- Late-Stage Solubilization of Poorly Soluble Peptides Using Hydrazide Chemistry
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A novel late-stage solubilization of peptides using hydrazides is described. A solubilizing tag was attached through a selective N-alkylation at a hydrazide moiety with the aid of a 2-picoline-borane complex in 50% acetic acid-hexafluoro-2-propanol. The tag, which tolerates ligation and desulfurization conditions, can be detached by a Cu-mediated selective oxidative hydrolysis of the N-alkyl hydrazide. This new method was validated through the synthesis of HIV-1 protease.
- Sato, Kohei,Tanaka, Shoko,Wang, Junzhen,Ishikawa, Kenya,Tsuda, Shugo,Narumi, Tetsuo,Yoshiya, Taku,Mase, Nobuyuki
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supporting information
p. 1653 - 1658
(2021/03/03)
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- Ru(ii)- And Ru(iv)-dmso complexes catalyze efficient and selective aqueous-phase nitrile hydration reactions under mild conditions
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New water-soluble ruthenium(ii)- and ruthenium(iv)-dmso complexes [RuCl2(dmso)2(NH3)(CH3CN)] (1), [RuCl2(dmso)3(CH3CN)] (2), and [RuCl2(dmso)3(NH3)]·PF6·Cl (3) have been synthesized and characterized using elemental analyses, IR, 1H and 31P NMR, and electronic absorption spectroscopy. The molecular structures of complexes 1-3 were determined crystallographically. The reactivity of complexes 1-3 has been tested for aqueous-phase nitrile hydration at 60 °C in air, and good efficiency and selectivity are shown for the corresponding amide derivatives. Best performance is achieved with complex 3. Amide conversions of 56-99% were obtained with a variety of aromatic, alkyl, and vinyl nitriles. The reaction tolerated hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Amides were isolated by simple decantation from the aqueous-phase catalyst. A catalyst loading down to 0.0001 mol% was examined and turnover numbers as high as 990?000 were observed. The catalyst was stable for weeks in solution and could be reused more than seven times without significant loss in catalytic activity. The gram-scale reaction was also performed to produce the desired product in high yields. This journal is
- Dubey, Santosh Kumar,Kaur, Gurmeet,Rath, Nigam P.,Trivedi, Manoj
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p. 17339 - 17346
(2021/10/08)
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- Arene-ruthenium(II)-phosphine complexes: Green catalysts for hydration of nitriles under mild conditions
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Three new arene-ruthenium(II) complexes were prepared by treating [{RuCl(μ-Cl)(η6-arene)}2] (η6-arene = p-cymene) dimer with tri(2-furyl)phosphine (PFu3) and 1,3,5-triaza-7-phosphaadamantane (PTA), respectively to obtain [RuCl2(η6-arene)PFu3] [Ru]-1, [RuCl(η6-arene)(PFu3)(PTA)]BF4 [Ru]-2 and [RuCl(η6-arene)(PFu3)2]BF4 [Ru]-3. All the complexes were structurally identified using analytical and spectroscopic methods including single-crystal X-ray studies. The effectiveness of resulting complexes as potential homogeneous catalysts for selective hydration of different nitriles into corresponding amides in aqueous medium and air atmosphere was explored. There was a remarkable difference in catalytic activity of the catalysts depending on the nature and number of phosphorus-donor ligands and sites available for catalysis. Experimental studies performed using structural analogues of efficient catalyst concluded a structural-activity relationship for the higher catalytic activity of [Ru]-1, being able to convert huge variety of aromatic, heteroaromatic and aliphatic nitriles. The use of eco-friendly water as a solvent, open atmosphere and avoidance of any organic solvent during the catalytic reactions prove the reported process to be truly green and sustainable.
