- Optimizing the deprotection of the amine protecting p-methoxyphenyl group in an automated microreactor platform
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Three factors (temperature, stoichiometry and reaction temperature) were investigated in continuous flow microreactors in an automated fashion for optimization of the removal of the p- methoxyphenyl (PMP) protecting group, thereby consuming only minute amounts of substrate (0.2 mg/sample). The optimal reaction conditions were also applied to a larger microreactor system, in which the corresponding free amine was obtained at a preparative scale.
- Koch, Kaspar,Van Weerdenburg, Bram J.A.,Verkade, Jorge M.M.,Nieuwland, Pieter J.,Rutjes, Floris P.J.T.,Van Hest, Jan C.M.
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Read Online
- Key Parameters for the Synthesis of Active and Selective Nanostructured 3d Metal Catalysts Starting from Coordination Compounds – Case Study: Nickel Mediated Reductive Amination
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The design of nanostructured catalysts based on earth-abundant metals that mediate important reactions efficiently, selectively and with a broad scope is highly desirable. Unfortunately, the synthesis of such catalysts is poorly understood. We report here on highly active Ni catalysts for the reductive amination of ketones by ammonia employing hydrogen as a reducing agent. The key functions of the Ni-salen precursor complex during catalyst synthesis have been identified: (1) Ni-salen complexes sublime during catalyst synthesis, which allows molecular dispersion of the metal precursor on the support material. (2) The salen ligand forms a nitrogen-doped carbon shell by decomposition, which embeds and stabilizes the Ni nanoparticles on the γ-Al2O3 support. (3) Parameters, such as flow rate of the pyrolysis gas, determine the carbon supply for the embedding process of Ni nanoparticles.
- Klarner, Mara,Blach, Patricia,Wittk?mper, Haiko,de Jonge, Niels,Papp, Christian,Kempe, Rhett
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Read Online
- Iridium-Catalyzed Hydroiodination and Formal Hydroamination of Olefins with N-Iodo Reagents and Molecular Hydrogen: An Umpolung Strategy
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We herein report a convenient method to convert olefins to organic iodides and amines using an Ir/ZhaoPhos catalyst, molecular hydrogen, and an electrophilic iodine(I) reagent. High yields and regioselectivities were obtained under mild conditions. In addition, basic workup with potassium carbonate leads to C-N products. Control experiments and DFT calculations tentatively excluded the pathway involving the in situ formation of HI. Instead, a catalytic cycle involving the hydrogenation of the haliranium ion intermediate was proposed.
- Wen, Jialin,Yang, Huaxin,Zhang, Xumu,Zhang, Zhihan,Zhou, Yang
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p. 1842 - 1847
(2022/03/14)
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- Indirect reduction of CO2and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes
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The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives, and even polyurethanes leading to the corresponding alcohols, amines, and methanol as products. Since these compound classes can be prepared using CO2as a C1 building block the reported reaction represents an approach to the indirect reduction of CO2. Notably, these are the first examples on the reduction of carbamates and urea derivatives as well as on the C-N bond cleavage in amides by transfer hydrogenation. The general applicability of this methodology is highlighted by the successful reduction of 12 urea derivatives, 26 carbamates and 11 amides. The corresponding amines, alcohols and methanol were obtained in good to excellent yields up to 97%. Furthermore, polyurethanes were successfully converted which represents a viable strategy towards a circular economy. Based on control experiments and the observed intermediates a feasible mechanism is proposed.
- Liu, Xin,Werner, Thomas
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p. 10590 - 10597
(2021/08/20)
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- Co-Catalyzed Synthesis of Primary Amines via Reductive Amination employing Hydrogen under very mild Conditions
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Nanostructured and reusable 3d-metal catalysts that operate with high activity and selectivity in important chemical reactions are highly desirable. Here, a cobalt catalyst was developed for the synthesis of primary amines via reductive amination employing hydrogen as the reducing agent and easy-to-handle ammonia, dissolved in water, as the nitrogen source. The catalyst operates under very mild conditions (1.5 mol% catalyst loading, 50 °C and 10 bar H2 pressure) and outperforms commercially available noble metal catalysts (Pd, Pt, Ru, Rh, Ir). A broad scope and a very good functional group tolerance were observed. The key for the high activity seemed to be the used support: an N-doped amorphous carbon material with small and turbostratically disordered graphitic domains, which is microporous with a bimodal size distribution and with basic NH functionalities in the pores.
- Elfinger, Matthias,Sch?nauer, Timon,Thom?, Sabrina L. J.,St?glich, Robert,Drechsler, Markus,Zobel, Mirijam,Senker, Jürgen,Kempe, Rhett
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p. 2360 - 2366
(2021/05/03)
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- Direct reductive amination of ketones with ammonium salt catalysed by Cp*Ir(iii) complexes bearing an amidato ligand
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A series of half-sandwich Ir(iii) complexes1-6bearing an amidato bidentate ligand were conveniently synthesized and applied to the catalytic Leuckart-Wallach reaction to produce racemic α-chiral primary amines. With 0.1 mol% of complex1, a broad range of ketones, including aryl ketones, dialkyl ketones, cyclic ketones, α-keto acids, α-keto esters and diketones, could be transformed to their corresponding primary amines with moderate to excellent yields (40%-95%). Asymmetric transformation was also attempted with chiral Ir complexes3-6, and 16% ee of the desired primary amine was obtained. Despite the unsatisfactory enantio-control achieved so far, the current exploration might stimulate more efforts towards the discovery of better chiral catalysts for this challenging but important transformation.
