild conditions. A series of primary amines and amides were obtained in moderate to excellent yields with high chemoselectivity and good functional group tolerance. This reaction can be performed with a cheap copper salt, a simple NHC ligand and a diboron reagent.
- Chen, Yang,Deng, Shengqi,Gao, Yihua,Liu, Liwen,Liu, Yu,Lu, Da,Wang, Qianwen,Zhang, Xiao
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supporting information
(2020/02/27)
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- Copper-Catalyzed Aerobic Oxidation of Amines to Benzothiazoles via Cross Coupling of Amines and Arene Thiolation Sequence
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A one-pot three-component synthesis of benzothiazoles has been developed using the copper-catalyzed aerobic cross coupling of amines followed by arene thiolation using elemental sulfur. The dual roles of elemental sulfur and CuCl(OH)-TMEDA in the aerobic amine oxidation and the aniline thiolation enable the facile access to benzothiazole derivatives from readily available starting materials. The operational simplicity of the current promiscuous catalyst system suggests the high synthetic potential in the preparation of heterocyclic compounds. (Figure presented.).
- Kim, Jihyeon,Oh, Kyungsoo
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supporting information
p. 3576 - 3582
(2020/08/05)
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- Highly chemoselective, sterically sensitive NHC-catalysed amine acylation with pyridil
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A new strategy for the protection of amines has been developed involving reaction with pyridil under the influence of N-heterocyclic carbene catalysis. The methodology is capable of distinguishing between two amines characterised by small differences in steric bulk and the resulting pyridoyl amides can be cleaved without requiring either strongly acidic or basic hydrolysis.
- Maguire, Amy C.,Kumar, Vikas,Connon, Stephen J.
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p. 13526 - 13529
(2019/11/14)
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- Structural Basis for Achieving GSK-3β Inhibition with High Potency, Selectivity, and Brain Exposure for Positron Emission Tomography Imaging and Drug Discovery
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Using structure-guided design, several cell based assays, and microdosed positron emission tomography (PET) imaging, we identified a series of highly potent, selective, and brain-penetrant oxazole-4-carboxamide-based inhibitors of glycogen synthase kinase-3 (GSK-3). An isotopologue of our first-generation lead, [3H]PF-367, demonstrates selective and specific target engagement in vitro, irrespective of the activation state. We discovered substantial ubiquitous GSK-3-specific radioligand binding in Tg2576 Alzheimer's disease (AD), suggesting application for these compounds in AD diagnosis and identified [11C]OCM-44 as our lead GSK-3 radiotracer, with optimized brain uptake by PET imaging in nonhuman primates. GSK-3β-isozyme selectivity was assessed to reveal OCM-51, the most potent (IC50 = 0.030 nM) and selective (>10-fold GSK-3β/GSK-3α) GSK-3β inhibitor known to date. Inhibition of CRMP2T514 and tau phosphorylation, as well as favorable therapeutic window against WNT/β-catenin signaling activation, was observed in cells.
- Bernard-Gauthier, Vadim,Mossine, Andrew V.,Knight, Ashley,Patnaik, Debasis,Zhao, Wen-Ning,Cheng, Chialin,Krishnan, Hema S.,Xuan, Lucius L.,Chindavong, Peter S.,Reis, Surya A.,Chen, Jinshan Michael,Shao, Xia,Stauff, Jenelle,Arteaga, Janna,Sherman, Phillip,Salem, Nicolas,Bonsall, David,Amaral, Brenda,Varlow, Cassis,Wells, Lisa,Martarello, Laurent,Patel, Shil,Liang, Steven H.,Kurumbail, Ravi G.,Haggarty, Stephen J.,Scott, Peter J. H.,Vasdev, Neil
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p. 9600 - 9617
(2019/10/28)
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- Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines
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Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot-two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.
- Membrat, Romain,Vasseur, Alexandre,Moraleda, Delphine,Michaud-Chevallier, Sabine,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
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p. 37825 - 37829
(2019/12/03)
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- Regioselective intramolecular Markovnikov and anti-Markovnikov hydrofunctionalization of alkenes: Via photoredox catalysis
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Highly regioselective Markovnikov hydrofunctionalization of alkenes was successfully realized via photoredox catalysis by introducing a urea group and fine tuning the hydrogen atom transfer catalysts. The anti-Markovnikov hydroamination of alkenes was also achieved with high yields and stereoselectivities in this work.
