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A “universal” catalyst for aerobic oxidations to synthesize (hetero)aromatic aldehydes, ketones, esters, acids, nitriles, and amides
Functionalized (hetero)aromatic compounds are indispensable chemicals widely used in basic and applied sciences. Among these, especially aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides represent valuable fine and bulk chemicals, which are used in chemical, pharmaceutical, agrochemical, and material industries. For their synthesis, catalytic aerobic oxidation of alcohols constitutes a green, sustainable, and cost-effective process, which should ideally make use of active and selective 3D metals. Here, we report the preparation of graphitic layers encapsulated in Co-nanoparticles by pyrolysis of cobalt-piperazine-tartaric acid complex on carbon as a most general oxidation catalyst. This unique material allows for the synthesis of simple, functionalized, and structurally diverse (hetero)aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides from alcohols in excellent yields in the presence of air.
Bartling, Stephan,Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Rabeah, Jabor,Rockstroh, Nils,Senthamarai, Thirusangumurugan
supporting information
p. 508 - 531
(2022/02/11)

Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
Catalytic aerobic oxidation of primary amines to the amides, using the precatalyst [Ru(COD)(L1)Br2] (1) bearing an annulated π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand L1, is disclosed. This catalytic protocol is distinguished by its high activity and selectivity, wide substrate scope and modest reaction conditions. A variety of primary amines, RCH2NH2 (R = aliphatic, aromatic and heteroaromatic), are converted to the corresponding amides using ambient air as an oxidant in the presence of a sub-stoichiometric amount of KOtBu in tBuOH. A set of control experiments, Hammett relationships, kinetic studies and DFT calculations are undertaken to divulge mechanistic details of the amine oxidation using 1. The catalytic reaction involves abstraction of two amine protons and two benzylic hydrogen atoms of the metal-bound primary amine by the oxo and hydroxo ligands, respectively. A β-hydride transfer step for the benzylic C-H bond cleavage is not supported by Hammett studies. The nitrile generated by the catalytic oxidation undergoes hydration to afford the amide as the final product. This journal is
Yadav, Suman,Reshi, Noor U Din,Pal, Saikat,Bera, Jitendra K.
p. 7018 - 7028
(2021/11/17)

Substrate access tunnel engineering for improving the catalytic activity of a thermophilic nitrile hydratase toward pyridine and pyrazine nitriles
Nitrile hydratase (NHase) is able to bio-transform nitriles into amides. As nitrile hydration being an exothermic reaction, a NHase with high activity and stability is needed for amide production. However, the widespread use of NHase for amide bio-production is limited by an activity-stability trade-off. In this study, through the combination of substrate access tunnel calculation, residue conservative analysis and site-saturation mutagenesis, a residue located at the substrate access tunnel entrance of the thermophilic NHase from extremophile Caldalkalibacillus thermarum TA2. A1, βLeu48, was semi-rationally identified as a potential gating residue that directs the enzymatic activity toward various pyridine and pyrazine nitriles. The specific activity of the corresponding mutant βL48H towards 3-cyanopyridine, 2-cyanopyridine and cyanopyrazine were 2.4-fold, 2.8-fold and 3.1-fold higher than that of its parent enzyme, showing a great potential in the industrial production of high-value pyridine and pyrazine carboxamides. Further structural analysis demonstrated that the βHis48 could form a long-lasting hydrogen bond with αGlu166, which contributes to the expansion of the entrance of substrate access tunnel and accelerate substrate migration.
Cheng, Zhongyi,Jiang, Shijin,Zhou, Zhemin
p. 8 - 13
(2021/08/30)

Arene-ruthenium(II)-phosphine complexes: Green catalysts for hydration of nitriles under mild conditions
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
(2019/12/11)

IRAK DEGRADERS AND USES THEREOF
The present invention provides compounds, compositions thereof, and methods of using the same. The compounds include an IRAK binding moiety capable of binding to IRAK4 and a degradation inducing moiety (DIM). The DIM could be DTM a ligase binding moiety (LBM) or lysine mimetic. The compounds could be useful as IRAK protein kinase inhibitors and applied to IRAK mediated disorders.
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Paragraph 00920; 002790-002791

