- Process Development of the Copper(II)-Catalyzed Dehydration of a Chiral Aldoxime and Rational Selection of the Co-Substrate
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The access towards chiral nitriles remains crucial in the synthesis of several pharmaceuticals. One approach is based on metal-catalyzed dehydration of chiral aldoximes, which are generated from chiral pool-derived aldehydes as substrates, and the use of a cheap and readily available nitrile as co-substrate and water acceptor. Dehydration of N-acyl α-amino aldoximes such as N-Boc-l-prolinal oxime catalyzed by copper(II) acetate provides access to the corresponding N-acyl α-amino nitriles, which are substructures of the pharmaceuticals Vildagliptin and Saxagliptin. In this work, a detailed investigation of the formation of the amide as a by-product at higher substrate loadings is performed. The amide formation depends on the electronic properties of the nitrile co-substrate. We could identify an acceptor nitrile which completely suppressed amide formation at high substrate loadings of 0.5 m even when being used with only 2 equivalents. In detail, utilization of trichloroacetonitrile as such an acceptor nitrile enabled the synthesis of N-Boc-cyanopyrrolidine in a high yield of 92 % and with full retention of the absolute configuration.
- Nonnhoff, Jannis,Gr?ger, Harald
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-
- Half-Sandwich Iridium Complexes Based on β-Ketoamino Ligands: Preparation, Structure, and Catalytic Activity in Amide Synthesis
-
A series of β-ketoamino-based N,O-chelate half-sandwich iridium complexes with the general formula [Cp*IrClL] have been prepared in good yields. These air-insensitive iridium complexes showed desirable catalytic activity in an amide preparation under mild conditions. A number of amides with diverse substituted groups were furnished in a one-pot reaction with good-to-excellent yields through an amidation reaction of NH2OH·HCl with aldehydes in the presence of these iridium(III) precursors. The excellent catalytic activity, mild reaction conditions, and broad substrate scope gave this type of iridium catalyst potential for use in industry. All of the obtained iridium complexes were well characterized by different spectroscopy techniques. The exact molecular structure of complex 3 has been confirmed by single-crystal X-ray analysis.
- Wang, Yang,Guo, Wen,Guan, Ai-Lin,Liu, Shuang,Yao, Zi-Jian
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p. 11514 - 11520
(2021/07/31)
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- Transamidation for the Synthesis of Primary Amides at Room Temperature
-
Various primary amides have been synthesized using the transamidation of various tertiary amides under metal-free and mild reaction conditions. When (NH4)2CO3 reacts with a tertiary amide bearing an N-electron-withdrawing substituent, such as sulfonyl and diacyl, in DMSO at 25 °C, the desired primary amide product is formed in good yield with good funcctional group tolerance. In addition, N-tosylated lactam derivatives afforded their corresponding N-tosylamido alkyl amide products via a ring opening reaction.
- Chen, Jiajia,Lee, Sunwoo,Xia, Yuanzhi
-
supporting information
(2020/05/05)
-
- Half-Sandwich Iridium Complexes for the One-Pot Synthesis of Amides: Preparation, Structure, and Diverse Catalytic Activity
-
Several types of air-stable N,O-coordinate half-sandwich iridium complexes containing Schiff base ligands with the general formula [Cp*IrClL] were synthesized in good yields. These stable iridium complexes displayed a good catalytic efficiency in amide synthesis. A variety of amides with different substituents were obtained in a one-pot procedure with excellent yields and high selectivities through the amidation of aldehydes with NH2OHHCl and nitrile hydration under the catalysis of complexes 1-4. The excellent and diverse catalytic activity, mild conditions, broad substance scope, and environmentally friendly solvent make this system potentially applicable in industrial production. Half-sandwich iridium complexes 1-4 were characterized by NMR, elemental analysis, and IR techniques. Molecular structures of complexes 2 and 3 were confirmed by single-crystal X-ray analysis.
- Fan, Xiao-Nan,Deng, Wei,Liu, Zhen-Jiang,Yao, Zi-Jian
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p. 16582 - 16590
(2020/11/13)
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- Hydration of nitriles using a metal-ligand cooperative ruthenium pincer catalyst
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Nitrile hydration provides access to amides that are important structural elements in organic chemistry. Here we report catalytic nitrile hydration using ruthenium catalysts based on a pincer scaffold with a dearomatized pyridine backbone. These complexes catalyze the nucleophilic addition of H2O to a wide variety of aliphatic and (hetero)aromatic nitriles in tBuOH as solvent. Reactions occur under mild conditions (room temperature) in the absence of additives. A mechanism for nitrile hydration is proposed that is initiated by metal-ligand cooperative binding of the nitrile.