- Vyas, Komal M.,Mandal, Poulami,Singh, Rinky,Mobin, Shaikh M.,Mukhopadhyay, Suman
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- Half-Sandwich Iridium Complexes for the One-Pot Synthesis of Amides: Preparation, Structure, and Diverse Catalytic Activity
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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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- Trash to treasure: Eco-friendly and practical synthesis of amides by nitriles hydrolysis in WepPA
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The hydration of nitriles to amides in a water extract of pomelo peel ash (WEPPA) was realized with moderate to excellent yields without using external transition metals, bases or organic solvents. This reaction features a broad substrate scope, wide functional group tolerance, prominent chemoselectivity, and good reusability. Notably, a magnification experiment in this bio-based solvent at 100 mmol further demonstrated its practicability.
- Sun, Yajun,Jin, Weiwei,Liu, Chenjiang
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supporting information
(2019/11/11)
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- Water-soluble superbulky (η6- p -cymene) ruthenium(ii) amine: An active catalyst in the oxidative homocoupling of arylboronic acids and the hydration of organonitriles
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A phosphine free water-soluble superbulky amine-ruthenium-arene complex (2) encompassing 2,6-bis(diphenylmethyl)-4-methylaniline was synthesised in good yield. 2 was characterized by FT-IR, 1H NMR, and 13C NMR spectroscopies, TGA and elemental analyses. The structure of 2 was confirmed by a single-crystal X-ray diffraction study. The ruthenium centre in 2 adopts the pseudo-octahedral geometry due to the η6-p-cymene ring and bulky aniline ligand along with two chloro groups. Besides, complex 2 was efficaciously employed as a catalyst in the hydration of organonitriles to amides. This reaction proceeds efficiently for a wide range of substrates in an environmentally benign medium and is an economically reasonable synthetic route to amides in good yields. In addition, 2 acts as an excellent catalyst in the oxidative homocoupling of arylboronic acids in water. A range of arylboronic acids undergo a homocoupling reaction in the presence of catalyst 2 to yield symmetrical biaryls in reasonable to good yields.
- Nirmala, Muthukumaran,Adinarayana, Mannem,Ramesh, Karupnaswamy,Maruthupandi, Mannarsamy,Vaddamanu, Moulali,Raju, Gembali,Prabusankar, Ganesan
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supporting information
p. 15221 - 15230
(2018/09/29)
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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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- Visible light photocatalysis with CBr4: A highly selective aerobic photooxidation of methylarenes to aldehydes
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A metal-free, operationally simple and efficient means of aerobic photooxidation of methylarenes to aromatic aldehydes at room temperature employing visible light photocatalysis with CBr4 is reported. The reaction is highly selective as it proceeds without any over oxidation to carboxylic acids. The utilisation of visible light and molecular oxygen is inexpensive, readily available, non-toxic and the sustainable reagents make the protocol compatible with green chemistry demands. A plausible mechanism for the formation of aldehydes from methylarenes is also provided.
- Tripathi, Shubhangi,Singh, Sachchida N.,Yadav, Lal Dhar S.
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p. 14547 - 14551
(2016/02/19)
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- Supported Gold Nanoparticles-Catalyzed Microwave-Assisted Hydration of Nitriles to Amides under Base-Free Conditions
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Polystyrene-supported gold (Au@PS) nanoparticles were synthesized by the reduction deposition approach and well characterized by UV-visible, XRD, TEM, SAED, EDX, and XPS studies. The Au@PS was applied as catalyst for the hydration of nitriles to amides in water under microwave irradiation. Several functionalized aromatic, heterocyclic and aliphatic nitriles were found to be active for synthesis of the corresponding amides where no activation of water by base, ligand and support is needed. Easy recovery, negligible leaching and recyclability for up to eight runs are added advantages of the catalyst under water-mediated reaction conditions. (Figure presented.).
