- Nitrogen Atom Transfer Catalysis by Metallonitrene C?H Insertion: Photocatalytic Amidation of Aldehydes
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C?H amination and amidation by catalytic nitrene transfer are well-established and typically proceed via electrophilic attack of nitrenoid intermediates. In contrast, the insertion of (formal) terminal nitride ligands into C?H bonds is much less developed and catalytic nitrogen atom transfer remains unknown. We here report the synthesis of a formal terminal nitride complex of palladium. Photocrystallographic, magnetic, and computational characterization support the assignment as an authentic metallonitrene (Pd?N) with a diradical nitrogen ligand that is singly bonded to PdII. Despite the subvalent nitrene character, selective C?H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N3SiMe3. Based on these results, a photocatalytic protocol for aldehyde C?H trimethylsilylamidation was developed that exhibits inverted, nucleophilic selectivity as compared to typical nitrene transfer catalysis. This first example of catalytic C?H nitrogen atom transfer offers facile access to primary amides after deprotection.
- Schmidt-R?ntsch, Till,Verplancke, Hendrik,Lienert, Jonas N.,Demeshko, Serhiy,Otte, Matthias,Van Trieste, Gerard P.,Reid, Kaleb A.,Reibenspies, Joseph H.,Powers, David C.,Holthausen, Max C.,Schneider, Sven
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- Visible light-mediated synthesis of amides from carboxylic acids and amine-boranes
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Here, a photocatalytic deoxygenative amidation protocol using readily available amine-boranes and carboxylic acids is described. This approach features mild conditions, moderate-to-good yields, easy scale-up, and up to 62 examples of functionalized amides with diverse substituents. The synthetic robustness of this method was also demonstrated by its application in the late-stage functionalization of several pharmaceutical molecules.
- Chen, Xuenian,Kang, Jia-Xin,Ma, Yan-Na,Miao, Yu-Qi
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supporting information
p. 3595 - 3599
(2021/06/06)
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- Manganese-Pincer-Catalyzed Nitrile Hydration, α-Deuteration, and α-Deuterated Amide Formation via Metal Ligand Cooperation
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A simple and efficient system for the hydration and α-deuteration of nitriles to form amides, α-deuterated nitriles, and α-deuterated amides catalyzed by a single pincer complex of the earth-abundant manganese capable of metal-ligand cooperation is reported. The reaction is selective and tolerates a wide range of functional groups, giving the corresponding amides in moderate to good yields. Changing the solvent from tert-butanol to toluene and using D2O results in formation of α-deuterated nitriles in high selectivity. Moreover, α-deuterated amides can be obtained in one step directly from nitriles and D2O in THF. Preliminary mechanistic studies suggest the transformations contributing toward activation of the nitriles via a metal-ligand cooperative pathway, generating the manganese ketimido and enamido pincer complexes as the key intermediates for further transformations.
- Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
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p. 10239 - 10245
(2021/08/24)
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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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- Activated Mont K10-Carbon supported Fe2O3: A versatile catalyst for hydration of nitriles to amides and reduction of nitro compounds to amines in aqueous media
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The iron oxide was successfully supported on activated clay/carbon through an experimentally viable protocol for both hydrations of nitrile to amide and reduction of nitro compounds to amines. The as-prepared catalyst has been extensively characterised by XPS, SEM-EDX, TEM, TGA, BET surface area measurements and powdered X-ray diffraction (PXRD). A wide variety of substrates could be converted to the desired products with good to excellent yields by using water as a green solvent for both the reactions. The catalyst was recyclable and reusable up to six consecutive cycles without compromising its catalytic proficiency. Graphical abstract: Activated Mont K10 carbon-supported Fe2O3 is a very efficient and versatile heterogeneous catalytic system for hydration of nitriles to amides and reduction of nitro compounds to amines and can be reused up to six consecutive cycles without significant loss in catalytic activity.[Figure not available: see fulltext.].
- Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K
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- Product selectivity controlled by manganese oxide crystals in catalytic ammoxidation
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The performances of heterogeneous catalysts can be effectively tuned by changing the catalyst structures. Here we report a controllable nitrile synthesis from alcohol ammoxidation, where the nitrile hydration side reaction could be efficiently prevented by changing the manganese oxide catalysts. α-Mn2O3 based catalysts are highly selective for nitrile synthesis, but MnO2-based catalysts including α, β, γ, and δ phases favour the amide production from tandem ammoxidation and hydration steps. Multiple structural, kinetic, and spectroscopic investigations reveal that water decomposition is hindered on α-Mn2O3, thus to switch off the nitrile hydration. In addition, the selectivity-control feature of manganese oxide catalysts is mainly related to their crystalline nature rather than oxide morphology, although the morphological issue is usually regarded as a crucial factor in many reactions.
