- A Convenient Palladium-Catalyzed Aminocarbonylation of Aryl Iodides to Primary Amides under Gas-Free Conditions
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A convenient procedure for the synthesis of aromatic primary amides through palladium-catalyzed aminocarbonylation of aryl iodides has been developed. With ammonium hydrogen carbonate as the solid nitrogen source and formic acid as the liquid CO source, a variety of primary amides were obtained in moderate to excellent yields under gas-free conditions.
- Qi, Xinxin,Ai, Han-Jun,Cai, Chuang-Xu,Peng, Jin-Bao,Ying, Jun,Wu, Xiao-Feng
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- Selective NaOH-catalysed hydration of aromatic nitriles to amides
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The selective synthesis of aromatic and heteroaromatic amides through base-catalysed hydration of nitriles was achieved using inexpensive and commercially available NaOH as the only catalyst. A wide range of nitriles was selectively converted to their corresponding amides. Kinetic studies show that the double hydration of nitriles towards undesirable carboxylic acids is negligible under our reaction conditions.
- Schmid, Thibault E.,Gómez-Herrera, Alberto,Songis, Olivier,Sneddon, Deborah,Révolte, Antoine,Nahra, Fady,Cazin, Catherine S. J.
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- Kinetics of the Reaction between Cobinamide and Isoniazid in Aqueous Solutions
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Abstract: The kinetics and mechanism of the reaction of diaquacobinamide (Cbi(III)) with isoniazid (iso-nicotinoyl hydrazide (INH)) are studied. It is determined that the composition of the products depends on the ratio between the concentrations of the reactants. Adding excess INH to cobinamide results in the rapid formation of a stable complex of Cbi(III) with two isoniazid molecules. If the concentrations of isoniazid and cobinamide are close, or cobinamide is in excess, then a complex of Cbi(III) with one isoniazid molecule initially forms. There is then a fast inner-sphere electron transfer to yield an unstable complex of reduced Cbi(II) with hydrazyl radical (RN2H2)(Cbi(II)) that decomposes to form reduced cobinamide and the products of the oxidation of isoniazid: isonicotinamide, pyridine-4-carboxaldehyde, and isonicotinic acid (INA). It is concluded that with a 1000% excess of cobinamide, the main product of the oxidation of INH is INA.
- Tumakov,Dereven’kov,Sal’nikov,Makarov
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- Synthesis of amidines and benzoxazoles from activated nitriles with Ni(0) catalysts
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Amidines and 2-substituted benzoxazoles were synthesized from N-heterocyclic nitriles under mild conditions (50 °C, 48 h, two steps) in an atom-economical process that involves addition of methanol, the solvent, to a nitrile moiety to yield a methyl imidate and the subsequent extrusion of solvent in the presence of amines to afford the title compounds. Methyl imidate formation was achieved by developing a new catalytic pathway using [(dippe)Ni(H)]2 (dippe = 1,2-bis(diisopropylphosphino)ethane), [Ni(cod)2]/dppe, or [Ni(cod)2]/P(OPh)3 (cod = 1,5-cyclooctadiene, dppe = 1,2-bis(diphenylphosphino)ethane, P(OPh)3 = triphenyl phosphite) as the catalyst precursor. Regarding the ligands, for a given substrate, namely 4-cyanopyridine, the best performance for the Ni(0)-catalyzed system was found for the σ-donor bidentate dippe, whereas the monodentate π acceptor P(OPh)3 was less efficient. In relation to the substrates, for a given Ni-dippe system, steric hindrance and, more importantly, substrate electron-withdrawing character control imidate formation and thus the yield of amidines and benzoxazoles.
- Gardu?o, Jorge A.,Garc?a, Juventino J.
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- Sustainable synthesis of drug intermediates via simultaneous utilization of carbon monoxide and ammonia over Pd@La-MOF
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Mitigation of carbon monoxide and ammonia to valuable primary aromatic amides is an imperative approach to control the environmentally harmful emissions thereby infusing towards sustainability. Designing of nanostructured catalyst for direct access to the synthetically valuable primary aromatic and heteroaromatic amides via carbonylative amination of aryl halides is always demanding since nano materials can bridge the gap between homogeneous and heterogeneous catalysis thus preserving the desirable attributes of both the systems towards sustainable catalysis. Herein, microwave assisted fabrication of highly uniform Pd NPs (3,4 nm) over La-MOFs has been performed and utilized efficiently for ligand free carbonylative amination of aryl iodides with carbon monoxide and ammonia. Moderate to high yields of benzamide derivatives, salicylamide, a drug having analgesic and antipyretic properties were achieved. The unsaturated metal sites in the MOF via synergistic mode of σ and π bonding binds with CO, which significantly enhances the catalytic activity of MOF-composite unlike other supported Pd NPs. DFT confirms the growth of pristine Pd13 cluster within the framework, as active metal center for the carbonylative amination.