- Dai, Zengjin,Pan, Ying-Min,Wang, Shou-Guo,Yin, Qin,Zhang, Xumu
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supporting information
p. 8934 - 8939
(2021/11/04)
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- Air Stable Iridium Catalysts for Direct Reductive Amination of Ketones
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Half-sandwich iridium complexes bearing bidentate urea-phosphorus ligands were found to catalyze the direct reductive amination of aromatic and aliphatic ketones under mild conditions at 0.5 mol % loading with high selectivity towards primary amines. One of the complexes was found to be active in both the Leuckart–Wallach (NH4CO2H) type reaction as well as in the hydrogenative (H2/NH4AcO) reductive amination. The protocol with ammonium formate does not require an inert atmosphere, dry solvents, as well as additives and in contrast to previous reports takes place in hexafluoroisopropanol (HFIP) instead of methanol. Applying NH4CO2D or D2 resulted in a high degree of deuterium incorporation into the primary amine α-position.
- Polishchuk, Iuliia,Sklyaruk, Jan,Lebedev, Yury,Rueping, Magnus
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supporting information
p. 5919 - 5922
(2021/03/08)
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- Oxidation Under Reductive Conditions: From Benzylic Ethers to Acetals with Perfect Atom-Economy by Titanocene(III) Catalysis
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Described here is a titanocene-catalyzed reaction for the synthesis of acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, with pendant epoxides. The reaction proceeds by catalysis in single-electron steps. The oxidative addition comprises an epoxide opening. An H-atom transfer, to generate a benzylic radical, serves as a radical translocation step, and an organometallic oxygen rebound as a reductive elimination. The reaction mechanism was studied by high-level dispersion corrected hybrid functional DFT with implicit solvation. The low-energy conformational space was searched by the efficient CREST program. The stereoselectivity was deduced from the lowest lying benzylic radical structures and their conformations are controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate. An interesting mechanistic aspect is that the oxidation of the benzylic center occurs under reducing conditions.
- Funk, Pierre,Richrath, Ruben B.,Bohle, Fabian,Grimme, Stefan,Gans?uer, Andreas
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p. 5482 - 5488
(2021/02/03)
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- Direct C(sp3)-N Radical Coupling: Photocatalytic C-H Functionalization by Unconventional Intermolecular Hydrogen Atom Transfer to Aryl Radical
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An unconventional approach for intermolecular direct C(sp3)-N radical coupling has been developed by photocatalytic C(sp3)-H activation of simple alkyl substrates using O-benzoyl oximes. The selective photocatalytic energy-transfer-driven homolysis followed by decarboxylation generates the persistent iminyl radical and aryl radical, which would undergo an unprecedented intermolecular hydrogen atom abstraction from the alkyl substrate to provide the key C(sp3) radical. Selective radical-radical C-N cross-coupling furnishes imines which are valuable amine building blocks.
- Cho, Eun Jin,Hwang, Ho Seong,Kang, Jihee,Soni, Vineet Kumar
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supporting information
(2020/08/12)
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- Cerium-Catalyzed C-H Functionalizations of Alkanes Utilizing Alcohols as Hydrogen Atom Transfer Agents
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Modern photoredox catalysis has traditionally relied upon metal-to-ligand charge-transfer (MLCT) excitation of metal polypyridyl complexes for the utilization of light energy for the activation of organic substrates. Here, we demonstrate the catalytic application of ligand-to-metal charge-transfer (LMCT) excitation of cerium alkoxide complexes for the facile activation of alkanes utilizing abundant and inexpensive cerium trichloride as the catalyst. As demonstrated by cerium-catalyzed C-H amination and the alkylation of hydrocarbons, this reaction manifold has enabled the facile use of abundant alcohols as practical and selective hydrogen atom transfer (HAT) agents via the direct access of energetically challenging alkoxy radicals. Furthermore, the LMCT excitation event has been investigated through a series of spectroscopic experiments, revealing a rapid bond homolysis process and an effective production of alkoxy radicals, collectively ruling out the LMCT/homolysis event as the rate-determining step of this C-H functionalization.
- An, Qing,Chen, Yuegang,Liu, Weimin,Pan, Hui,Wang, Xin,Wang, Ziyu,Zhang, Kaining,Zuo, Zhiwei
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p. 6216 - 6226
(2020/04/27)
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- Effects of ruthenium hydride species on primary amine synthesis by direct amination of alcohols over a heterogeneous Ru catalyst
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Heterogeneously catalysed synthesis of primary amines by direct amination of alcohols with ammonia has long been an elusive goal. In contrast to reported Ru-based catalytic systems, we report that Ru-MgO/TiO2 acts as an effective heterogeneous catalyst for the direct amination of a variety of alcohols to primary amines at low temperatures of ca. 100 °C without the introduction of H2 gas. The present system could be applied to a variety of alcohols and provides an efficient synthetic route for 2,5-bis(aminomethyl)furan (BAMF), an attention-getting biomonomer. The high catalytic performance can be rationalized by the reactivity tuning of Ru-H species using MgO. Spectroscopic measurements suggest that MgO enhances the reactivity of hydride species by electron donation from MgO to Ru.