- Li, Na,Man, Yunquan,Tang, Bo,Wang, Hongyu,Wang, Kaiye,Xiang, Yanan
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supporting information
p. 11426 - 11429
(2019/09/30)
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- Metal-free nitrogen -doped carbon nanosheets: A catalyst for the direct synthesis of imines under mild conditions
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Herein, a highly stable, porous, multifunctional and metal-free catalyst was developed, which exhibited significant catalytic performance in the oxidation of amines and transfer hydrogenation of nitriles under mild conditions; this could be attributed to the presence of numerous active sites and their outstanding BET surface area. The obtained results showed that most of the yields of imines exceeded 90%, and the cycling performance of the catalyst could be at least seven runs without any decay in the reaction activity, which could be comparable to those of metal catalysts. Subsequently, a kinetic study has demonstrated that the apparent activation energy for the direct synthesis of imines from amines is 67.39 kJ mol-1, which has been performed to testify that the catalytic performances are rational. Via catalyst characterizations and experimental data, graphitic-N has been proven to be the active site of the catalyst. Hence, this study is beneficial to comprehend the mechanism of action of a metal-free N-doped carbon catalyst in the formation of imines.
- Wang, Kaizhi,Jiang, Pengbo,Yang, Ming,Ma, Ping,Qin, Jiaheng,Huang, Xiaokang,Ma, Lei,Li, Rong
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p. 2448 - 2461
(2019/05/17)
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- Efficient and stable small molecule agonist of v [gamma] 9v delta 2t cells
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The invention relates to a formula (I) compound as an efficient and stable small molecule agonist of v [gamma] 9v delta 2t cells, wherein the groups are defined in the specification and the claims. The present invention also relates to pharmaceutical compositions containing the formula (I) compound and use thereof in the treatment of proliferative diseases.
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Paragraph 0676-0678
(2019/04/30)
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- Practical regio- and stereoselective azidation and amination of terminal alkenes
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There is significant interest in developing more rapid and efficient production of nitrogen-containing allylic compounds, as widely used in various syntheses. This work reports a variety of allylic azides and allylic amines synthesized by an efficient, new one-pot protocol that employs readily available terminal alkenes as starting materials. This method is highly regio- and stereoselective, affording the linear (E)-isomer, under metal-free conditions. This process tolerates several functional groups including halogen-containing molecules; it is general for azides and amine nucleophiles; and, adducts were obtained in good yields.
- Ojo, Olatunji S.,Miranda, Octavio,Baumgardner, Kyle C.,Bugarin, Alejandro
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supporting information
p. 9354 - 9358
(2019/01/03)
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- Organocatalytic Synthesis of Oxazolines and Dihydrooxazines from Allyl-Amides: Bypassing the Inherent Regioselectivity of the Cyclization
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A selective and efficient methodology for the construction of either oxazolines or dihydrooxazines from the corresponding allyl-amides is reported. Bypassing the inherent selectivity of the cyclization and depending on the substitution pattern of the substrate, a selective epoxidation-cyclization was developed leading to either the five-membered or the six-membered ring, upon simple and complementary reaction conditions. The cyclization products were obtained in good to excellent yields and high selectivities. (Figure presented.).
- Theodorou, Alexis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
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supporting information
p. 951 - 957
(2018/01/22)
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- Catalytic Diastereo- and Enantioselective Fluoroamination of Alkenes
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The stereoselective synthesis of syn-β-fluoroaziridine building blocks via chiral aryl iodide-catalyzed fluorination of allylic amines is reported. The method employs HF-pyridine as a nucleophilic fluoride source together with mCPBA as a stoichiometric oxidant, and affords access to arylethylamine derivatives featuring fluorine-containing stereocenters in high diastereo- and enantioselectivity. Catalyst-controlled diastereoselectivity in the fluorination of chiral allylic amines enabled the preparation of highly enantioenriched 1,3-difluoro-2-amines bearing three contiguous stereocenters. The enantioselective catalytic method was applied successfully to other classes of multifunctional alkene substrates to afford anti-β-fluoropyrrolidines, as well as a variety of 1,2-oxyfluorinated products.
- Mennie, Katrina M.,Banik, Steven M.,Reichert, Elaine C.,Jacobsen, Eric N.
