- Eco-friendly synthesis of m-tolunitrile by heterogeneously catalysed liquid phase ammoxidation
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The ammoxidation of m-xylene to m-tolunitrile over silica-supported Co-Mn-Ni catalyst was conducted for the first time in liquid phase without solvent in one-step procedure. Copyright
- Zhong, Min,Liang, Yong-Guang,Liu, Yuan,Ma, Yu-Long
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- Thermally stable imidazole/heteropoly acid composite as a heterogeneous catalyst for m-xylene ammoxidation
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Ammoxidation of m-xylene is evaluated in the presence of a customized heteropoly acid catalyst as an imidazole/molybdovanadophosphoric acid (imidazole/PMoV). Imidazole is employed to maintain its heterogeneous phase during the ammoxidation reaction and to provide the thermal stability of PMoV with the expectation that imidazole can generate strong electronic interactions with terminal molybdenum-oxygen on PMoV. The characterizations of the prepared catalysts are performed using SEM–EDX, XRD, FT-IR, Raman, XPS, and TGA to prove the physical and chemical changes by incorporating imidazole to PMoV, respectively. Also, the thermal stability of the developed catalyst is confirmed by the means of heat treatment test at relatively high temperature. The composite catalyst, imidazole/PMoV, shows an excellent conversion rate of over 98% with high selectivity of isophthalonitrile in m-xylene ammoxidation. Moreover, while the imidazole-free PMoV catalyst is deactivated and washed out during the reaction, the catalyst durability of the imidazole/PMoV is preserved without significant activity loss after 5 reaction cycles at 380 °C.
- Jeon, Yukwon,Lee, Chanmin,Lee, Gicheon,Kwon, Ohchan,Kim, Jinsol,Park, Sang Sun,Oh, Kyeongseok,Shul, Yong-Gun
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Read Online
- Synthesis method of m (p)-site alkyl substituted cyanobenzene
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The invention relates to a synthesis method of m (p)-alkyl substituted benzonitrile, which comprises the following steps: (1) m (p)-alkyl substituted benzoate is mixed with ammonia gas after passing through a vaporization furnace, the mixture enters a reactor filled with a catalyst to react, and a gas phase at an outlet of the reactor is introduced into a receiving tank with cooling water to obtain a reaction liquid; and (2) layering the reaction liquid in the step (1) to obtain an oil phase which is an m (p)-alkyl substituted cyanobenzene crude product, and rectifying to obtain an m (p)-alkyl substituted cyanobenzene finished product. According to the synthetic method disclosed by the invention, the m (p)-alkyl substituted cyanobenzene can be prepared only by a one-step method, the reaction only needs to be carried out in a tubular reactor filled with a catalyst, the process route is short, the production efficiency is high, the yield is high, the purity is good, the method is safe, economical and environment-friendly, and the obtained product is high in yield and purity.
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Paragraph 0020-0023; 0026-0029
(2022/04/03)
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- Cyanide-Free Cyanation of sp2 and sp-Carbon Atoms by an Oxazole-Based Masked CN Source Using Flow Microreactors
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This work reports a cyanide-free continuous-flow process for cyanation of sp2 and sp carbons to synthesize aryl, vinyl and acetylenic nitriles from (5-methyl-2-phenyloxazol-4-yl) boronic acid [OxBA] reagent as a sole source of carbon-bound mask
- Sharma, Brijesh M.,Nikam, Arun V.,Lahore, Santosh,Ahn, Gwang-Noh,Kim, Dong-Pyo
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supporting information
(2022/02/25)
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- Method for catalyzing oxidation of amines to generate nitrile by using nonmetal mesoporous nitrogen-doped carbon material
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The invention discloses a method for preparing nitrile by catalyzing amine oxidation with a non-metal mesoporous nitrogen-doped carbon material catalyst, which is applied to the field of synthesis, the material is prepared by using a nitrogen-containing organic ligand as a precursor and silica sol as a template agent, calcining in the atmosphere of inert gases such as N2 or Ar and then removing the template agent; oxygen or air is used as an oxygen source, the reaction is performed at 80-130 DEG C under the action of ammonia water in the presence of a solvent, the effect is good, and the product still keeps higher activity after being recycled for more than 8 times, and has a wide industrial application prospect. The invention provides a heterogeneous non-metal catalytic system for catalyzing amine oxidation to prepare nitrile for the first time, and compared with a reported metal catalyst, the heterogeneous non-metal catalytic system does not bring metal pollution to a product to influence the effect of cyano drugs.
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Paragraph 0019; 0031
(2021/05/08)
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- Method for dehydrating primary amide into nitriles under catalysis of cobalt
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The invention provides a method for dehydrating primary amide into nitrile. The method comprises the following steps: mixing primary amide (II), silane, sodium triethylborohydride, aminopyridine imine tridentate nitrogen ligand cobalt complex (I) and a reaction solvent under the protection of inert gas, carrying out reacting at 60-100 DEG C for 6-24 hours, and post-treating reaction liquid to obtain a nitrile compound (III). According to the invention, an effective method for preparing nitrile compounds by cobalt-catalyzed primary amide dehydration reaction by using the novel aminopyridine imine tridentate nitrogen ligand cobalt complex catalyst is provided; and compared with existing methods, the method has the advantages of simple operation, mild reaction conditions, wide application range of reaction substrates, high selectivity, stable catalyst, high efficiency, and relatively high practical application value in synthesis.