(2021/01/23)

Method for preparing pyrazinamide
The invention discloses a method for preparing pyrazinamide. The method comprises the steps that 2-methyl pyrazine serves as a raw material, a metal catalyst is added, oxidation is conducted through an oxidant to obtain 2-aldehyde pyrazine, after oxidation is finished, ammonia serving as an aminating agent is added for an amination reaction, and pyrazinamide is obtained; the metal catalyst is ferrous salt. Accordingly, the reaction conditions of high temperature and high pressure in an original process are avoided, use of highly toxic raw materials is avoided, and the process is simplified. Bymeans of experiment and exploration, it is found that under the catalysis of the ferrous salt, the 2-methylpyrazine is oxidized through the oxidant and then reacts with the ammonia to produce the pyrazinamide, special reaction equipment is not needed for the reaction, and the yield is high (the yield can reach 85-95%). The method has the advantages of being safe and reliable on the whole, good ineconomic benefit and suitable for industrial production.
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Paragraph 0022-0032

(2019/06/30)

Hydration of nitriles using a metal-ligand cooperative ruthenium pincer catalyst
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.
p. 10647 - 10652
(2019/12/02)

Modular Continuous Flow Synthesis of Imatinib and Analogues
A modular continuous flow synthesis of imatinib and analogues is reported. Structurally diverse imatinib analogues are rapidly generated using three readily available building blocks via a flow hydration/chemoselective C-N coupling sequence. The newly developed continuous flow hydration and amidation modules each exhibit a broad scope with good to excellent yields. Overall, the method described does not require solvent switches, in-line purifications, or packed-bed apparatuses due to the judicious manipulation of flow setups and solvent mixtures.
Fu, Wai Chung,Jamison, Timothy F.
supporting information
p. 6112 - 6116
(2019/08/26)

A Facile Synthesis of Substituted 2-(5-(Benzylthio)-1,3,4-oxadiazol-2-yl)pyrazine Using Microwave Irradiation and Conventional Method with Antioxidant and Anticancer Activities
A series of novel substituted 2-(5-(benzylthio)-1,3,4-oxadiazol-2-yl)pyrazine derivatives (6a–n) were synthesized under microwave irradiation and conventional conditions with less reaction time with good to excellent yields. All the synthesized compounds were screened for antioxidant and anticancer activities. Out of the 14 prepared derivatives, compounds 6f and 6m were most potent and active with antioxidant and anticancer activities, respectively. Also, the developed technique was simple, easy, and less time consuming.
Patil, Sanjeev R.,Sarkate, Aniket P.,Karnik, Kshipra S.,Arsondkar, Ashish,Patil, Vrushali,Sangshetti, Jaiprakash N.,Bobade, Anil S.,Shinde, Devanand B.
p. 859 - 866
(2019/02/01)

Bifunctional organometallic catalysts for selective hydration of nitriles to amides
In this report, we highlight our recent contributions towards the development of bifunctional catalysts for selective hydration of nitriles to amides.
Singh, Kuldeep,Sarbajna, Abir,Bera, Jitendra K.
p. 853 - 861
(2020/06/26)

Water-soluble superbulky (η6- p -cymene) ruthenium(ii) amine: An active catalyst in the oxidative homocoupling of arylboronic acids and the hydration of organonitriles
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
supporting information
p. 15221 - 15230
(2018/09/29)

Magnetic Nanoparticle-Supported Cu–NHC Complex as an Efficient and Recoverable Catalyst for Nitrile Hydration
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
p. 3378 - 3388
(2018/09/11)

Nitrile Hydration Reaction Using Copper Iodide/Cesium Carbonate/DBU in Nitromethane-Water
The catalytic nitrile hydration (amide formation) in a copper iodide/cesium carbonate/1,8-diazabicyclo[5.4.0]undec-7-ene/nitromethane-water system is described. The protocol is robust and reliable; it can be applied to a broad range of substrates with high chemoselectivity.
Kuwabara, Jun,Sawada, Yoshiharu,Yoshimatsu, Mitsuhiro
supporting information
p. 2061 - 2065
(2018/09/14)