- Hui, Yu,Luo, Qingsong,Qin, Yucai,Song, Lijuan,Wang, Hai,Wang, Liang,Xiao, Feng-Shou
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p. 2164 - 2172
(2021/09/20)
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- Nano-construction of CuO nanorods decorated with g-C3N4 nanosheets (CuO/g-C3N4-NS) as a superb colloidal nanocatalyst for liquid phase C[sbnd]H conversion of aldehydes to amides
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Herein, we describe an intelligent strategy to fabricate nanosheets of graphitic carbon nitride (g-C3N4) decorated with nanorods copper oxide (CuO NRs). Then, the catalytic activity of CuONRs/g-C3N4-NS was developed for the synthesis of primary amides in water. The morphology of CuO and its synergetics effect with nanosheets g-C3N4 a major role in the yield of products. Furthermore, hydroxylamine hydrochloride (NH2OH·HCl) due to availability and affordability was used as a suitable substitute for ammonia source. The findings demonstrate that this layer nanostructure is a superb catalyst for converting various derivatives of aldehyde to their corresponding amides. The current protocol can be useful criterion in the synthesis and stabilization of metal oxides and provides new insight in organic transformation.
- Mohammadi, Robabeh,Gholipour, Behnam,Alamgholiloo, Hassan,Rostamnia, Sadegh,Mohtasham, Hamed,Zonouzi, Afsaneh,Ramakrishna, Seeram,Shokouhimehr, Mohammadreza
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- Half-Sandwich Iridium Complexes Based on β-Ketoamino Ligands: Preparation, Structure, and Catalytic Activity in Amide Synthesis
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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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- Efficient nitriding reagent and application thereof
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The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
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Paragraph 0295-0297
(2021/03/31)
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- Green and efficient Beckmann rearrangement by Cu(II) contained nano-silica triazine based dendrimer in water
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In this research, a Cu(II) contained nano-silica triazine based dendrimer was prepared, characterized, and utilized as a retrievable catalytic system (Cu(II)-TrDen@nSiO2) for green formation of primary amides in water at room temperature. The structure of nanoparticles was fully characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry analysis (TGA). The results revealed that the nanoparticles have spherical morphology and an average size of around 40 nm. The analysis also illustrated that the copper nanoparticles had been successfully loaded on the nitrogen-rich dendritic structure with a uniform distribution. The inductively coupled plasma analysis showed that about 0.67 mmol/g of Cu was loaded on the Cu(II)-TrDen@nSiO2 support. Mild reaction conditions, excellent yields, environment-friendly synthesis, and easily prepared starting materials are the key features of the present method. The catalyst is easily removed from the reaction media using a simple filtration and can be re-used at least five times without any considerable loss of its catalytic activity.
- Bahreininejad, Mohammad Hasan,Moeinpour, Farid
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p. 893 - 901
(2021/01/12)
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- Does electrophilic activation of nitroalkanes in polyphosphoric acid involve formation of nitrile oxides?
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The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process? This experiment demonstrates that at least in some cases this could happen, as generated nitrile oxides were successfully intercepted as adducts of [3 + 2] cycloadditions. This journal is
- Aksenov, Alexander V.,Aksenov, Dmitrii A.,Aksenov, Nicolai A.,Kirilov, Nikita K.,Kurenkov, Igor A.,Nobi, Mezvah A.,Rubin, Michael,Skomorokhov, Anton A.,Sorokina, Elena A.
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p. 35937 - 35945
(2021/12/02)
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- Metal-Free Solvent Promoted Oxidation of Benzylic Secondary Amines to Nitrones with H2O2
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An environmentally benign protocol for the generation of nitrones from benzylic secondary amines via catalyst-free oxidation of secondary amines using H2O2 in MeOH or CH3CN is described. This methodology provides a selective access to a variety of C-aryl nitrones in yields of 60 to 93%. Several studies have been performed to shed light on the reaction mechanism and the role of the solvent.
- Adrio, Javier,Amarante, Giovanni Wilson,Granato, álisson Silva
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p. 13817 - 13823
(2021/10/01)
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- Ring Opening/Site Selective Cleavage in N-Acyl Glutarimide to Synthesize Primary Amides
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A LiOH-promoted hydrolysis selective C-N cleavage of twisted N-acyl glutarimide for the synthesis of primary amides under mild conditions has been developed. The reaction is triggered by a ring opening of glutarimide followed by C-N cleavage to afford primary amides using 2 equiv of LiOH as the base at room temperature. The efficacy of the reactions was considered and administrated for various aryl and alkyl substituents in good yield with high selectivity. Moreover, gram-scale synthesis of primary amides using a continuous flow method was achieved. It is noted that our new methodology can apply under both batch and flow conditions for synthetic and industrial applications.
- Govindan, Karthick,Lin, Wei-Yu
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supporting information
p. 1600 - 1605
(2021/03/03)
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- Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
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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.