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Paragraph 0051-0053
(2021/06/21)
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- METHOD FOR PRODUCING AROMATIC NITRILE COMPOUND AND CATALYST FOR SYNTHESIS OF AROMATIC NITRILE COMPOUND
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PROBLEM TO BE SOLVED: To efficiently produce an aromatic nitrile compound by oxidizing a methyl group directly bonded to an aromatic ring into a cyano group by ammoxidation. SOLUTION: The present invention relates to a method for producing an aromatic nitrile compound wherein a zeolite carrying at least one selected from the group consisting of an alkali metal and an alkaline earth metal is used to, in the presence of ammonia, oxidize an aromatic compound having a methyl group bound to a carbon atom of an aromatic ring with oxygen. SELECTED DRAWING: Figure 2 COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0053-0065; 0093-0098
(2021/05/07)
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- Biomass chitosan-derived nitrogen-doped carbon modified with iron oxide for the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles
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Nitrogen-doped carbon catalysts have attracted increasing research attention due to several advantages for catalytic application. Herein, cost-effective, renewable biomass chitosan was used to prepare a N-doped carbon modified with iron oxide catalyst (Fe2O3@NC) for nitrile synthesis. The iron oxide nanoparticles were uniformly wrapped in the N-doped carbon matrix to prevent their aggregation and leaching. Fe2O3@NC-800, which was subjected to carbonization at 800 °C, exhibited excellent activity, selectivity, and stability in the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles. This study may provide a new method for the fabrication of an efficient and cost-effective catalyst system for synthesizing nitriles.
- Wang, Wei David,Wang, Fushan,Chang, Youcai,Dong, Zhengping
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- Pd/CoFe2O4/chitosan: A highly effective and easily recoverable hybrid nanocatalyst for synthesis of benzonitriles and reduction of 2-nitroaniline
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In this study, a novel catalyst system with high activity and easy recoverability was successfully prepared through the deposition of Pd nanoparticles (NPs) onto designed sustainable hybrid beads containing magnetic cobalt ferrite and chitosan (Pd/CoFe2O4/chitosan). The catalytic potential of Pd/CoFe2O4/chitosan hybrid nanocatalyst was then assessed in i) preparation of benzonitriles via aryl halides cyanation and ii) reduction of 2-nitroaniline (2-NA). Various aryl iodides and bromides were successfully cyanated by Pd/CoFe2O4/chitosan hybrid nanocatalyst with excellent reaction yields within 3 h. In addition to the production of benzonitriles, the hybrid nanocatalyst showed excellent activity by reducing 2-NA in 65 s. It was proved that the Pd/CoFe2O4/chitosan hybrid nanocatalyst outperformed many catalysts used in the cyanation of aryl halides and catalytic reduction of 2-NA previously reported in the literature. Moreover, it was found that the designed Pd/CoFe2O4/chitosan hybrid nanocatalyst was easily and effectively separated from the reaction mixture using an external magnet and reused several times in catalytic reactions without considerable loss of catalytic activity.
- Baran, Talat,Nasrollahzadeh, Mahmoud
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- Recyclable and Reusable Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O System for Cyanation of Aryl Chlorides with Potassium Ferrocyanide
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Pd(OAc)2/XPhos–SO3Na in a mixture of poly(ethylene glycol) (PEG-400) and water is shown to be a highly efficient catalyst for the cyanation of aryl chlorides with potassium ferrocyanide. The reaction proceeded smoothly at 100 or 120?oC with K2CO3 or KOAc as base, delivering a variety of aromatic nitriles in good to excellent yields. The isolation of the crude products is facilely performed by extraction with cyclohexane and more importantly, both expensive Pd(OAc)2 and XPhos–SO3Na in PEG-400/H2O system could be easily recycled and reused at least six times without any apparent loss of catalytic efficiency. Graphical Abstract: Palladium-catalyzed cyanation of aryl chlorides with potassium ferrocyanide leading to aryl nitriles by using Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O as a highly efficient and recyclable catalytic system is described.[Figure not available: see fulltext.]
- Cai, Mingzhong,Huang, Bin,Liu, Rong,Xu, Caifeng
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- One pot synthesis of aryl nitriles from aromatic aldehydes in a water environment
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In this study, we found a green method to obtain aryl nitriles from aromatic aldehyde in water. This simple process was modified from a conventional method. Compared with those approaches, we used water as the solvent instead of harmful chemical reagents. In this one-pot conversion, we got twenty-five aryl nitriles conveniently with pollution to the environment being minimized. Furthermore, we confirmed the reaction mechanism by capturing the intermediates, aldoximes.
- Chen, Qingqing,Han, Hongwei,Lin, Hongyan,Ma, Xiaopeng,Qi, Jinliang,Wang, Xiaoming,Yang, Yonghua,Zhou, Ziling
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p. 24232 - 24237
(2021/07/29)
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- Sequential Ir/Cu-Mediated Method for the Meta-Selective C-H Radiofluorination of (Hetero)Arenes
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This article describes a sequential Ir/Cu-mediated process for the meta-selective C-H radiofluorination of (hetero)arene substrates. In the first step, Ir-catalyzed C(sp2)-H borylation affords (hetero)aryl pinacolboronate (BPin) esters. The intermediate organoboronates are then directly subjected to copper-mediated radiofluorination with [18F]tetrabutylammonium fluoride to afford fluorine-18 labeled (hetero)arenes in high radiochemical yield and radiochemical purity. This entire process is performed on a benchtop without Schlenk or glovebox techniques and circumvents the need to isolate (hetero)aryl boronate esters. The reaction was automated on a TracerLab FXFN module with 1,3-dimethoxybenzene and a meta-tyrosine derivative. The products, [18F]1-fluoro-3,5-dimethoxybenzene and an 18F-labeled meta-tyrosine derivative, were obtained in 37 ± 5% isolated radiochemical yield and >99% radiochemical purity and 25% isolated radiochemical yield and 99% radiochemical purity, and 0.52 Ci/μmol (19.24 GBq/μmol) molar activity (Am), respectively.