- Bhattacharya, Sumantra,Bordoloi, Ankur,Das, Subhasis,Gazi, Jahiruddin,Islam, Sk Manirul,Prasad, V. V. D. N.,Sengupta, Manideepa
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- Mechanochemical Synthesis of Primary Amides
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Ball milling of aromatic, heteroaromatic, vinylic, and aliphatic esters with ethanol and calcium nitride afforded the corresponding primary amides in a transformation that was compatible with a variety of functional groups and maintained the integrity of a stereocenter α to carbonyl. This methodology was applied to α-amino esters and N-BOC dipeptide esters and also to the synthesis of rufinamide, an antiepileptic drug.
- Gómez-Carpintero, Jorge,Sánchez, J. Domingo,González, J. Francisco,Menéndez, J. Carlos
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p. 14232 - 14237
(2021/10/20)
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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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- A CONTINUOUS FLOW SYNTHESIS METHOD FOR THE MANUFACTURE OF ISONIAZID
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A multistep continuous flow synthesis method for the manufacture of isonicotinyl-hydrazide (Isoniazid) comprising reacting 4-cyano pyridine with NaOH at a specified molar ratio and temperature range to produce the intermediate isonicotinamide, which intermediate is reacted with hydrazine hydrate, without isolation thereof, at a specified molar ratio and temperature range to produce isonicotinyl-hydrazide (Isoniazid) in a yield greater than about 90%.
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Page/Page column 10; 12-18
(2021/04/17)
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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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- Cu2O-Catalyzed Conversion of Benzyl Alcohols Into Aromatic Nitriles via the Complete Cleavage of the C≡N Triple Bond in the Cyanide Anion
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Nitrogen transfer from cyanide anion to an aldehyde is emerging as a promising method for the synthesis of aromatic nitriles. However, this method still suffers from a disadvantage that a use of stoichiometric Cu(II) or Cu(I) salts is required to enable the reaction. As we report herein, we overcame this drawback and developed a catalytic method for nitrogen transfer from cyanide anion to an alcohol via the complete cleavage of the C≡N triple bond using phen/Cu2O as the catalyst. The present condition allowed a series of benzyl alcohols to be smoothly converted into aromatic nitriles in moderate to high yields. In addition, the present method could be extended to the conversion of cinnamic alcohol to 3-phenylacrylonitrile.
- Liu, Wenbo,Tang, Peichen,Zheng, Yi,Ren, Yun-Lai,Tian, Xinzhe,An, Wankai,Zheng, Xianfu,Guo, Yinggang,Shen, Zhenpeng
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p. 3509 - 3513
(2021/10/04)
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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 aryl primary amide by adopting metal-catalyzed one-pot method
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The invention discloses a method for synthesizing aryl primary amide by adopting a metal-catalyzed one-pot method. The method comprises the steps of: taking aryl bromidess as raw materials, allowing the aryl bromidess to react with a cyanide source under the action of a palladium catalyst, substituting bromine on an aromatic ring with cyano to obtain cyano aromatic hydrocarbon, directly adding anaqueous solution of alkali into the reaction solution without aftertreatment, and carrying out hydrolysis reaction to obtain aryl primary amide. Compared with the prior art, the method for preparing aryl primary amide from the aryl bromides has the advantages of the short synthesis route, fewer reaction steps, simple operation, mild conditions, the high conversion rate, low toxicity and industrialproduction potential.
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Paragraph 0031; 0032
(2020/04/06)
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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 0136-0137
(2020/06/05)
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- Method for synthesizing amide compound by catalyzing heterocyclic compound through non-metal porous carbon
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The invention discloses a method for synthesizing an amide compound by catalyzing a heterocyclic compound through non-metal porous carbon. The preparation method comprises the following steps of: taking a methyl-containing heterocyclic compound as a raw material, adopting a small molecular nitrogen-containing compound as a nitrogen source, and taking non-metal porous carbon as a catalyst, carryingout reaction for 0.5-48h in an oxidizing atmosphere under a pressure of 0.1-10MPa and a temperature of 50-200DEG C to obtain the amide compound. The method starts from an sp3 C-H bond, adopts oxygenor air serves as an oxidizing agent, takes the nitrogen-containing organic small molecule as a nitrogen source, and employs porous carbon as the catalyst to synthesize the amide compound by one step,and the whole catalytic reaction process has the advantages of high efficiency, short route, low cost, easily available raw materials, etc. In addition, the porous carbon catalyst can be recycled, andmeets the technical requirements of China for establishing a green ecological society.