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p. 7018 - 7028
(2021/11/17)
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- Method for preparing 4-bromobenzamide
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The invention relates to a method for preparing 4-bromobenzamide, which comprises the steps of mixing 4-bromobenzyl chloride, potassium ferrocyanide trihydrate and an organic solvent, and reacting in oxygen at the temperature of 120-160 DEG C for 10-60 hours in the presence of a catalyst 1, 10-phenanthroline/copper salt to prepare the 4-bromobenzamide. According to the method, potassium ferrocyanide trihydrate is used as a reaction reagent, the synthesis method is simple and convenient, the production cost is low, and pollution is small.
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Paragraph 0018-0028
(2021/11/14)
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- Ru-based complexes as heterogeneous potential catalysts for the amidation of aldehydes and nitriles in neat water
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Five novel heterogeneous mononuclear complex-anchored Ru(III) have been efficiently sono-synthesized and characterized by utilizing several analytical techniques. The assembled complexes could be utilized as effective, robust and recyclable (up to eight consecutive runs) catalysts for one-pot transformation of a vast array of nitriles and aldehydes to primary amides in H2O under aerobic conditions. Moreover, some unreported di- and tetra-amide derivatives were obtained also under the optimal conditions. The results of ICP/OES analysis demonstrated that there is no detected leaching of the recycled catalyst, which suggests the real heterogeneity of the present protocol. The present Ru-complexes exhibited superiority compared to other reported catalysts for amide preparation in terms of low catalyst load, short reaction time, low operating temperature, no hazardous additives required, and high values of TON (990) and TOF (1980 h11).
- Arafa, Wael Abdelgayed Ahmed
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p. 1056 - 1064
(2020/11/09)
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- Fe3O4@GlcA@Cu-MOF: A Magnetic Metal-Organic Framework as a Recoverable Catalyst for the Hydration of Nitriles and Reduction of Isothiocyanates, Isocyanates, and Isocyanides
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A novel magnetic metal-organic framework (Fe3O4@GlcA@Cu-MOF) has been prepared and characterized by spectroscopic, microscopic, and magnetic techniques. This magnetically separable catalyst exhibited high catalytic activity for nitrile hydration and the ability to reduce isothiocyanates, isocyanates, and isocyanides with excellent activity and selectivity without any additional reducing agent.
- Ghorbani-Choghamarani, Arash,Taherinia, Zahra
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supporting information
p. 902 - 909
(2020/11/30)
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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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- Substrate Profiling of the Cobalt Nitrile Hydratase from Rhodococcus rhodochrous ATCC BAA 870
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The aromatic substrate profile of the cobalt nitrile hydratase from Rhodococcus rhodochrous ATCC BAA 870 was evaluated against a wide range of nitrile containing compounds (>60). To determine the substrate limits of this enzyme, compounds ranging in size from small (90 Da) to large (325 Da) were evaluated. Larger compounds included those with a biaryl axis, prepared by the Suzuki coupling reaction, Morita–Baylis–Hillman adducts, heteroatomlinked diarylpyridines prepared by Buchwald–Hartwig crosscoupling reactions and imidazo[1,2a]pyridines prepared by the Groebke–Blackburn–Bienaymé multicomponent reaction. The enzyme active site was moderately accommodating, accepting almost all of the small aromatic nitriles, the diarylpyridines and most of the biaryl compounds and Morita–Baylis–Hillman products but not the Groebke–Blackburn–Bienaymé products. Nitrile conversion was influenced by steric hindrance around the cyano group, the presence of electron donating groups (e.g., methoxy) on the aromatic ring, and the overall size of the compound.
- Mashweu, Adelaide R.,Chhiba‐Govindjee, Varsha P.,Bode, Moira L.,Brady, Dean
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- Method for preparing amide compounds by using supported metal oxide catalytic material
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The invention relates to a catalyst for preparing amide compounds, and aims to provide a method for preparing amide compounds by using a supported metal oxide catalytic material. The method comprisesthe following steps: uniformly mixing a solvent, water, an organic nitrile compound and the catalytic material; performing a reaction at 50-180 DEG C for 0.5-48 h; and hydrating and converting the organic nitrile compound into the corresponding amide compounds through the catalytic hydration effect of the catalyst in the reaction process. Adsorption and activation of the catalytic material to water molecules can be effectively regulated by regulating metal components loaded on the catalytic material and a catalytic material carrier, so that important amide compounds in chemical and agricultural processes are efficiently prepared. The provided method for preparing the amide compounds is effect, and has the advantages of high atom utilization rate in the reaction process, low reaction temperature, no additional reaction assistant in the synthesis process, no generation of toxic or harmful byproducts after the reaction, and green and environment-friendly synthesis process.