- Wright, Jay S.,Sharninghausen, Liam S.,Preshlock, Sean,Brooks, Allen F.,Sanford, Melanie S.,Scott, Peter J. H.
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supporting information
p. 6915 - 6921
(2021/05/29)
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- Copper-promoted cyanation of aryl iodides with N,N-dimethyl aminomalononitrile
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A copper-promoted cyanation of aryl iodides has been successfully developed by using N,N-dimethyl aminomalononitrile as the cyanide source with moderate toxicity and better stability. This reaction features broad substrate scope, excellent reaction yields, readily available catalyst, and simple reaction conditions.
- Liu, Si-Zhan,Li, Jing,Xue, Cao-Gen,Xu, Xue-Tao,Lei, Lin-Sheng,Huo, Chen-Yu,Wang, Zhen,Wang, Shao-Hua
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supporting information
(2021/02/01)
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- Pd@CeO2-catalyzed cyanation of aryl iodides with K4Fe(CN)6·3H2O under visible light irradiation
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Cyanation of aryl iodides is still challenging work for chemical researchers because of harsh reaction conditions and toxic cyanide sources. Herein, we have developed a new protocol based on the combination of the catalyst Pd@CeO2, nontoxic cyanide source K4[Fe (CN)6]·3H2O, and driving force visible light irradiation. The reaction is operated at relatively moderate temperature (55°C) and exhibits good catalytic efficiency of product aryl nitriles (yields of 89.4%). Moreover, the catalyst Pd@CeO2 possesses good reusability with a slight loss of photocatalytic activity after five consecutive runs. The reaction system based on the above combination shows a wide range of functional group tolerance under the same conditions. Reaction conditions such as temperature, time, the component of catalyst, and solutions are optimized by studying cyanation of 1-iodo-4-nitrobenzene as model reaction. According to these results, the possible mechanism of Pd@CeO2-catalyzed cyanation of aryl iodides under visible light irradiation is proposed based on the influence of visible light on the catalyst and reactant compounds. In all, we provided an environmental and economic method for preparation of aryl nitriles from cyanation of aryl iodides based on the goal of green chemistry for sustainable development.
- Wang, Shengyu,Wang, Jianqiang,Pan, Junyi,Liu, Cheng,Gong, Xubin,Guo, Cheng
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- Decarbonylative Synthesis of Aryl Nitriles from Aromatic Esters and Organocyanides by a Nickel Catalyst
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A decarbonylative cyanation of aromatic esters with aminoacetonitriles in the presence of a nickel catalyst was developed. The key to this reaction was the use of a thiophene-based diphosphine ligand, dcypt, permitting the synthesis of aryl nitrile without the generation of stoichiometric metal- or halogen-containing chemical wastes. A wide range of aromatic esters, including hetarenes and pharmaceutical molecules, can be converted into aryl nitriles.
- Iizumi, Keiichiro,Kurosawa, Miki B.,Isshiki, Ryota,Muto, Kei,Yamaguchi, Junichiro
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supporting information
p. 1555 - 1559
(2020/11/10)
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- A Combined Experimental–Theoretical Study on Diels-Alder Reaction with Bio-Based Furfural: Towards Renewable Aromatics
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The synthesis of relevant renewable aromatics from bio-based furfural derivatives and cheap alkenes is carried out by using a Diels-Alder/aromatization sequence. The prediction and the control of the ortho/meta selectivity in the Diels-Alder step is an important issue to pave the way to a wide range of renewable aromatics, but it remains a challenging task. A combined experimental-theoretical approach reveals that, as a general trend, ortho and meta cycloadducts are the kinetic and thermodynamic products, respectively. The nature of substituents, both on the dienes and dienophiles, significantly impacts the feasibility of the reaction, through a modulation on the nucleo- and electrophilicity of the reagents, as well as the ortho/meta ratio. We show that the ortho/meta selectivity at the reaction equilibrium stems from a subtle interplay between charge interactions, favoring the ortho products, and steric interactions, favoring the meta isomers. This work also points towards a path to optimize the aromatization step.
- van Scodeller,De Oliveira Vigier, Karine,Muller, Eric,Ma, Changru,Guégan, Frédéric,Wischert, Raphael,Jér?me, Fran?ois
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p. 313 - 323
(2020/10/19)
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- Method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by Ru coordination compound
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The invention discloses a method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by a Ru coordination compound. The method comprises: adding a Ru coordination compound, an alkali, a primary amine and an organic solvent into a reaction test tube according to a mol ratio of 1:100:(100-500):1000-3000, and carrying out a stirring reaction under the condition of 80 to120 DEG C; and when gas chromatography monitors that the raw materials completely disappear, stopping the reaction, collecting the reaction solution, centrifuging the reaction solution, taking the supernatant, extracting with dichloromethane, merging the organic phases, drying, filtering, evaporating the organic solvent under reduced pressure to obtain a filtrate, and carrying out column chromatography purification on the filtrate to obtain the target product nitrile. According to the invention, the catalyst is good in activity, single in catalytic system, good in product selectivity, simple in subsequent treatment and good in system universality after the reaction is finished, has a good catalytic effect on various aryl, alkyl and heteroaryl substituted primary amines, and also has a gooddehydrogenation performance on secondary amines.