- Hara, Michikazu,Kamata, Keigo,Kita, Yusuke,Kuwabara, Midori,Yamadera, Satoshi
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p. 9884 - 9890
(2020/10/06)
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- Co-immobilization of metal and enzyme into hydrophobic nanopores for highly improved chemoenzymatic asymmetric synthesis
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Chemoenzymatic catalysts with hydrophobic nanopores were fabricated by co-immobilizing metal nanoparticles and enzymes into the dendritic organosilica nanoparticles. They demonstrated highly improved catalytic performance in chemoenzymatic asymmetric synthesis of chiral amines and alcohols. The hydrophobic microenvironment proved to be critical to enhanced stability, activity and cascade efficiency. This journal is
- Gao, Liya,Wang, Zihan,Liu, Yunting,Liu, Pengbo,Gao, Shiqi,Gao, Jing,Jiang, Yanjun
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supporting information
p. 13547 - 13550
(2020/11/17)
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- Synthesis and characterization of a magnetic hybrid catalyst containing lipase and palladium and its application on the dynamic kinetic resolution of amines
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Recent papers estimates that about 40 % of drugs present chiral amines in their structure and their synthesis in a sustainable and cost-competitive way is still a challenge for the industry. Kinetic resolution is one of the most applied method to produce these desired compounds where the association with lipase as a catalyst is a good alternative. However, the use of separate racemization catalyst and enzymes in the reaction medium still limits recovery, recycling and can occasionally be responsible for decreasing in selectivity for the desired product. In this work we proposed the synthesis and characterization of a hybrid magnetic catalyst composed containing lipase CaL B and Pd immobilized on the same recovered nanometric magnetic support for the application on Dynamic Kinetic Resolution of (rac)-1-phenylethylamine both in batch and continuous flow conditions. As results it was possible to achieve 99 % of conversion, with 95 % of selectivity and 93 % of enantiomeric excess after 12 h in batch. For a continuous flow system, it was possible to achieve 95 % of conversion with 71 % of selectivity and ee > 99 % after 60 min of reaction. The hybrid catalyst had around 50?100 nm with nanoparticulated Pd (5?10 nm) on its surface, presented a superparamagnetic behavior without remaining magnetization and 22 emu/g of saturation magnetization.
- Almeida, Rhudson F. O.,Caraballo, Richard,Dalm?nico, Gisele,Ferraz, Clara A.,Finotelli, Priscilla V.,Itabaiana, Ivaldo,Junior, Aldo A. T.,Le?o, Raquel A. C.,Sergio, Gabriella G.,Wojcieszak, Robert,de Souza, Rodrigo O. M. A.,do Nascimento, Marcelo A.
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- Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
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The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
- Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
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supporting information
(2020/07/15)
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- Ambient-Temperature Synthesis of Primary Amines via Reductive Amination of Carbonyl Compounds
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Efficient synthesis of primary amines via low-temperature reductive amination of carbonyl compounds using NH3 and H2 as the nitrogen and hydrogen resources is highly desired and challenging in the chemistry community. Herein, we employed naturally occurring phytic acid as a renewable precursor to fabricate titanium phosphate (TiP)-supported Ru nanocatalysts with different reduction degrees of RuO2 (Ru/TiP-x, x represents the reduction temperature) by combining ball milling and molten-salt processes. Very interestingly, the obtained Ru/TiP-100 had good catalytic performance for the reductive amination of carbonyl compounds at ambient temperature, resulting from the synergistic cooperation of the support (TiP) and the Ru/RuO2 with a suitable proportion of Ru0 (52%). Various carbonyl compounds could be efficiently converted into the corresponding primary amines with high yields. More importantly, the conversion of other substrates with reducible groups could also be achieved at ambient temperature. Detailed investigations indicated that the partially reduced Ru and the support (TiP) were indispensable. The high activity and selectivity of Ru/TiP-100 catalyst originates from the relatively high acidity and the suitable electron density of metallic Ru0.
- Xie, Chao,Song, Jinliang,Hua, Manli,Hu, Yue,Huang, Xin,Wu, Haoran,Yang, Guanying,Han, Buxing
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p. 7763 - 7772
(2020/08/21)
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- Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines
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We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N′-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kalevaru, Narayana V.,Kamer, Paul C. J.,Senthamarai, Thirusangumurugan,Zbo?il, Radek
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p. 2973 - 2981
(2020/03/27)
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- Method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds
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The invention discloses a method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds. The method comprises the following steps: 1) mixing nickel nitrate hexahydrate, citric acid and an organic solvent, carrying out heating and stirring until a colloidal material is obtained, drying the colloidal material, roasting the colloidal material in a protective atmosphere, pickling, washing and drying a roasted product, and performing a partial oxidation reaction on a dried product in an oxygen-nitrogen mixed atmosphere to obtain a catalyst for a reductive amination reaction; and 2) mixing aldehyde or ketone compounds, a methanol solution of ammonia and the reductive amination reaction catalyst, introducing hydrogen, and carrying out a reductive amination reaction. The method has the advantages of high primary amine yield, high selectivity, wide aldehyde ketone substrate range, short reaction time, mild reaction conditions, low cost, greenness, economicalperformance and the like; the used reductive amination reaction catalyst can be recycled more than 10 times, and the catalytic activity of the catalyst is not obviously changed in gram-level reactions; and the method is suitable for large-scale application.
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Paragraph 0064-0065; 0080-0083
(2020/05/30)
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- Direct Catalytic Conversion of Furfural to Furan-derived Amines in the Presence of Ru-based Catalyst
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The production of amine intermediates from biomass is capturing increasing attention. Herein, a simple and efficient preparation of l furan-derived amines was developed [e.g., 1-(furan-2-yl)-4-methylpentan-2-amine] with high yield (up to 95 %) from (E)-1-(furan-2-yl)-5-methylhex-1-en-3-one. The catalyst used was Ru/C, and it was recyclable up to the fourth cycle. To further realize cost-efficiency, a one-reactor tandem concept was attempted. To this aim direct reaction from furfural was investigated. A high yield (74 %) towards 1-(furan-2-yl)-4-methylpentan-2-amine could be achieved starting directly from furfural in the presence of methyl isobutyl ketone, NH3, H2, and Ru/C catalyst.