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Paragraph 0132; 0133
(2020/06/05)
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- Method for preparing amide compounds by catalyzing organic nitrile hydration with oxide material
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The invention relates to a catalyst for preparing amide compounds, and aims to provide a method for preparing amide compounds by catalyzing organic nitrile hydration with an oxide material. The methodcomprises the following steps: adding a solvent, an organic nitrile substrate, water and a catalyst into a sealable reaction container, and uniformly mixing; performing a reaction at 50-180 DEG C for0.5-24 h; and catalyzing hydration in the reaction process to make the nitrile compounds finally hydrated and converted into corresponding amide compounds. The catalyst is cheap and easy to obtain, and no precious metal is used, so that the preparation cost of the catalyst is low, and large-scale production of the catalyst is facilitated. In the reaction process, the atom utilization rate is high, the reaction temperature is low, no additional reaction assistant is needed in the synthesis process, no toxic or harmful byproduct is generated after the reaction, and the whole synthesis process is green and environmentally friendly.
- -
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Paragraph 0122-0123
(2020/06/05)
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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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- Ruthenium(III) 2-(aminofluoreneazo)phenolate complexes: Synthesis, characterization, catalytic activity in amidation reaction and Fluorescence quenching studies
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A series of ruthenium(III)2-(aminofluoreneazo)phenolate complexes with general formula [RuCl(PPh3)2(L1-5)] (1–5) (L = 2-(aminofluoreneazo)phenolate ligands) have been synthesized. The characterization of the synthesized complexes was accomplished by elemental analysis, spectroscopic (FT-IR, UV–Vis, Fluorescence and EPR) and ESI-MStechniques. The catalytic performance of one of the synthesized complexes 3 for the amidation of aldehyde in the presence of NaHCO3/NH2OH·HCl has been evaluated. The fluorescence emission of complexes [RuCl(PPh3)2(L2)] (2) and [RuCl(PPh3)2(L3) (3)] are effectively quenched by 1,4-benzoquinone and 1,4-naphthoquinone in acetonitrile medium.
- Thirumal, Muniyappan,Venkatachalam, Galmari,Venkattappan, Anbazhagan
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- Nitromethane as a nitrogen donor in Schmidt-type formation of amides and nitriles
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The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.
- Jiao, Ning,Liu, Jianzhong,Qiu, Xu,Song, Song,Wei, Jialiang,Wen, Xiaojin,Zhang, Cheng,Zhang, Ziyao
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supporting information
p. 281 - 285
(2020/01/28)
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- Cu(II)–metformin immobilized on graphene oxide: an efficient and recyclable catalyst for the Beckmann rearrangement
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Abstract: In this study, for the first time, the copper(II) nanoparticles (NPs) have been immobilized on metformin-functionalized graphene oxide and then its catalytic applications have been investigated in synthesis of amides from aldoximes (Beckmann rearrangement). The chemical structure of prepared catalyst has been characterized by various analyses like FT-IR, TGA, TEM, SEM, EDX, and ICP. All analyses confirm the successful and stable immobilization of copper NPs on functionalized graphene oxide. This synthesized heterogeneous nanocatalyst showed excellent catalytic activity with high product yields and short reaction times. Also, the suggested catalyst could be recycled ten times without a drastic decrease in its catalytic activity. Graphic abstract: [Figure not available: see fulltext.].
- Solaiman Hamed, Ahmed,Mohammad Ali, Ehab
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p. 701 - 714
(2019/11/03)
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- Method for preparing derivatives of benzamide under microwave condition in aqueous phase
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The invention discloses a method for preparing derivatives of benzamide under a microwave condition in an aqueous phase. A coupling reaction is carried out between substituted benzoic acid and amine under the microwave condition in the aqueous phase. The method for preparing the derivatives of benzamide is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applicable to a large number of functional groups, is high in yield, produces fewer by-products, and further is easy to operate, safe, low in cost and environmentally friendly. A formula is shown in the description.
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Paragraph 0018; 0080
(2019/03/28)
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- Ru (III) Schiff-base complex anchored on nanosilica as an efficient and retrievable catalyst for hydration of nitriles
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Transition metal catalyzed hydration of nitriles is an attractive methodology for amide synthesis, and hence recently attracted wide attention. It is one of the significant organic transformations as amides play a vital role in biological, pharmaceutical and industrial applications. In this work, we report the synthesis of a new solid supported Ru (III) Schiff base complex, Ru@imine-nanoSiO2 immobilized on nanosilica obtained from rice husk. The complex was characterized by FTIR, powder X-ray diffraction, BET surface area measurement, UV–vis, SEM–EDX, TEM, ESR, X-ray photoelectron spectroscopy and ICP-AES analysis. Using Ru@imine-nanoSiO2 as the catalyst, the hydration of nitriles in i-PrOH at 40?°C was studied which resulted in good isolated yields (60–99%). The catalyst can be recycled and reused up to 5th cycle without any loss in activity. The products were characterized by FTIR, GC–MS and 1H-NMR spectroscopy and compared with authentic samples.
- Sultana, Samim,Borah, Geetika,Gogoi, Pradip K.