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Paragraph 0034-0039; 0100-0105
(2020/09/16)
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- Silicon hydrogenation reaction method of organic boron and inorganic alkali catalysis amide (by machine translation)
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The method is characterized in that organic boron and inorganic bases are used as catalysts, silane is used as a reducing agent, primary amide is reduced to primary amine or dehydration dinitrile, the secondary amide is reduced to a secondary amine or aldimine, and the tertiary amide is reduced to tertiary amine. The method has the advantages of simple operation, mild reaction conditions, wide substrate universality, good functional group compatibility and the like, and has the characteristics of good stability, cheap and accessible catalyst, simple and convenient operation, high practicality and the like. (by machine translation)
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Paragraph 0201-0207; 0229-0232
(2020/08/18)
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- Method for continuous preparation of nitriles in a pipelined reactor (by machine translation)
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The method comprises the following steps that a tin catalyst is coated on the inner wall of the pipeline reactor; and the method comprises the following steps: coating a tin catalyst on the inner wall of the pipeline reactor. The amide solution and the catalytic auxiliary agent are mixed and then sent to a pipeline reactor, and the amide is dehydrated to generate nitrile at the reaction pressure of 0.1 - 2.0 mpa and 100 - 200 °C reaction temperature. The resulting reaction product was separated to give the crude product of the nitrile to which the amide corresponded. In the pipeline reactor, the corresponding nitrile is continuously prepared under the action of the tin catalyst, a dehydrating agent is not needed, byproducts only are water, and three wastes are reduced. (by machine translation)
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Paragraph 0036-0047; 0056-0057
(2020/12/14)
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- Acceptorless dehydrogenation of amines to nitriles catalyzed by N-heterocyclic carbene-nitrogen-phosphine chelated bimetallic ruthenium (II) complex
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We have developed a clean, atom-economical and environmentally friendly route for acceptorless dehydrogenation of amines to nitriles by combining a new dual N-heterocyclic carbene-nitrogen-phosphine ligand R(CNP)2 (R = o-xylyl) with a ruthenium precursor [RuCl2(η6-C6H6)]2. In this system, the electronic and steric factors of amines had a negligible influence on the reaction and a broad range of functional groups were well tolerated. All of the investigated amines could be converted to nitriles in good yield of up to 99% with excellent selectivity. The unprecedented catalytic performance of this system is attributed to the synergistic effect of two ruthenium centers chelated by R(CNP)2 and a plausible reaction mechanism is proposed according to the active species found via in situ NMR and HRMS.
- Chen, Hua,Fu, Haiyan,Ji, Li,Li, Ruixiang,Nie, Xufeng,Zheng, Yanling
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p. 378 - 385
(2020/10/02)
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- Aerobic oxidation of primary benzylic amines to amides and nitriles catalyzed by ruthenium carbonyl clusters carrying N,O-bidentate ligands
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Four trinuclear ruthenium carbonyl clusters, (6-BrPyCHRO)2Ru3(CO)8 (R = 4-OCH3C6H4, 1a; R = 4-BrC6H4, 1b) and (2-OC6H4-HCN-C6H4R)2Ru3(CO)8 (R = 4-OCH3, 2a; R = 4-Br, 2b), were synthesized from the reactions of Ru3(CO)12 with the corresponding N,O-bidentate ligands (two pyridyl alcohols and two Schiff bases) respectively in a ratio of 1:2. Three new complexes 1b, 2a and 2b have been fully characterized by elemental analysis, FT-IR, NMR and X-ray crystallography. The catalytic activity of these ruthenium complexes for the aerobic oxidation of primary benzylic amines to amides and nitriles in the presence of t-BuOK was investigated, of which the Schiff base complex 2a was found to exhibit the highest activity.
- Dong, Qing,Han, Zhangang,Hao, Zhiqiang,Li, Ying,Lin, Jin,Lu, Guo-Liang,Meng, Lizhen,Yan, Xinlong
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p. 3480 - 3487
(2020/04/02)
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- Nitrosation of Cyanamide: Preparation and Properties of the Elusive E- and Z-N'-Cyanodiazohydroxides
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Nitrosation of cyanamide leads to unstable E/Z-cyanodiazohydroxides that easily deprotonate to E/Z-cyanodiazotates. Pursuing observations of E. Drechsel 145 years ago, the structure and reactivity of those products was determined, mainly in aqueous solution. Depending on the pH, three different thermal decomposition pathways give either N2O + HCN or N2 + HNCO. They were evaluated experimentally and by quantum mechanical calculations.
- Guethner, Thomas,Huber, Evi,Sans, Juergen,Thalhammer, Franz
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supporting information
(2020/04/29)
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- An Air-Stable N-Heterocyclic [PSiP] Pincer Iron Hydride and an Analogous Nitrogen Iron Hydride: Synthesis and Catalytic Dehydration of Primary Amides to Nitriles
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An air-stable N-heterocyclic PSiP pincer iron hydride FeH(PMe3)2(SiPh(NCH2PPh2)2C6H4) (4) was synthesized by Si-H activation of a Ph-substituted [PSiP] pincer ligand. The analogous strong electron-donating iPr-substituted [PSiP] pincer ligand was prepared and introduced into iron complex to give an iron nitrogen complex FeH(N2)(PMe3)(SiPh(NCH2PiPr2)2C6H4) (6). Both 4 and 6 showed similar high efficiency for catalytic dehydration of primary amides to nitriles. Air-stable iron hydride 4 was the best catalyst for its stabilization and convenient preparation. A diverse range of cyano compounds including aromatic and aliphatic species was obtained in moderate to excellent yields. A plausible catalytic reaction mechanism was proposed.