A continuous-flow synthesis of primary amides from hydrolysis of nitriles using hydrogen peroxide as oxidant
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
p. 1527 - 1532
(2018/02/21)

Corresponding amine nitrile and method of manufacturing thereof
The invention relates to a manufacturing method of nitrile. Compared with the prior art, the manufacturing method has the characteristics of significantly reduced using amount of an ammonia source, low environmental pressure, low energy consumption, low production cost, high purity and yield of a nitrile product and the like, and nitrile with a more complex structure can be obtained. The invention also relates to a method for manufacturing corresponding amine from nitrile.
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Paragraph 0135; 0136; 0137; 0145

(2018/05/07)

Transition-metal-free synthesis of primary to tertiary carboxamides: A quick access to prodrug-pyrazinecarboxamide
One-pot expedient and direct carbamoylation of heterocyclics is described. The transformation is realized via direct dehydrogenative aminocarbonylation of heterocyclic compounds under transition-metal-free conditions. This method is regioselective and the protocol is proved to be scalable on a gram scale. Further, the therapeutically useful antitubercular agent pyrazinecarboxamide is successfully synthesized by employing this protocol.
Mete, Trimbak B.,Singh, Ankit,Bhat, Ramakrishna G.
supporting information
p. 4709 - 4712
(2017/11/21)

Hemilability-Driven Water Activation: A NiII Catalyst for Base-Free Hydration of Nitriles to Amides
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.
supporting information
p. 7761 - 7771
(2017/06/06)

Continuous flow hydration of pyrazine-2-carbonitrile in a manganese dioxide column reactor
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Battilocchio, Claudio,Lau, Shing-Hing,Hawkins, Joel M.,Ley, Steven V.
p. 34 - 45
(2017/06/08)

Poly(amic acid) salt-stabilized silver nanoparticles as efficient and recyclable quasi-homogeneous catalysts for the aqueous hydration of nitriles to amides
Water-soluble silver nanoparticles stabilized by poly(amic acid) salt (Ag-PAAS) were synthesized by a one-pot method and were characterized by using UV-vis absorption, transmission electron microscopy, powder X-ray diffraction, and ζ potential measurements. The Ag-PAAS catalyzed selective hydration of nitriles to amides in water allowed for not only highly efficient quasi-homogeneous catalytic reactions under mild conditions, but also an easy recovery and reuse of the catalyst attributed to the pH response of the PAAS.
Li, Jun,Tang, Guannan,Wang, Yuchen,Wang, Ya,Li, Zixi,Li, Hengfeng
p. 358 - 364
(2016/01/12)

Bis(allyl)-ruthenium(IV) complexes with phosphinous acid ligands as catalysts for nitrile hydration reactions
Several mononuclear ruthenium(iv) complexes with phosphinous acid ligands [RuCl2(η3:η3-C10H16)(PR2OH)] have been synthesized (78-86% yield) by treatment of the dimeric precursor [{RuCl(μ-Cl)(η3:η3-C10H16)}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) with 2 equivalents of different aromatic, heteroaromatic and aliphatic secondary phosphine oxides R2P(O)H. The compounds [RuCl2(η3:η3-C10H16)(PR2OH)] could also be prepared, in similar yields, by hydrolysis of the P-Cl bond in the corresponding chlorophosphine-Ru(iv) derivatives [RuCl2(η3:η3-C10H16)(PR2Cl)]. In addition to NMR and IR data, the X-ray crystal structures of representative examples are discussed. Moreover, the catalytic behaviour of complexes [RuCl2(η3:η3-C10H16)(PR2OH)] has been investigated for the selective hydration of organonitriles in water. The best results were achieved with the complex [RuCl2(η3:η3-C10H16)(PMe2OH)], which proved to be active under mild conditions (60 °C), with low metal loadings (1 mol%), and showing good functional group tolerance.
Tomás-Mendivil, Eder,Francos, Javier,González-Fernández, Rebeca,González-Liste, Pedro J.,Borge, Javier,Cadierno, Victorio
p. 13590 - 13603
(2016/09/04)

