- Cyclic guanidine organic catalysts: What is magic about triazabicyclodecene?
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(Chemical Equation Presented) The bicyclic guanidine 1,5,7- triazabicyclo[4.4.0]dec-5-ene (TBD) is an effective organocatalyst for the formation of amides from esters and primary amines. Mechanistic and kinetic investigations support a nucleophilic mechanism where TBD reacts reversibly with esters to generate an acyl-TBD intermediate that acylates amines to generate the amides. Comparative investigations of the analogous bicyclic guanidine 1,4,6-triazabicyclo[3.3.0]oct-4-ene (TBO) reveal it to be a much less active acylation catalyst than TBD. Theoretical and mechanistic studies imply that the higher reactivity of TBD is a consequence of both its higher basicity and nucleophilicity than TBO as well as the high reactivity of the acyl-TBD intermediate, which is sterically prevented from adopting a planar amide structure.
- Kiesewetter, Matthew K.,Scholten, Marc D.,Kirn, Nicole,Weber, Ryan L.,Hedrick, James L.,Waymouth, Robert M.
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- Lower primary alkanols and their esters in a Ritter-type reaction with nitriles. An efficient method for obtaining N-primary-alkyl amides
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N-Primary-alkyl amides RCONHR1 were obtained by a Ritter-type reaction of nitriles RCN with lower primary alkanols R1OH or their esters in the presence of acids.
- Lebedev, Mikhail Y.,Erman, Mark B.
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- Nucleophilic substitution in carboxylic esters in oil-in-water microemulsions
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In hydrolysis and aminolysis of p-nitrophenyl esters of carboxylic acids in oil-in-water microemulsions on the basis of surfactants of various nature, a complex mechanism of the effect of the medium is operative, including shift of acid-base equilibria in the nucleophile. The rate constants of the processes studied are quantitatively related to the surface potential of the microdroplet. Varied hydrophobicity of the nucleophile and substrate changes the site of the reaction act and the relative contributions of aminolysis and hydrolysis.
- Mirgorodskaya,Kudryavtseva
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- The Amidation of Carboxylic Acid with Amine over Hydrous Zirconium(IV) Oxide
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The reaction of a carboxylic acid or an ester with an amine to give the corresponding amide was carried out efficiently over hydrous zirconium(IV) oxide, whether in the vapor phase or in the liquid phase.
- Takahashi, Kyoko,Shibagaki, Makoto,Kuno, Hideyuki,Kawakami, Hiroshi,Matsushita, Hajime
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- Kinetic Analysis of Ester Aminolysis Catalyzed by Nucleosides in a Nonpolar Medium. Evidence of Bifunctional Catalysis
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Kinetic analysis of ester aminolysis in benzene catalyzed by 2′,3′,5′-O-tris(tert-butyldimethylsilyl)-protected nucleosides and 2-pyridone is reported. The catalytic rate constant k3′ was determined for protected nucleosides A, C, G, U, and pseudouridine (Ψ). The relatively high value associated with C and 2-pyridone is indicative of bifunctional catalysis occurring through stabilization of the aminolysis transition state. The implications of this finding on the possible role C plays in biological catalysis during protein synthesis is hypothesized. ? Abstract published in Advance ACS Abstracts, December 1, 1997.
- Melander, Christian,Horne, David A.
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- The mechanism of photoinduced acylation of amines by N-acyl-5,7- dinitroindoline as determined by time-resolved infrared spectroscopy
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(Chemical Equation Presented) The photochemistry of N-acyl-5,7- dinitroindoline (1) was studied in acetonitrile using nanosecond time-resolved infrared (TRIR) spectroscopy. Upon photolysis, two nearly but not completely overlapping sets of transient IR ba
- Cohen, Andrew D.,Helgen, Celine,Bochet, Christian G.,Toscano, John P.
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- Pivotal role of intramolecular catalysis in the selective acetylation of alkyl amines
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Preparation of amides by the use of esters as the "acyl donor" is less explored because they are less reactive and usually more steric demanding than conventional acid halides and anhydrides. Here, we report that 3-acetoxy-2-naphthoic acid, an aspirin analogue, can be used as a mild amine acetylating agent in ethanol at 25°C. The reaction is sensitive to steric and polar effects of the attacking amine, and the rate constants can be appropriately fitted by the Pavelich-Taft correlation. Density functional theory calculations used to study all reaction steps indicate that the o-carboxy group plays a pivotal role, guiding the attacking amine and accelerating the reaction. The reaction can be conveniently used for the acylation of a variety of primary and secondary amines.