- Guo, Beibei,Otten, Edwin,De Vries, Johannes G.
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p. 10647 - 10652
(2019/12/02)
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- (Ar-tpy)RuII(ACN)3: A Water-Soluble Catalyst for Aldehyde Amidation, Olefin Oxo-Scissoring, and Alkyne Oxygenation
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The synthetic chemists always look for developing new catalysts, sustainable catalysis, and their applications in various organic transformations. Herein, we report a new class of water-soluble complexes, (Ar-tpy)RuII(ACN)3, utilizing designed terpyridines possessing electron-donating and -withdrawing aromatic residues for tuning the catalytic activity of the Ru(II) complex. These complexes displayed excellent catalytic activity for several oxidative organic transformations including late-stage C-H functionalization of aldehydes with NH2OR to valuable primary amides in nonconventional aqueous media with excellent yield. Its diverse catalytic power was established for direct oxo-scissoring of a wide range of alkenes to furnish aldehydes and/or ketones in high yield using a low catalyst loading in the water. Its smart catalytic activity under mild conditions was validated for dioxygenation of alkynes to highly demanding labile synthons, 1,2-diketones, and/or acids. This general and sustainable catalysis was successfully employed on sugar-based substrates to obtain the chiral amides, aldehydes, and labile 1,2-diketones. The catalyst is recovered and reused with a moderate turnover. The proposed mechanistic pathway is supported by isolation of the intermediates and their characterization. This multifaceted sustainable catalysis is a unique tool, especially for late-stage functionalization, to furnish the targeted compounds through frequently used amidation and oxygenation processes in the academia and industry.
- Joarder, Dripta De,Gayen, Subrata,Sarkar, Rajarshi,Bhattacharya, Rajarshi,Roy, Sima,Maiti, Dilip K.
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p. 8468 - 8480
(2019/07/03)
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- Magnetic Nanoparticle-Supported Cu–NHC Complex as an Efficient and Recoverable Catalyst for Nitrile Hydration
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Magnetic nanoparticles supported N-heterocyclic carbene–Cu complex was prepared and authenticated by FT-IR, SEM, EDX, VSM, powder-XRD. The catalytic activity of these magnetically retrievable NPs was investigated for hydration of nitriles as the simplest route for the synthesis of amides in an atom-economical manner. A wide range of nitriles containing various functional groups such as olefin, aldehyde, nitro, carboxylic acid was examined in this transformation to generate their corresponding amides in the aqueous medium. The immobilized catalyst was easily recovered using an external magnet and reused for six times without significant loss of its catalytic activity. Graphical Abstract: [Figure not available: see fulltext.].
- Kazemi Miraki, Maryam,Arefi, Marzban,Salamatmanesh, Arefeh,Yazdani, Elahe,Heydari, Akbar
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p. 3378 - 3388
(2018/09/11)
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- A continuous-flow synthesis of primary amides from hydrolysis of nitriles using hydrogen peroxide as oxidant
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A continuous-flow synthesis of primary amides from hydrolysis of nitriles using hydrogen peroxide as oxidant has been developed. Using this procedure, a variety of nitriles could be smoothly transformed into the desired primary amides in good to excellent yields. The mild reaction conditions and the flowing reaction system greatly improved the safety and make the reaction easy to scale up.
- Zhan, Wei,Ji, Ling,Ge, Ze-mei,Wang, Xin,Li, Run-tao
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p. 1527 - 1532
(2018/02/21)
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- Investigation of Nitrile Hydration Chemistry by Two Transition Metal Hydroxide Complexes: Mn-OH and Ni-OH Nitrile Insertion Chemistry
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Herein we describe the synthesis of a series of nickel complexes, including the formation of [(iPrPNHP)Ni(PMe3)][BPh4] (iPrPNHP = HN(CH2CH2(PiPr2))2). The ability of this phosphine complex to perform the 1,2-addition of H2O to produce the Ni-OH species [(iPrPNHP)NiOH][BPh4] has been investigated. The nucleophilicity of the hydroxide moiety of both [(iPrPNHP)NiOH][BPh4] and the previously reported (iPrPNHP)MnOH(CO)2 was investigated through the hydration of aryl and alkyl nitriles, leading to the formation of a number of metal carboxamide (RC(O)NH-) bonds. This reactivity generated complexes with the general structures of [(iPrPNHP)Ni(NHC(O)R)][BPh4] for nickel and (iPrPNHP)Mn(NHC(O)R)(CO)2 for manganese. Under catalytic conditions, the hydration of nitriles using nickel complexes yielded only a single turnover. However, (iPrPNHP)MnOH(CO)2 produced several turnovers, and the reaction conditions were probed for optimization.