Clean synthesis of primary to tertiary carboxamides by CsOH-catalyzed aminolysis of nitriles in water
Using CsOH as the only catalyst and utilizing its "cesium effect", a clean synthesis of a wide range of primary, secondary, and tertiary carboxamides was achieved by aminolysis reactions of nitriles with ammonia, primary, or secondary amines in water. Studies on the control reactions revealed that the reactions with ammonia most probably proceed via an aminolysis path by the initial addition of ammonia to Cs-activated nitriles to form unsubstituted amidine intermediates, while the reactions with primary or secondary amines may proceed via a hydration/transamidation path by the initial hydration of the Cs-activated nitriles to form primary carboxamide intermediates followed by their transamidation with amines through the formation of substituted amidine intermediates.
Li, Yang,Chen, Haonan,Liu, Jianping,Wan, Xujun,Xu, Qing
supporting information
p. 4865 - 4870
(2016/10/06)

Ruthenium(II) complexes incorporating salicylaldiminato-functionalized N-heterocyclic carbene ligands as efficient and versatile catalysts for hydration of organonitriles
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
p. 134 - 144
(2016/01/09)

Synthesis of primary amides by aminocarbonylation of aryl/hetero halides using non-gaseous NH3 and CO sources
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
supporting information
p. 4864 - 4867
(2015/07/28)

Substrate-Specific Heterogeneous Catalysis of CeO2 by Entropic Effects via Multiple Interactions
Achieving complete substrate specificity through multiple interactions like an enzyme is one of the ultimate goals in catalytic studies. Herein, we demonstrate that multiple interactions between the CeO2 surface and substrates are the origin of substrate-specific hydration of nitriles in water by CeO2, which is exclusively applicable to the nitriles with a heteroatom (N or O) adjacent to the α-carbon of the CN group but is not applicable to the other nitriles. Kinetic studies reveal that CeO2 reduces the entropic barrier (TΔS?) for the reaction of the former reactive substrate, leading to 107-fold rate enhancement compared with the latter substrate. Density functional theory (DFT) calculations confirmed multiple interaction of the reactive substrate with CeO2, as well as preferable approximation and alignment of the nitrile group of the substrate to the active OH group on CeO2 surface. This can lead to the reduction of the entropic barrier. This is the first example of an entropy-driven substrate-specific catalysis of a nonporous metal oxide surface, which will provide a new design strategy for enzyme-inspired synthetic catalysts.
Tamura, Masazumi,Sawabe, Kyoichi,Tomishige, Keiichi,Satsuma, Atsushi,Shimizu, Ken-Ichi
p. 20 - 26
(2015/04/27)

Transition-metal-free hydration of nitriles using potassium tert -butoxide under anhydrous conditions
Potassium tert-butoxide acts as a nucleophilic oxygen source during the hydration of nitriles to give the corresponding amides under anhydrous conditions. The reaction proceeds smoothly for a broad range of substrates under mild conditions, providing an efficient and economically affordable synthetic route to the amides in excellent yields. This protocol does not need any transition-metal catalyst or any special experimental setup and is easily scalable to bulk scale synthesis. A single-electron-transfer radical mechanism as well as an ionic mechanism have been proposed for the hydration process.
Midya, Ganesh Chandra,Kapat, Ajoy,Maiti, Subhadip,Dash, Jyotirmayee
supporting information
p. 4148 - 4151
(2015/05/05)

