- 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.
- -
-
Paragraph 0027-0030; 0051-0055
(2020/05/30)
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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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- 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)
-
- 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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- 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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- Continuous-Flow Hydrogenation and Reductive Deuteration of Nitriles: a Simple Access to α,α-Dideutero Amines
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A simple and efficient continuous flow methodology has been developed for hydrogenation and reductive deuteration of nitriles to yield primary amines and also valuable α,α-dideutero analogues. Raney nickel proved to be a useful catalyst for the transformation of a wide range of nitriles under reasonably mild conditions with excellent deuterium incorporation (>90 %) and quantitative conversion. Among known model compounds, three new deuterated primary amines were prepared. The large-scale synthesis of deuterated tryptamine was also carried out to deliver 1.1 g product under flow conditions.
- Mészáros, Rebeka,Peng, Bai-Jing,?tv?s, Sándor B.,Yang, Shyh-Chyun,Fül?p, Ferenc
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p. 1508 - 1511
(2019/11/03)
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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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- Cobalt complex, preparation method thereof, and application thereof in selective catalysis of transfer hydrogenation reaction of cyano group
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The invention discloses a cobalt complex, a preparation method thereof, and an application thereof in the selective catalysis of a transfer hydrogenation reaction of a cyano group. The structural formula of the cobalt complex is represented by formula I. The cobalt complex is prepared through a reaction of a cobalt salt and an NNP ligand or a PNP ligand under the protection of an inert atmosphere;and the chemical formula of the cobalt salt is CoX12, wherein X1 represents halogen, a sulfate radical, a perchlorate radical, a hexafluorophosphate radical, a hexafluoroantimonate radical, a tetrafluoroborate radical, a trifluoromethanesulfonate radical or a tetra(pentafluorophenyl)borate radical. The cobalt complex can be used in the selective catalysis of the transfer hydrogenation reaction ofthe cyano group to obtain a primary amine compound, a secondary amine compound and a tertiary amine compound, the primary amine compound, the secondary amine compound and the tertiary amine compoundare important intermediates in a series of subsequent functionalizing reactions, and the cobalt complex has a very high catalysis activity, and has great research values and a great application prospect.
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-
Paragraph 0157-0159; 0161
(2018/05/07)
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- Design and synthesis of neolamellarin a derivatives targeting heat shock protein 90
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In this study, we designed and synthesized a novel family of neolamellarin A derivatives that showed high inhibitory activity toward heat shock protein 90 (Hsp90), a kinase associated with cell proliferation. The 3,4-bis(catechol)pyrrole scaffold and the benzyl group with methoxy modification at N position of pyrrole are essential to the Hsp90 inhibitory activity and cytotoxicity of these compounds. Western blot analysis demonstrated that these compounds induced dramatic depletion of the examined client proteins of Hsp90, and accelerated cancer cell apoptosis. Docking simulations suggested that the binding mode of 9p was similar to that of the VER49009, a potent inhibitor of Hsp90. Further molecular dynamics simulation indicated that the hydrophobic interactions as well as the hydrogen bonds contributed to the high affinity of 9p to Hsp90.
- Jiang, Long,Yin, Ruijuan,Wang, Xueting,Dai, Jiajia,Li, Jing,Jiang, Tao,Yu, Rilei
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supporting information
p. 24 - 33
(2017/04/21)
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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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- Low-Pressure Hydrogenation of Nitriles to Primary Amines Catalyzed by Ruthenium Pincer Complexes. Scope and mechanism
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The catalytic hydrogenation of nitriles to primary amines constitutes an environmentally benign and atom-economical methodology in synthetic organic chemistry. However, selective hydrogenation can be challenging, and usually elevated pressure and the use of various additives is required. Herein the hydrogenation of aromatic and aliphatic nitriles to form primary amines catalyzed by ruthenium pincer complexes is described. The reactions are conducted at low H2 pressure, low catalytic loadings and, in case of a variety of benzonitriles, under neutral conditions and without any additives. Mechanistic insight is provided.