- Anderson, Nickolas H.,Boncella, James M.,Tondreau, Aaron M.
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supporting information
p. 4675 - 4684
(2019/01/08)
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- Expedient Synthesis of N-Methyl- and N-Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles
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N-Methyl- and N-alkylamines represent important fine and bulk chemicals that are extensively used in both academic research and industrial production. Notably, these structural motifs are found in a large number of life-science molecules and play vital roles in regulating their activities. Therefore, the development of convenient and cost-effective methods for the synthesis and functionalization of amines by using earth-abundant metal-based catalysts is of scientific interest. In this regard, herein we report an expedient reductive amination process for the selective synthesis of N-methylated and N-alkylated amines by using nitrogen-doped, graphene-activated nanoscale Co3O4-based catalysts. Starting from inexpensive and easily accessible nitroarenes or amines and aqueous formaldehyde or aldehydes in the presence of formic acid, this cost-efficient reductive amination protocol allows the synthesis of various N-methyl- and N-alkylamines, amino acid derivatives, and existing drug molecules.
- Senthamarai, Thirusangumurugan,Murugesan, Kathiravan,Natte, Kishore,Kalevaru, Narayana V.,Neumann, Helfried,Kamer, Paul C. J.,Jagadeesh, Rajenahally V.
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p. 1235 - 1240
(2018/02/09)
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- Metal-Free Thermal Activation of Molecular Oxygen Enabled Direct α-CH2-Oxygenation of Free Amines
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Direct oxidation of α-CH2 group of free amines is hard to achieve due to the higher reactivity of amine moiety. Therefore, oxidation of amines involves the use of sophisticated metallic reagents/catalyst in the presence or absence of hazardous oxidants under sensitive reaction conditions. A novel method for direct C-H oxygenation of aliphatic amines through a metal-free activation of molecular oxygen has been developed. Both activated and unactivated free amines were oxygenated efficiently to provide a wide variety of amides (primary, secondary) and lactams under operationally simple conditions without the aid of metallic reagents and toxic oxidants. The method has been applied to the synthesis of highly functionalized amide-containing medicinal drugs, such as O-Me-alibendol and -buclosamide.
- Ghosh, Santanu,Jana, Chandan K.
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p. 260 - 266
(2018/02/19)
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- POLYMERIZABLE DENTAL MATERIAL
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The invention relates to a dental material, which contains: at least one monomer, containing at least one radically polymerizable ehtylenically unsaturated group and at least one acid group; at least one monomer, which contains no acid groups and at least one radically polymerizable ethylenically unsaturated group; at least one photoinitiator; and at least one tertiary aromatic amine as a coinitiator, which amine has a benzene ring, to which at least one dialkylamine group and at least one further group are directly bonded. According to the invention, the further group is selected from carboxylic acid ester groups containing at least one polyoxyalkylene group having at least 2 oxyethylene and/or oxypropylene units; and amide groups.
- -
-
Paragraph 0071
(2017/03/28)
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- Hemilability-Driven Water Activation: A NiII Catalyst for Base-Free Hydration of Nitriles to Amides
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The NiII complex 1 containing pyridyl- and hydroxy-functionalized N-heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base-free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen-bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α-hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds 2 and 4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds 1 and 3) show substantial activity. The linkage isomer 1′ where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pKa measurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand-promoted nucleophilic water addition to a metal-bound nitrile group. This work reports a Ni-based catalyst that exhibits functional hemilability for hydration chemistry.
- Singh, Kuldeep,Sarbajna, Abir,Dutta, Indranil,Pandey, Pragati,Bera, Jitendra K.
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p. 7761 - 7771
(2017/06/06)
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- Acetic Acid Accelerated Visible-Light Photoredox Catalyzed N-Demethylation of N,N-Dimethylaminophenyl Derivatives
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N,N-Dimethylaminophenyl moiety is a common fragment in medicinal chemistry as several pharmaceuticals bearing this privileged motif are on the market and under clinical evaluation. Oxidative N-demethylation is generally regarded as the major metabolic pathway. However, pharmacokinetics, metabolites studies as well as the further structural modification are precluded by the impracticality of chemical synthesis. Here we report that acetic acid can significantly accelerate visible-light photoredox catalyzed N-demethylation of N,N-dimethylaminophenyl derivatives. This approach is easy for large scale reaction and even for potential industrial manufacture. (Figure presented.).