Pyrazine-imide complexes: Reversible redox and MOF building blocks
The synthesis of the symmetric pyrazine imide ligand, N-(2-pyrazylcarbonyl)-2-pyrazinecarboxamide, (Hdpzca) and five new first row transition metal complexes of it are reported: [MII(dpzca)2], MII = Fe, Cu, Zn; [CuII(dpzca)(H2O)2]BF4, [CuII(dpzca)(H2O)3]2SiF6. The crystal structures of Hdpzca, [CoII(dpzca)2], [CuII(dpzca)2], {[CoIII(dpzca)2](BF4)}2·5CH3CN and [CuII(dpzca)(H2O)3]2SiF6·2H2O were determined and reveal an orthogonal positioning of the 'spare' pyrazine nitrogen atoms and 'spare' pairs of imide oxygen atoms. The [MII(dpzca)2] complexes are therefore useful six-coordinate building blocks for producing larger supramolecular assemblies. Two examples of secondary assembly of [MII(dpzca)2] complexes, with M = Co and Ni, with silver nitrate gave single crystals; {[CoIII(dpzca)2Ag](NO3)2·2H2O}n and {([NiII(dpzca)2AgI1/2](1/2NO3)(xH2O}n were structurally characterised. The redox processes of [MII(dpzca)2], with MII = Fe, Ni, Cu and Zn, are reported and, as seen for MII = Co, reversible metal- and ligand-based redox processes are observed, with Em(MII/MIII) values 0.15-0.24 V higher than for the analogous complexes of Hpypzca (non-symmetric pyridine/pyrazine imide ligand), and 0.35-0.36 V higher than for the complexes of Hbpca (symmetric pyridine imide ligand). This journal is
Cowan, Matthew G.,Miller, Reece G.,Brooker, Sally
p. 2880 - 2892
(2015/02/19)

Mild and selective heterogeneous catalytic hydration of nitriles to amides by flowing through manganese dioxide
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.
supporting information
p. 1060 - 1063
(2016/10/17)

Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide
Here we describe the use of a new open-source software package and a Raspberry Pi computer for the simultaneous control of multiple flow chemistry devices and its application to a machine-assisted, multi-step flow preparation of pyrazine-2-carboxamide - a component of Rifater, used in the treatment of tuberculosis - and its reduced derivative piperazine-2- carboxamide.
Ingham, Richard J.,Battilocchio, Claudio,Hawkins, Joel M.,Ley, Steven V.
supporting information
p. 641 - 652
(2014/04/17)

Exploring rhodium(I) complexes [RhCl(COD)(PR3)] (COD = 1,5-cyclooctadiene) as catalysts for nitrile hydration reactions in water: The aminophosphines make the difference
Several rhodium(I) complexes, [RhCl(COD)(PR3)], containing potentially cooperative phosphine ligands, have been synthesized and evaluated as catalysts for the selective hydration of organonitriles into amides in water. Among the different phosphines screened, those of general composition P(NR 2)3 led to the best results. In particular, complex [RhCl(COD){P(NMe2)3}] was able to promote the selective hydration of a large range of nitriles in water without the assistance of any additive, showing a particularly high activity with heteroaromatic and heteroaliphatic substrates. Employing this catalyst, the antiepileptic drug rufinamide was synthesized in high yield by hydration of 4-cyano-1-(2,6- difluorobenzyl)-1H-1,2,3-triazole. For this particular transformation, complex [RhCl(COD){P(NMe2)3}] resulted more effective than related ruthenium catalysts.
Tomas-Mendivil, Eder,Garcia-Alvarez, Rocio,Vidal, Cristian,Crochet, Pascale,Cadierno, Victorio
p. 1901 - 1910
(2014/06/24)

Efficient and selective nitrile hydration reactions in water catalyzed by an unexpected dimethylsulfinyl anion generated in situ from CsOH and DMSO
Unexpected dimethylsulfinyl anions (I), generated in situ from the superbase system CsOH-DMSO, was found to be a highly active catalyst for controllable nitrile hydration reactions in water, which selectively afforded the versatile amides via interesting Cs-activated I-catalyzed direct and indirect hydration mechanisms involving an O-transfer process from DMSO onto the nitriles. the Partner Organisations 2014.
Chen, Haonan,Dai, Wujie,Chen, Yi,Xu, Qing,Chen, Jianhui,Yu, Lei,Zhao, Yajuan,Ye, Mingde,Pan, Yuanjiang
supporting information
p. 2136 - 2141
(2014/04/17)