- Kumar, Sandeep,Sharma, Saurabh,Das, Pralay
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supporting information
p. 2889 - 2894
(2016/09/16)
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- Chlorophosphines as auxiliary ligands in ruthenium-catalyzed nitrile hydration reactions: Application to the preparation of β-ketoamides
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The catalytic hydration of nitriles into amides, in water under neutral conditions, has been studied using a series of arene-ruthenium(ii) complexes containing commercially available chlorophosphines as auxiliary ligands, i.e. compounds [RuCl2(η6-p-cymene)(PR2Cl)] (R = aryl, heteroaryl or alkyl group). In the reaction medium, the coordinated chlorophosphines readily undergo hydrolysis to generate the corresponding phosphinous acids PR2OH, which are well-known "cooperative" ligands for this catalytic transformation. Among the complexes employed, best results were obtained with [RuCl2(η6-p-cymene){P(4-C6H4F)2Cl}]. Performing the catalytic reactions at 40 °C with 2 mol% of this complex, a large variety of organonitriles could be selectively converted into the corresponding primary amides in high yields and relatively short times. The application of [RuCl2(η6-p-cymene){P(4-C6H4F)2Cl}] in the preparation of synthetically useful β-ketoamides is also presented.
- González-Fernández, Rebeca,González-Liste, Pedro J.,Borge, Javier,Crochet, Pascale,Cadierno, Victorio
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p. 4398 - 4409
(2016/07/06)
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- Ruthenium(II) complexes incorporating salicylaldiminato-functionalized N-heterocyclic carbene ligands as efficient and versatile catalysts for hydration of organonitriles
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We describe a new synthetic procedure for synthesis of ruthenium(II) complexes containing salicylaldiminato functionalized mixed N-heterocyclic carbene (NHC) ligand and phosphine co-ligand. The complexes (3a-3d) have been obtained in good to excellent yields by transmetalation from the corresponding Ag-NHC complexes (2a-2d) as carbene transfer reagents. All the [Ru-NHC] complexes have been characterized by elemental analyses, spectroscopic methods as well as ESI mass spectrometry. The ligands 1a-1d show their versatility by switching to be O,N,C-chelating in these ruthenium(II) complexes. The resulting complexes have been evaluated as potential catalysts for the selective hydration of nitriles to primary amides, and related amide bond forming reactions, in environmentally friendly medium. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl and alkyl functional groups. The catalyst was stable for weeks and could be recovered and reused more than six times without significant loss of activity.
- Nirmala, Muthukumaran,Saranya, Gandhi,Viswanathamurthi, Periasamy
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p. 134 - 144
(2016/01/09)
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- Synthesis of primary amides by aminocarbonylation of aryl/hetero halides using non-gaseous NH3 and CO sources
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Abstract A practically simple method for the synthesis of primary amides via the palladium-catalysed aminocarbonylation of aromatic halides by using solid sources of gaseous ammonia and carbon monoxide is described. The system tolerated a wide variety of hindered and functionalized aryl/hetero halides and afforded good to excellent yields (69-94%) of the amide. Pharmacologically active Exalamide and Pyrazinecarboxamide were synthesised in high yields to demonstrate the effectiveness of this method.
- Suresh,Baburajan, Poongavanam,Ahmed, Mansur
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supporting information
p. 4864 - 4867
(2015/07/28)
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- Synthesis of a copper(ii) complex covalently anchoring a (2-iminomethyl)phenol moiety supported on HAp-encapsulated-α-Fe2O3 as an inorganic-organic hybrid magnetic nanocatalyst for the synthesis of primary and secondary amides
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A novel hydroxyapatite-encapsulated-α-Fe2O3-based Cu(ii) organic-inorganic hybrid (interphase) catalyst was prepared. The prepared nanocatalyst provided an efficient, useful and green method for the oxidative amidation of aromatic aldehydes with ammonium hydrochloride and aniline hydrochloride, in short reaction times and good yields. The magnetic nature of the catalyst led to its easy recovery by an external magnetic field and convenient reuse.