- Fenske, Dieter,Fuhr, Olaf,Li, Xiaoyan,Sun, Hongjian,Wang, Yajie,Xie, Shangqing,Zhang, Hua
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- Lewis acid promoted dehydration of amides to nitriles catalyzed by [PSiP]-pincer iron hydrides
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The dehydration of primary amides to their corresponding nitriles using four [PSiP]-pincer hydrido iron complexes 1–4 [(2-Ph2PC6H4)2MeSiFe(H)(PMe3)2 (1), (2-Ph2PC6H4)2HSiFe(H)(PMe3)2 (2), (2-(iPr)2PC6H4)2HSiFe(H)(PMe3)2 (3) and (2-(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (4)] as catalysts in the presence of (EtO)3SiH as dehydrating reagent was explored in the good to excellent yields. It was proved for the first time that Lewis acid could significantly promote this catalytic system under milder reaction conditions than other Lewis acid-promoted system, such as shorter reaction time or lower reaction temperature. This is also the first example that dehydration of primary amides to nitriles was catalyzed by silyl hydrido iron complexes bearing [PSiP]-pincer ligands with Lewis acid as additive. This catalytic system has good tolerance for many substituents. Among the four iron hydrides 1 is the best catalyst. The effects of substituents of the [PSiP]-pincer ligands on the catalytic activity of the iron hydrides were discussed. A catalytic reaction mechanism was proposed. Complex 4 is a new iron complex and was fully characterized. The molecular structure of 4 was determined by single crystal X-ray diffraction.
- Chang, Guoliang,Li, Xiaoyan,Zhang, Peng,Yang, Wenjing,Li, Kai,Wang, Yajie,Sun, Hongjian,Fuhr, Olaf,Fenske, Dieter
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- NHC-catalyzed silylative dehydration of primary amides to nitriles at room temperature
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Herein we report an abnormal N-heterocyclic carbene catalyzed dehydration of primary amides in the presence of a silane. This process bypasses the energy demanding 1,2-siloxane elimination step usually required for metal/silane catalyzed reactions. A detailed mechanistic cycle of this process has been proposed based on experimental evidence along with computational study.
- Ahmed, Jasimuddin,Hota, Pradip Kumar,Maji, Subir,Mandal, Swadhin K.,Rajendran, N. M.
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supporting information
p. 575 - 578
(2020/01/29)
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- Pd NPs?Fe3O4/chitosan/pumice hybrid beads: A highly active, magnetically retrievable, and reusable nanocatalyst for cyanation of aryl halides
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In this study, Fe3O4/chitosan/pumice hybrid beads were developed as a new stabilizer agent, and palladium nanoparticles (Pd NPs) were successfully decorated on the designed stabilizer without adding any toxic reducing resource. Then, the potential use of Pd NPs?Fe3O4/chitosan/pumice hybrid beads as a heterogeneous catalyst against different aryl halide cyanations was investigated with K4[Fe(CN)6]. In these reactions, Pd NPs? Fe3O4/chitosan /pumice hybrid beads showed high catalytic activity by converting aryl halides to the desired benzonitriles with high product yields (80 %–98 %). Due to the magnetically separable nature of Pd NPs?Fe3O4/chitosan/pumice hybrid beads, they were reused several times, and 86 % yield was obtained even after six successive runs. This paper reveals that Pd NPs?Fe3O4/chitosan/pumice hybrid beads have a high potential to synthesis a broad range of nitriles due to their excellent catalytic and retrievable capability.
- Baran, Talat
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- An Efficient Synthesis of Nitriles from Aldoximes in the Presence of Trifluoromethanesulfonic Anhydride in Mild Conditions
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Abstract: A new and convenient protocol has been proposed for the transformation of aldoximes to nitriles using trifluoromethanesulfonic anhydride and triethylamine. The proposed method allows a range of aldoximes, including aromatic, heterocyclic, aliphatic, and cycloaliphatic aldoximes, to be converted to the corresponding nitriles in good to excellent yields.
- Uludag, N.
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p. 1640 - 1645
(2020/10/22)
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- SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)
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A simple, mild and practical cascade process for the direct conversion of aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various complicated molecules.
- Ding, Chengrong,Ge, Shuting,Wei, Junjie,Zhang, Guofu,Zhao, Yiyong
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p. 17288 - 17292
(2020/05/18)
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- Rate Constants of the CN + Toluene Reaction from 15 to 294 K and Interstellar Implications
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CN is known for its fast reactions with hydrocarbons at low temperatures, but relatively few studies have focused on the reactions between CN and aromatic molecules. The recent detection of benzonitrile in the interstellar medium, believed to be produced by the reaction of CN and benzene, has ignited interest in studying these reactions. Here, we report rate constants of the CN + toluene (C7H8) reaction between 15 and 294 K using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme; reaction kinetics in uniform supersonic flow) apparatus coupled with the pulsed laser photolysis-laser-induced fluorescence (PLP-LIF) technique. We also present the stationary points on the potential energy surface of this reaction to study the available reaction pathways. We find the rate constant does not change over this temperature range, with an average value of (4.1 ± 0.2) × 10-10 cm3 s-1, which is notably faster than the only previous measurement at 105 K. While the reason for this disagreement is unknown, we discuss the possibility that it is related to enhanced multiphoton effects in the previous work.