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supporting information
p. 4797 - 4802
(2018/04/17)
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- Rapid synthesis method of biomass-based amide
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The invention discloses a rapid synthesis method of biomass-based amide, which comprises the steps: formamide is used as an amine source, formic acid is used as a hydrogen source, biomass aldehyde andketone is used as a raw material, the direct addition of formamide and aldehyde and ketone components and the reduction of formic acid is promoted to prepare the corresponding formamide derivative byrapidly heating under microwave-assisted heating and in the absence of a solvent and a catalyst; the formamide derivative is selectively converted to the corresponding primary amide by alcoholysis under the action of a base. The microwave assisted heating reaction system of the invention has higher catalytic efficiency than the corresponding oil bath system, greatly shortens the reaction time, remarkably improves the selectivity. The conversion rate of the biomass aldehyde or ketone compound is at least 99%, and the yield of the formamide derivative can reach 85 to 99%; the formamide can be synthesized by alcoholysis to obtain a primary amide with a yield of 92 to 99%.
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Paragraph 0046; 0049-0051
(2019/01/15)
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- Metagenomic discovery of a novel transaminase for valorization of monoaromatic compounds
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The profitability of next-generation biorefineries is acutely contingent on the discovery and utilization of biocatalysts that can valorize lignin. To this end, the metabolic catalogues of diverse microbiota have been mined previously using functional metagenomics in order to identify biocatalysts that can selectively degrade lignin into monoaromatic compounds. Herein, we have further improved the valorization factor of biorefining by deploying functional metagenomics toward the identification of a novel transaminase that can selectively functionalize lignin-derived monoaromatics to produce value-added feedstocks for pharmaceutical synthesis. We implemented a high-throughput colorimetric assay using o-xylylenediamine as the amino donor and successfully identified a transaminase that utilizes the canonical cofactor, pyridoxal 5′-phosphate, to aminate as many as 14 monoaromatic aldehydes and ketones. We subsequently identified the optimal conditions for enzyme activity towards the most favoured amino acceptor, benzaldehyde, including temperature, pH and choice of co-solvent. We also evaluated the specificity of the enzyme towards a variety of amino donors, as well as the optimal concentration of the most favoured amino donor. Significantly, the novel enzyme is markedly smaller than typical transaminases, and it is stably expressed in E. coli without any modifications to its amino acid sequence. Finally, we developed and implemented a computational methodology to assess the activity of the novel transaminase. The methodology is generalizable for assessing any transaminase and facilitates in silico screening of enzyme-substrate combinations in order to develop efficient biocatalytic routes to value-added amines. The computational pipeline is an ideal complement to metagenomics and opens new possibilities for biocatalyst discovery.
- Pawar, Sandip V.,Hallam, Steven J.,Yadav, Vikramaditya G.
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p. 22490 - 22497
(2018/06/29)
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- Evidence for a Sigmatropic and an Ionic Pathway in the Winstein Rearrangement
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The spontaneous rearrangement of allylic azides is thought to be a sigmatropic reaction. Presented herein is a detailed investigation into the rearrangement of several allylic azides. A combination of experiments including equilibrium studies, kinetic ana
- Ott, Amy A.,Packard, Mary H.,Ortuno, Manuel A.,Johnson, Alayna,Suding, Victoria P.,Cramer, Christopher J.,Topczewski, Joseph J.
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p. 8214 - 8224
(2018/06/13)
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- Direct use of allylic alcohols and allylic amines in palladium-catalyzed allylic amination
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Allylic alcohols and allylic amines were directly utilized in a Pd-catalyzed hydrogen-bond-activated allylic amination under mild reaction conditions in the absence of any additives. The cooperative action of a Pd-catalyst and a hydrogen-bonding solvent is most likely responsible for its high reactivity. The catalytic system is compatible with a variety of functional groups and can be used to prepare a wide range of linear allylic amines in good to excellent yields. Furthermore, this methodology can be easily applied to the one-step synthesis of two drugs, cinnarizine and naftifine, on a gram scale.