3H-1,2,4-Dithiazol-3-one compounds as novel potential affordable antitubercular agents
Small molecules with oxathiazol-2-one moiety were recently reported as potent inhibitors of Mycobacterium bovis var. bacilli Calmette-Guérin (BCG), among which HT1171 was the most potent and selective proteasome inhibitor. Herein we synthesized a series of novel compounds by bioisosteric replacement of the oxathiazol-2-one ring with 3H-1,2,4-dithiazol-3-one, and also fifteen 1,3,4-oxathiazol-2-one molecules in order for potency comparison and structure-activity relationship elucidation since their antibacterial effects on the virulent strains were not evaluated before. All the compounds were assessed for antitubercular activities on the virulent H37Rv strain by a serial dilution method. Among the tested compounds, 3H-1,2,4-dithiazol-3-one compound 4n was found to be the most active with a lowest MIC90 value of 1 μg/mL. Furthermore, the cytotoxicities of all the compounds against normal human liver cell line L02 were determined by an MTT method. Compound 4n displayed a lower inhibitory ratio than HT1171 at the concentration of 100 μM, indicating its better safety profile.
Yang, Jianzhong,Pi, Weiyi,Xiong, Li,Ang, Wei,Yang, Tao,He, Jun,Liu, Yuanyuan,Chang, Ying,Ye, Weiwei,Wang, Zhenling,Luo, Youfu,Wei, Yuquan
supporting information
p. 1424 - 1427
(2013/03/14)

Ceria-catalyzed conversion of carbon dioxide into dimethyl carbonate with 2-cyanopyridine
DMC run: Carbon dioxide can be converted into dimethyl carbonate in a reaction system involving 2-cyanopyridine as a dehydration agent, catalyzed by CeO2. Regeneration of the coproduct 2-picolinamide can be achieved over a Na2O/SiO2 catalyst. As a whole, the system servest to react carbon dioxide with methanol to produce dimethyl carbonate. Copyright
Honda, Masayoshi,Tamura, Masazumi,Nakagawa, Yoshinao,Sonehara, Satoru,Suzuki, Kimihito,Fujimoto, Ken-Ichiro,Tomishige, Keiichi
p. 1341 - 1344
(2013/09/12)

PROCESS FOR PREPARATION OF ANTI-TUBERCULAR COMBINATION AND PHARMACEUTICAL COMPOSITION PREPARED THEREFROM
This invention relates to a process for preparing a pharmaceutical composition comprising four antitubercular drugs: rifampin or a pharmaceutically acceptable salt thereof, isoniazid or a pharmaceutically acceptable salt thereof, pyrazinamide or a pharmaceutically acceptable salt thereof and ethambutol or a pharmaceutically acceptable salt thereof, wherein rifampin and isoniazid are in separate layers. The invention also provides a pharmaceutical composition prepared therefrom having advantageous stability and bioavailability.
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(2012/02/06)

A general and efficient heterogeneous gold-catalyzed hydration of nitriles in neat water under mild atmospheric conditions
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
scheme or table
p. 1392 - 1396
(2012/10/07)

Hydration of nitriles to amides in water by SiO2-supported Ag catalysts promoted by adsorbed oxygen atoms
A series of silica-supported silver catalysts with similar Ag loading (5 or 7 wt%) but with different preparation methods (calcination in air and reduction by H2 or NaBH4) were prepared, and their structure was characterized by microscopy (STEM), X-ray absorption fine structure (XAFS), and CO-titration of surface oxygen atom. Ag is present as metal nanoparticle with a size range of 17-30 nm. Their surface was partially covered with oxygen atoms, and the surface coverage of the oxygen depends on the preparation condition. For hydration of 2-cyanopyridine as a test reaction, turnover frequency (TOF) per surface Ag species is estimated. TOF does not show a good correlation with Ag particle size, but it linearly increases with the coverage of the surface oxygen atoms on Ag particles. The Ag/SiO2 catalyst prepared by H 2 reduction at 700 °C shows the highest TOF and it acts as effective and recyclable heterogeneous catalyst for selective hydration of various nitriles to the corresponding amides. Kinetic and Raman spectroscopic studies suggest that the surface oxygen atom adjacent to Ag0 sites plays an important role in the dissociation of H2O.
Shimizu, Ken-Ichi,Imaiida, Naomichi,Sawabe, Kyoichi,Satsuma, Atsushi
experimental part
p. 114 - 120
(2012/06/04)