- Jiang, Shi,Ramdani, Wahiba,Muller, Eric,Ma, Changru,Pera-Titus, Marc,Jer?me, Fran?ois,De Oliveira Vigiera, Karine
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p. 1699 - 1704
(2020/02/25)
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- Design, synthesis and antifungal activity of threoninamide carbamate derivatives via pharmacophore model
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Thirty-six novel threoninamide carbamate derivatives were designed and synthesised using active fragment-based pharmacophore model. Antifungal activities of these compounds were tested against Oomycete fungi Phytophthora capsici in vitro and in vivo. Interestingly, compound I-1, I-2, I-3, I-6 and I-7 exhibited moderate control effect (>50%) against Pseudoperonospora cubensis in greenhouse at 6.25 μg/mL, which is better than that of control. Meanwhile most of these compounds exhibited significant inhibitory against P. capsici. The other nine fungi were also tested. More importantly, some compounds exhibited remarkably high activities against Sclerotinia sclerotiorum, P. piricola and R. solan in vitro with EC50 values of 3.74–9.76 μg/mL. It is possible that the model is reliabile and this method can be used to discover lead compounds for the development of fungicides.
- Dong, Wei-Li,Du, Xiu-Jiang,Liu, Xing-Hai,Peng, Xing-Jie,Zhao, Rui-Qi,Zhao, Wei-Guang
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p. 682 - 691
(2020/03/19)
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- Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant
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The Rh(III)-catalyzed coupling of N-chloroimines with alkynes for the efficient synthesis of isoquinolines is reported. This represents the first use of the N-Cl bond of N-chloroimines as an internal oxidant for construction of the isoquinoline skeleton. The synthesis features atom and step economy, a green solvent (EtOH), mild reaction conditions, and a broad substrate scope.
- Chu, Benfa,Fang, Lili,Guo, Shan,Qi, Bing,Shi, Pengfei,Wang, Qi,Zhu, Jin
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supporting information
(2020/03/10)
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- General and selective synthesis of primary amines using Ni-based homogeneous catalysts
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The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
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p. 4332 - 4339
(2020/05/18)
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- The Synthesis of Primary Amines through Reductive Amination Employing an Iron Catalyst
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The reductive amination of ketones and aldehydes by ammonia is a highly attractive method for the synthesis of primary amines. The use of catalysts, especially reusable catalysts, based on earth-abundant metals is similarly appealing. Here, the iron-catalyzed synthesis of primary amines through reductive amination was realized. A broad scope and a very good tolerance of functional groups were observed. Ketones, including purely aliphatic ones, aryl–alkyl, dialkyl, and heterocyclic, as well as aldehydes could be converted smoothly into their corresponding primary amines. In addition, the amination of pharmaceuticals, bioactive compounds, and natural products was demonstrated. Many functional groups, such as hydroxy, methoxy, dioxol, sulfonyl, and boronate ester substituents, were tolerated. The catalyst is easy to handle, selective, and reusable and ammonia dissolved in water could be employed as the nitrogen source. The key is the use of a specific Fe complex for the catalyst synthesis and an N-doped SiC material as catalyst support.
- B?umler, Christoph,Bauer, Christof,Kempe, Rhett
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p. 3110 - 3114
(2020/06/01)
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- Facile synthesis of controllable graphene-co-shelled reusable Ni/NiO nanoparticles and their application in the synthesis of amines under mild conditions
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The primary objective of many researchers in chemical synthesis is the development of recyclable and easily accessible catalysts. These catalysts should preferably be made from Earth-abundant metals and have the ability to be utilised in the synthesis of pharmaceutically important compounds. Amines are classified as privileged compounds, and are used extensively in the fine and bulk chemical industries, as well as in pharmaceutical and materials research. In many laboratories and in industry, transition metal catalysed reductive amination of carbonyl compounds is performed using predominantly ammonia and H2. However, these reactions usually require precious metal-based catalysts or RANEY nickel, and require harsh reaction conditions and yield low selectivity for the desired products. Herein, we describe a simple and environmentally friendly method for the preparation of thin graphene spheres that encapsulate uniform Ni/NiO nanoalloy catalysts (Ni/NiO?C) using nickel citrate as the precursor. The resulting catalysts are stable and reusable and were successfully used for the synthesis of primary, secondary, tertiary, and N-methylamines (more than 62 examples). The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, and H2 under very mild industrially viable and scalable conditions (80 °C and 1 MPa H2 pressure, 4 h), offering cost-effective access to numerous functionalized, structurally diverse linear and branched benzylic, heterocyclic, and aliphatic amines including drugs and steroid derivatives. We have also demonstrated the scale-up of the heterogeneous amination protocol to gram-scale synthesis. Furthermore, the catalyst can be immobilized on a magnetic stirring bar and be conveniently recycled up to five times without any significant loss of catalytic activity and selectivity for the product.