- Mukherjee, Arup,Srimani, Dipankar,Ben-David, Yehoshoa,Milstein, David
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p. 559 - 563
(2017/02/26)
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- Selective Hydrogenation of Nitriles to Primary Amines by using a Cobalt Phosphine Catalyst
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A general procedure for the catalytic hydrogenation of nitriles to primary amines by using a non-noble metal-based system is presented. Co(acac)3 in combination with tris[2-(dicyclohexylphosphino)ethyl]phosphine efficiently catalyzes the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to give the corresponding amines.
- Adam, Rosa,Bheeter, Charles Beromeo,Cabrero-Antonino, Jose R.,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
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p. 842 - 846
(2017/03/17)
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- MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
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The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
- Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
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p. 326 - 332
(2017/09/28)
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- DUAL SITE CATALYST FOR MILD, SELECTIVE NITRILE REDUCTION
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A ruthenium bis(pyrazolyl)borate scaffold that enables cooperative reduction reactivity in which boron and ruthenium centers work in concert to effect selective nitrile reduction is provided. The pre-catalyst compound [κ3-(1-pz)2HB(N═CHCH3)]Ru(cymene)? TfO? (pz=pyrazolyl) was synthesized using readily-available materials through a straightforward route, thus making it an appealing catalyst for a number of reactions.
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Paragraph 0052
(2016/06/09)
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- M-CPBA mediated metal free, rapid oxidation of aliphatic amines to oximes
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An efficient, rapid oxidation of various aliphatic amines to oximes using m-CPBA as an oxidant in ethyl acetate is described. High conversion (100%) with >90% oxime selectivity is achieved at room temperature under catalyst-free conditions. Mild reaction conditions along with an easy work up procedure offer lower byproduct formation and high selectivity for oximes in good yield and purity.
- Patil, Vilas V.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
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p. 781 - 786
(2016/02/18)
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- NNP-Type Pincer Imidazolylphosphine Ruthenium Complexes: Efficient Base-Free Hydrogenation of Aromatic and Aliphatic Nitriles under Mild Conditions
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A series of seven novel NImNHP-type pincer imidazolylphosphine ruthenium complexes has been synthesized and fully characterized. The use of hydrogenation of benzonitrile as a benchmark test identified [RuHCl(CO)(NImNHPtBu)] as the most active catalyst. With its stable Ru-BH4 analogue, in which chloride is replaced by BH4, a broad range of (hetero)aromatic and aliphatic nitriles, including industrially interesting adiponitrile, has been hydrogenated under mild and base-free conditions.
- Adam, Rosa,Alberico, Elisabetta,Baumann, Wolfgang,Drexler, Hans-Joachim,Jackstell, Ralf,Junge, Henrik,Beller, Matthias
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p. 4991 - 5002
(2016/04/05)
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- Mild and Selective Cobalt-Catalyzed Chemodivergent Transfer Hydrogenation of Nitriles
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Herein, we describe a selective cobalt-catalyzed chemodivergent transfer hydrogenation of nitriles to synthesize primary, secondary, and tertiary amines. The solvent effect plays a key role for the selectivity control. The general applicability of this procedure was highlighted by the synthesis of more than 70 amine products bearing various functional groups in high chemoselectivity. Moreover, this mild system achieved >2000 TONs (turnover numbers) for the transfer hydrogenation of nitriles.
- Shao, Zhihui,Fu, Shaomin,Wei, Mufeng,Zhou, Shaolin,Liu, Qiang
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supporting information
p. 14653 - 14657
(2016/11/23)
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- Selective hydrogenation of nitriles to primary amines catalyzed by a novel iron complex
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Hydrogenation of nitriles to primary amines constitutes an atom-efficient and environmentally benign synthetic reaction. Herein we present a novel complex based on earth-abundant iron, and its application in the catalytic homogeneous hydrogenation of (hetero)aromatic, benzylic, and aliphatic nitriles to selectively form primary amines.