RADIOPROTECTOR COMPOUNDS AND METHODS
The invention relates to novel compounds, processes for their preparation and their use in protecting biological materials from radiation damage (radioprotection). Preferred compounds of the invention are those of Formula (II), as follows: wherein W represents -N(R1R2) where R1 and R2 are not both hydrogen and where they may together form a 5, 6 or 7 membered ring structure, -NHN(R1R2), NHR3N(R1R2), -NHR3OR2, -N(R3)R3OR2, -N(R1)R3OR3OR3, OR3NR1R2, -OR3 or W represents piperidyl, piperazinyl, morpholinyl, thiomorpholinyl or diazepanyl each of which may be optionally substituted by C1 to C4 alkyl, C2 to C4 alkenyl, -N(CO)N(R1R2), -N(CO)OR1, -N(CO)OR3OH, -(CO)NR1R2, -R3(CO)NR1R2, -R3OR1, -OR1, -N(R1R2) OR -NH-; R1 and R2 are the or different and are selected from hydrogen, C1 to C4 alkyl or C2 to C4 alkenyl; group or chain; Z is the same or different and represents N or CH; Z' is the same or different and represents N or C; X represents CH, N or NH, where .. is a double bond when X is CH or N and a single bond when X is NH; X' represents N or NH, wherein when X is CH or N X' is NH and wherein X and X' are different and further where ～～～is a double bond when X' is N and a single bond when X' is NH; Q represents H, alkoxyl, -NR1R2, F or Cl; Q1 is absent when Z' is N and when Z' is C it represents H, alkoxyl, -NR1R2, F or Cl; A represents a five to ten membered single or multiple ring structure with heterocyclic N or O located at the ortho position, said ring including optional double bonds, substitutions and/or other heteroatoms and pharmaceutically acceptable derivatives thereof.
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Page/Page column 63-64

(2011/10/31)

Tuning the surface composition of novel metal vanadates and its effect on the catalytic performance
Tuning the surface composition of metal vanadates using different cations leads to the development of a new class of highly effective catalysts tested in the ammoxidation of 2-methylpyrazine. Especially, an enrichment of V in the near-surface region is beneficial for improved selectivity. With this approach, a knowledge based optimisation of the catalysts was possible for the first time, which indeed led to highly efficient novel LaVOx catalysts with a high yield of 2-cyanopyrazine (≥85%) and extremely high space-time-yields (ca. 525 g-1CP kg-1cat h-1).
Dhachapally, Naresh,Kalevaru, V. Narayana,Radnik, Joerg,Martin, Andreas
body text
p. 8394 - 8396
(2011/09/12)

Efficient and substrate-specific hydration of nitriles to amides in water by using a CeO2 catalyst
CeO2 acted as a reusable and effective catalyst for the hydration of various nitriles to amides in water under neutral conditions at low temperature (30-100 °C). CeO2 showed notable substrate specificity for nitriles that have a heteroatom adjacent to the α-carbon atom of the CN group (see scheme).
Tamura, Masazumi,Wakasugi, Hiroko,Shimizu, Ken-Ichi,Satsuma, Atsushi
supporting information; experimental part
p. 11428 - 11431
(2011/10/18)

HYDROXYAPATITE WITH SILVER SUPPORTED ON THE SURFACE THEREOF
An object of the present invention is to provide a hydroxyapatite with silver supported on the surface thereof, a new compound useful as a catalyst for the reaction of producing an amide compound by hydration of the corresponding nitrile compound. The hydroxyapatite with silver supported on the surface thereof according to the present invention is obtained by supporting zero-valent Ag on the surface of a hydroxyapatite. Also provided are a hydroxyapatite with silver supported on the surface thereof used as a catalyst, and a method for producing an amide compound, comprising producing the amide compound by hydration of the corresponding nitrile compound in the presence of a hydroxyapatite with silver supported on the surface thereof having zero-valent Ag supported on the surface of the hydroxyapatite.
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Page/Page column 5; 6

(2011/01/11)