- Cui, Zhibing,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Singh, Thishana,Wang, Chenguang,Wang, Nan,Zhu, Yuting
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supporting information
p. 7387 - 7397
(2020/11/19)
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- Nano-Fe3O4@SiO2-SO3H: A magnetic, reusable solid-acid catalyst for solvent-free reduction of oximes to amines with the NaBH3CN/ZrCl4 system
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In this study, the immobilization of sulfonic acid on silica-layered magnetite was carried out by the reaction of ClSO3H with silica-layered magnetite. The prepared magnetic nanoparticles of Fe3O4@SiO2-SO3H were then characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and transmission electron microscopy. The sulfonated nanocomposite exhibited excellent catalytic activity and reusability in the reduction of various aldoximes and ketoximes with NaBH3CN in the presence of ZrCl4. All reactions were carried out under solvent-free conditions (r.t. or 75–80°C) within 3–70 min to afford amines in high to excellent yields.
- Sadighnia, Leila,Zeynizadeh, Behzad,Karami, Shiva,Abdollahi, Mohammad
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p. 535 - 542
(2019/01/04)
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- A Comprehensive Quantitative Assay for Amine Transaminases
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The development of effective high-throughput screening assays has contributed greatly to the wealth of designer enzymes available, by enabling rapid identification of desired variants from large mutant libraries. Here, we report a general and operationally simple end-point assay for transaminases that enables the screening of both amine donors and acceptors in liquid phase. The spectrophotometric-based screen exploits the amine donor 2-aminoethylaniline (2-AEA) and relies on reaction of in situ generated indole with Ehrlich's reagent. The assay has also been adapted to allow screening in the reverse direction by addition of indole and subsequent spectrophotometric analysis. Importantly, the screen provides qualitative information on the enantio-preference of the individual biocatalysts. To increase the assay throughput, an engineered expression strain (E. coli BL21(DE3) ΔtnaA) lacking tryptophanase activity, was generated to enable reliable and direct evaluation of individual colonies arrayed on agar plates.
- Cairns, Ryan,Gomm, Andrew,Peel, Christopher,Sharkey, Michael,O'Reilly, Elaine
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p. 4738 - 4743
(2019/11/05)
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- Photochemical C?H Amination of Ethers and Geminal Difunctionalization Reactions in One Pot
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A mild, atom-economic, and metal-free α-C?H amination of ethers using relatively stable nonafluorobutanesulfonyl (nonaflyl, Nf) azide as the aminating reagent to give N-sulfonyl hemiaminals is reported. This enables unprecedented C(sp3) difunctionalization reactions, leading to diverse functionalized amino group containing compounds starting from simple ethers in one pot.
- Hernández-Guerra, Daniel,Hlava?ková, Anna,Pramthaisong, Chiranan,Vespoli, Ilaria,Pohl, Radek,Slanina, Tomá?,Jahn, Ullrich
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supporting information
p. 12440 - 12445
(2019/08/07)
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- Reductive amination of ketonic compounds catalyzed by Cp*Ir(III) complexes bearing a picolinamidato ligand
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Cp*Ir complexes bearing a 2-picolinamide moiety serve as effective catalysts for the direct reductive amination of ketonic compounds to give primary amines under transfer hydrogenation conditions using ammonium formate as both the nitrogen and hydrogen source. The clean and operationally simple transformation proceeds with a substrate to catalyst molar ratio (S/C) of up to 20,000 at relatively low temperature and exhibits excellent chemoselectivity toward primary amines.
- Tanaka, Kouichi,Miki, Takashi,Murata, Kunihiko,Yamaguchi, Ayumi,Kayaki, Yoshihito,Kuwata, Shigeki,Ikariya, Takao,Watanabe, Masahito
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p. 10962 - 10977
(2019/09/03)
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- Chemoenzymatic Dynamic Kinetic Resolution of Primary Benzylic Amines using Pd0-CalB CLEA as a Biohybrid Catalyst
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Herein, we report on the use a biohybrid catalyst consisting of palladium nanoparticles immobilized on cross-linked enzyme aggregates of lipase B of Candida antarctica (CalB CLEA) for the dynamic kinetic resolution (DKR) of benzylic amines. A set of amines were demonstrated to undergo an efficient DKR and the recyclability of the catalysts was studied. Extensive efforts to further elucidate the structure of the catalyst are presented.
- Gustafson, Karl P. J.,G?rbe, Tamás,de Gonzalo-Calvo, Gonzalo,Yuan, Ning,Schreiber, Cynthia L.,Shchukarev, Andrey,Tai, Cheuk-Wai,Persson, Ingmar,Zou, Xiaodong,B?ckvall, Jan-E.
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supporting information
p. 9174 - 9179
(2019/07/04)
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- Rapid and Quantitative Profiling of Substrate Specificity of ω-Transaminases for Ketones
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ω-Transaminases (ω-TAs) have gained growing attention owing to their capability for asymmetric synthesis of chiral amines from ketones. Reliable high-throughput activity assay of ω-TAs is essential in carrying out extensive substrate profiling and establishing a robust screening platform. Here we report spectrophotometric and colorimetric methods enabling rapid quantitation of ω-TA activities toward ketones in a 96-well microplate format. The assay methods employ benzylamine, a reactive amino donor for ω-TAs, as a cosubstrate and exploit aldehyde dehydrogenase (ALDH) as a reporter enzyme, leading to formation of benzaldehyde detectable by ALDH owing to concomitant NADH generation. Spectrophotometric substrate profiling of two wild-type ω-TAs of opposite stereoselectivity was carried out at 340 nm with 22 ketones, revealing subtle differences in substrate specificities that were consistent with docking simulation results obtained with cognate amines. Colorimetric readout for naked eye detection of the ω-TA activity was also demonstrated by supplementing the assay mixture with color-developing reagents whose color reaction could be quantified at 580 nm. The colorimetric assay was applied to substrate profiling of an engineered ω-TA for 24 ketones, leading to rapid identification of reactive ketones. The ALDH-based assay is expected to be promising for high-throughput screening of enzyme collections and mutant libraries to fish out the best ω-TA candidate as well as to tailor enzyme properties for efficient amination of a target ketone.