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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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- Activation of nitriles by silver(I) N-heterocyclic carbenes: An efficient on-water synthesis of primary amides
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A first example of silver(I) N-heterocyclic carbene (Ag(I)-NHC) catalyzed on-water synthesis of primary amides by hydration of nitriles under mild reaction conditions is described. This organometallic catalytic system has excellent tolerance for various homo-aromatic, hetero-aromatic and aliphatic nitriles to afford primary amides in good yields in neat water.
- Thirukovela, Narasimha Swamy,Balaboina, Ramesh,Kankala, Shravankumar,Vadde, Ravindhar,Vasam, Chandra Sekhar
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supporting information
p. 2637 - 2641
(2019/03/21)
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- Solvent-Tailored Pd3P0.95 nano catalyst for amide-nitrile inter-conversion, the hydration of nitriles and transfer hydrogenation of the CO bond
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For the first time, a one pot thermolysis of [Pd(PPh3)2Cl2] prepared by reacting Ph3P with PdCl2 in a 2:1 molar ratio in MeOH at 280 °C in a trioctylphosphine (TOP) and oleylamine(OA)-octadecane(ODE) mixture (1:1) was used to prepare quantum dots (QDs; size ~2-3 nm) and nanoparticles (NPs; size ~13-14 nm), respectively, of composition Pd3P0.95. TEM, SEM-EDX, powder-XRD and XPS (for QDs only) were used to authenticate the two nanophases. 31P{1H}NMR experiments performed to monitor the progress of thermolysis reactions revealed that the phosphorus present in the Pd3P0.95 QDs had come from TOP, whereas in Pd3P0.95 NPs, its source is triphenylphosphine. The nature of the solvent did not affect the chemical composition of the nano-phase but controlled its size. Probably, solvent dependent, unique, single source precursors (SSPs) of palladium were generated in situ, and controlled the size. The catalytic activity of both Pd3P0.95 QDs and NPs was explored. The QDs were found to be efficient as a catalyst for the amide-nitrile interconversion at room temperature (yield up to 92% in 4 h), hydration of nitriles and transfer hydrogenation (TH) of carbonyl compounds with yields up to 96% in 3-4 h. The yields and reaction rates of amide-nitrile inter-conversion and TH when catalyzed by Pd3P0.95 QDs were found to be higher compared to the ones observed with the Pd/C catalyst. The binding energy of Pd(3d) in the X-ray photoelectron spectrum (XPS) of Pd3P0.95 indicated an electron transfer from the metal to phosphorus, resulting in electron deficient palladium, which facilitates the coordination of a substrate to Pd and drives the reaction. The reusability of Pd3P0.95 QDs for the interconversion was found to be up to 4-Times, while for the transfer hydrogenation of carbonyl compounds it was up to 6-Times, but with a diminished yield. Pd3P0.95 NPs were found to be less active (yield up to 36% in optimized reaction conditions) in comparison to Pd3P0.95 QDs. The mercury poisoning test suggested that the catalysis predominantly proceeded heterogeneously on the surface of the QDs. The PXRD and XPS results did not suggest a significant variation in the phase of QDs after the third catalytic cycle. The bleeding of Pd during catalysis (determined by flame AAS) and the agglomeration of QDs as supported by the SEM-EDX and TEM results are probably responsible for the reduction in the catalytic activity of QDs after reusing three times.
- Sharma, Alpesh K.,Joshi, Hemant,Bhaskar, Renu,Singh, Ajai K.
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supporting information
p. 10962 - 10970
(2019/07/31)
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- Aqueous-Phase Nitrile Hydration Catalyzed by an In Situ Generated Air-Stable Ruthenium Catalyst
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RuCl2(PTA)4 (PTA=1,3,5-triaza-7-phosphaadamantane) is an active, recyclable, air-stable, aqueous-phase nitrile hydration catalyst. The development of an in situ generated aqueous-phase nitrile hydration catalyst (RuCl3?3 H2O+6 equivalents PTA) is reported. The activity of the in situ catalyst is comparable to RuCl2(PTA)4. The effects of [PTA] on the activity of the reaction were investigated: the catalytic activity, in general, increases as the pH goes up, which shows a positive correlation with [PTA]. The pH effects were further explored for both the in situ and RuCl2(PTA)4 catalyzed reaction in phosphate buffer solutions with particular attention given to pH 6.8 buffer. Increased catalytic activity was observed at pH 6.8 versus water for both systems with turnover frequency (TOF) up to 135 h?1 observed for RuCl2(PTA)4 and 64 h?1 for the in situ catalyst. Catalyst loading down to 0.001 mol % was examined with turnover numbers as high as 22 000 reported. Similar to the preformed catalyst, RuCl2(PTA)4, the in situ catalyst could be recycled more than five times without significant loss of activity from either water or pH 6.8 buffer.
- Ounkham, Whalmany L.,Weeden, Jason A.,Frost, Brian J.