- Nishida, Elvis N.,Vitto, Ramon,Peixoto, R?mulo C.R.,Nome, Faruk,Souza, Bruno S.
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- Structure-reactivity correlation in the aminolysis of 4-fluorophenyl acetate in aqueous medium
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The reaction of the title substrate with a series of amines of varying pKa, viz. ammonia, ethanolamine, glycine, 1,2-diaminopropane, 1,3-diaminopropane, n-butylamine, piperidine, hydrazine, imidazole, and hydroxylamine is subjected to a kinetic study in aqueous medium, 25°C, ionic strength 0.1 M (KCl). Pseudo-first-order rate coefficients (kobs) are found throughout under amine excess at various pH values for each amine. For amines, excluding hydrazine, ammonia, and hydroxylamine the reaction follows clean second-order kinetics and the plots of (kobs - kH) against free amine concentration are linear at constant pH. The macroscopic nucleophilic substitution rate coefficients (kN) are obtained as the slopes of these plots and found to be pH independent. For hydrazine, ammonia, and hydroxylamine, a rate dependence on more than first power of the amine is observed, accordingly, the rate constants for the assisted paths have been disseminated for these amines besides kN. The Broensted-type plot (logkN against amine pKa) is linear with a slope value of β = 1.02. The magnitude of the slope value is consistent with a stepwise mechanism through a zwitterionic tetrahedral addition intermediate whose breakdown to products is rate-determining (k2 step). A remarkable reactivity difference is observed among the diamines, the reason for which is discussed in detail.
- Rajarathnam,Jeyakumar,Ananthakrishna Nadar
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- Acylmethanesulfonamides as new acylating agents for primary amines
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A new, simple and efficient procedure for the preparation of secondary amides through internal condensation of acylmethanesulfonamides ammonium salts is described. The selective acylation of mixed primary-secondary amines could be an attractive application of the new method.
- Coniglio, Silvia,Aramini, Andrea,Cesta, M. Candida,Colagioia, Sandro,Curti, Roberto,D'Alessandro, Fabrizio,D'Anniballe, Gaetano,D'Elia, Valerio,Nano, Giuseppe,Orlando, Valerie,Allegretti, Marcello
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- A CO2-Catalyzed Transamidation Reaction
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Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
- Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
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p. 16867 - 16881
(2021/11/18)
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- Environmentally benign decarboxylative: N-, O-, and S-Acetylations and acylations
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An operationally simple and general method for acetylation and acylation of a wide variety of substrates (amines, alcohols, phenols, thiols, and hydrazones) has been reported. Meldrum's acid and its derivatives have been used as an air-stable, non-volatile, cost-effective, and easy to handle acetylating/acylating agent. Easily separable byproducts (CO2 and acetone) allowed the isolation of analytically pure acetylated products without the requirement of work-up and any chromatography. This journal is
- Ghosh, Santanu,Purkait, Anisha,Jana, Chandan K.
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supporting information
p. 8721 - 8727
(2020/12/30)
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- PRODUCTION METHOD OF AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0018; 0089-0106
(2020/10/08)
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- Synthesis of acetamides via oxidative C–C bond cleavage of ketones catalyzed by Cu-immobilized magnetic nanoparticles
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Copper supported on magnetite nanoparticles modified with environmentally friendly ligand tricine was devised for synthesis of acetamides via C–C oxidative cleavage of ketones with amines. The catalyst was characterized using different techniques, including Fourier transform infrared, X-ray diffraction, scannin electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and energy dispersive x-ray spectroscopy. The protocol showed relatively high yields of acetamide products. Furthermore, the magnetic recovery of the catalyst rendered the overall process fast and efficient. It was used in the reaction for six consecutive cycles with negligible loss of catalytic activity. This research is the first report of application of magnetic nanocatalysts for synthesis of acetamides from ketones of low activity through a C–C bond cleavage strategy.
- Yazdani, Elahe,Pazoki, Farzane,Salamatmanesh, Arefe,Nejad, Masoume Jadidi,Miraki, Maryam Kazemi,Heydari, Akbar
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- Direct synthesis of secondary amides from ketones through Beckmann rearrangement using O-(mesitylsulfonyl)hydroxylamine
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The Beckmann rearrangement is a versatile method for the preparation of secondary amides from ketones via oxime intermediates and has been widely used in the synthesis of bioactive natural products and pharmaceuticals. Herein, we have developed a highly efficient direct method for the preparation of secondary amides and lactams from ketones using O-(mesitylsulfonyl)hydroxylamine (MSH). The reactions proceed rapidly at room temperature under mild condition without requiring any additive, and tolerate multiple functional groups. A simple aqueous work-up often furnished the products in excellent yield with high purity.