- Jing, Jiangyan,Huo, Xiaohong,Shen, Jiefeng,Fu, Jingke,Meng, Qinghua,Zhang, Wanbin
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p. 5151 - 5154
(2017/07/12)
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- Flavin-Mediated Visible-Light [2+2] Photocycloaddition of Nitrogen- and Sulfur-Containing Dienes
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The [2+2] photocycloaddition mediated by 1-butyl-3-methyl-7,8-dimethoxyalloxazine (1) has been found to be an effective tool for cyclising ω-phenyl- and ω,ω′-diphenyl-4-aza-1,6-heptadienes, in which the nitrogen atom is protected by acylation or quaternisation, towards the synthesis of a variety of phenyl- and diphenyl-3-azabicyclo[3.2.0]heptanes and their corresponding quaternary salts. Thia derivatives, with the sulfur atom in the form of a sulfone group, underwent an analogous cyclisation. Advantageously, visible light (400 nm) was used for the cycloadditions in the presence of 1, in contrast to the previously described procedures affording azabicyclo[3.2.0]heptanes by using UV irradiation. Practical applications are demonstrated through the synthesis of bicyclic quaternary ammonium salts, 6-phenyl-azabicyclo[3.2.0]heptanes known to exhibit biological activity or chiral spiro ammonium salts. Flavin 1 was also found to promote the efficient E→Z isomerisation of electron-rich cinnamyl derivatives to produce mixtures enriched with the Z isomer (with Z/E ratios of up to 77:23).
- Jirásek, Michael,Straková, Karolína,Nevesely, Tomá?,Svobodová, Eva,Rottnerová, Zdeňka,Cibulka, Radek
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p. 2139 - 2146
(2017/04/24)
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- Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether
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Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.
- Hari Babu, Madala,Ranjith Kumar, Gadi,Kant, Ruchir,Sridhar Reddy, Maddi
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supporting information
p. 3894 - 3897
(2017/04/04)
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- A metagenomics approach for new biocatalyst discovery: Application to transaminases and the synthesis of allylic amines
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Transaminase enzymes have significant potential for the sustainable synthesis of amines using mild aqueous reaction conditions. Here a metagenomics mining strategy has been used for new transaminase enzyme discovery. Starting from oral cavity microbiome samples, DNA sequencing and bioinformatics analyses were performed. Subsequent in silico mining of a library of contiguous reads built from the sequencing data identified 11 putative Class III transaminases which were cloned and overexpressed. Several screening protocols were used and three enzymes selected of interest due to activities towards substrates covering a wide structural diversity. Transamination of functionalized cinnamaldehydes was then investigated for the production of valuable amine building blocks.
- Baud, Damien,Jeffries, Jack W. E.,Moody, Thomas S.,Ward, John M.,Hailes, Helen C.
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p. 1134 - 1143
(2017/08/14)
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- Metal-Free Oxidation of Primary Amines to Nitriles through Coupled Catalytic Cycles
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Synergism among several intertwined catalytic cycles allows for selective, room temperature oxidation of primary amines to the corresponding nitriles in 85-98 % isolated yield. This metal-free, scalable, operationally simple method employs a catalytic quantity of 4-acetamido-TEMPO (ACT; TEMPO=2,2,6,6-tetramethylpiperidine N-oxide) radical and the inexpensive, environmentally benign triple salt oxone as the terminal oxidant under mild conditions. Simple filtration of the reaction mixture through silica gel affords pure nitrile products.
- Lambert, Kyle M.,Bobbitt, James M.,Eldirany, Sherif A.,Kissane, Liam E.,Sheridan, Rose K.,Stempel, Zachary D.,Sternberg, Francis H.,Bailey, William F.
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p. 5156 - 5159
(2016/04/09)
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- Rhodium/Yanphos-Catalyzed Asymmetric Interrupted Intramolecular Hydroaminomethylation of trans-1,2-Disubstituted Alkenes
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The first interrupted asymmetric hydroaminomethylation reaction was developed. The challenging trans-1,2-disubstituted olefins were employed as substrates, and a series of valuable chiral pyrrolidinones and pyrrolidines were obtained in high yields with high regioselectivities and excellent enantioselectivities. Several synthetic transformations were conducted, demonstrating the high synthetic utility of our method. A creative route for the synthesis of vernakalant and Enablex was also developed.