- Han, Sang-Woo,Shin, Jong-Shik
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p. 3287 - 3295
(2019/06/21)
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- Reusable Nickel Nanoparticles-Catalyzed Reductive Amination for Selective Synthesis of Primary Amines
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The preparation of nickel nanoparticles as efficient reductive amination catalysts by pyrolysis of in situ generated Ni-tartaric acid complex on silica is presented. The resulting stable and reusable Ni-nanocatalyst enables the synthesis of functionalized and structurally diverse primary benzylic, heterocyclic and aliphatic amines starting from inexpensive and readily available carbonyl compounds and ammonia in presence of molecular hydrogen. Applying this Ni-based amination protocol, -NH2 moiety can be introduced in structurally complex compounds, for example, steroid derivatives and pharmaceuticals.
- Murugesan, Kathiravan,Beller, Matthias,Jagadeesh, Rajenahally V.
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supporting information
p. 5064 - 5068
(2019/03/19)
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- Rh(III)-Catalyzed Coupling of N-Chloroimines with α-Diazo-α-phosphonoacetates for the Synthesis of 2 H-Isoindoles
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We report herein the first use of N-chloroimines as effective synthons for directed C-H functionalization. Rh(III)-catalyzed coupling of N-chloroimines with α-diazo-α-phosphonoacetates allows for efficient dechlorinative/dephosphonative access to 2H-isoindoles. Further deesterification under Ni(II) catalysis enables the complete elimination of reactivity-assisting groups and full exposure of reactivity of C3 and N2 ring atoms for attaching structurally distinct appendages.
- Qi, Bing,Li, Lei,Wang, Qi,Zhang, Wenjing,Fang, Lili,Zhu, Jin
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supporting information
p. 6860 - 6863
(2019/09/12)
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- Selective synthesis of mono- and di-methylated amines using methanol and sodium azide as C1 and N1 sources
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A Ru(ii) complex mediated synthesis of various N,N-dimethyl and N-monomethyl amines from organic azides using methanol as a methylating agent is reported. This methodology was successfully applied for a one-pot reaction of bromide derivatives and sodium azide in methanol. Notably, by controlling the reaction time several N-monomethylated and N,N-dimethylated amines were synthesized selectively. The practical applicability of this tandem process was revealed by preparative scale reactions with different organic azides and synthesis of an anti-vertigo drug betahistine. Several kinetic experiments and DFT studies were carried out to understand the mechanism of this transformation.
- Chakrabarti, Kaushik,Mishra, Anju,Panja, Dibyajyoti,Paul, Bhaskar,Kundu, Sabuj
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supporting information
p. 3339 - 3345
(2018/07/29)
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- Benzhydrylamine: An effective aminating agent for the synthesis of primary amines
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Aldehydes, ketones, alkyl toluene-p-sulfonates and halides are converted into the corresponding primary amines with benzhydrylamine as a valuable ammonia synthon in moderate to excellent yields.
- Sun, Quan-Wei,Xing, Jun-De,Qin, Yu-Hong,Yin, Xu-Wen,Zhou, Yi
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p. 181 - 183
(2018/05/26)
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- Direct Primary Amination of Alkylmetals with NH-Oxaziridine
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A method for the primary electrophilic amination of primary, secondary, and tertiary organometallic substrates from a bench-stable NH-oxaziridine reagent is described. This facile and highly chemoselective transformation occurs at ambient temperature and without transition metal catalysts or purification by column chromatography to provide alkylamine products in a single step. Density functional theory (DFT) calculations revealed that, despite the basicity of alkylmetals, the direct NH-transfer pathway is favored over proton and O-transfer.
- Behnke, Nicole Erin,Kielawa, Russell,Kwon, Doo-Hyun,Ess, Daniel H.,Kürti, László
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supporting information
p. 8064 - 8068
(2019/01/04)
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- An Efficient Ruthenium Catalyst Bearing Tetradentate Ligand for Hydrogenations of Carbon Dioxide
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A ruthenium complex with a tetradentate bipyridine ligand was proved to be a highly efficient catalyst for the conversions of CO2. Turnover numbers up to 300 000, 9800, and 2100 were achieved for the hydrogenations of CO2 to formamides, formamides to methanol and amines, and the direct hydrogenation of CO2 to methanol, respectively.
- Zhang, Feng-Hua,Liu, Chong,Li, Wei,Tian, Gui-Long,Xie, Jian-Hua,Zhou, Qi-Lin
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supporting information
p. 1000 - 1002
(2018/09/21)
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- Metal Acetylide Elimination: The Key Step in the Cascade Decomposition and Transformation of Metalated Propargylamines
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Metal acetylide elimination facilitates a novel one-pot cascade metalation and elimination/addition route to a series of unsymmetrical secondary amines from the reaction of secondary propargylamines with organometallic reagents. Spectroscopic evidence suggests a dimetalated amido intermediate rather than an allene.
- Flynn, Matthew T.,Blair, Victoria L.,Andrews, Philip C.