- Cooke, Ilsa R.,Gupta, Divita,Messinger, Joseph P.,Okumura, Mitchio,Sims, Ian R.
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p. 7950 - 7958
(2020/11/09)
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- Green synthesis of palladium nanocatalyst derived from the β-cyclodextrin used as effective heterogeneous catalyst for cyanation of aryl halides
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In this study, preparation of highly stable palladium nanoparticles (Pd NPs) on Schiff base modified β-cyclodextrin (β-CD-Sch) in the absence of reducing agents has been successfully carried out. Pd NPs&at;β-CD-Sch has then been applied as nanocatalyst in the synthesis of benzonitriles via cyanation reaction using K4Fe(CN)6, which is a low cost, commercially available and non-toxic cyanide source. A series of benzonitriles containing different substrates were successfully fabricated with 77–98percent yields using Pd NPs&at;β-CD-Sch. Moreover, Pd NPs&at;β-CD-Sch catalyst was quantitatively recovered and reutilized several times, showing good reaction yields. This work revealed that i) prepared β-CD-Sch is an effective stabilizer for the fabrication of Pd NPs and ii) Pd NPs&at;β-CD-Sch catalyst play an important role in the fabrication of benzonitriles.
- Baran, Talat,Nasrollahzadeh, Mahmoud
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- Zn-catalyzed cyanation of aryl iodides
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We report the first example of zinc-catalyzed cyanation of aryl iodides with formamide as the cyanogen source. The transformation was promoted by the bisphosphine Nixantphos ligand. Under optimized conditions, a variety of electron-donating and electron-withdrawing aryl iodides were converted into nitrile products in good to excellent yields. This approach is an exceedingly simple and benign method for the synthesis of aryl nitriles and is likely to proceed via a dinuclear Zn-concerted catalysis.
- Zhao, Lulu,Dong, Yanan,Xia, Qiangqiang,Bai, Jianfei,Li, Yuehui
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p. 6471 - 6477
(2020/06/08)
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- Efficient dehydration of primary amides to nitriles catalyzed by phosphorus-chalcogen chelated iron hydrides
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A series of phosphorus-chalcogen chelated hydrido iron (II) complexes 1–7, (o-(R'2P)-p-R-C6H4Y)FeH (PMe3)3 (1: R = H, R' = Ph, Y = O; 2: R = Me, R' = Ph, Y = O; 3: R = H, R' = iPr, Y = O; 4: R = Me, R' = iPr, Y = O; 5: R = H, R' = Ph, Y = S; 6: R = Me, R' = Ph, Y = S; 7: R = H, R' = Ph, Y = Se), were synthesized. The catalytic performances of 1–7 for dehydration of amides to nitriles were explored by comparing three factors: (1) different chalcogen coordination atoms Y; (2) R' group of the phosphine moiety; (3) R substituent group at the phenyl ring. It is confirmed that 5 with S as coordination atom has the best catalytic activity and 7 with Se as coordination atom has the poorest catalytic activity among complexes 1, 5 and 7. Electron-rich complex 4 is the best catalyst among the seven complexes and the dehydration reaction was completed by using 2 mol% catalyst loading at 60 °C with 24 hr in the presence of (EtO)3SiH in THF. Catalyst 4 has good tolerance to many functional groups. Among the seven iron complexes, new complexes 3 and 4 were obtained via the O-H bond activation of the preligands o-iPr2P(C6H4)OH and o-iPr2P-p-Me-(C6H4)OH by Fe(PMe3)4. Both 3 and 4 were characterized by spectroscopic methods and X-ray diffraction analysis. The catalytic mechanism was experimentally studied and also proposed.
- Li, Kai,Sun, Hongjian,Yang, Wenjing,Wang, Yajie,Xie, Shangqing,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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- Ru@UiO-66(Ce) catalyzed acceptorless dehydrogenation of primary amines to nitriles: The roles of Lewis acid-base pairs in the reaction
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UiO-66(Ce)-encapsulated ruthenium nanoparticles (Ru@UiO-66(Ce)) was designed and used for dehydrogenation of primary amines to nitriles in water without any hydrogen acceptors and additives. Introduction of metal Ru to UiO-66(Ce) contributes to the formation of Lewis acid-base pairs on the catalyst owing to the metal-support interaction, acting as active sites for activation of amines and transfer of hydrogen. Ab initio calculation results further confirm the roles of Lewis acid-base pairs in the reaction.
- Lu, Guo-Ping,Li, Xinxin,Zhong, Lixiang,Li, Shuzhou,Chen, Fei
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supporting information
p. 5386 - 5393
(2019/10/11)
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- A BEt3-Base catalyst for amide reduction with silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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- A BEt3-Base Catalyst for Amide Reduction with Silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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p. 6084 - 6093
(2019/05/24)
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- Dehydration of primary amides to nitriles catalyzed by [CNC]-pincer hydrido cobalt(III) complexes
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The dehydration reactions from primary amides to nitriles were catalyzed by the [CNC]-pincer hydrido cobalt(III) complexes [(ortho-F4C6–CH[dbnd]N–C10H6)Co(III)(H)(PMe3)2] (1), [(2,5-F2C6H2–CH[dbnd]N–C10H6)Co(III)(H)(PMe3)2] (2) and [(2,4,5-F3C6H–CH[dbnd]N–C10H6)Co(III)(H)(PMe3)2] (3) as catalysts with (EtO)3SiH as an efficient reducing agent. These hydrido cobalt(III) complexes as catalysts are suitable for many substrates and have good functional group tolerance. Among the three cobalt hydrides, complex 2 is the best catalyst. This is the first hydrido cobalt complex-catalyzed dehydration of primary amides to nitriles.