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supporting information
p. 10013 - 10020
(2019/07/15)
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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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- One-Pot Anodic Conversion of Symmetrical Bisamides of Ethylene Diamine to Unsymmetrical gem-Bisamides of Methylene Diamine
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Symmetrical bisamides of ethylene diamine of type ArCONHCH2CH2NHCOAr undergo anodic C-C bond cleavage in acetonitrile-LiClO4 under controlled-potential electrolysis. The electrogenerated carbocation intermediates react with the solvent acetonitrile to afford unsymmetrical gem-bisamides of type ArCONHCH2NHCOMe in a one-pot reaction. The yields of the latter products are moderate (up to 60%). Other minor products involve two symmetrical gem-bisamides of type ArCONHCH2NHCOAr and MeCONHCH2NHCOMe and fragmentation products (e.g., ArCONHCHO, ArCONH2, and ArCN).
- Golub, Tatiana,Dou, Gui-Yuan,Zeng, Cheng-Chu,Becker, James Y.
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p. 7961 - 7964
(2019/10/11)
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- (η6-Benzene)Ru(II) half-sandwich complexes of pyrazolated chalcogenoethers for catalytic activation of aldehydes to amides transformation
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The reaction of [(η6-C6H6)RuCl(μ-Cl)]2 with chalcogenoether substituted 1H-pyrazole ligands (L1-L3) in methanol have yielded three novel Ru(II) half-sandwich complexes [(η6-C6H6)RuCl(L)]PF6 (1–3) in high yield under the ambient reaction conditions. The NMR, MS and FT-IR analytical techniques were used to identify their structures. The molecular structures of the complexes 2 and 3 were established with X-ray crystallographic analysis and revealed a pseudo-octahedral half sandwich piano-stool geometry around ruthenium in each complex. Complexes 1–3 are thermally robust and were found to be insensitive towards the air and moisture. All the complexes were found to be catalytically active and produced the excellent yields of amides (up to 95%) from corresponding aldehydes. In contrast to the previous reported catalytic systems for aldehyde to amide transformation, the present complexes 1–3 are very efficient and have several advantages in terms of low catalyst loading, reaction time, temperature and wide applicability for various substituted aldehydes. Owing to the stronger σ-donor coordination properties of selenium containing ligands, the complex 2 was found to be more efficient as compare to the sulphur and tellurium analogues.
- Sharma, Kamal Nayan,Ali, Munsaf,Srivastava, Avinash Kumar,Joshi, Raj Kumar
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- Appraisal of Ruthenium(II)complexes of (4-phenoxyphenylazo)ligands for the synthesis of primary amides by dint of hydroxylamine hydrochloride and aldehydes
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A new family of O, N donor-functionalized (4-phenoxyphenylazo)-2-naphthol/4-substituted phenol-based ligands (HL1-HL4)has been synthesized. The prepared ligands were successfully utilized for the access of a series of ruthenium(II)carbonyl complexes of the type [Ru(L)Cl(CO)(EPh3)3](E = phosphine/arsine), (L = 1-(4-phenoxyphenylazo)-2-naphthol (HL1), 2-(4-phenoxyphenylazo)-4-chlorophenol (HL2), 2-(4-phenoxyphenylazo)-4-methylphenol (HL3)and 2-(4-phenoxyphenylazo)-4-methoxyphenol (HL4)). All of the ruthenium(II)carbonyl complexes and ligands have been fully characterized by FT-IR, UV–visible, 1H NMR, 31P NMR, mass spectrometry and CHN analysis. The ligands have been analyzed by 13C NMR. The UV–visible spectroscopic study reveals that both the ligands and Ru(II)complexes exhibit excellent charge transfer transitions. This is the basic criteria for the oxidative amidation reaction, which is an influential strategy for the transformation of oxygenated organic compounds to the profitable amides. However, this catalytic process makes more impact on the application of new divalent ruthenium(II)azo compounds as catalyst in a single-pot conversion of aldehydes to amides in the presence of NaHCO3.
- Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Sounthararajan, Muniyan,Sakthi, Dharmalingam,Bharathi, Kuppannan Shanmuga
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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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- Amidation of aldehydes using mono-cationic half-sandwich rhodium(III) complexes with functionalized phenylhydrazone ligands
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A series of mono-cationic half-sandwich rhodium(III) complexes have been synthesized in methanol using phenylhydrazone-derived ligands (L1–L6) and the starting precursor [(η5-C5Me5)2Rh2(μ-Cl)2Cl2] in a 2:1 molar ratio. The N,N′-phenylhydrazone complexes have been isolated as tetraphenylborate salts. All complexes were characterized by elemental analysis, FT-IR, UV–visible, NMR spectroscopy and mass spectrometry. The molecular structure of complex [(η5-C5Me5)Rh(L1)Cl](BPh4) (1) was confirmed by single-crystal X-ray structure analysis. Complex [(η5-C5Me5)Rh(L3)Cl](BPh4) (3) was used as an efficient catalyst for the amide formation reaction, with up to 99% conversion after 2 h in toluene at 110 °C in the presence of hydroxyl amine hydrochloride and sodium bicarbonate.