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supporting information
p. 1225 - 1228
(2018/04/30)
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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 0070; 0073-0075
(2019/01/15)
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- N-Alkylation of Aqueous Ammonia with Alcohols Leading to Primary Amines Catalyzed by Water-Soluble N-Heterocyclic Carbene Complexes of Iridium
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A new catalytic system for the N-monoalkylation of aqueous ammonia with a variety of alcohols was developed. Water-soluble dicationic complexes of iridium bearing N-heterocyclic carbene and diammine ligands exhibited high catalytic activity for this type of reaction on the basis of hydrogen-transfer processes without generating harmful or wasteful byproducts. Various primary amines were efficiently synthesized by using safe, inexpensive, and easily handled aqueous ammonia as a nitrogen source. For example, the reaction of 1-(4-methylphenyl)ethanol with aqueous ammonia in the presence of a water-soluble N-heterocyclic carbene complex of iridium at 150 °C for 40 h gave 1-(4-methylphenyl)ethylamine in 83 % yield.
- Fujita, Ken-Ichi,Furukawa, Shohichi,Morishima, Namino,Shimizu, Mineyuki,Yamaguchi, Ryohei
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p. 1993 - 1997
(2018/03/13)
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- METHOD FOR THE HOMOGENEOUS CATALYTIC REDUCTIVE AMINATION OF CARBONYL COMPOUNDS
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The present invention relates to a method for the reductive amination of a carbonyl compound, comprising one or more carbonyl groups amenable to reductive amination, forming the corresponding primary amine, characterized in that the reaction is carried out in the presence of a homogeneously dissolved catalyst complex K, comprising at least one metal atom from Group 8, 9 or 10 of the periodic table, bearing a bidentate phosphane ligand, a carbonyl ligand, a neutral ligand and a hydride ligand, and also an acid as co-catalyst.
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Paragraph 0212; 0213-0214; 0217-0218
(2018/07/29)
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- Highly efficient nitrobenzene and alkyl/aryl azide reduction in stainless steel jars without catalyst addition
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The mechanochemical and selective reduction of aryl nitro and aryl/alkyl azide derivatives, with either formate salts or hydrazine, to the corresponding, synthetically useful amines occurs in excellent yields in a planetary ball mill without the addition of a catalyst. This newly developed and solvent-free protocol is efficient, fast and does not require the addition of a metal hydrogenation catalyst as the stainless steel jar itself fulfils that role. The method has been applied to a broad range of compounds and excellent yields have been obtained. The formylation of alkyl amines has been successfully performed, by means of mechanochemical activation, in the presence of ammonium formate alone.
- Martina, Katia,Baricco, Francesca,Tagliapietra, Silvia,Moran, Maria Jesus,Cravotto, Giancarlo,Cintas, Pedro
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supporting information
p. 18881 - 18888
(2018/11/26)
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- Preparation, characterization and catalytic activity of palladium catalyst supported on MgCO3 for dynamic kinetic resolution of amines
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Pd nanoparticle catalyst loading 4.7 wt.percent was prepared by the deposition-precipitation method and characterized by X-ray diffraction and transmission electron microscopy (TEM). The crystallite size estimated from the integral width of the highest intensity line using the Scherrer equation was 2.3 nm. Images obtained from TEM showed an equal distribution of the particles size between 0-2 and 2-4 nm, and also a good dispersion of the nanoparticles on the catalyst support. The catalytic activity of this nanocatalyst was studied for racemization reactions of (S)-(-)-1-phenylethylamine. After that, the catalyst was used in the chemoenzymatic dynamic kinetic resolution (DKR) of some primary amines. Expressive yields and optical purities were obtained.
- Ferreira, Marina M. M.,Cabreira, Camila R.,Chaves, Pedro H. K.,Labussiére, Gabriela M.,Zimpeck, Renata C.,De Lima, Sania M.,De Siqueira, Fernanda A.
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p. 2144 - 2149
(2018/09/29)
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- Synthesis of cobalt nanoparticles by pyrolysis of Vitamin B12: A non-noble-metal catalyst for efficient hydrogenation of nitriles
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A facile preparation of vitamin B12-derived carbonaceous cobalt particles supported on ceria is reported. The resulting composite material is obtained upon wet impregnation of ceria with natural cyanocobalamin and consecutive pyrolysis under inert conditions. The novel catalyst shows good to excellent performance in the industrially relevant heterogeneous hydrogenation of nitriles to the corresponding primary amines.
- Ferraccioli, Raffaella,Borovika, Diana,Surkus, Annette-Enrica,Kreyenschulte, Carsten,Topf, Christoph,Beller, Matthias
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p. 499 - 507
(2018/02/07)
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- Substituent effects on chiral resolutions of derivatized 1-phenylalkylamines by heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin GC stationary phase
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Chiral resolutions of trifluoroacetyl-derivatized 1-phenylalkylamines with different type and position of substituent were investigated by capillary gas chromatography by using heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin diluted in OV-1701 as a chiral stationary phase. The influence of column temperature on retention and enantioselectivity was examined. All enantiomers of meta-substituted analytes as well as fluoro-substituted analytes could be resolved. Temperature had a favorable influence on enantioselectivity for small amines with substituents at the ortho-position. The type of substituent at the stereogenic center of amines also had a crucial effect as the ethyl group led to poor enantioseparation. Among all analytes studied, trifluoroacetyl-derivatized 1-(2′-fluorophenyl)ethylamine exhibited baseline resolution with the shortest analysis time.