- Chakraborty, Subrata,Leitus, Gregory,Milstein, David
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supporting information
p. 1812 - 1815
(2016/02/05)
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- A Mild and Base-Free Protocol for the Ruthenium-Catalyzed Hydrogenation of Aliphatic and Aromatic Nitriles with Tridentate Phosphine Ligands
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A novel protocol for the general hydrogenation of nitriles in the absence of basic additives is described. The system is based on the combination of [Ru(cod)(methylallyl)2] (cod=cyclooctadiene) and L2. A variety of aromatic and aliphatic nitriles is hydrogenated under mild conditions (50 °C and 15 bar H2) with this system. Kinetic studies revealed higher activity in the case of aromatic nitriles compared with aliphatic ones.
- Adam, Rosa,Bheeter, Charles Beromeo,Jackstell, Ralf,Beller, Matthias
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p. 1329 - 1334
(2016/04/20)
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- SYNTHESIS OF AMIDES AND AMINES FROM ALDEHYDES OR KETONES BY HETEROGENEOUS METAL CATALYSIS
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This invention concerns the first mild and efficient synthesis of primary amines and amides from aldehydes or ketones using a heterogeneous metal catalystand amine donor. The initial heterogeneous metal- catalyzed reaction between the carbonyl and the amine donor components is followed up with the addition of a suitable acylating agent component in one-pot. Hence, the present invention provides a novel catalytic one-pot three-component synthesis of amides. Moreover, the integration of enzyme catalysis allows for eco-friendly one-pot co-catalytic synthesis ofamides from aldehyde and ketone substrates, respectively. The process can be applied to the co-catalytic one-pot three-component synthesis of capsaicin and its analogues from vanillin or vanillyl alcohol. It can also be applied for asymmetric synthesis. In the present invention, a novel co-catalytic reductive amination/dynamic kinetic resolution (dkr) relay sequence for the asymmetric synthesis of optically active amides from ketones is disclosed. Moreover, implementation of a catalytic reductive amination/kinetic resolution (kr) relay sequence produces the corresponding optically active amide product and optical active primary amine product with the opposite stereochemistry from the starting ketones.
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Page/Page column 19
(2016/07/05)
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- Integrated Heterogeneous Metal/Enzymatic Multiple Relay Catalysis for Eco-Friendly and Asymmetric Synthesis
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Organic synthesis is in general performed using stepwise transformations where isolation and purification of key intermediates is often required prior to further reactions. Herein we disclose the concept of integrated heterogeneous metal/enzymatic multiple relay catalysis for eco-friendly and asymmetric synthesis of valuable molecules (e.g., amines and amides) in one-pot using a combination of heterogeneous metal and enzyme catalysts. Here reagents, catalysts, and different conditions can be introduced throughout the one-pot procedure involving multistep catalytic tandem operations. Several novel cocatalytic relay sequences (reductive amination/amidation, aerobic oxidation/reductive amination/amidation, reductive amination/kinetic resolution and reductive amination/dynamic kinetic resolution) were developed. They were next applied to the direct synthesis of various biologically and optically active amines or amides in one-pot from simple aldehydes, ketones, or alcohols, respectively.
- Palo-Nieto, Carlos,Afewerki, Samson,Anderson, Mattias,Tai, Cheuk-Wai,Berglund, Per,Córdova, Armando
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p. 3932 - 3940
(2016/07/06)
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- GLUCOSE METABOLISM MODULATING COMPOUNDS
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The present invention provides, inter alia, dihydropyridone compounds and compositions, including analogs of a vesicular monoamine transporter type 2 (VMAT2) antagonist. The present invention also provides methods of using such compounds/analogs for modulating glucose levels, and/or preventing, treating, or ameliorating the effects of diabetes and hyperglycemia.
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-
Sheet sheet 12 of 13
(2016/11/14)
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- Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Cobalt Pincer Complex
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The catalytic hydrogenation of nitriles to primary amines represents an atom-efficient and environmentally benign reduction methodology in organic chemistry. This has been accomplished in recent years mainly with precious-metal-based catalysts, with a single exception. Here we report the first homogeneous Co-catalyzed hydrogenation of nitriles to primary amines. Several (hetero)aromatic, benzylic, and aliphatic nitriles undergo hydrogenation to the corresponding primary amines in good to excellent yields under the reaction conditions.