- Wu, Guolin,Li, Yazhen,Yu, Xuemei,Gao, Yu,Chen, Haijun
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supporting information
p. 687 - 692
(2017/02/23)
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- Copper (II)-catalysed direct conversion of aldehydes into nitriles in acetonitrile
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A mild one-pot method for the direct conversion of aryl, heteroaryl and alkyl aldehydes into nitriles was achieved by forming the corresponding oximes in situ with NH2OH and allowing them to react with CuO and acetonitrile. Yields of the 13 nitriles prepared were moderate to very good (62–91%).
- Ma, Xiaoyun,Ao, Jun,Chen, Zhengjian,Liu, Yi
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p. 465 - 468
(2017/08/18)
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- One–pot green catalytic synthesis of primary amides in aqueous medium by CuII–immobilized silica–based magnetic retrievable nanocatalyst
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In order to develop a new nanocatalyst, a copper–birhodanine derivative complex crafted onto Fe3O4@SiO2nanoparticle [abbreviated as Fe3O4@SiO2–Ligand–Cu(II)] was synthesized and their structure characterized by different physicochemical techniques such as FT–IR, FE–SEM, XRD, EDX, TGA, AGFM, and ICP. This new magnetic nanoparticle revealed high catalytic performance for one–pot green synthesis of primary amides from aldehydes and NH2OH·HCl in water as a green solvent. The effects of catalyst amounts, reaction temperature, various bases and type of solvent on catalytic activity were also investigated. The catalyst was retrieved eight times without significant loss of its catalytic activity.
- Rezaei, Manuchehr,Amani, Kamal,Darvishi, Kamran
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- Aminofluorene-Mediated Biomimetic Domino Amination-Oxygenation of Aldehydes to Amides
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A conceptually novel biomimetic strategy based on a domino amination-oxygenation reaction was developed for direct amidation of aldehydes under metal-free conditions employing molecular oxygen as the oxidant. 9-Aminofluorene derivatives acted as pyridoxamine-5′-phosphate equivalents for efficient, chemoselective, and operationally simple amine-transfer oxygenation reaction. Unprecedented RNH transfer involving secondary amine to produce secondary amides was achieved. In the presence of 18O2, 18O-amide was formed with excellent (95%) isotopic purity.
- Ghosh, Santanu,Jana, Chandan K.
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supporting information
p. 5788 - 5791
(2016/11/29)
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- Copper(II) acetate-catalysed conversion of aldoximes to amides under mild conditions
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A mild method for the metal-catalysed conversion of aldoximes to amides has been achieved by the combined use of copper(II) acetate and MeCN in EtOH under reflux. The presence of a catalytic amount of MeCN (0.05 equiv.) accelerated the reaction and improved the yield. Aryl, heteroaryl and alkyl aldoximes were transformed into the corresponding amides in moderate to good yield. 2-Furyl and 2-Thiophenyl aldoximes, which possess a heteroatom lone pair positioned ortho to the oximido group, showed enhanced reactivity, and the corresponding amides were obtained in excellent yield.
- Ma, Xiaoyun,Lu, Ming
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p. 594 - 596
(2016/10/21)
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- Chemoselective hydration of nitriles to amides using hydrated ionic liquid (IL) tetrabutylammonium hydroxide (TBAH) as a green catalyst
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A transition metal-free process, catalyzed by tetrabutylammonium hydroxide (TBAH), has been developed for the convenient and selective hydration of nitriles to the corresponding amides. The present process converts aromatic, aliphatic, and heteroaromatic nitriles with a wide variety of functional groups into amides. The regioselective hydration of one nitrile moiety in the presence of another nitrile group gives the present protocol high impact.
- Veisi, Hojat,Maleki, Behrooz,Hamelian, Mona,Ashrafi, Samaneh Sedigh
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p. 6365 - 6371
(2015/02/19)
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- Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides
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Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride, and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which proceeds exclusively in aqueous medium under neutral conditions. the Partner Organisations 2014.
- Baig, R. B. Nasir,Nadagouda, Mallikarjuna N.,Varma, Rajender S.