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Paragraph 0022-0023
(2020/06/20)
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- Pyridine-Enabled C-N Bond Activation for the Rapid Construction of Amides and 4-Pyridylglyoxamides by Cooperative Palladium/Copper Catalysis
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A pyridine-enabled C-N bond activation of peptidomimetics employing cooperative palladium/copper catalysis in water is developed. Diverse amides and 4-pyridylglyoxamides are simultaneously synthesized through two steps from commercially available materials in a rapid, environmentally friendly, and high atom-economical manner.
- Song, Liangliang,Claessen, Sander,Van Der Eycken, Erik V.
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p. 8045 - 8054
(2020/07/15)
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- Transamidation for the Synthesis of Primary Amides at Room Temperature
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Various primary amides have been synthesized using the transamidation of various tertiary amides under metal-free and mild reaction conditions. When (NH4)2CO3 reacts with a tertiary amide bearing an N-electron-withdrawing substituent, such as sulfonyl and diacyl, in DMSO at 25 °C, the desired primary amide product is formed in good yield with good funcctional group tolerance. In addition, N-tosylated lactam derivatives afforded their corresponding N-tosylamido alkyl amide products via a ring opening reaction.
- Chen, Jiajia,Lee, Sunwoo,Xia, Yuanzhi
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supporting information
(2020/05/05)
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- Preparation method of aromatic amide compound
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The present invention provides a preparation method of an aromatic amide compound. In an organic solvent, under the effect of a catalyst, an aromatic acid compound and an amine source are subjected toa dehydration reaction to obtain the aromatic amide compound, wherein the aromatic acid compound is an aromatic acid, a substituted aromatic acid, a heterocyclic aromatic acid or a substituted heterocyclic aromatic acid; and the substituent group of amide is any substituent group of H, a C1-C8 straight-chain alkyl or branched-chain alkyl group, a benzene ring or an aromatic ring. The aromatic amide compound is an important chemical intermediate, and the synthesis method is mild in reaction condition and high in yield.
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Paragraph 0050-0051
(2020/07/15)
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- Metal-free nitrogen -doped carbon nanosheets: A catalyst for the direct synthesis of imines under mild conditions
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Herein, a highly stable, porous, multifunctional and metal-free catalyst was developed, which exhibited significant catalytic performance in the oxidation of amines and transfer hydrogenation of nitriles under mild conditions; this could be attributed to the presence of numerous active sites and their outstanding BET surface area. The obtained results showed that most of the yields of imines exceeded 90%, and the cycling performance of the catalyst could be at least seven runs without any decay in the reaction activity, which could be comparable to those of metal catalysts. Subsequently, a kinetic study has demonstrated that the apparent activation energy for the direct synthesis of imines from amines is 67.39 kJ mol-1, which has been performed to testify that the catalytic performances are rational. Via catalyst characterizations and experimental data, graphitic-N has been proven to be the active site of the catalyst. Hence, this study is beneficial to comprehend the mechanism of action of a metal-free N-doped carbon catalyst in the formation of imines.
- Wang, Kaizhi,Jiang, Pengbo,Yang, Ming,Ma, Ping,Qin, Jiaheng,Huang, Xiaokang,Ma, Lei,Li, Rong
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p. 2448 - 2461
(2019/05/17)
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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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- 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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- 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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- Light-Activated generation of nitric oxide (NO) and sulfite anion radicals (SO3-) from a ruthenium(ii) nitrosylsulphito complex
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This manuscript describes the preparation of a new Ru(ii) nitrosylsulphito complex, trans-[Ru(NH3)4(isn)(N(O)SO3)]+ (complex 1), its spectroscopic and structural characterization, photochemistry, and thermal reactivity. Complex 1 was obtained by the reaction of sulfite ions (SO32-) with the nitrosyl complex trans-[Ru(NH3)4(isn)(NO)]3+ (complex 2) in aqueous solution resulting in the formation of the N-bonded nitrosylsulphito (N(O)SO3) ligand. To the best of our knowledge, only four nitrosylsulphito metal complexes have been described so far (J. Chem. Soc., Dalton Trans., 1983, 2465-2472), and there is no information about the photochemistry of such complexes. Complex 1 was characterized by spectroscopic means (UV-Vis, EPR, FT-IR, 1H-and 15N-NMR), elemental analysis and single-crystal X-ray diffraction. The X-ray structure of the precursor complex 2 is also discussed in the manuscript and is used as a reference for comparisons with the structure of 1. Complex 1 is water-soluble and kinetically stable at pH 7.4, with a first-order rate constant of 3.1 × 10-5 s-1 for isn labilization at 298 K (t1/2 ～ 373 min). Under acidic conditions (1.0 M trifluoroacetic acid), 1 is stoichiometrically converted into the precursor complex 2. The reaction of hydroxide ions (OH-) with 1 and with 2 yields the Ru(ii) nitro complex trans-[Ru(NH3)4(isn)(NO2)]+ with second-order rate constants of 2.1 and 10.5 M-1 s-1 (at 288 K), respectively, showing the nucleophilic attack of OH- at the nitrosyl in 2 (Ru-NO) and at the nitrosylsulphito in 1 (Ru-N(O)SO3). The pKa value of the-SO3 moiety of the N(O)SO3 ligand in 1 was determined to be 5.08 ± 0.06 (at 298 K). The unprecedented photochemistry of a nitrosylsulphito complex is investigated in detail with 1. The proposed mechanism is based on experimental (UV-Vis, EPR, NMR and Transient Absorption Laser Flash Photolysis) and theoretical data (DFT) and involves photorelease of the N(O)SO3- ligand followed by formation of nitric oxide (NO) and sulfite radicals (SO3-, sulfur trioxide anion radical).