- Ren, Shishuai,Wang, Yangyang,Yang, Fei,Sun, Hongjian,Li, Xiaoyan
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- Primary amides to amines or nitriles: A dual role by a single catalyst
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We report a manganese-catalyzed hydrosilylative reduction of various primary amides to amines (25 examples). On simple modification of the reaction conditions such as in the presence of a catalytic amount of secondary amide, the same catalyst can transform the primary amides into intermediate nitrile compounds (16 examples) in excellent yields. This is the first example where such a controlled catalytic transformation of primary amides to amines or nitriles with a single catalyst has been demonstrated.
- Das, Hari S.,Das, Shyamal,Dey, Kartick,Singh, Bhagat,Haridasan, Rahul,Das, Arpan,Ahmed, Jasimuddin,Mandal, Swadhin K.
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supporting information
p. 11868 - 11871
(2019/10/11)
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- Transformation of aromatic bromides into aromatic nitriles with n-BuLi, pivalonitrile, and iodine under metal cyanide-free conditions
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Various aromatic nitriles could be obtained in good yields by the treatment of aryl bromides with n-butyllithium and then pivalonitrile, followed by the treatment with molecular iodine at 70 °C, without metal cyanides under transition-metal-free conditions. The present reaction proceeds through the radical β-elimination of imino-nitrogen-centered radicals formed from the reactions of imines and N-iodoimines under warming conditions.
- Uchida, Ko,Togo, Hideo
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- Uniform silver nanoparticles on tunable porous N-doped carbon nanospheres for aerobic oxidative synthesis of aryl nitriles from benzylic alcohols
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Tunable N-doped carbon nanospheres from sucrose as carbon source and Tris(2-aminoethyl)amine (TAEA) as nitrogen source by a simple and easily reproducible method were prepared. It was demonstrated that the tunable N-doping of carbon spheres could be realized by altering the ratio of TAEA in the raw materials. The content of doped nitrogen, surface area, pore volume and pore size of carbon nanospheres were increased with the increasing of TAEA amount in the hydrothermal process. Prepared N-doped carbon nanospheres act as solid ligand for anchoring of Ag NPs which generated via chemical reduction of Ag ions. Benzylic alcohols and aldehydes were converted into the aryl nitriles by using Ag/N-CS-1 nanospheres as the catalyst and O2 as the oxidant, efficiently. This catalyst was stable and could use for 6 successful runs.
- Hashemi, Alireza Nemati,Eshghi, Hossein,Lamei, Kamran
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- Enhanced catalytic activity of cobalt nanoparticles encapsulated with an N-doped porous carbon shell derived from hollow ZIF-8 for efficient synthesis of nitriles from primary alcohols in water
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A cobalt catalyst derived from a unique core-shell structure based on hollow ZIF-8 and ZIF-67 (ZIF-67@ZIF-8) is prepared, which exhibits excellent catalytic efficiency for the synthesis of nitriles from alcohols in water under mild conditions (1 atm O2, 50 °C) owing to its large BET surface area, high pore volume, high basicity and hydrophilicity.
- Sun, Kang-Kang,Sun, Jia-Lin,Lu, Guo-Ping,Cai, Chun
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supporting information
p. 4334 - 4340
(2019/08/21)
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- Visible light-induced direct conversion of aldehydes into nitriles in aqueous medium using Co@g-C3N4 as photocatalyst
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Unprecedented Co@g-C3N4 catalyzed visible light driven efficient conversion of a variety of aldehydes into corresponding nitriles is reported. Operational simplicity, excellent yield of pure products (87–94%), ambient reaction condition, using aqueous methanol as solvent, visible-light photocatalysis are the salient features of envisaged methodology for direct conversion of aldehydes into nitriles. Furthermore, reusability of Co@g-C3N4 was checked up to five runs and it was noticed that there was no substantial change in morphology as well as the catalytic efficiency of catalyst.
- Verma, Fooleswar,Shukla, Prashant,Bhardiya, Smita R.,Singh, Manorama,Rai, Ankita,Rai, Vijai K.
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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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- Nickel-Catalyzed Decarbonylative Cyanation of Acyl Chlorides
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Ni-catalyzed decarbonylative cyanation of acyl chlorides with trimethylsilyl cyanide has been achieved. This transformation is applicable to the synthesis of an array of nitrile compounds bearing a wide range of functional groups under neutral conditions. The step-by-step experimental studies revealed that the reaction sequences of the present catalytic reaction are oxidative addition, transmetalation, decarbonylation, and reductive elimination.
- Wang, Zhenhua,Wang, Xiu,Ura, Yasuyuki,Nishihara, Yasushi
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supporting information
p. 6779 - 6784
(2019/08/26)
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- Method for preparing nitrile
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The invention provides a method for preparing nitrile. Aldoxime carboxylic ester is used as a reactant to prepare a nitrile compound. The aldoxime carboxylic ester can be completely converted into corresponding nitrile under common catalysis of ferric salt and phenol within a few minutes. The method for preparing the nitrile has the advantages of gentle reaction conditions, simple and easy-to-getused reagents, cheap and environment-friendly catalyst, wide substrate application range, simple operation, rapid reaction and the like.