- Mamaghani,Shirini,Sheykhan,Mohsenimehr
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p. 44524 - 44529
(2015/06/02)
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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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- Hydration of nitriles to amides by a chitin-supported ruthenium catalyst
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Chitin-supported ruthenium (Ru/chitin) promotes the hydration of nitriles to carboxamides under aqueous conditions. The nitrile hydration can be performed on a gram-scale and is compatible with the presence of various functional groups including olefins, aldehydes, carboxylic esters and nitro and benzyloxycarbonyl groups. The Ru/chitin catalyst is easily prepared from commercially available chitin, ruthenium(III) chloride and sodium borohydride. Analysis of Ru/chitin by high-resolution transmission electron microscopy indicates the presence of ruthenium nanoparticles on the chitin support.
- Matsuoka, Aki,Isogawa, Takahiro,Morioka, Yuna,Knappett, Benjamin R.,Wheatley, Andrew E. H.,Saito, Susumu,Naka, Hiroshi
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p. 12152 - 12160
(2015/02/19)
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- Design, synthesis, and structure-activity relationship of a novel series of GluN2C-selective potentiators
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NMDA receptors are tetrameric complexes composed of GluN1 and GluN2A-D subunits that mediate a slow Ca2+-permeable component of excitatory synaptic transmission. NMDA receptors have been implicated in a wide range of neurological diseases and thus represent an important therapeutic target. We herein describe a novel series of pyrrolidinones that selectively potentiate only NMDA receptors that contain the GluN2C subunit. The most active analogues tested were over 100-fold selective for recombinant GluN2C-containing receptors over GluN2A/B/D-containing NMDA receptors as well as AMPA and kainate receptors. This series represents the first class of allosteric potentiators that are selective for diheteromeric GluN2C-containing NMDA receptors.
- Zimmerman, Sommer S.,Khatri, Alpa,Garnier-Amblard, Ethel C.,Mullasseril, Praseeda,Kurtkaya, Natalie L.,Gyoneva, Stefka,Hansen, Kasper B.,Traynelis, Stephen F.,Liotta, Dennis C.
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supporting information
p. 2334 - 2356
(2014/04/17)
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- One-pot transformation of methylarenes into aromatic aldehydes under metal-free conditions
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On the basis of studies of the transformation of benzylic bromides into the corresponding aromatic aldehydes by treatment with N-methylmorpholine N-oxide, various methylarenes were treated either with DBDMH in the presence of AIBN in acetonitrile at reflux (Method A) or with NBS in CCl4 under irradiation with a tungsten lamp at 30 °C (Method B), followed by treatment with N-methylmorpholine N-oxide to provide aromatic aldehydes in good yields. These methods could be adopted in one-pot transformations of methylarenes into aromatic aldehydes under conditions free of less toxic reagents and transition metals. Copyright
- Tabata, Masayuki,Moriyama, Katsuhiko,Togo, Hideo
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p. 3402 - 3410
(2014/06/09)
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- Mild and selective heterogeneous catalytic hydration of nitriles to amides by flowing through manganese dioxide
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A sustainable flow chemistry process for the hydration of nitriles, whereby an aqueous solution of the nitrile is passed through a column containing commercially available amorphous manganese dioxide, has been developed. The product is obtained simply by concentration of the output stream without any other workup steps. The protocol described is rapid, robust, reliable, and scalable, and it has been applied to a broad range of substrates, showing a high level of chemical tolerance.
- Battilocchio, Claudio,Hawkins, Joel M.,Ley, Steven V.
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supporting information
p. 1060 - 1063
(2016/10/17)
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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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- Thiazolyl-phosphine hydrochloride salts: Effective auxiliary ligands for ruthenium-catalyzed nitrile hydration reactions and related amide bond forming processes in water
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A series of water-soluble N-protonated thiazolyl-phosphine hydrochloride salts have been synthesized and coordinated to the ruthenium(ii) fragment [RuCl2(η6-p-cymene)]. The resulting complexes were evaluated as potential catalysts for the selective hydration of nitriles to primary amides in environmentally friendly aqueous medium. The best results in terms of activity were achieved when tris(5-(2-aminothiazolyl))phosphine trihydrochloride was used as ligand. Using the Ru(ii) complex 9 derived from this salt (3 mol%), the catalytic reactions proceeded cleanly in pure water at 100 °C without the assistance of any additive, affording the desired amides in high yields (>78%) after short reaction periods (0.5-7 h). The process was operative with both aromatic, heteroaromatic, α,β-unsaturated and aliphatic nitriles, and tolerated several functional groups. The utility of 9 in promoting the formation of primary amides in water by catalytic rearrangement of aldoximes and direct coupling of aldehydes with NH2OH·HCl has also been demonstrated.