Supported silver nanoparticle catalyst for selective hydration of nitriles to amides in water
Hydroxyapatite-supported silver nanoparticles (AgHAP) acted as a highly efficient reusable heterogeneous catalyst for hydration of diverse nitriles, including heteroaromatic ones, into amides in water.
Mitsudome, Takato,Mikami, Yusuke,Mori, Haruhiko,Arita, Shusuke,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
supporting information; scheme or table
p. 3258 - 3260
(2009/12/01)

Ceric ammonium nitrate (CAN) promoted efficient solid phase synthesis of amide derivatives: A green approach
Ceric ammonium nitrate (CAN) has been found to be an efficient catalyst for the solid phase synthesis of amide derivatives of a wide range of substituted carboxylic acids and urea in excellent yields under microwave irradiation conditions. High yields are achieved even on a gram scale, while reaction times are considerably shortened. This method displays both economic and environmental advantages.
Reddy, Ch. Sanjeeva,Raghu,Nagaraj
p. 315 - 318
(2008/09/20)

Experimental thermochemical study of three monosubstituted pyrazines
The standard (p° = 0.1 MPa) molar enthalpies of formation of liquid pyrazinecarbonitrile and of crystalline pyrazinecarboxylic acid and pyrazinamide were measured, at T= 298.15 K, by static bomb calorimetry and the standard molar enthalpies of vaporization or of sublimation, at T= 298.15 K, were obtained using Calvet microcalorimetry. These values were used to derive the respective standard molar enthalpies of formation in gaseous phase.
Ribeiro Da Silva, Maria D. M. C.,Miranda, Margarida S.,Vaz, Claudia M. V.,Matos, M. Agostinha R.,Acree Jr.
p. 49 - 53
(2007/10/03)

Selective and efficient heterogeneous hydration of nitriles to amides using silica supported manganese dioxide
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.
p. 2814 - 2819
(2007/10/03)

A novel, selective free-radical carbamoylation of heteroaromatic bases by Ce(IV) oxidation of formamide, catalysed by N-hydroxyphthalimide
The Ce(IV)-NHPI system was used to generate a carbamoyl radical by oxidation of formamide; this nucleophilic radical has been successfully used in the carbamoylation of heteroaromatic bases.
Minisci, Francesco,Recupero, Francesco,Punta, Carlo,Gambarotti, Cristian,Antonietti, Fabrizio,Fontana, Francesca,Pedulli, Gian Franco
p. 2496 - 2497
(2007/10/03)

Totally selective dry microwave assisted amide synthesis by hydration of nitrile using silica supported MnO2 reagent
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.
p. 1731 - 1734
(2007/10/03)

N-acylbenzotriazoles: Neutral acylating reagents for the preparation of primary, secondary, and tertiary amides
Readily available N-acylbenzotriazoles 2a-q efficiently acylate aqueous ammonia and primary and secondary amines to give primary, secondary, and tertiary amides in good to excellent yields. The wide applicability of the procedure is illustrated by the preparation of (i) α-hydroxyamides from α-hydroxy acids and of (ii) perfluoroalkylated amides.
Katritzky,He,Suzuki
p. 8210 - 8213
(2007/10/03)

Selective hydrolysis of nitriles to amides using NaOH-PEG under microwave irradiation
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.
p. 1713 - 1718
(2007/10/03)

Catalytic synthesis of pyrazinamide from 2,5-dimethylpyrazine
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Kagarlitskii,Krichevskii,Amirkhanova
p. 381 - 383
(2007/10/03)

SYNTHESIS OF 2-AMIDOPYRAZINE
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Kagarlitskii, A. D.,Krichevskii, L. A.,Suvorov, B. V.
p. 219 - 220
(2007/10/02)

Polycyclic N-Hetero Compounds. XXII. . Reaction of Pyridine N-oxides and Pyrazino Di-N-Oxides with Formamide
Reactions of pyridine N-oxides, pyrazine N-oxides and their benzologues with formamide are described.Carbamoylation mainly occured at aromatic ring with loss of the N-oxide oxygen atom, however, 2,4,6-trimethylpyridine 1-oxide gave 2- and 4-pyrimidinyl derivatives.
Hirota, Takashi,Namba, Tetsuto,Sasaki, Kenji
p. 949 - 953
(2007/10/02)