- Devika, Neelakandan,Ananthalakshmi, Subbiah,Raja, Nandhagopal,Gupta, Gajendra,Therrien, Bruno
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- Green synthesis of bromo organic molecules and investigations on their antibacterial properties: An experimental and computational approach
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A simple, environmentally benign methodology has been developed to synthesize some bromoorganic compounds which have potential as antimicrobial agents. The required compounds were obtained through microwave (MW) irradiation, on-water reactions and using cetyltrimethylammonium tribromide (CTMATB) as the bromine source. The high yield of the product could be achieved within short reaction times, thus representing the main attribute of the present synthetic approach. The compounds were evaluated for in vitro antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Bacillus subtilis. Further, in silico studies were carried out to elucidate the interactions of the compounds with the bacterial proteins.
- Longkumer, Naruti,Richa, Kikoleho,Karmaker, Rituparna,Kuotsu, Visekhonuo,Supong, Aola,Jamir, Latonglila,Bharali, Pranjal,Sinha, Upasana Bora
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p. 276 - 283
(2019/07/12)
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- Selectivity-tunable amine aerobic oxidation catalysed by metal-free N,O-doped carbons
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Herein, we present a series of N,O-doped mesoporous carbons obtained at different pyrolysis temperatures as the first metal-free catalysts which successfully switch between imine and nitrile products for amine oxidation. Systematic characterization studies and control experiments revealed that the C-O group on the surface could function as a catalytically active site for nitrile synthesis and the N-doping environment was essential.
- Li, Yingguang,Shang, Sensen,Wang, Lianyue,Lv, Ying,Niu, Jingyang,Gao, Shuang
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supporting information
p. 12251 - 12254
(2019/10/21)
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- Aerobic Activation of C-H Bond in Amines Over a Nanorod Manganese Oxide Catalyst
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The development of heterogeneous catalysts for the synthesis of pharmaceutically relevant compounds is always important for chemistry research. Here, we report a selective aerobic oxidation of aromatic and aliphatic amines to corresponding amides over a nanorod manganese oxide (NR-MnOx) catalyst. The kinetic studies reveal that the NR-MnOx catalyzed amine-to-amide reaction proceeds the oxidative dehydrogenation of the amines into nitriles, followed by hydrolysis of nitrile into amides. The NR?MnOx exhibits fast kinetics and high selectivities in these steps, as well as hinders the by-product formation. More importantly, the NR-MnOx catalyst is stable and reusable in the continuous recycle tests with water as a sole by-product, exhibiting superior sustainability and significant advancement to outperform the traditional amide production route in acidic or basic media with toxic by-products.
- Wang, Hai,Wang, Liang,Wang, Sai,Dong, Xue,Zhang, Jian,Xiao, Feng-Shou
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p. 401 - 406
(2018/08/11)
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- Mechanochemical synthesis of primary amides from carboxylic acids using TCT/NH4SCN
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A facile and effective approach toward the synthesis of primary amides from carboxylic acids has been developed. In the presence of 2,4,6-trichloro-1,3,5-triazine, a combination of ammonium thiocyanate and potassium carbonate led to the rapid conversion of carboxylic acids into the corresponding amides within five minutes grinding at room temperature. The use of ammonium thiocyanate as the amine source is unprecedented and exclusive formation of primary amides is observed only under the liquid-assisted grinding conditions.
- Jaita, Subin,Phakhodee, Wong,Chairungsi, Neeranuch,Pattarawarapan, Mookda
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supporting information
p. 3571 - 3573
(2018/09/10)
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- Direct and facile synthesis of primary amides from carboxylic acids via acyl isocyanate intermediates using mukaiyama reagent
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A very simple and efficient procedure for the preparation of primary amides is described from carboxylic acids using Mukaiyama reagent/KNCO in aqueous acetonitrile. Availability of the reagents, simplicity, and easy workup of the reaction crude make this method attractive for organic chemists.
- Azadi, Roya,Motamedpoor, Zahra
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p. 801 - 804
(2018/09/26)
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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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- 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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- Structure-Guided Modification of Heterocyclic Antagonists of the P2Y14 Receptor
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The P2Y14 receptor (P2Y14R) mediates inflammatory activity by activating neutrophil motility, but few classes of antagonists are known. We have explored the structure-activity relationship of a 3-(4-phenyl-1H-1,2,3-triazol-1-yl)-5-(aryl)benzoic acid antagonist scaffold, assisted by docking and molecular dynamics (MD) simulation at a P2Y14R homology model. A computational pipeline using the High Throughput MD Python environment guided the analogue design. Selection of candidates was based upon ligand-protein shape and complementarity and the persistence of ligand-protein interactions over time. Predictions of a favorable substitution of a 5-phenyl group with thiophene and an insertion of a three-methylene spacer between the 5-aromatic and alkyl amino moieties were largely consistent with empirical results. The substitution of a key carboxylate group on the core phenyl ring with tetrazole or truncation of the 5-aryl group reduced affinity. The most potent antagonists, using a fluorescent assay, were a primary 3-aminopropyl congener 20 (MRS4458) and phenyl p-carboxamide 30 (MRS4478).