- Garcia-Alvarez, Rocio,Zablocka, Maria,Crochet, Pascale,Duhayon, Carine,Majoral, Jean-Pierre,Cadierno, Victorio
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p. 2447 - 2456
(2013/09/12)
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- NITRILE HYDRATION CATALYZED BY RECYCLABLE RUTHENIUM COMPLEXES
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A method for hydrating a nitrile derivative to generate an amide derivative is provided. The method includes mixing the nitrile derivative with a ruthenium catalyst complex in an aqueous solution to form a mixture, and reacting the nitrile derivative with water in the aqueous solution and in the presence of the ruthenium catalyst complex to form a reacted mixture comprising the amide derivative. The ruthenium catalyst complex is represented by the following structural formula: RuX2(L)n, wherein X is an anionic ligand, L is a bifunctional phosphine ligand, and n is 3 or 4.
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Paragraph 0030; 0031; 0032; 0033; 0034
(2013/04/24)
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- Hemilabile β-aminophosphine ligands derived from 1,3,5-triaza-7- phosphaadamantane: Application in aqueous ruthenium catalyzed nitrile hydration
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A series of β-aminophosphines derived from 1,3,5-triaza-7- phosphaadamantane (PTA) are described. PTA-CHPhNHPh (1), PTA-CH(p-C 6H4OCH3)NHPh (2), and PTA-CPh2NHPh (3) were prepared in good yield (62-77%) by reaction of lithiated PTA with the corresponding imine followed by hydrolysis. Compounds 1 and 2 were synthesized as pairs of diastereomers which were separated by successive recrystallization from THF/hexane. Compounds 1-3 are somewhat soluble in water (S 25o = 4.8 (1), 4.9 (2), 2.7 (3) g/L). Upon coordination to Ru(II) arene centers both monodentate (κ1-P) [RuCl 2(η6-toluene)(1-3)] and bidentate (κ 2-P,N) [RuCl(η6-toluene)(1-3)]Cl coordination modes were observed. Ru(II) arene complexes 4-6 exhibited hemilabile behavior transitioning between κ1-P and κ2-P,N coordination upon change in solvent or addition of a coordinating ligand such as Cl- or CH3CN. Complexes (4-6) were found to be active air stable catalysts for the aqueous phase hydration of various nitriles with TOF up to 285 h-1 and TON of up to 97 000 observed.
- Lee, Wei-Chih,Sears, Jeremiah M.,Enow, Raphel A.,Eads, Kelly,Krogstad, Donald A.,Frost, Brian J.
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p. 1737 - 1746
(2013/03/29)
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- Combined catalytic system of scandium triflate and boronic ester for amide bond cleavage
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We have found that the combination of scandium with boronic ester enables the cleavage of amide bonds. Primary amides were converted to the corresponding esters in the presence of catalytic amounts of scandium triflate and boronic ester under mild and neutral conditions. This unique catalytic system can be applied to the deprotection of acetylaniline derivatives. In addition, control NMR experiments were carried out to examine the effect of the boronic esters. Copyright
- Kita, Yusuke,Nishii, Yuji,Onoue, Akihiro,Mashima, Kazushi
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supporting information
p. 3391 - 3395
(2013/12/04)
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- A general palladium-catalyzed aminocarbonylation of phenols to primary benzamides via in situ generation of aryl nonaflates
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Amides in mind! A novel palladium-catalyzed amino-carbonylation of in situ formed aryl nonaflates to give primary amides in moderate to excellent yields has been developed (see scheme). Copyright
- Wu, Xiao-Feng,Neumann, Helfried,Beller, Matthias
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experimental part
p. 419 - 422
(2012/02/04)
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- CYCLODEXTRIN-MODIFIED POLYAMINES FOR DELIVERY OF THERAPEUTIC MOLECULES
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The present invention is directed to drug delivery vehicles comprising one or more cyclodextrin moieties conjugated to a dendritic polyamine for the delivery of small molecule and protein therapeutic molecules and nucleic acid therapeutic molecules, and methods of making and using the delivery vehicles.