- Issaraseriruk, Natthapol,Sritana-anant, Yongsak,Shitangkoon, Aroonsiri
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p. 900 - 906
(2018/05/08)
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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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- A high performance catalyst of shape-specific ruthenium nanoparticles for production of primary amines by reductive amination of carbonyl compounds
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The creation of metal catalysts with highly active surfaces is pivotal to meeting the strong economic demand of the chemical industry. Specific flat-shaped pristine fcc ruthenium nanoparticles having a large fraction of atomically active {111} facets exposed on their flat surfaces have been developed that act as a highly selective and reusable heterogeneous catalyst for the production of various primary amines at exceedingly high reaction rates by the low temperature reductive amination of carbonyl compounds. The high performance of the catalyst is attributed to the large fraction of metallic Ru serving as active sites with weak electron donating ability that prevail on the surface exposed {111} facets of flat-shaped fcc Ru nanoparticles. This catalyst exhibits a highest turnover frequency (TOF) of ca. 1850 h-1 for a model reductive amination of biomass derived furfural to furfurylamine and provides a reaction rate approximately six times higher than that of an efficient and selective support catalyst of Ru-deposited Nb2O5 (TOF: ca. 310 h-1).
- Chandra, Debraj,Inoue, Yasunori,Sasase, Masato,Kitano, Masaaki,Bhaumik, Asim,Kamata, Keigo,Hosono, Hideo,Hara, Michikazu
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p. 5949 - 5956
(2018/07/25)
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- Isopropylamine as Amine Donor in Transaminase-Catalyzed Reactions: Better Acceptance through Reaction and Enzyme Engineering
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Amine transaminases (ATA) have now become frequently used biocatalysts in chemo-enzymatic syntheses including industrial applications. They catalyze the transfer of an amine group from a donor to an acceptor leading to an amine product with high enantiopurity. Hence, they represent an environmentally benign alternative for waste intensive chemical amine synthesis. Isopropylamine (IPA) is probably one of the most favored amine donors since it is cheap and achiral, but nevertheless there is no consistency in literature concerning reaction conditions when IPA is best to be used. At the same time there is still a poor understanding which structural properties in ATA are responsible for IPA acceptance. Herein, we demonstrate, on the basis of the 3FCR enzyme scaffold, a substantial improvement in catalytic activity towards IPA as the amine donor. The asymmetric synthesis of industrial relevant amines was used as model reaction. A systematic investigation of the pH-value as well as concentration effects using common benchmark substrates and several ATA indicates the necessity of a substrate- and ATA-dependent reaction engineering.
- Dawood, Ayad W. H.,Wei?, Martin S.,Schulz, Christian,Pavlidis, Ioannis V.,Iding, Hans,de Souza, Rodrigo O. M. A.,Bornscheuer, Uwe T.
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p. 3943 - 3949
(2018/07/31)
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- Direct Catalytic Hydrogenation of Simple Amides: A Highly Efficient Approach from Amides to Amines and Alcohols
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A highly chemoselective and reactive direct catalytic reduction of various amides to amines and alcohols was developed by using a tetradentate ruthenium complex. The catalytic system showed excellent activity (turnover numbers up to 19 600) and great functional group tolerance under mild reaction conditions, compared to several bidentate and tridentate ruthenium-catalyzed systems.
- Shi, Liyang,Tan, Xuefeng,Long, Jiao,Xiong, Xiong,Yang, Song,Xue, Peng,Lv, Hui,Zhang, Xumu
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supporting information
p. 546 - 548
(2017/01/18)
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- A su ammonia amide carbamate derivative and application thereof
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The invention belongs to the field of plant bactericide, and relates to a threonyl amine carbamate derivative shown as the general formula (I) and salt capable of being accepted pharmaceutically. Substituent groups R1, R2 and R3 have the definitions given by a specification. The invention further relates to a preparation method of the compound of the general formula (I), a midbody specially developed for preparing the threonyl amine carbamate derivative and an application of the threonyl amine carbamate derivative in plant disease prevention and control. The formula is shown in the specification.
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Paragraph 0089; 0090; 0091; 0092
(2017/09/02)
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- Versatile Dynamic Covalent Assemblies for Probing π-Stacking and Chirality Induction from Homotopic Faces
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Herein we report for the first time the use of dynamic covalent reactions (DCRs) for building a π-stacking model system and further quantifying its substituent effects (SEs), which remain a topic of debate despite the rich history of stacking. A general DCR between 10-methylacridinium ion and primary amines was discovered, in which π-stacking played a stabilizing role. Facile quantification of SEs with in situ competing π-stacking systems was next achieved in the form of amine exchange exhibiting structural diversity by simply varying components. The linear correlation with σm in Hammett plots indicates the dominance of purely electrostatic SEs, and the additivity of SEs is in line with the direct interaction model. With α-chiral amines π-stacking within the adduct enabled chirality transfer from homotopic faces. The strategy of dynamic covalent assembly should be appealing to future research of probing weak interactions and manipulating chirality.
- Ye, Hebo,Hai, Yu,Ren, Yulong,You, Lei
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supporting information
p. 3804 - 3809
(2017/03/27)
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- Hybrid Organo- and Biocatalytic Process for the Asymmetric Transformation of Alcohols into Amines in Aqueous Medium
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A hybrid organo- and biocatalytic system for the asymmetric conversion of racemic alcohols into amines was developed. Combining an organocatalyst, AZADO, an oxidant, NaOCl, and an enzyme, ω-transaminase, we implemented a one-pot oxidation-transamination sequential process in aqueous medium. The method showed broad substrate scope and was successfully applied to conventional secondary alcohols and sterically hindered β-substituted cycloalkanols, where a highly stereoselective dynamic asymmetric bioamination enabled us to set up both contiguous stereocenters with very high enantio- and diastereomeric ratio (>90% yield, >99% ee, and up to 49:1 dr).
- Liardo, Elisa,Ríos-Lombardía, Nicolás,Morís, Francisco,Rebolledo, Francisca,González-Sabín, Javier
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p. 4768 - 4774
(2017/07/24)
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