- Yu, Jinha,Ciancetta, Antonella,Dudas, Steven,Duca, Sierra,Lottermoser, Justine,Jacobson, Kenneth A.
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supporting information
p. 4860 - 4882
(2018/06/20)
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- Metal-Free Nitrogen- and Boron-Codoped Mesoporous Carbons for Primary Amides Synthesis from Primary Alcohols via Direct Oxidative Dehydrogenation
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Metal-free catalysts show environmental friendliness and cost-effectiveness, as well as less susceptibility to poisoning over metal and metal oxide catalysts. In this respect, we present the synthesis and characterization of metal-free mesoporous nitrogen- and boron-codoped nanocarbon (meso-N,B/C), which exhibits good catalytic performance with conversion of 89% and selectivity of 83% toward amide synthesis from primary alcohols using NH4OAc as an ammonia resource under an oxygen atmosphere. The facile codoping synthetic strategy was executed by pyrolysis of nitrogen-enriched ligand 4,5-diazafluorene-9-one azine (DAA) and H3BO3 as a nitrogen and boron content modulator, respectively. Significantly, control experiments revealed that the reaction proceeded through direct oxidative dehydrogenation of hemiaminal after aldehyde-ammonia condensation, which was remarkably different from that in the previous literature. Density functional theory (DFT) calculations further demonstrate that the selective preference for benzamide largely benefits from the strong adsorption and enhanced activity of oxygen molecules via the interaction with a B atom doped in the catalyst. The active sites in the meso-N,B/C catalyst are proposed to be B atom bonded with N within the graphitic carbon sheets. This founding opens up avenues for the development of modified carbon materials on metal-free catalysis.
- Shang, Sensen,Chen, Pei-Pei,Wang, Lianyue,Lv, Ying,Li, Wei-Xue,Gao, Shuang
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p. 9936 - 9944
(2018/10/15)
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- Novel design of recyclable copper(II) complex supported on magnetic nanoparticles as active catalyst for Beckmann rearrangement in poly(ethylene glycol)
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Copper complex-functionalized magnetic core–shell nanoparticles (Fe3O4@SiO2-Lig-Cu) were prepared and characterized using various techniques. The activity of the new catalyst was tested for the Beckmann rearrangement. The reaction conditions allow for the conversion of a wide variety of aldoximes, including aromatic and heterocyclic ones, to amides in good to excellent yields. High efficiency, mild reaction conditions, easy work-up, use of poly(ethylene glycol) as a green medium and simple purification of products are important advantages of this system. Moreover, the eco-friendly heterogeneous nanocatalyst could be easily recovered from the reaction mixture using an external magnet and reused several times.
- Keyhaniyan, Mahdi,Shiri, Ali,Eshghi, Hossein,Khojastehnezhad, Amir
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- The use of a manganese oxide of the amine of preparation of amides oxidation method (by machine translation)
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The invention relates to the synthesis of amide compound catalyst, and aims at providing a oxidation using manganese oxide of the amine of preparation of amides method. Including: the pressure in the container adding organic solvent, organic amine substrate and catalyst and uniformly mixed, and then filled with oxygen, the reaction process through the catalyst in the catalytic oxidation, organic amine substrate of alpha nanotube growing C=O double bond is formed, thereby obtaining the amide group and finally generates the amide compound. The invention relates to catalyst of the cheap and easy to obtain, in the catalyst of gas relates to oxide, unused to any noble metal, so that the preparation cost of the catalyst is relatively low, conducive to the realization of large-scale production of the catalyst. The method the reaction temperature is low, and in the course of synthesizing reaction assistant without additional added, after reaction without harmful toxic by-product to produce, in the whole synthesis process is environment-friendly. (by machine translation)
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Paragraph 0079; 0080
(2018/10/19)
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- One-Pot Preparation of Aromatic Amides, 4-Arylthiazoles, and 4-Arylimidazoles from Arenes
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Simple treatment of arenes with α-bromoacetyl chloride and AlCl3, followed by the reaction with molecular iodine and aq. NH3, thioamides, or amidines gave the corresponding primary aromatic amides, 4-arylthiazoles, or 4-arylimidazoles in good yields, respectively. Aryl α-bromomethyl ketones are the key intermediates in those reactions. Primary aromatic amides were formed from arenes through the reaction of aryl α-bromomethyl ketones with molecular iodine and aq. NH3, and 4-arylthiazoles and 4-arylimidazoles were formed from arenes through the reactions of aryl α-bromomethyl ketones with thioamides and amidines, respectively, in one pot under transition-metal-free conditions.
- Yamamoto, Takahiro,Togo, Hideo
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p. 4187 - 4196
(2018/08/21)
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