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p. 2122 - 2127
(2014/04/17)
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- Novel acylureidoindolin-2-one derivatives as dual Aurora B/FLT3 inhibitors for the treatment of acute myeloid leukemia
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A series of 6-acylureido derivatives containing a 3-(pyrrol-2- ylmethylidene)indolin-2-one scaffold were synthesized as potential dual Aurora B/FLT3 inhibitors by replacing the 6-arylureido moiety in 6-arylureidoindolin-2- one-based multi-kinase inhibitors. (Z)-N-(2-(pyrrolidin-1-yl)ethyl)-5-((6-(3-(2- fluoro-4-methoxybenzoyl)ureido)-2-oxoindolin-3-ylidene)methyl)-2, 4-dimethyl-1H-pyrrole-3-carboxamide (54) was identified as a dual Aurora B/FLT3 inhibitor (IC50 = 0.4 nM and 0.5 nM, respectively). Compound 54 also exhibited potent cytotoxicity with single-digit nanomolar IC50 values against the FLT3 mutant-associated human acute myeloid leukemia (AML) cell lines MV4-11 (FLT3-ITD) and MOLM-13 (FLT3-ITD). Compound 54 also specifically induced extrinsic apoptosis by inhibiting the phosphorylation of the Aurora B and FLT3 pathways in MOLM-13 cells. Compound 54 had a moderate pharmacokinetic profile. The mesylate salt of 54 efficiently inhibited tumor growth and reduced the mortality of BALB/c nude mice (subcutaneous xenograft model) that had been implanted with AML MOLM-13 cells. Compound 54 is more potent than sunitinib not only against FLT3-WT AML cells but also active against sunitinib-resistant FLT3-ITD AML cells. This study demonstrates the significance of dual Aurora B/FLT3 inhibitors for the development of potential agents to treat AML.
- Jagtap, Ajit Dhananjay,Chang, Pei-Teh,Liu, Jia-Rong,Wang, Hsiao-Chun,Kondekar, Nagendra B.,Shen, Li-Jiuan,Tseng, Hsiang-Wen,Chen, Grace Shiahuy,Chern, Ji-Wang
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supporting information
p. 268 - 288
(2014/08/18)
-
- Evaluation of benzoic acid derivatives as sirtuin inhibitors
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Employing a genetically modified yeast strain as a screening tool, 4-dimethylaminobenzoic acid (5) was isolated from the marine sediment-derived Streptomyces sp. CP27-53 as a weak yeast sirtuin (Sir2p) inhibitor. Using this compound as a scaffold, a series of disubstituted benzene derivatives were evaluated to elucidate the structure activity relationships for Sir2p inhibition. The results suggested that 4-alkyl or 4-alkylaminobenzoic acid is the key structure motif for Sir2p inhibitory activity. The most potent Sir2p inhibitor, 4-tert-butylbenzoic acid (20), among the tested compounds in this study turned out to be a weak but selective SIRT1 inhibitor. The calculated binding free energies between the selected compounds and the catalytic domain of SIRT1 were well correlated to their measured SIRT1 inhibitory activities.
- Chen, Yi-Pei,Catbagan, Chad C.,Bowler, Jeannette T.,Gokey, Trevor,Goodwin, Natalie D.M.,Guliaev, Anton B.,Wu, Weiming,Amagata, Taro
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supporting information
p. 349 - 352
(2014/01/17)
-
- Evaluation of benzoic acid derivatives as sirtuin inhibitors
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Employing a genetically modified yeast strain as a screening tool, 4-dimethylaminobenzoic acid (5) was isolated from the marine sediment-derived Streptomyces sp. CP27-53 as a weak yeast sirtuin (Sir2p) inhibitor. Using this compound as a scaffold, a series of disubstituted benzene derivatives were evaluated to elucidate the structure activity relationships for Sir2p inhibition. The results suggested that 4-alkyl or 4-alkylaminobenzoic acid is the key structure motif for Sir2p inhibitory activity. The most potent Sir2p inhibitor, 4-tert-butylbenzoic acid (20), among the tested compounds in this study turned out to be a weak but selective SIRT1 inhibitor. The calculated binding free energies between the selected compounds and the catalytic domain of SIRT1 were well correlated to their measured SIRT1 inhibitory activities.