- Roveda, Antonio C.,Santos, Willy G.,Souza, Maykon L.,Adelson, Charles N.,Gon?alves, Felipe S.,Castellano, Eduardo E.,Garino, Claudio,Franco, Douglas W.,Cardoso, Daniel R.
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supporting information
p. 10812 - 10823
(2019/07/31)
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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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- 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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- 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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- Mn(i) organometallics containing the iPr2P(CH2)2PiPr2 ligand for the catalytic hydration of aromatic nitriles
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The first example of a homogeneous hydration of aromatic nitriles catalyzed by manganese molecular compounds is reported. The Mn(i) organometallics fac-[(CO)3Mn(dippe)(Z)]1-nX1-n (n = 0, 1; Z = Br, OTf, PhCN; X = OTf) were synthesized and characterized, and their reactivity was studied. The species fac-[(CO)3Mn(dippe)(OTf)] (2) was used as a catalyst precursor for the selective hydration of benchmark benzonitrile (2 mol% 2, THF/H2O 1:2 v/v, 18 h, 100 °C) to produce benzamide in 90% isolated yield. A series of (hetero)aromatic nitriles were hydrated to synthesize the corresponding amides in very good to excellent yields (88-94%). Isotopic labeling studies accounted for a proton transfer as the rate-determining step.
- Gardu?o, Jorge A.,Arévalo, Alma,Flores-Alamo, Marcos,García, Juventino J.
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p. 2606 - 2616
(2018/05/30)
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- Nitrile Hydration Reaction Using Copper Iodide/Cesium Carbonate/DBU in Nitromethane-Water
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The catalytic nitrile hydration (amide formation) in a copper iodide/cesium carbonate/1,8-diazabicyclo[5.4.0]undec-7-ene/nitromethane-water system is described. The protocol is robust and reliable; it can be applied to a broad range of substrates with high chemoselectivity.
- Kuwabara, Jun,Sawada, Yoshiharu,Yoshimatsu, Mitsuhiro
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supporting information
p. 2061 - 2065
(2018/09/14)
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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 0093; 0094
(2018/10/19)
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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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- Corresponding amine nitrile and method of manufacturing thereof
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The invention relates to a manufacturing method of nitrile. Compared with the prior art, the manufacturing method has the characteristics of significantly reduced using amount of an ammonia source, low environmental pressure, low energy consumption, low production cost, high purity and yield of a nitrile product and the like, and nitrile with a more complex structure can be obtained. The invention also relates to a method for manufacturing corresponding amine from nitrile.
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Paragraph 0135; 0136; 0137; 0139
(2018/05/07)
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- Phosphinous Acid-Assisted Hydration of Nitriles: Understanding the Controversial Reactivity of Osmium and Ruthenium Catalysts
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The synthesis and catalytic behavior of the osmium(II) complexes [OsCl2(η6-p-cymene)(PR2OH)] [R=Me (2 a), Ph (2 b), OMe (2 c), OPh (2 d)] in nitrile hydration reactions is presented. Among them, the best catalytic results were obtained with the phosphinous acid derivative [OsCl2(η6-p-cymene)(PMe2OH)] (2 a), which selectively provided the desired primary amides in excellent yields and short times at 80 °C, employing directly water as solvent, and without the assistance of any basic additive (TOF values up to 200 h?1). The process was successful with aromatic, heteroaromatic, aliphatic, and α,β-unsaturated organonitriles, and showed a high functional group tolerance. Indeed, complex 2 a represents the most active and versatile osmium-based catalyst for the hydration of nitriles reported so far in the literature. In addition, it exhibits a catalytic performance similar to that of its ruthenium analogue [RuCl2(η6-p-cymene)(PMe2OH)] (4). However, when compared to 4, the osmium complex 2 a turned out to be faster in the hydration of less-reactive aliphatic nitriles, whereas the opposite trend was generally observed with aromatic substrates. DFT calculations suggest that these differences in reactivity are mainly related to the ring strain associated with the key intermediate in the catalytic cycle, that is, a five-membered metallacyclic species generated by intramolecular addition of the hydroxyl group of the phosphinous acid ligand to the metal-coordinated nitrile.