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- Aqueous and biphasic nitrile hydration catalyzed by a recyclable Ru(ii) complex under atmospheric conditions
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[RuCl2(PTA)4] (PTA = 1,3,5-triaza-7- phosphaadamantane) was found to be a highly active catalyst for aqueous phase nitrile hydration at 100 °C in air. Near quantitative conversion of aromatic, alkyl, and vinyl nitriles to their corresponding amides was observed. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Some amides were isolated by simple decantation from the aqueous phase catalyst. Catalyst loading down to 0.001 mol% was examined with turnover numbers as high as 22000 observed. The catalyst was stable for weeks in solution and could be reused more than five times without significant loss of activity.
- Lee, Wei-Chih,Frost, Brian J.
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supporting information; experimental part
p. 62 - 66
(2012/03/26)
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- A general and efficient heterogeneous gold-catalyzed hydration of nitriles in neat water under mild atmospheric conditions
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Mild, efficient and general: Titania decorated with nanometer-sized gold particles acts as an efficient catalyst for the selective hydration of a wide range of chemically diverse nitriles into valuable amides in neutral water, under mild atmospheric conditions (see image). The process shows promise for a facile and direct one-pot synthesis of ?μ-caprolactam, an industrially important molecule, starting from 6-aminocapronitrile. Copyright
- Liu, Yong-Mei,He, Lin,Wang, Miao-Miao,Cao, Yong,He, He-Yong,Fan, Kang-Nian
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scheme or table
p. 1392 - 1396
(2012/10/07)
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- Palladium-catalyzed approach to primary amides using nongaseous precursors
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A simple protocol is reported for the preparation of primary aryl amides under Pd-catalyzed carbonylation chemistry applying a two-chamber system with crystalline and nontransition metal based sources of carbon monoxide and ammonia. The method is suitable for the synthesis of a number of primary amides with good functional group tolerance. Incorporation of 13CO into the primary amide group was also found to be effective making this approach useful for accessing carbon isotope labeled derivatives.
- Nielsen, Dennis U.,Taaning, Rolf H.,Lindhardt, Anders T.,Gogsig, Thomas M.,Skrydstrup, Troels
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supporting information; experimental part
p. 4454 - 4457
(2011/10/05)
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- Chemistry by nanocatalysis: First example of a solid-supported RAPTA complex for organic reactions in aqueous medium
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A ruthenium-arene-PTA (RAPTA) complex has been supported for the first time on an inorganic solid, that is, silica-coated ferrite nanoparticles. The resulting magnetic material proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentration, environmentally friendly water as a reaction medium, with no use at all of organic solvent during or after the reactions, and microwaves as an alternative energy source renders the synthetic processes reported herein "truly" green and sustainable. RAPTA's delight: A nano-RAPTA complex supported on silica-coated ferrite nanoparticles proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentrations, water as a reaction medium, and microwaves as an energy source renders these processes green and sustainable.