- Chen, Caiyou,Jin, Shicheng,Zhang, Zhefan,Wei, Biao,Wang, Heng,Zhang, Kai,Lv, Hui,Dong, Xiu-Qin,Zhang, Xumu
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supporting information
p. 9017 - 9020
(2016/08/05)
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- A method for the production of primary amines
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The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
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Paragraph 0237; 0347
(2016/10/09)
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- Selective catalytic hydrogenation of nitriles to primary amines using iron pincer complexes
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The selective catalytic hydrogenation of nitriles to primary amines with the well-defined Fe(PNPCy) pincer complex 2 is reported. This iron pincer catalyst shows superior catalytic activity and selectivity in the reduction of various nitriles including industrially relevant adipodinitrile in high yields under relatively mild conditions.
- Lange,Elangovan,Cordes,Spannenberg,Jiao,Junge,Bachmann,Scalone,Topf,Junge,Beller
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p. 4768 - 4772
(2016/07/11)
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- Chemo- and Site-Selective Alkyl and Aryl Azide Reductions with Heterogeneous Nanoparticle Catalysts
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Site-selective modification of bioactive natural products is an effective approach to generating new leads for drug discovery. Herein, we show that heterogeneous nanoparticle catalysts enable site-selective monoreduction of polyazide substrates for the generation of aminoglycoside antibiotic derivatives. The nanoparticle catalysts are highly chemoselective for reduction of alkyl and aryl azides under mild conditions and in the presence of a variety of easily reduced functional groups. High regioselectivity for monoazide reduction is shown to favor reduction of the least sterically hindered azide. We hypothesize that the observed selectivity is derived from the greater ability of less-hindered azide groups to interact with the surface of the nanoparticle catalyst. These results are complementary to previous Staudinger reduction methods that report a preference for selective reduction of electronically activated azides.
- Udumula, Venkatareddy,Nazari, S. Hadi,Burt, Scott R.,Alfindee, Madher N.,Michaelis, David J.
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p. 4423 - 4427
(2016/07/12)
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- Cascade reaction of propargylic alcohols with hydroxylamine hydrochloride: facile synthesis of α,β-unsaturated oximes and nitriles
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We have developed an easy and practical method for the synthesis of α,β-unsaturated oximes and nitriles from readily available propargylic alcohols with hydroxylamine hydrochloride (NH2OH·HCl) under metal-free conditions. By using or not using p-toluenesulfonyl chloride (p-TsCl) as the dehydrating promoter, the desired nitriles or oximes could be obtained, respectively via a three-step one-pot or two-step one-pot process in moderate to excellent yields with good functional group compatibility.
- Zhang, Qi,Zhang, Linjing,Tang, Chaojun,Luo, Huan,Cai, Xuediao,Chai, Yonghai
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p. 6935 - 6942
(2016/10/14)
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- Chemoselective hydrogenation of unsaturated nitriles to unsaturated primary amines: Conversion of cinnamonitrile on metal-supported catalysts
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The liquid-phase hydrogenation of cinnamonitrile to selectively obtain the unsaturated primary amine (cinnamylamine) was studied at 383 K and 13 bar on Ni, Co, Ru and Cu metals supported on a commercial silica. Ni/SiO2 and Co/SiO2 were the most active catalysts for cinnamonitrile conversion but formed only small amounts of cinnamylamine. In contrast, Cu/SiO2 and Ru/SiO2 presented low activity for cinnamonitrile hydrogenation but formed selectively cinnamylamine in the liquid phase; nevertheless, on both samples the carbon balance was only about 40%. In an attempt of promoting the rate and yield to cinnamylamine, additional catalytic runs were carried out at higher temperatures and H2 pressures on a highly dispersed Cu(11%)/SiO2 catalyst prepared by the chemisorption-hydrolysis method. Results showed that when cinnamonitrile hydrogenation was performed at 403 K and 40 bar on Cu(11%)/SiO2, the yield to cinnamylamine was 74% giving as by-product only the unsaturated secondary amine (dicinnamylamine).