- González-Fernández, Rebeca,Crochet, Pascale,Cadierno, Victorio,Menéndez, M. Isabel,López, Ramón
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p. 15210 - 15221
(2017/10/12)
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- Trinuclear complexes of palladium(II) with chalcogenated N-heterocyclic carbenes: Catalysis of selective nitrile-primary amide interconversion and Sonogashira coupling
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3-Methyl-1-(2-(phenylthio/seleno)ethyl)-1H-benzo[d]imidazol-3-ium iodide (L1/L2), a precursor of sulfated/selenated N-heterocyclic carbene, was synthesized by the reaction of benzimidazole with 1,2-dichloroethane followed by treatment with PhS/SeNa and MeI. The reaction of L1/L2 with Ag2O followed by treatment with [Pd(CH3CN)2Cl2] (metal to ligand ratio 3:2), i.e. transmetallation, resulted in trinuclear palladium(ii) complexes [Pd3(L1/L2-HI)2(CH3CN)Cl6] (1-2). The complexes were characterized with 1H, 13C{1H} and 77Se{1H} NMR (2 only), elemental analyses, HR-MS and single-crystal X-ray diffraction. The geometry of three Pd atoms in each complex is nearly square planar. The Pd-S/Se, Pd-C, Pd-N and Pd-Cl bond distances (?) in 1/2 are 2.3179(19)/2.4312(10), 1.968(7)/1.952(4), 2.073(8)/2.079(4) and 2.2784(19)-2.298(2)/2.292(2)-2.3003(15), respectively. In both the complexes, all Cl are trans to each other. For the central Pd atom, two benzimidazole rings are also trans to each other. The C-H?Cl non-covalent interactions result in a three-dimensional network. The moisture and air insensitive trinuclear Pd(ii) complexes 1 and 2 are thermally stable and efficient as a catalyst for nitrile-amide interconversion and amine-free Sonogashira C-C coupling (in the presence of CuI). The optimum temperature is 80 °C for the interconversion and 110 °C for the coupling. The catalytic protocols are applicable to both aliphatic and aromatic amides/nitriles. The optimum catalyst loading is 1 mol% for the C-C coupling and 0.5 to 1 mol% for the interconversion. K2CO3 as a base gives the best result for Sonogashira C-C coupling. In the conversion of nitriles to amides, the formation of an acid was not detected. After using once, 1/2 can carry out the conversion of ten fresh lots of nitriles to amides with almost the same efficiency. The real catalytic species for the interconversion and coupling appear to be based on Pd(ii) and Pd(0), respectively.
- Dubey, Pooja,Gupta, Sonu,Singh, Ajai K.
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p. 13065 - 13076
(2017/10/13)
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- A selective hydration of nitriles catalysed by a Pd(OAc)2-based system in water
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In situ formation of a [Pd(OAc)2bipy] (bipy = 2,2′-bipyridyl) complex in water selectively catalyses the hydration of a wide range of organonitriles at 70 °C. Catalyst loadings of 5 mol% afford primary amide products in excellent yields in the absence of hydration-promoting additives such as oximes and hydroxylamines.
- Sanz Sharley, Daniel D.,Williams, Jonathan M.J.
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supporting information
p. 4090 - 4093
(2017/09/27)
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- Preparation method of reaches the side pyridine (by machine translation)
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The invention relates to a method for preparing reaches the side pyridine, comprises the following steps: 1) the amino resin and isonicotinic acid coupling agent of preparing nicotinic acid amide resin; 2) the lysate to get rid of the resin, of preparing nicotinic acid amide; 3) step 2) the resulting different nicotinic acid amide by degrading reagent and alkali, obtained by Hofmann degradation reaches the side pyridine. (by machine translation)
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Paragraph 0032; 0033; 0034; 0035; 0036; 0037; 0038
(2017/08/28)
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- Ruthenium-Catalyzed Deaminative Hydrogenation of Aliphatic and Aromatic Nitriles to Primary Alcohols
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The deaminative hydrogenation of nitriles towards alcohols is a useful reaction to transform nitriles into alcohols with NH3 as the sole byproduct. Using the simple and robust RuHCl(CO)(PPh3)3 complex as a catalyst, at low H2 pressures a series of aliphatic and aromatic nitriles could be transformed into the corresponding alcohols. Suitable solvent systems for these reactions were 1,4-dioxane/water and EtOH/water mixtures. In most cases, the selectivity for the alcohols was excellent, and the corresponding amines were formed only in trace amounts.