- García-Garrido, Sergio E.,Francos, Javier,Cadierno, Victorio,Basset, Jean-Marie,Polshettiwar, Vivek
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experimental part
p. 104 - 111
(2012/01/06)
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- 2-Diphenylphosphanyl-4-pyridyl(dimethyl)amine as an effective ligand for the ruthenium(II) complex catalyzed homogeneous hydration of nitriles under neutral conditions
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New homogeneous catalyst comprised of [Ru(methallyl)2(cod)] (cod = 1,5-cyclooctadiene) (1) and 2-diphenylphosphanyl-4-pyridyl(dimethyl)amine (2) is shown to efficiently catalyze the hydration of various nitriles under neutral conditions. The hydration proceeds in the presence of 0.5 mol% of the ruthenium catalyst at 80 °C in 1,2-dimethoxyethane solution and the corresponding amide is obtained within few hours without the formation of byproducts. Comparison of some phosphine ligands for the hydration reveals that the dimethylamino moiety of 2 improves the catalytic performance dramatically.
- Muranaka, Makoto,Hyodo, Isao,Okumura, Wataru,Oshiki, Toshiyuki
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experimental part
p. 552 - 555
(2012/01/15)
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- RhI-catalyzed hydration of organonitriles under ambient conditions
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(Chemical Presented) New scoop on scope and selectivity: The hydration of organonitriles catalyzed by a RhI(OMe) species under nearly pH-neutral and ambient conditions (25°C, 1 atm) is chemoselective and high-yielding (93 to 99%), has a broad substrate scope, and may thus be complementary to enzymatic hydration methods for the introduction of a terminal amido group (CONH2) onto a carbon chain.
- Goto, Akihiro,Endo, Kohei,Saito, Susumu
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p. 3607 - 3609
(2008/12/23)
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- Selective ruthenium-catalyzed hydration of nitriles to amides in pure aqueous medium under neutral conditions
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A study was conducted to demonstrate that water-soluble ruthenium(II) complexes can be used as catalysts for the hydration of nitriles in pure aqueous media and under neutral conditions. The hydration of benzonitrile was investigated as a model reaction and the ruthenium precursor was added to a 0.33M aqueous solution of benzonitrile at 100°C, while the reaction was monitored by gas chromatography. All the complexes checked, were found to be active and selective catalysts in the hydration process, providing benzamide as a specific reaction product. The most relevant results were obtained by using ruthenium complexes, bearing a nitrogen-containing ligand, which led to appropriate production of benzamide. The most effective ruthenium complex was found to be an efficient catalyst for the selective hydration of a large number of other nitriles.
- Cadierno, Victorio,Francos, Javier,Gimeno, Jose
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scheme or table
p. 6601 - 6605
(2009/07/10)
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- ALPHA 7 NICOTINIC RECEPTOR SELECTIVE LIGANDS
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The invention relates to the design and synthesis of 3-arylidene-anabaseine compounds that exhibit enhanced selectivity toward alpha7 nicotinic receptors. The compounds are expected to be useful in treating a wide variety of conditions, including neurodegenerative conditions such as Alzheimer's Disease, neurodevelopmental diseases such as schizophrenia, and certain peripherally located inflammations mediated by macrophage infiltration.
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Page/Page column 76-77
(2008/06/13)
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- HYDROXAMIC ACIDS USEFUL IN THE TREATMENT OF HYPER-PROLIFERATIVE DISORDERS
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This invention relates to a compound of Formula (I) and its use in treating hyper-proliferative disorders.
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- Platinum-Catalyzed Selective Hydration of Hindered Nitriles and Nitriles with Acid- or Base-Sensitive Groups
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Hindered tertiary nitriles can be hydrolyzed under neutral and mild conditions to the corresponding amides using platinum(II) catalysts with dimethylphosphine oxide or other secondary phosphine oxides (SPOs, phosphinous acids) as ligands. We have found that this procedure also works well for nitriles with acid- or base-sensitive groups, which is unprecedented in terms of yield and selectivity. The catalyst loading can be as low as 0.5 mol %. Amides are isolated as the only product in high yield, and no further hydrolysis to the corresponding acids takes place. Reactions are carried out at 80 °C but take place even at room temperature. When enantiopure secondary phosphine oxide ligands are used in the hydrolysis of racemic nitriles, no kinetic resolution is observed, presumably due to racemization of the ligand during the reaction.