- Chandra, Dinesh,Verma, Saumya,Pandey, Chandra Bhan,Yadav, Ajay K.,Kumar, Puneet,Tiwari, Bhoopendra,Jat, Jawahar L.
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supporting information
(2020/03/23)
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- Zinc(II)-Catalyzed Synthesis of Secondary Amides from Ketones via Beckmann Rearrangement Using Hydroxylamine-O-sulfonic Acid in Aqueous Media
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A zinc(II)-catalyzed single-step protocol for the Beckmann rearrangement using hydroxylamine-O-sulfonic acid (HOSA) as the nitrogen source in water was developed. This direct method efficiently produces secondary amides under open atmosphere in a pure form after basic aqueous workup. It isenvironmentally benign and operationally simple.
- Verma, Saumya,Kumar, Puneet,Khatana, Anil K.,Chandra, Dinesh,Yadav, Ajay K.,Tiwari, Bhoopendra,Jat, Jawahar L.
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p. 3272 - 3276
(2020/11/02)
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- IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: A photochemical pathway
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An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein. Various amides and esters are synthesized as the reaction products, with nitriles being the acid equivalents. A mini-library of different types of amides and esters is made using this mild and efficient process, which uses only 1 mol% of photocatalyst under visible light irradiation (λ = 445 nm). The reaction strategy is also efficient for gram-scale synthesis.
- Talukdar, Ranadeep
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supporting information
p. 5303 - 5308
(2020/04/17)
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- Cu(OTf) 2 -Catalyzed Beckmann Rearrangement of Ketones Using Hydroxylamine- O -sulfonic Acid (HOSA)
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The Beckmann rearrangement (BKR) of ketones to secondary amides often requires harsh reaction conditions that limit its practicality and scope. Herein, the Cu(OTf) 2 -catalyzed BKR of ketones under mild reaction conditions using hydroxylamine- O -sulfonic acid (HOSA), a commercial water soluble aminating agent, is described. This method is compatible with most functional groups and directly provides the desired amides in good to excellent yields.
- Anugu, Raghunath Reddy,Chandra, Dinesh,Falck, John R.,Jat, Jawahar L.,Munnuri, Sailu,Verma, Saumya
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p. 3709 - 3714
(2019/09/30)
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- Hydrative syntheses of amides from alkynes catalyzed by an Au(I) complex containing pyridyl-functionalized NHC ligand
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An Au(I)-NHC complex [L1AuBr] (1) with appended pyridyl group on the ligand scaffold is synthesized and its catalytic efficacy for the direct synthesis of the amide from alkyne and sodium azide in acidic water is evaluated. Catalyst 1 readily converts a wide range of internal and terminal alkynes to the corresponding amides with low catalyst loading in TFA/DCE (2 mL, 1:1 v/v) at room temperature in short reaction time (2 h) and without the use of Ag(I) additive. A related catalyst that is devoid of the pyridyl fragment displays significantly lower activity illustrating the role of the promoter ligand for water activation. Mechanistic studies reveal an initial alkyne hydration to ketone followed by the Schmidt reaction to afford the amide.
- Singh, Kuldeep,Pal, Nilay Kumar,Guha, Chirajyoti,Bera, Jitendra K.
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- A magnetically recoverable copper–salen complex as a nano-catalytic system for amine protection via acetylation using thioacetic acid
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A novel copper(II)–salen complex was immobilized on the surface of magnetite nanoparticles using chitosan as a linker. This system exhibits superior catalytic activity in acetyl protection of various amines with thioacetic acid as the acetylating reagent. The method has advantages over others in high selectivity, simple work-up, green reaction medium and the application of an easily recoverable heterogeneous catalyst.