- Molnár, István Gábor,Calleja, Pilar,Ernst, Martin,Hashmi, A. Stephen K.,Schaub, Thomas
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p. 4175 - 4178
(2017/10/09)
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- Amidation of carboxylic acids via the mixed carbonic carboxylic anhydrides and its application to synthesis of antidepressant (1S,2R)-tranylcypromine
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Primary amidations of carboxylic acids 1 or 3 with NH4Cl in the presence of ClCO2Et and Et3N were developed to afford the corresponding primary amides in 22% to quantitative yields. Additionally, we have applied the amidation to the preparation of various amides containing hydroxamic acids and achieved the synthesis of (1S,2R)-tranylcypromine as an antidepressant medicine via Lossen rearrangement.
- Ezawa, Tetsuya,Kawashima, Yuya,Noguchi, Takuya,Jung, Seunghee,Imai, Nobuyuki
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p. 1690 - 1699
(2017/11/14)
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- Highly efficient synthesis of primary amides: Via aldoximes rearrangement in water under air atmosphere catalyzed by an ionic ruthenium pincer complex
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The transformation of aldoximes to primary amides has been evaluated using pincer ruthenium complexes a-c, among which the ionic Ru catalyst a proved to be the most efficient in water under air atmosphere. A variety of (hetero)arene aldoximes proceeded smoothly to afford amides in high yields with good functional group compatibilities. Furthermore, a direct synthetic route of amides from aldehydes, hydroxylamine hydrochloride and sodium carbonate was also described with broad substrates including conjugated and aliphatic aldehydes. This protocol is operationally simple and proceeds with a low catalyst loading (0.5 mol%).
- Yang, Fa-Liu,Zhu, Xinju,Rao, Dun-Kang,Cao, Xiao-Niu,Li, Ke,Xu, Yan,Hao, Xin-Qi,Song, Mao-Ping
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p. 37093 - 37098
(2016/05/24)
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- Copper(II) acetate-catalysed conversion of aldoximes to amides under mild conditions
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A mild method for the metal-catalysed conversion of aldoximes to amides has been achieved by the combined use of copper(II) acetate and MeCN in EtOH under reflux. The presence of a catalytic amount of MeCN (0.05 equiv.) accelerated the reaction and improved the yield. Aryl, heteroaryl and alkyl aldoximes were transformed into the corresponding amides in moderate to good yield. 2-Furyl and 2-Thiophenyl aldoximes, which possess a heteroatom lone pair positioned ortho to the oximido group, showed enhanced reactivity, and the corresponding amides were obtained in excellent yield.
- Ma, Xiaoyun,Lu, Ming
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p. 594 - 596
(2016/10/21)
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- A pyridine amide synthetic method of compound
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The invention discloses a method for synthesizing a pyridine-amide compound. The method comprises the steps of carrying out hydrolysis on a pyridine cyanogen compound shown by a formula II as a starting material in water as a solvent in the presence of an ETS-10 molecular sieve as a catalyst, heating to 100-150 DEG C, reacting until the reaction, which is tracked and detected by virtue of TLC (Thin-Layer Chromatography), is completed and carrying out post-treatment on the reaction solution to obtain the pyridine-amide compound represented by the formula I. According to the method disclosed by the invention, the ETS-10 molecular sieve is taken as a catalyst to carry out hydrolysis on pyridine cyanogen to obtain a single pyridine-amide product, the conversion rate is 100%, the yield is above 95% and the catalyst can be repeatedly used for at least 5 times.
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Paragraph 0032-0035
(2019/02/02)
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- Supported Gold Nanoparticles-Catalyzed Microwave-Assisted Hydration of Nitriles to Amides under Base-Free Conditions
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Polystyrene-supported gold (Au@PS) nanoparticles were synthesized by the reduction deposition approach and well characterized by UV-visible, XRD, TEM, SAED, EDX, and XPS studies. The Au@PS was applied as catalyst for the hydration of nitriles to amides in water under microwave irradiation. Several functionalized aromatic, heterocyclic and aliphatic nitriles were found to be active for synthesis of the corresponding amides where no activation of water by base, ligand and support is needed. Easy recovery, negligible leaching and recyclability for up to eight runs are added advantages of the catalyst under water-mediated reaction conditions. (Figure presented.).