- Mukherjee, Arup,Srimani, Dipankar,Chakraborty, Subrata,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 8888 - 8891
(2015/08/03)
-
- Hydrogenation of Aliphatic and Aromatic Nitriles Using a Defined Ruthenium PNP Pincer Catalyst
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Selective catalytic reductions of nitriles are presented using the commercially available Ru-Macho-BH complex. A variety of aliphatic, aromatic and (hetero)cyclic nitriles including industrially important adipodinitrile are hydrogenated to the corresponding primary amines. Modelling suggests the reaction follows an outer sphere hydrogenation mechanism. An efficient and selective catalytic reduction of nitriles is presented using the commercially available Ru-Macho-BH complex. A variety of aliphatic, aromatic and (hetero)cyclic nitriles including the industrially important adipodinitrile are hydrogenated to the corresponding primary amines. The reaction follows an outer-sphere mechanism.
- Neumann, Jacob,Bornschein, Christoph,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
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supporting information
p. 5944 - 5948
(2015/09/22)
-
- CuI-catalyzed coupling of gem-dibromovinylanilides and sulfonamides: An efficient method for the synthesis of 2-amidoindoles and indolo[1,2-a] quinazolines
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A Cu(I)-catalyzed, intermolecular protocol for the synthesis of 2-amidoindoles and tetrahydroindolo[1,2-a]quinazolines in shorter time and high yields is reported. The key highlight of this disclosure is the formation of 2-amidoindole and tetrahydroindolo[1,2-a]quinazoline moieties directly from gem-dibromovinylanilides and sulfonamides in a one-pot fashion through the in situ formation of ynamides followed by a base-promoted intramolecular hydroamidation.
- Kiruthika, Selvarangam E.,Perumal, Paramasivan Thirumalai
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supporting information
p. 484 - 487
(2014/04/03)
-
- A dual site catalyst for mild, selective nitrile reduction
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We report a novel ruthenium bis(pyrazolyl)borate scaffold that enables cooperative reduction reactivity in which boron and ruthenium centers work in concert to effect selective nitrile reduction. The pre-catalyst compound [κ3-(1-pz)2HB(N = CHCH3)]Ru(cymene) + TfO- (pz = pyrazolyl) was synthesized using readily-available materials through a straightforward route, thus making it an appealing catalyst for a number of reactions. the Partner Organisations 2014.
- Lu, Zhiyao,Williams, Travis J.
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supporting information
p. 5391 - 5393
(2014/05/06)
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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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- Selective ruthenium-catalyzed transfer hydrogenations of nitriles to amines with 2-butanol
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Transfer your hydrogen: Fast and general transfer hydrogenation of nitriles to form primary amines is possible with a homogeneous Ru/1,4- bis(diphenylphosphino)butane (DPPB) catalyst (see scheme). The use of 2-butanol as the hydrogen-transfer reagent is essential for the selective reduction of aromatic, heteroaromatic, and aliphatic nitriles with this system. Copyright
- Werkmeister, Svenja,Bornschein, Christoph,Junge, Kathrin,Beller, Matthias
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supporting information
p. 4437 - 4440
(2013/04/23)
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- Reduction of nitriles to amines with H2 catalyzed by nonclassical ruthenium hydrides - Water-promoted selectivity for primary amines and mechanistic investigations
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Catalytic hydrogenation of nitriles to amines by nonclassical ruthenium hydride complexes derived from PNP pincer ligands is described. Aromatic as well as aliphatic nitriles are reduced to the corresponding primary amines. Hydrogen pressure influences the selectivity for the primary amines. The mechanism of nitrile reduction with nonclassical ruthenium hydride pincer complexes is investigated by DFT calculations. A catalytic cycle involving the coordination of nitrile trans to the pincer backbone after an initial hydride rearrangement at the ruthenium center, and the subsequent first transfer of the hydride ligand to the carbon center of the nitrile ligand is suggested as a possible reaction mechanism. Interestingly, the use of water as additive increases the selectivity for the primary amines and the rate of the reactions. Selective synthesis of primary amines by the catalytic hydrogenation of nitriles with nonclassical ruthenium hydride pincer complexes is reported. Use of water as additive increases the selectivity and rate of the reactions. Possible catalytic cycles were identified for this important reaction of industrial significance by means of DFT calculations. Copyright
- Gunanathan, Chidambaram,Hoelscher, Markus,Leitner, Walter
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experimental part
p. 3381 - 3386
(2011/09/20)
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- Reduction of aldehydes and oximes to their corresponding alcohols and amines by catalytic hydrogenation method
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The reduction of aldehydes such as 2-butyl-5-chloro-3H-imidazole-5- carbaldehyde and veratraldehyde, which are pharmaceutical key intermediates, have been reduced to alcohols by catalytic hydrogenation method in the presence of magnesium and also oximes are reduced to primary amines successively by magnesium/ammonium formate system, is a large scale feasible and cheaper method. The crystal structure of the product, (2-butyl-5-chloro-3H-imidazole-4-yl)- methanol 1 is reported.