- Chen, Yi-Pei,Catbagan, Chad C.,Bowler, Jeannette T.,Gokey, Trevor,Goodwin, Natalie D.M.,Guliaev, Anton B.,Wu, Weiming,Amagata, Taro
-
supporting information
p. 349 - 352
(2015/05/12)
-
- Organic synthesis via magnetic attraction: Benign and sustainable protocols using magnetic nanoferrites
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Magnetic nano-catalysts have been prepared using simple modification of iron ferrites. The nm size range of these particles facilitates the catalysis process, as an increased surface area is available for the reaction; the easy separation of the catalysts by an external magnet and their recovery and reuse are additional beneficial attributes. Glutathione bearing nano-ferrites have been used as organocatalysts for the Paal-Knorr reaction and homocoupling of boronic acids. Nanoferrites, post-synthetically modified by ligands, were used to immobilize nanometals (Cu, Pd, Ru, etc.) which enabled the development of efficient, sustainable and green procedures for azide-alkynes-cycloaddition (AAC) reactions, C-S coupling, O-allylation of phenol, Heck-type reactions and hydration of nitriles.
- Nasir Baig,Varma, Rajender S.
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p. 398 - 417
(2013/03/14)
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- INDOLIN-2-ONE DERIVATIVES AS PROTEIN KINASE INHIBITORS
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A novel class of indoline-2-one derivatives are disclosed. These compounds are protein kinase inhibitors which are useful for treating hyperproliferative diseases such as cancer.
- -
-
Paragraph 0160; 0161
(2013/11/05)
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- Sequential one-pot synthesis of benzoxazoles from aryl bromides: Successive palladium- and copper-catalyzed reactions
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A convenient one-pot process has been developed for the synthesis of benzoxazoles. Starting from aryl bromides and 1,2-dibromobenzenes palladium-catalyzed aminocarbonylation and subsequent copper-catalyzed coupling reaction gave a variety of substituted benzoxazoles in moderate to good yields.
- Wu, Xiao-Feng,Neumann, Helfried,Neumann, Stephan,Beller, Matthias
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supporting information
p. 3040 - 3042
(2013/06/27)
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- I2-TEMPO as an efficient oxidizing agent for the one-pot conversion of alcohol to amide using FeCl3 as the catalyst
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A high yield one-pot method for the synthesis of amides from alcohols is described. The aldehyde was generated in situ using iodine-TEMPO as oxidizing agent followed by intermediate oxime formation through reaction with NH 2OH?HCl and finally rearrangement of oxime catalyzed by FeCl3.
- Das, Rima,Chakraborty, Debashis
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experimental part
p. 48 - 53
(2012/08/28)
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- The hydration of nitriles catalyzed by simple transition metal salt of the fourth period with the aid of acetaldoxime
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We describe here a method for selective hydration of nitriles into the corresponding amides by employing commercially available acetaldoxime and simple transition metal catalysts such as nickel salts, zinc salts, cobalt salts and manganese salts in water. Nickel salts show the highest catalytic activity, owing to their relatively small diameter of the metal cation. Nitriles having electron-withdrawing groups could be converted into the corresponding amides in excellent yields using nickel catalyst at room temperature. Heterocyclic nitriles with heteroatom lone pair positioned ortho to the nitrile group show high reactivity; even these special nitriles could be hydrated by transition metal catalyst and water at refluxing temperature in the absence of acetaldoxime. Copyright
- Ma, Xiaoyun,He, Ying,Wang, Pengcheng,Lu, Ming
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experimental part
p. 377 - 382
(2012/08/08)
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- A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides
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One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involves the in situ generation of magnetic silica (Fe 3O4@SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this catalyst which proceeds exclusively in aqueous medium under neutral conditions. The Royal Society of Chemistry 2012.
- Baig, R. B. Nasir,Varma, Rajender S.
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supporting information; experimental part
p. 6220 - 6222
(2012/07/03)
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- An efficient hydration of nitriles to amides in aqueous media by hydrotalcite-clay supported nickel nanoparticles
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Hydrotalcite-clay supported nickel nanoparticles catalyze hydration of nitriles to amides in aqueous media. This Ni NPs/HT system is efficient for the synthesis of a diverse range of amides and affords the expected products with good yields in aqueous media. The synthesized nickel nanoparticles are characterized by UV-DRS, powder XRD, SEM and HRTEM. The catalyst is reused at least three times and a plausible mechanism is proposed. This fast, simple, effective and environmentally benign heterogeneous protocol provides a safer alternative to hazardous, corrosive and more polluting conventional catalysts.
- Subramanian, Thirumeni,Pitchumani, Kasi
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p. 109 - 113
(2013/01/15)
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- MnO2/graphene oxide: A highly active catalyst for amide synthesis from alcohols and ammonia in aqueous media
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Rod-like MnO2 uniformly attached on both side of GO sheets (MnO2/GO) is an efficient heterogeneous catalyst for the synthesis of primary amides from primary alcohols and ammonia as well as from aldehydes or nitriles. Water is the best solvent for these reactions, analytically pure crystals of product could be isolated by simply cooling in ice and this catalyst has excellent recyclability.