- Segobia,Trasarti,Apesteguía
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- Kinetic resolution of primary allylic amines via palladium-catalyzed asymmetric allylic alkylation of malononitriles
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A range of primary allylic amines were resolved with selectivity factors of up to 491 through [Pd(allyl)Cl]2/(S)-BINAP-catalyzed and mesitylsulfonyl hydrazide-accelerated asymmetric allylic alkylation of malononitriles involving enantioselectiv
- Wang, Yong,Xu, Ya-Nan,Fang, Guo-Sheng,Kang, Hong-Jian,Gu, Yonghong,Tian, Shi-Kai
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p. 5367 - 5371
(2015/05/20)
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- Amide and amine nucleophiles in polar radical crossover cycloadditions: Synthesis of γ-lactams and pyrrolidines
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In this work we present a direct catalytic synthesis of γ-lactams and pyrrolidines from alkenes and activated unsaturated amides or protected unsaturated amines, respectively. Using a mesityl acridinium single electron photooxidant and a thiophenol cocata
- Gesmundo, Nathan J.,Grandjean, Jean-Marc M.,Nicewicz, David A.
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p. 1316 - 1319
(2015/03/14)
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- EFFICIENT SYNTHESIS OF AMINES AND AMIDES FROM ALCOHOLS AND ALDEHYDES BY USING CASCADE CATALYSIS
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The present invention relates generally to an eco-friendly methodology for the conversion of alcohols and aldehydes to amines and amides using an integrated enzyme cascade system with metal-and organocatalysis. More specifically, the present invention relates to synthesis of capsaicinoids starting from vanillin alcohol and using a combination of an enzyme cascade system and catalysts. Furthermore, the method also relates to synthesis of capsaicinoids derivatives starting from vanillin alcohol derivatives and using a combination of an enzyme cascade system and catalysts.
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Page/Page column 10
(2015/11/24)
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- Characterization of a novel amine transaminase from Halomonas elongata
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Chiral amines are indispensable building blocks in the production of biologically active compounds. They are fundamental for the pharmaceutical industry, both as active molecules themselves and as chiral auxiliaries in asymmetric synthesis; however, the available synthetic strategies often present disadvantages. ω-Transaminases (ω-TAs) appear as an attractive alternative by driving the stereoselective amination of prochiral ketones. HEWT is a novel amine transaminase from the moderate halophilic bacterium, Halomonas elongata DSM 2581, which is highly (S)-selective, being able to fully convert (S)-1-phenylethylamine to acetophenone and showing no activity with the corresponding (R)-1-phenylethylamine. HEWT has a broad substrate scope, active with a range of amino donors and acceptors, and naturally accepts isopropylamine (IPA) as amino donor in asymmetric synthesis providing a 41% conversion of pyruvate in 24 h at 37°C starting with 1:1 molar ratio between the reagents. HEWT also accepts ortho-xylylenediamine as amino donor in for amine synthesis, in particular, with benzaldehyde yielding high conversions between 90 and 95%. The enzyme is also tolerant to the presence of cosolvents up to 20% making it a promising candidate for industrial applications.
- Cerioli, Lorenzo,Planchestainer, Matteo,Cassidy, Jennifer,Tessaro, Davide,Paradisi, Francesca
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p. 141 - 150
(2015/09/01)
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- Palladium-catalyzed regioselective azidation of allylic C-H bonds under atmospheric pressure of dioxygen
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A palladium-catalyzed allylic azidation of alkenes with sodium azide under atmospheric pressure of dioxygen was developed. This methodology provides a new efficient and simple route for accessing allylic azides. Furthermore, the one-pot process consisting of Pd-catalyzed allylic azidation of alkenes and Cu-catalyzed 1,3-dipolar cycloaddition led directly to the 1,2,3-triazole from the alkene. The formed allylic azide can be also in situ reduced to the allylic amine or oxidized to the alkenyl nitrile. the Partner Organisations 2014.
- Chen, Huoji,Yang, Wanfei,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 3340 - 3343
(2014/05/20)
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- Synthesis and structure-activity relationship study of substituted caffeate esters as antinociceptive agents modulating the TREK-1 channel
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The TWIK-related K+ channel, TREK-1, has recently emerged as an attractive therapeutic target for the development of a novel class of analgesic drugs. It has been reported that TREK-1 -/- mice were more sensitive than wild-type mice to painful stimuli, suggesting that activation of TREK-1 could result in pain inhibition. Here we report the synthesis of a series of substituted caffeate esters (12a-u) based on the hit compound CDC 2 (cinnamyl 3,4-dihydroxyl-α-cyanocinnamate). These analogs were evaluated for their ability to modulate TREK-1 channel by electrophysiology and for their in vivo antinociceptive activity (acetic acid induced-writhing assay) leading to the identification a series of novel molecules able to activate TREK-1 and displaying potent analgesic activity in vivo.