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Paragraph 0015
(2019/06/13)
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- Iron and Phenol Co-Catalysis for Rapid Synthesis of Nitriles under Mild Conditions
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A mild, scalable, high yielding, and rapid route to access diverse nitriles from aldehyde oxime esters enabled by iron(III) and phenol co-catalysis has been developed. The reaction was performed at room temperature to give nitriles in excellent yield within minutes. Mechanistic studies show that the reaction may proceed through a radical process in which benzoyl aldehyde oxime is not only a substrate, but also an ancillary ligand to support iron salt in the promotion of the transformation.
- Meng, Hong,Gao, Sen,Luo, Meiming,Zeng, Xiaoming
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p. 4617 - 4623
(2019/07/15)
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- Pd(II)-immobilized on a nanoporous triazine-based covalent imine framework for facile cyanation of haloarenes with K4Fe(CN)6
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A porous covalent organic framework incorporated with both imine and triazine functionalities (TPA-TCIF) was synthesized by Schiff-base condensation of 2,4,6-tris(4-aminophenyl)triazine and tris(4-formylphenyl)amine under the solvothermal condition of a 1-butanol:1,2-dichlorobenzene mixture. The resulting TPA-TCIF was a highly ordered crystalline network with surface area of 2938 m2 g?1, which was among the highest reported imine-based porous covalent organic frameworks. TPA-TCIF was also stable in water and other organic solvents. Pd(II) was immobilized into TPA-TCIF network and the resultant Pd/TPA-TCIF was tested as a catalyst for the additive-free cyanation of haloarenes with non-toxic K4[Fe(CN)6]. The catalyst showed excellent catalytic activity, and both electron-donating / -withdrawing groups attached to the para- and meta-positions of bromoarenes produced the respective nitriles with good to excellent yields. The catalyst could be reused up to five times without noticeable loss of activity or catalyst poisoning by cyanide ions during the reaction.
- Puthiaraj, Pillaiyar,Yu, Kwangsun,Shim, Sang Eun,Ahn, Wha-Seung
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- Palladium-Catalyzed Methylation of Aryl, Heteroaryl, and Vinyl Boronate Esters
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A method for the direct methylation of aryl, heteroaryl, and vinyl boronate esters is reported, involving the reaction of iodomethane with aryl-, heteroaryl-, and vinylboronate esters catalyzed by palladium and PtBu2Me. This transformation occurs with a remarkably broad scope and is suitable for late-stage derivatization of biologically active compounds via the boronate esters. The unique capabilities of this method are demonstrated by combining carbon-boron bond-forming reactions with palladium-catalyzed methylation in a tandem transformation.
- Haydl, Alexander M.,Hartwig, John F.
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supporting information
p. 1337 - 1341
(2019/02/26)
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- Dual Ligand-Enabled Nondirected C-H Cyanation of Arenes
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Aromatic nitriles are key structural units in organic chemistry and, therefore, highly attractive targets for C-H activation. Herein, the development of an arene-limited, nondirected C-H cyanation based on the use of two cooperatively acting commercially available ligands is reported. The reaction enables the cyanation of arenes by C-H activation in the absence of directing groups and is therefore complementary to established approaches.
- Chen, Hao,Mondal, Arup,Wedi, Philipp,Van Gemmeren, Manuel
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p. 1979 - 1984
(2019/02/19)
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- Palladium-Catalyzed Late-Stage Direct Arene Cyanation
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Methods for direct benzonitrile synthesis are sparse, despite the versatility of cyano groups in organic synthesis and the importance of benzonitriles for the dye, agrochemical, and pharmaceutical industries. We report the first general late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance. The reaction is enabled by a dual-ligand combination of quinoxaline and an amino acid-derived ligand. The method is applicable to direct cyanation of several marketed small-molecule drugs, common pharmacophores, and organic dyes. Benzonitriles are some of the most versatile building blocks for organic synthesis, in particular in the pharmaceutical industry, but general methods to make them by direct C–H functionalization are unknown. In this issue of Chem, Ritter and coworkers describe a late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance, enabled by a palladium-dual-ligand catalyst system. The reaction may serve for the late-stage modification of drug candidates. Aryl nitriles constitute an important class of organic compounds that are widely found in natural products, pharmaceuticals, agricultural chemicals, dyes, and materials. Moreover, nitriles are versatile building blocks to access numerous other important molecular structure groups. However, no general method for direct aromatic C–H cyanation is known. All approaches to date require either an appropriate directing group or reactive electron-rich substrates, such as indoles, which limit their synthetic applications. Here we describe an undirected, palladium-catalyzed late-stage aryl C–H cyanation reaction for the synthesis of complex aryl nitriles that would otherwise be more challenging to produce. The wide substrate scope and good functional-group tolerance of this reaction provide direct and quick access to structural diversity for pharmaceutical and agrochemical development.
- Zhao, Da,Xu, Peng,Ritter, Tobias
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supporting information
p. 97 - 107
(2019/01/21)
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- Ligand-Promoted Non-Directed C?H Cyanation of Arenes
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This article reports the first example of a 2-pyridone accelerated non-directed C?H cyanation with an arene as the limiting reagent. This protocol is compatible with a broad scope of arenes, including advanced intermediates, drug molecules, and natural products. A kinetic isotope experiment (kH/kD=4.40) indicates that the C?H bond cleavage is the rate-limiting step. Also, the reaction is readily scalable, further showcasing the synthetic utility of this method.
- Liu, Luo-Yan,Yeung, Kap-Sun,Yu, Jin-Quan
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supporting information
p. 2199 - 2202
(2019/01/24)
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