- Nie, Renfeng,Shi, Juanjuan,Xia, Shuixin,Shen, Lian,Chen, Ping,Hou, Zhaoyin,Xiao, Feng-Shou
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supporting information; experimental part
p. 18115 - 18118
(2012/09/22)
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- FeIII-catalyzed synthesis of primary amides from aldehydes
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A direct synthetic route for the transformation of aldehydes into primary amides in the presence of catalytic amounts of FeCl3 in water is described. A direct synthetic route for the transformation of aldehydes into primary amides in the presence of catalytic amounts of FeCl3 in water is described. Copyright
- Gowda, Ravikumar R.,Chakraborty, Debashis
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supporting information; experimental part
p. 2226 - 2229
(2011/06/17)
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- Highly efficient one-pot synthesis of primary amides catalyzed by scandium(III) triflate under controlled MW
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The present Letter highlights a versatile synthetic protocol for the one-pot synthesis of primary amides employing scandium(III) triflate as a catalyst in water under controlled MW. This methodology offers excellent yields in shorter reaction times with enhanced selectivity.
- Allam, Bharat Kumar,Singh, Krishna Nand
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experimental part
p. 5851 - 5854
(2011/12/03)
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- Synthesis and evaluation of some novel dibenzo[b,d]furan carboxylic acids as potential anti-diabetic agents
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A series of novel dibenzo[b,d]furan mono-carboxylic acid derivatives were synthesized, characterized and evaluated for their ability to inhibit Protein Tyrosine Phosphatase 1B (PTP1B) in vitro in order to use them as potential anti-diabetic agents. Structure-activity relationship study led to the identification of potent compound 5E which inhibited PTP1B with IC50 value of 82 ± 0.43 nM. Compound 5E was screened in vivo as drug candidate for anti-diabetic activity using rosiglitazone maleate as the standard. Compound 5E showed significant reduction in body weight, fed-state whole blood glucose (WBG), fasting WBG, plasma glucose and plasma cholesterol levels and non-significant reduction in fasting plasma triglyceride levels in ob/ob mice. A series of dibenzo[b,d]furan carboxylic acids were synthesized and evaluated for anti-diabetic activity. Compound 5E inhibited PTP1B with IC50 of 82 nM and reduced WBG and plasma glucose in ob/ob mice.
- Lakshminarayana,Prasad, Y. Rajendra,Gharat, Laxmikant,Thomas, Abraham,Narayanan, Shridhar,Raghuram,Srinivasan,Gopalan, Balasubramanian
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experimental part
p. 3709 - 3718
(2010/11/04)
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- Nanoparticle-supported and magnetically recoverable ruthenium hydroxide catalyst: Efficient hydration of nitriles to amides in aqueous medium
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A simple and efficient synthesis of nanoferrite-supported, magnetically recyclable ruthenium hydroxide [Ru(OH)x] catalyst and its applications in the hydration of nitriles in a benign aqueous medium, was reported. The catalyst was prepared by sonicating nanoferrites with dopamine in water for 2 hr followed by addition of ruthenium (Ru) chloride at a basic pH. The reaction temperature increased to 130°C results in the reaction proceeded with 65% conversion within 20 min. Various benzonitriles derivatives and aliphatic nitriles are smoothly hydrated to corresponding amides in excellent yield. The nanoferrite-supported ruthenium hydroxide catalyst could be used at least 3 times without any change in the activity. The Ru concentration of the catalyst is found to be 3.22% before the reaction and 3.16% after the reaction.
- Polshettiwar, Vivek,Varma, Rajender S.
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supporting information; experimental part
p. 1582 - 1586
(2009/09/05)
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- Hydrosilanes are not always reducing agents for carbonyl compounds but can also induce dehydration: A ruthenium-catalyzed conversion of primary amides to nitriles
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A practical procedure for production of nitriles is offered by the triruthenium carbonyl cluster catalyzed dehydration of primary carboxamides with hydrosilanes under neutral conditions. This is the first example that a transition-metal-catalyzed activation of Si-H bonds does not lead to the reduction of carbonyl compounds but to dehydration. Possible mechanisms for the dehydration is discussed on the basis of NMR spectroscopic detection of intermediary species. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Hanada, Shiori,Motoyama, Yukihiro,Nagashima, Hideo
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supporting information; experimental part
p. 4097 - 4100
(2009/04/10)
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- Cannizzaro-type disproportionation of aromatic aldehydes to amides and alcohols by using either a stoichiometric amount or a catalytic amount of lanthanide compounds
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Aromatic aldehydes can be directly converted to the corresponding amides and alcohols in good to excellent yields by the treatment of aromatic aldehydes with lithium amide LiN(SiMe3)2 in the presence of catalytic lanthanide chlorides LnCIs or by the treatment of aromatic aldehydes with a stoichiometric amount of lanthanide amides [(Me3Si)2N]3Ln(μ-Cl) Li(THF)3 at ambient temperature. The effects of solvents, substitutents on the phenyl ring, and lanthanide metals on the reaction have been examined. The mechanism of the disproportionation reaction was proposed based on the experimental results.