- Basappa,Doreswamy,Mahendra,Mantelingu,Sridhar,Prasad, J. Shashidhara,Rangappa
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p. 148 - 151
(2007/10/03)
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- THIENOPYRIMIDINES
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Thienopyrimidines of the formula (I) and their physiologically acceptable salts, in which R1, R2 and X are as defined in claim 1, exhibit phosphodiesterase V inhibition and can be employed for the treatment of illnesses of the cardiovascular system and for the treatment and/or therapy of impotence.
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- Pharmaceutically active pyrrolidine derivatives
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The present invention is related to pyrrolidine derivatives of formula (I). Said compounds are preferably for use as pharmaceutically active compounds. Specifically, pyrrolidine derivatives of formula (I) are useful in the treatment and/or prevention of premature labor, premature birth and dysmenorrhea. In particular, the present invention is related to pyrrolidine derivatives displaying a substantial modulatory, notably an antagonist activity of the oxytocin receptor. More preferably, said compounds are useful in the treatment and/or prevention of disease states mediated by oxytocin, including premature labor, premature birth and dysmenorrhea. The present invention is furthermore related to novel pyrrolidine derivatives as well as to methods of their preparation, wherein X is selected from the group consisting of CR6R7, NOR6, NNR6R7; A is selected from the group consisting of —(C═O)—, —(C═O)—O—, —C(═NH)—, —(C═O)—NH—, —(C═S)—NH, —SO22—, —SO2NH—, —CH2—,B is either a group —(C═O)—NR8R9 or represents a heterocyclic residue having the formula (a) wherein Q is NR10, O or S; n is an integer selected of 0, 1 or 2; Y, Z and E form together with the 2 carbons to which they are attached a 5-6 membered aryl or heteroaryl ring.
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- Pharmaceutically active pyrrolidine derivatives as bax inhibitors
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The present invention is related to new substituted pyrrolidine derivatives of formula (I). Said compounds are preferably for use as pharmaceutically active compounds. Specifically, pyrrolidine derivatives of formula (I) are useful in the treatment and/or prevention of neurodegenerative disorders, diseases associated with polygultamine tracts, epilepsy, ischemia, infertility, cardiovascular disorders renal hypoxia, hepatitis and AIDS. Said pyrrolidine derivatives display a modulatory and most notably a down-regulating-up to an inhibitory-activity with respect to the cellular death agonist Bax and/or the activation pathways leading to Bax and allows therefore to block the release of cytochrome (c). The present invention is furthermore related to novel pharmaceutically activity substituted pyrrolidine derivatives as well as to methods of their preparation, wherein X is selected from the group consisting of O, S, CRR, NOR, NNRR; A is selected from the group consisting of —(C═O)—, —(C═O)—O—, —C(═NH)—, —(C═O)—NH—, —(C═S)—NH, —SO2-, —SO2NH—; —CH2-; B is either a group —(C═O)—NRR or represents a heterocyclic residue having the formula (II) wherein Q is NR, O or S; n is an integer selected of 0, 1 or 2; Y, Z and E form together with the 2 carbons to which they are attached a 5-6 membered aryl or heteroaryl ring.
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- Rapid reduction of nitriles to primary amines with nickel boride at ambient temperature
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Reduction of a variety of nitriles to their corresponding primary amines can be achieved with nickel boride generated in situ in dry ethanol at ambient temperature. The reductions are very rapid and chemoselective.
