698-67-9Relevant academic research and scientific papers
Nitrogen Atom Transfer Catalysis by Metallonitrene C?H Insertion: Photocatalytic Amidation of Aldehydes
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
, (2022/01/20)
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.
Green and efficient Beckmann rearrangement by Cu(II) contained nano-silica triazine based dendrimer in water
Bahreininejad, Mohammad Hasan,Moeinpour, Farid
, p. 893 - 901 (2021/01/12)
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.
Manganese-Pincer-Catalyzed Nitrile Hydration, α-Deuteration, and α-Deuterated Amide Formation via Metal Ligand Cooperation
Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
, p. 10239 - 10245 (2021/08/24)
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.
Ru(ii)- And Ru(iv)-dmso complexes catalyze efficient and selective aqueous-phase nitrile hydration reactions under mild conditions
Dubey, Santosh Kumar,Kaur, Gurmeet,Rath, Nigam P.,Trivedi, Manoj
, p. 17339 - 17346 (2021/10/08)
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
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
Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K
, (2021/03/14)
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.].
Metal-Free Solvent Promoted Oxidation of Benzylic Secondary Amines to Nitrones with H2O2
Adrio, Javier,Amarante, Giovanni Wilson,Granato, álisson Silva
, p. 13817 - 13823 (2021/10/01)
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.
Ring Opening/Site Selective Cleavage in N-Acyl Glutarimide to Synthesize Primary Amides
Govindan, Karthick,Lin, Wei-Yu
supporting information, p. 1600 - 1605 (2021/03/03)
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.
Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
Yadav, Suman,Reshi, Noor U Din,Pal, Saikat,Bera, Jitendra K.
, p. 7018 - 7028 (2021/11/17)
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
Method for preparing 4-bromobenzamide
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Paragraph 0018-0028, (2021/11/14)
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.
Product selectivity controlled by manganese oxide crystals in catalytic ammoxidation
Hui, Yu,Luo, Qingsong,Qin, Yucai,Song, Lijuan,Wang, Hai,Wang, Liang,Xiao, Feng-Shou
, p. 2164 - 2172 (2021/09/20)
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.