- Kumar, Sandeep,Sharma, Saurabh,Das, Pralay
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supporting information
p. 2889 - 2894
(2016/09/16)
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- Bis(allyl)-ruthenium(IV) complexes with phosphinous acid ligands as catalysts for nitrile hydration reactions
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Several mononuclear ruthenium(iv) complexes with phosphinous acid ligands [RuCl2(η3:η3-C10H16)(PR2OH)] have been synthesized (78-86% yield) by treatment of the dimeric precursor [{RuCl(μ-Cl)(η3:η3-C10H16)}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) with 2 equivalents of different aromatic, heteroaromatic and aliphatic secondary phosphine oxides R2P(O)H. The compounds [RuCl2(η3:η3-C10H16)(PR2OH)] could also be prepared, in similar yields, by hydrolysis of the P-Cl bond in the corresponding chlorophosphine-Ru(iv) derivatives [RuCl2(η3:η3-C10H16)(PR2Cl)]. In addition to NMR and IR data, the X-ray crystal structures of representative examples are discussed. Moreover, the catalytic behaviour of complexes [RuCl2(η3:η3-C10H16)(PR2OH)] has been investigated for the selective hydration of organonitriles in water. The best results were achieved with the complex [RuCl2(η3:η3-C10H16)(PMe2OH)], which proved to be active under mild conditions (60 °C), with low metal loadings (1 mol%), and showing good functional group tolerance.
- Tomás-Mendivil, Eder,Francos, Javier,González-Fernández, Rebeca,González-Liste, Pedro J.,Borge, Javier,Cadierno, Victorio
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p. 13590 - 13603
(2016/09/04)
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- Clean synthesis of primary to tertiary carboxamides by CsOH-catalyzed aminolysis of nitriles in water
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Using CsOH as the only catalyst and utilizing its "cesium effect", a clean synthesis of a wide range of primary, secondary, and tertiary carboxamides was achieved by aminolysis reactions of nitriles with ammonia, primary, or secondary amines in water. Studies on the control reactions revealed that the reactions with ammonia most probably proceed via an aminolysis path by the initial addition of ammonia to Cs-activated nitriles to form unsubstituted amidine intermediates, while the reactions with primary or secondary amines may proceed via a hydration/transamidation path by the initial hydration of the Cs-activated nitriles to form primary carboxamide intermediates followed by their transamidation with amines through the formation of substituted amidine intermediates.
- Li, Yang,Chen, Haonan,Liu, Jianping,Wan, Xujun,Xu, Qing
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supporting information
p. 4865 - 4870
(2016/10/06)
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- Ruthenium(II) complexes incorporating salicylaldiminato-functionalized N-heterocyclic carbene ligands as efficient and versatile catalysts for hydration of organonitriles
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We describe a new synthetic procedure for synthesis of ruthenium(II) complexes containing salicylaldiminato functionalized mixed N-heterocyclic carbene (NHC) ligand and phosphine co-ligand. The complexes (3a-3d) have been obtained in good to excellent yields by transmetalation from the corresponding Ag-NHC complexes (2a-2d) as carbene transfer reagents. All the [Ru-NHC] complexes have been characterized by elemental analyses, spectroscopic methods as well as ESI mass spectrometry. The ligands 1a-1d show their versatility by switching to be O,N,C-chelating in these ruthenium(II) complexes. The resulting complexes have been evaluated as potential catalysts for the selective hydration of nitriles to primary amides, and related amide bond forming reactions, in environmentally friendly medium. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl and alkyl functional groups. The catalyst was stable for weeks and could be recovered and reused more than six times without significant loss of activity.
- Nirmala, Muthukumaran,Saranya, Gandhi,Viswanathamurthi, Periasamy
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p. 134 - 144
(2016/01/09)
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- Ruthenium(II) complexes bearing pyridine-functionalized N-heterocyclic carbene ligands: Synthesis, structure and catalytic application over amide synthesis
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A series of four imidazolium salts was synthesized by the reaction of 2-bromopyridine with 1-substituted imidazoles. These imidazolium salts (1a–d) were successfully employed as ligand precursors for the syntheses of new ruthenium(II) complexes bearing neutral bidentate ligands of N-heterocyclic carbene and pyridine donor moiety. The NHC-ruthenium(II) complexes (3a–d) were synthesized by reacting the appropriately substituted pyridine-functionalized N-heterocyclic carbenes with Ag2O forming the NHC–silver bromide in situ followed by transmetalation with [RuHCl(CO)(PPh3)3]. The new complexes were characterized by elemental analyses and spectroscopy (IR, UV-Vis,1H,13C,31P-NMR) as well as ESI mass spectrometry. Based on the spectral results, an octahedral geometry was assigned for all the complexes. The complexes were shown to be efficient catalysts for the one-pot conversion of various aldehydes to their corresponding primary amides with good to excellent isolated yields using NH2OH.HCl and NaHCO3. The effects of solvent, base, temperature, time and catalyst loading were also investigated. A broad range of amides were successfully synthesized with excellent isolated yields using the above optimized protocol. Notably, the complex 3a was found to be a very efficient and versatile catalyst towards amidation of a wide range of aldehydes. [Figure not available: see fulltext.]