- Khurana, Jitender M.,Kukreja, Gagan
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p. 1265 - 1269
(2007/10/03)
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- 2-aminobenzoxazole derivatives and combinatorial libraries thereof
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The present invention relates to novel 2-aminobenzoxazole derivative compounds of the following formula: wherein R1 to R4 and Z have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminobenzoxazole derivative compounds.
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- 5-HT2A receptor inverse agonists
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Disclosed herein is a new class of pyrazole compounds which act at the 5HT2A receptors.
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- Small molecule modulators of non-endogenous, constitutively activated human serotonin receptors
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Disclosed herein are non-endogenous, constitutively activated forms of the human 5-HT2A and human 5-HT2C receptors and uses of such receptors to screen candidate compounds. Further disclosed herein are candidate compounds identified by the screening method which act at the 5HT2A receptors. Yet further disclosed is a new class of compounds which act at the 5HT2A receptors.
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- Amberlyst-15(H+)-NaBH4-LiCl: An effective reductor for oximes and hydrazones
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A simple and mild procedure reduces oximes and hydrazones on amberlyst 15(H+) support with LiCl-NaBH4 to the corresponding amines and hydrazines respectively in high yield and purity.
- Baruah, Bipul,Dutta, Manu P.,Boruah, Anima,Prajapati, Dipak,Sandhu, Jagir S.
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p. 409 - 410
(2007/10/03)
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- N-Substituted aziridine-2-carboxylic acid derivatives and their immuno-stimulation compositions and methods
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A 2-cyanaziridine derivative of the formula STR1 wherein R' is a straight-chained or branched, saturated or mono- or polyunsaturated aliphatic hydrocarbon radical with up to 8 carbon atoms, which is substituted by an aromatic nitrogen-containing heterocyclic radical with 5 or 6 ring-members and 1, 2 or 3 nitrogen atoms optionally substituted by halogen, alkoxy with up to 8 carbon atoms, alkyl with up to 8 carbon atoms, hydroxyl, carbalkoxy with up to 9 carbon atoms, carbamoyl, dialkylamino the alkyl moieties of which having up to 8 carbon atoms, cycloalkylamino, the cycloalkyl moiety having 3-10 carbon atoms, acetylamino, nitro, cyano, acetyl, alkylthio with up to 8 carbon atoms, alkylsulphinyl with up to 8 carbon atoms, alkylsulphonyl with up to 8 carbon atoms, sulphamoyl, phenyl, trifluoromethyl, phenoxy, acetoxy or methylenedioxy; or a pharmacologically acceptable salt thereof, exhibits immune stimulating activity.
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- N-Substituted aziridine-2-carboxylic acid derivatives for immuno stimulation
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Aziridine-2-carboxylic acid derivatives of the formula STR1 wherein X is a carboxyl, nitrile, alkoxycarbonyl or carbamoyl group, and R and R1 are various organic radicals, or pharmacologically acceptable salts thereof, exhibit marked immunostimulant activity, especially in conjunction with added chemotherapeutic agents such as a penicillin, a cephalosporin, a nitrofuran or chloramphenicol. Those compounds are new where X is a cyano group or an alkoxycarbonyl radical and R1 is a hydrogen atom, but R' is not an unsubstituted alkyl radical or an alkyl radical substituted by hydroxyl, alkoxy, dialkylamino, phenyl, 4-chlorophenyl or 4-methoxyphenyl or a vinyl radical substituted by a phenyl or methyl radical, or a cycloalkyl radical, a phenyl a 4-chlorophenyl, a 4-methoxyphenyl, an s-triazinyl or a pyridinyl radical; or where X is a carbamoyl group and R1 is a hydrogen atom, R' is not an unsubstituted cyclohexyl, alkyl or benzyl radical; or where X is a cyano group or an alkoxycarbonyl radical and R1 is a phenyl radical, R' is not an isopropyl, cyclohexyl, phenyl, benzyl or p-chlorobenzyl radical; or where R1 is a methyl radical, R1 is not a benzyl, p-chloro- or p- methoxybenzyl radical.
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