- Zhang, Lijun,Wang, Shaowu,Zhou, Shuangliu,Yang, Gaosheng,Sheng, Enhong
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p. 3149 - 3153
(2007/10/03)
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- Mono-N-methylation of functionalized anilines with alkyl methyl carbonates over NaY faujasites. 4. Kinetics and selectivity
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(Chemical Equation Presented) In the presence of NaY faujasite as the catalyst, the reaction of bifunctional anilines (1-4: XC6H 4-NH2; X = OH, CO2H, CH2OH, and CONH2) with methyl alkyl carbonates [MeOCO2R′: R′ = Me or MeO(CH2)2O(CH2)2] proceeds with a very high mono-N-methyl selectivity (XC6H 4NHMe up to 99%), and chemoselectivity as well, with other nucleophilic functions (OH, CO2H, CH2OH, CONH2) fully preserved from alkylation and/or transesterification reactions. Aromatic substituents, however, modify the relative reactivity of amines 1-4: good evidence suggests that, not only steric and electronic effects, but, importantly, direct acid-base interactions between substituents and the catalyst are involved. Weakly acidic groups (OH, CH2OH, CONH2, pKa ≥ 10) may help the reaction, while aminobenzoic acids (pK a of 4-5) are the least reactive substrates. The solvent polarity also affects the reaction, which is faster in xylene than in the more polar diglyme. The mono-N-methyl selectivity is explained by the adsorption pattern of reagents within the zeolite pores: a BAl2 displacement of the amine on methyl alkyl carbonate should occur aided by the geometric features of the NaY supercavities. Different factors account for the reaction chemoselectivity. Evidence proves that the polarizability of the two nucleophilic terms (NH 2 and X groups) of anilines is relevant, although adsorption and confinement phenomena of reagents promoted by the zeolite should also be considered.
- Selva, Maurizio,Tundo, Pietro,Foccardi, Tommaso
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p. 2476 - 2485
(2007/10/03)
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- Reaction of functionalized anilines with dimethyl carbonate over NaY faujasite. 3. Chemoselectivity toward mono-N-methylation
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In the presence of NaY faujasite, dimethyl carbonate (MeOCO2Me, DMC) is a highly chemoselective methylating agent of functionalized anilines such as aminophenols (1), aminobenzyl alcohols (2), aminobenzoic acids (3), and aminobenzamides (4). The reaction proceeds with the exclusive formation of N-methylanilines without any concurrent O-methylation or N-/O-methoxy carbonylation side processes. Particularly, only mono-N-methyl derivatives [XC6H4NHMe, X = o-, m-, and p-OH; o- and p-CH 2OH; o- and P-CO2H; o- and p-CONH2] are obtained with selectivity up to 99% and isolated yields of 74-99%. DMC, which usually promotes methylations only at T > 120 °C, is activated by the zeolite catalyst and it reacts with compounds 1, 2, and 4, at 90 °C. Aminobenzoic acids (3) require a higher reaction temperature (≥130 °C).
- Selva, Maurizio,Tundo, Pietro,Perosa, Alvise
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p. 7374 - 7378
(2007/10/03)
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- On the Nature of Resonance Interactions in Substituted Benzenes. Part 3. A 13C Nuclear Magnetic Resonance Study of Substituent Effects in 4-Substituted Benzamides and Methyl Benzoates in Dimethyl sulphoxide
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The substituent effect on the carbonyl-carbon chemical shift in 4-X-benzamides 2 and in 2,6-dimethyl-4-X-benzamides 2' has been studied in (CD3)2SO.Comparison of the results with those obtained from the corresponding methyl 4-X-benzoates 1 and 1'in the sa
- Dell'Erba, Carlo,Mele, Andrea,Novi, Marino,Petrillo, Giovanni,Sancassan, Fernando,Spinelli, Domenico
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p. 2055 - 2058
(2007/10/02)
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