- Nirmala, Muthukumaran,Viswanathamurthi, Periasamy
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p. 1725 - 1735
(2017/03/08)
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- Direct Transformation of Ethylarenes into Primary Aromatic Amides with N -Bromosuccinimide and I2-Aqueous NH3
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A variety of ethylarenes were converted into the corresponding primary aromatic amides in good yields via treatment with N-bromosuccinimide in the presence of a catalytic amount of 2,2′-azobis(isobutyronitrile) in a mixture of ethyl acetate and water, acetonitrile and water, or chloroform and water, followed by reaction with molecular iodine and aq NH3 in one pot. It was found that aryl α-bromomethyl ketones and/or aryl methyl ketones were formed at the first reaction step and their iodoform-type reaction occurred at the second reaction step to provide primary aromatic amides. The present reaction is a useful and practical transition-metal-free method for the preparation of primary aromatic amides from ethylarenes. (Chemical Equation Presented).
- Shimokawa, Shohei,Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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supporting information
p. 784 - 787
(2016/03/01)
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- Palladium-catalyzed synthesis of primary benzamides from aryl bromides via a cyanation and hydration sequence
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An interesting and effective procedure for the synthesis of benzamides from aryl bromides has been developed. In the presence of a palladium catalyst, various primary benzamides have been produced in moderate to excellent yields in a one-pot one-step manner.
- Sharif, Muhammad,Wu, Xiao-Feng
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p. 21001 - 21004
(2015/03/30)
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- Cobalt/nitrophenolate-catalyzed selective conversion of aldoximes into nitriles or amides
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A novel cobalt/nitrophenolate complex has been synthesized, characterized and studied for their catalytic activities. Conversion of aldoximes to nitriles can be performed via in situ conditions from cobalt(II) acetate and 2,4-dinitrophenol. The rearrangement of aldoximes to amides via cobalt(II) acetate and 2-nitro-1-naphthol has also been demonstrated. A complete reversal of transformation was accomplished by modifying the cobalt salt and careful choice of both the nitrophenol ligand and reaction conditions.
- Jang, Wonseok,Kim, Se Eun,Yang, Cheol Mo,Yoon, Sungwoo,Park, Myunghwan,Lee, Junseong,Kim, Youngjo,Kim, Min
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p. 120 - 123
(2015/02/02)
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- Direct oxidative esterification of alcohols and hydration of nitriles catalyzed by a reusable silver nanoparticle grafted onto mesoporous polymelamine formaldehyde (AgNPs@mPMF)
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A nitrogen-rich mesoporous organic polymer was synthesized as a novel support. A silver nanoparticle was synthesized and grafted onto it. The prepared catalyst (AgNPs@mPMF) was characterized by powder X-ray diffraction (XRD), scanning electron microscopy(SEM) and energy dispersive X-ray spectrometry (EDS), thermogravimetric analysis (TGA), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectroscopy (DRS), N2 adsorption, Raman spectroscopy and EPR study. The catalytic activity was evaluated for the oxidative esterification reaction of alcohols and hydration of nitriles. The oxidative esterification reaction was carried out for various activated alcohols giving excellent yields of the corresponding ester products. The catalyst was also efficient in the hydration of nitriles. Both reactions were optimized by varying the bases, temperatures and solvents. The catalyst can be facilely recovered and reused six times without a significant decrease in its activity and selectivity.
- Ghosh, Kajari,Iqubal, Md. Asif,Molla, Rostam Ali,Mishra, Ashutosh,Kamaluddin,Islam, Sk Manirul
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p. 1606 - 1622
(2015/04/27)
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- Transition-metal-free hydration of nitriles using potassium tert -butoxide under anhydrous conditions
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Potassium tert-butoxide acts as a nucleophilic oxygen source during the hydration of nitriles to give the corresponding amides under anhydrous conditions. The reaction proceeds smoothly for a broad range of substrates under mild conditions, providing an efficient and economically affordable synthetic route to the amides in excellent yields. This protocol does not need any transition-metal catalyst or any special experimental setup and is easily scalable to bulk scale synthesis. A single-electron-transfer radical mechanism as well as an ionic mechanism have been proposed for the hydration process.
- Midya, Ganesh Chandra,Kapat, Ajoy,Maiti, Subhadip,Dash, Jyotirmayee
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supporting information
p. 4148 - 4151
(2015/05/05)
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