- Rodrigues, Nuno,Bennis, Khalil,Vivier, Delphine,Pereira, Vanessa,Chatelain, Franck C.,Chapuy, Eric,Deokar, Hemantkumar,Busserolles, Jér?me,Lesage, Florian,Eschalier, Alain,Ducki, Sylvie
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p. 391 - 402
(2014/03/21)
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- Bronsted acid mediated nitrogenation of propargylic alcohols: An efficient approach to alkenyl nitriles
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A novel and efficient approach to alkenyl nitriles from readily available propargylic alcohols has been developed. This nitrogenation reaction is transition-metal-free and could be conducted under air at ambient temperature, which makes this protocol promising and practical. Moreover, NH4Br is disclosed as an efficient additive to promote the stereoselectivity of this reaction. the Partner Organisations 2014.
- Huang, Xiaoqiang,Jiao, Ning
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supporting information
p. 4324 - 4328
(2014/06/23)
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- Selective catalytic transfer hydrogenation of nitriles to primary amines using Pd/C
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The catalytic transfer hydrogenation of (hetero)aryl nitriles using ammonium formate has been investigated in detail. In the presence of commercially available Pd/C, a straightforward and selective reduction is achieved without any additives under mild conditions.
- Vilches-Herrera, Marcelo,Werkmeister, Svenja,Junge, Kathrin,Boerner, Armin,Beller, Matthias
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p. 629 - 632
(2014/03/21)
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- Facile oxidation of primary amines to nitriles using an oxoammonium salt
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The oxidation of primary amines using a stoichiometric quantity of 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1) in CH2Cl2-pyridine solvent at room temperature or at gentle reflux affords nitriles in good yield under mild conditions. The mechanism of the oxidation, which has been investigated computationally, involves a hydride transfer from the amine to the oxygen atom of 1 as the rate-limiting step.
- Lambert, Kyle M.,Bobbitt, James M.,Eldirany, Sherif A.,Wiberg, Kenneth B.,Bailey, William F.
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p. 6484 - 6487
(2015/01/09)
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- Enantioselective intermolecular bromoesterification of allylic sulfonamides
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Highly enantioselective intermolecular bromoesterification of alkenes was achieved for the first time. Both C-O and C-Br bonds were introduced enantioselectively in this olefin addition reaction. The sulfonamide NH directing group is important for both th
- Zhang, Wei,Liu, Na,Schienebeck, Casi M.,Zhou, Xin,Izhar, Izarin I.,Guzei, Ilia A.,Tang, Weiping
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p. 2652 - 2656
(2013/07/11)
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- The Heck reaction of polymer-supported allylamine with aryl iodides
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The Heck reaction of Wang resin-bound allylamine with aryl iodides produces various, substituted cinnamylamines. The catalyst and additive system consisting of palladium(II) acetate, n-Bu4NOAc and potassium chloride, in addition to potassium carbonate in N,N-dimethylformamide, accomplishes a regioselective γ-arylation. By utilising the easily formed and stable carbamate linker on Wang resin, the incompatibility of free amines with the palladium catalyst is avoided. The cinnamylamine products are cleaved from the resin with trifluoroacetic acid under mild conditions and are converted into chromatographically separable acetamides. Our solid-phase method offers a new alternative for the synthesis of cinnamylamine derivatives, as biologically interesting compounds and useful synthetic intermediates.
- Leikoski, Tuomo,Wrigstedt, Pauli,Helminen, Jussi,Matikainen, Jorma,Sipil?, Jussi,Yli-Kauhaluoma, Jari
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p. 839 - 843
(2013/07/27)
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- Organophosphorus-catalysed Staudinger reduction
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The first Staudinger reduction that is catalytic in phosphine has been developed, showing excellent yields and functional group selectivity. To this end we utilised dibenzophosphole catalysts and mild in situ reduction of the intermediate iminophosphoranes. We could avoid the necessity of water during the reduction, obtained no phosphine oxides as waste and thus enabled facile purification of the product. A range of azides was converted into amines with good to excellent yields and high functional group tolerance. Copyright
- Van Kalkeren, Henri A.,Bruins, Jorick J.,Rutjes, Floris P. J. T.,Van Delft, Floris L.