- Jiang, Xiao-Bin,Minnaard, Adriaan J.,Feringa, Ben L.,De Vries, Johannes G.
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p. 2327 - 2331
(2007/10/03)
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- Scale-up of the synthesis of a pyrimidine derivative directly on solid support
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The solid-phase synthesis of 4-(2-amino-6-phenylpyrimidin-4-yl)benzamide, a compound obtained through combinatorial chemistry and parallel synthesis, can be scaled up directly on solid support in excellent yields and high purity. By applying highly loaded aminomethyl polystyrene as solid support, a good ratio between the product and the starting resin is achieved. For comparison, the synthesis was also performed in solution. The solid-phase synthesis approach has the advantage that the desired compound is easily and quickly accessible in sufficient quantities for early development demands.
- Meisenbach, Mark,Allmendinger, Thomas,Mak, Ching-Pong
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p. 553 - 558
(2013/09/05)
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- Selective and efficient heterogeneous hydration of nitriles to amides using silica supported manganese dioxide
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A highly efficient and selective method for hydration of nitriles to amides without formation of any detectable amount of acid, under heterogeneous reaction condition using silica supported manganese dioxide is reported. The mechanism of the reaction has been discussed. The reagent preparation is easy and carried out under microwave exposure within 5 min. The silica supported MnO2 reagent has been characterized by DRIFT and XRD techniques. Quantitative yields are obtained for commercially important heterocyclic amides such as pyridinecarboxamide, nicotinamide and pyrazinamide.
- Khadilkar, Bhushan M.,Madyar, Virendra R.
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p. 2814 - 2819
(2007/10/03)
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- Totally selective dry microwave assisted amide synthesis by hydration of nitrile using silica supported MnO2 reagent
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An easy, facile and efficient method for nitrile hydrolysis is developed using the combination of a silica supported MnO2 reagent and microwave irradiation under dry reaction conditions.
- Khadilkar, Bhushan M.,Madyar, Virendra R.
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p. 1731 - 1734
(2007/10/03)
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- Microwave-promoted transformation of nitriles to amides with aqueous sodium perborate
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Microwave irradiation of several aromatic and aliphatic nitriles, including an α,β-bistrimethysilylnitrile, with sodium perborate tetrahydrate in a mixture of water/ethanol (2:1), smoothly produced corresponding amide in short times and with high yields. Other functional groups, such as aldehyde, are unaffected under these conditions.
- Sharifi,Mohsenzadeh,Mojtahedi,Saidi,Balalaie
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p. 431 - 434
(2007/10/03)
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- Selective hydrolysis of nitriles to amides using NaOH-PEG under microwave irradiation
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We describe here an efficient, rapid and selective method for the conversion of nitriles in to their corresponding amides in the presence of PEG-400, aqueous sodium hydroxide system under microwave irradiation.
- Bendale, Pravin M.,Khadilkar, Bhushan M.
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p. 1713 - 1718
(2007/10/03)
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- Benzopyridazinone and pyridopyridazinone compounds
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Benzo or pyridopyridazinones and pyridazinthiones of the formula STR1 wherein: X and Y are nitrogen or carbon, provided that at least one is carbon, and Z is oxygen or sulfur; R1 is hydrogen, lower alkyl, aryl, aralkyl, heterocyclo, heterocyclo lower-alkyl, heteroaryl, or heteroaralkyl; R2, R3, R4, R5 and R6 are independently selected from hydrogen, lower alkyl, halo, carboxy, alkoxycarbonyl, carbamoyl, lower-alkyl carbonyl, halocarbonyl, thiomethyl, trifluoromethyl, cyano or nitro; or a pharmaceutically acceptable ester, ether or salt thereof, have been found to be useful as an anti-inflammatory, antasthmatic, immunosuppressive, anti-allograft rejection, anti-graft-vs-host rejection, autoimmune disease or analgetic agent(s).
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