- Yazdani, Elahe,Kazemi Miraki, Maryam,Salamatmanesh, Arefe,Azarnia, Jamshid,Azizi, Kobra,Ghandi, Leila,Heydari, Akbar
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p. 1775 - 1793
(2019/01/16)
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- Acylation of Phenols, Alcohols, Thiols, Amines and Aldehydes Using Sulfonic Acid Functionalized Hyper-Cross-Linked Poly(2-naphthol) as a Solid Acid Catalyst
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Abstract: The hyper-cross-linked porous poly(2-naphthol) fabricated by the Friedel–Crafts alkylation of 2-naphthol has been functionalized with sulfonic acid to obtain a solid acid catalyst. The catalyst is applied for the protection of phenol, alcohols, thiols, amines and aldehydes with acetic anhydride at room temperature. The catalytic protection using the new solid acid is featured by achieving high yield at neat condition, needing no aqueous work-up and/or chromatographic separation, and showing excellent recycling efficiency, suggesting the potential of this sulfonated porous polymers as a new protection protocol in a wide range of sustainable chemical reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Kalla, Reddi Mohan Naidu,Reddy, Sirigireddy Sudharsan,Kim, Il
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p. 2696 - 2705
(2019/05/28)
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- 3D Micropatterned All-Flexible Microfluidic Platform for Microwave-Assisted Flow Organic Synthesis
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A large-area, all-flexible, microwaveable polydimethoxysilane microfluidic reactor was fabricated by using a 3D printing system. The sacrificial microchannels were printed on polydimethoxysilane substrates by a direct ink writing method using water-soluble Pluronic F-127 ink and then encapsulated between polydimethoxysilane layers. The structure of micron-sized channels was analyzed by optical and electron microscopy techniques. The fabricated flexible microfluidic reactors were utilized for the acetylation of different amines under microwave irradiation to obtain acetamides in shorter reaction times and good yields by flow organic synthesis.
- Hur, Deniz,Say, Mehmet G.,Diltemiz, Sibel E.,Duman, Fatma,Ers?z, Arzu,Say, R?dvan
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- Mild and eco-friendly chemoselective acylation of amines in aqueous medium using a green, superparamagnetic, recoverable nanocatalyst
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Copper-grafted guanidine acetic acid-modified magnetite nanoparticles (Fe3O4@GAA-Cu(II)) as a green, superparamagnetic and recoverable nanocatalyst is found to promote quantitative N-acylation of various amines in a very short time with an equimolar amount of thioacetic acid in water at room temperature. This method is found to be highly selective for amines and not sensitive to other functional groups. Mild reaction condition, high selectivity, efficiency, simple workup and excellent yields are some of the major advantages of the procedure.
- Miraki, Maryam Kazemi,Yazdani, Elahe,Ghandi, Leila,Azizi, Kobra,Heydari, Akbar
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- Sulfated choline ionic liquid-catalyzed acetamide synthesis by grindstone method
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Sulfated choline ionic liquid (SCIL) has been found to be an efficient solid acid IL catalyst for the protection of amine groups with acetic anhydride under solvent-free grindstone conditions. The attractive features of this new catalytic methodology include its sustainability, facile work-up procedure, economic viability, and biodegradability. The SCIL catalyst was characterized using infrared spectroscopy, wide-angle X-ray scattering analysis, and scanning electron microscopy with energy dispersive X-ray spectroscopy. The catalyst could be reused six times without significant loss in activity. Furthermore, no chromatographic separations were needed to obtain the desired products.
- Kalla, Reddi Mohan Naidu,Lim, Jaehwa,Bae, Jaeyeong,Kim, Il
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supporting information
p. 1595 - 1599
(2017/04/03)
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- Dehydrogenative Coupling of Ethanol and Ester Hydrogenation Catalyzed by Pincer-Type YNP Complexes
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The "Y" donor group (Y = -OMe, -SEt, -PPh2, -NH2, -NMe2, -Py, pyrrolidinyl, quinolyl) of the pincer-type ruthenium complexes RuHCl(CO)[κ3-YNP] has a dramatic influence on the catalytic activity in the dehydrogenative homocoupling and cross-coupling of ethanol and ester hydrogenation reactions. The observations are connected with the mechanisms of the catalytic reactions, and this paper provides evidence for ester C-O bond formation/cleavage assisted by the bifunctional catalysts in an outer-sphere fashion, reminiscent of the Tishchenko chemistry.
- Gusev, Dmitry G.