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supporting information; experimental part
p. 1417 - 1421
(2012/07/03)
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- Platinum-catalyzed direct amination of allylic alcohols with aqueous ammonia: Selective synthesis of primary allylamines
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Direct amination of unactivated allylic alcohols with aqueous ammonia was catalyzed by a Pt/phosphine complex to give the corresponding allylamines along with water as the sole by-product. Under optimized reaction conditions, primary allylamines were obtained as major products with excellent monoallylation selectivity. cod=1,5-cyclooctadiene.
- Das, Kalpataru,Shibuya, Ryozo,Nakahara, Yasuhito,Germain, Nicolas,Ohshima, Takashi,Mashima, Kazushi
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supporting information; scheme or table
p. 150 - 154
(2012/02/16)
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- Redox self-sufficient biocatalyst network for the amination of primary alcohols
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Driving the machinery: A biocatalytic redox-neutral cascade for the preparation of terminal primary amines from primary alcohols at the expense of ammonia has been established in a one-pot one-step method (see picture). Applying this artificial biocatalyst network, long-chain 1,ω-alkanediols were converted into diamines, which are building blocks for polymers, in up to 99 % conversion. Copyright
- Sattler, Johann H.,Fuchs, Michael,Tauber, Katharina,Mutti, Francesco G.,Faber, Kurt,Pfeffer, Jan,Haas, Thomas,Kroutil, Wolfgang
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supporting information
p. 9156 - 9159
(2012/10/30)
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- A one-pot, three-component synthesis of thiazolidine-2-thiones
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An efficient method for the synthesis of thiazolidine-2-thiones is described via regiospecific iodocyclization of an allyl amine, carbon disulfide, and iodine. Dehydrohalogenation of the iodo-derivatives gives thiazole-2(3H)-thiones. In addition, nucleoph
- Ziyaei-Halimehjani, Azim,Marjani, Katayoun,Ashouri, Akram
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body text
p. 3490 - 3492
(2012/08/27)
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- Regioselective and stereospecific cross-coupling of primary allylic amines with boronic acids and boronates through palladium-catalyzed C-N bond cleavage
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The NH2 group serves as an effective leaving group in the palladium-catalyzed regioselective and stereospecific title reaction (see scheme). The reaction works well with aryl- and alkenylboronic acids and aryl-, alkenyl-, allyl-, and benzylboronates, and complete transfer of chirality has been achieved when using α-chiral primary allylic amines as the allylic electrophiles. Copyright
- Li, Man-Bo,Wang, Yong,Tian, Shi-Kai
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supporting information; experimental part
p. 2968 - 2971
(2012/04/18)
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- Integrated electrochemical-chemical oxidation mediated by alkoxysulfonium Ions
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Generation of carbocations by the "cation pool" method followed by reaction with dimethyl sulfoxide (DMSO) gave the corresponding alkoxysulfonium ions. Alkoxysulfonium ions could also be generated by in situ DMSO trapping of electrochemically generated carbocations. The resulting alkoxysulfonium ions were transformed into carbonyl compounds by treatment with triethylamine. The present integrated electrochemical-chemical oxidation can be applied to the oxidation of diarylmethanes to diaryl ketones, toluenes to benzaldehydes, and aryl-substituted alkenes to 1,2-diketones. Moreover, the oxidation of unsaturated compounds bearing a nucleophilic group in an appropriate position gives cyclized carbonyl compounds.
- Ashikari, Yosuke,Nokami, Toshiki,Yoshida, Jun-Ichi
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supporting information; experimental part
p. 11840 - 11843
(2011/09/21)
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- Heck reaction of arenediazonium salts with N,N-diprotected allylamines. Synthesis of cinnamylamines and indoles
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Novel palladium-catalyzed reactions of arenediazonium tetrafluoroborates with N,N-diprotected allylamines are presented. The reaction of arenediazonium tetrafluoroborates with N,N-(Boc)2 allylamine allows for an easy approach to cinnamylamines whereas using 2-alkynyl-N-(allyl) trifluoroacetanilides and 2-iodo-N-(allyl)trifluoroacetanilide the reaction provides a useful tool for appending indole rings to aniline fragments.
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Sferrazza, Alessio
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scheme or table
p. 1727 - 1730
(2011/05/03)
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