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p. 6967 - 6981
(2016/10/14)
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- CeO2-catalyzed direct synthesis of dialkylureas from CO2 and amines
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CeO2 showed higher activity for the direct synthesis of 1,3-dibutylurea (DBU) from CO2 and n-butylamine than the metal oxides tested. The solvent largely influenced the reaction over CeO2, and N-methylpyrrolidone (NMP) was preferable among various solvents tested from the viewpoints of activity and selectivity. The catalyst system composed of CeO2 catalyst and NMP solvent (CeO2 in NMP) was applicable to the reactions of various amines such as linear primary alkylamines or branched primary alkylamines, although tert-butylamine afforded low conversion. In contrast, secondary amines and aniline provided no yield of the ureas. The combination of 2-cyanopyridine with CeO2 in NMP (CeO2 in NMP with 2-cyanopyridine) promoted the transformation of the unreactive amines, showing that tert-butylamine and aniline were converted to the corresponding ureas in 82% and 80% yields, respectively. These yields are much higher than those reported in the previous literatures, indicating that CeO2 in NMP with 2-cyanopyridine drastically promoted transformation of amines with low reactivity.
- Tamura, Masazumi,Ito, Kazuki,Nakagawa, Yoshinao,Tomishige, Keiichi
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- Doping of copper (I) oxide onto a solid support as a recyclable catalyst for acetylation of amines/alcohols/phenols and synthesis of trisubstituted imidazole
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A study of copper-mediated C-heteroatom especially C-N and C-O bond formations using simpler methodologies has been carried out. In the present work, acetylation of various substrates such as amines, phenols and alcohols; synthesis of 2,4,5-trisubstituted imidazole is done using simple and easily available starting materials. Copper (I) oxide was synthesized in situ by the reduction of Fehling's solution with glucose followed by its anchoring onto different supports like silica, HAP, basic alumina and cellulose. Comparison and contrasts between the reactivity of copper (I) oxide supported onto different supports for these reactions are made. The reactivity of copper (I) oxide seems to be largely dependent on the nature of support and the most active catalyst for a particular reaction was further characterized by different spectroscopic techniques such as FTIR, XRD, TGA, XPS, SEM, TEM and AAS. The catalysts were found to be stable, easily recyclable without any significant loss in activity. Graphical abstract: Applications of solid supported copper (I) oxides (where solid support is silica, HAP, cellulose and basic alumina) are studied for various organic transformations with special emphasis on C-N and C-O bond formation reactions.[Figure not available: see fulltext.]
- Gupta, Manjulla,Gupta, Monika
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p. 231 - 241
(2016/01/09)
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- Competitive Deprotonation and Superoxide [O2 -?] Radical-Anion Adduct Formation Reactions of Carboxamides under Negative-Ion Atmospheric-Pressure Helium-Plasma Ionization (HePI) Conditions
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Carboxamides bearing an N-H functionality are known to undergo deprotonation under negative-ion-generating mass spectrometric conditions. Herein, we report that N-H bearing carboxamides with acidities lower than that of the hydroperoxyl radical (HO-O?) preferentially form superoxide radical-anion (O2 -?) adducts, rather than deprotonate, when they are exposed to the glow discharge of a helium-plasma ionization source. For example, the spectra of N-alkylacetamides show peaks for superoxide radical-anion (O2 -?) adducts. Conversely, more acidic amides, such as N-alkyltrifluoroacetamides, preferentially undergo deprotonation under similar experimental conditions. Upon collisional activation, the O2 -? adducts of N-alkylacetamides either lose the neutral amide or the hydroperoxyl radical (HO-O?) to generate the superoxide radical-anion (m/z 32) or the deprotonated amide [m/z (M - H)-], respectively. For somewhat acidic carboxamides, the association between the two entities is weak. Thus, upon mildest collisional activation, the adduct dissociates to eject the superoxide anion. Superoxide-adduct formation results are useful for structure determination purposes because carboxamides devoid of a N-H functionality undergo neither deprotonation nor adduct formation under HePI conditions. [Figure not available: see fulltext.]
- Hassan, Isra,Pinto, Spencer,Weisbecker, Carl,Attygalle, Athula B.
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p. 394 - 401
(2016/02/23)
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- Convenient N-acetylation of amines in N,N-dimethylacetamide with N,N-carbonyldiimidazole
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Dimethylacetamide (DMAc) acts as an efficient source of acetyl and dimethylamine gas in the presence of N,N-carbonyldiimidazole (CDI). Addition of amines to the reaction mixture delivers the corresponding amides in good to excellent yields. The acetylation of amines reported herein, which relies on the in situ generation of N-acetylimidazole on warming of DMAc with CDI at 120-125 °C, serves as a convenient alternative to other acetylation methods.
- Chikkulapalli, Anil,Aavula, Sanjeev Kumar,Mona Np, Rifahath,Karthikeyan, Karthikeyan,Kumar C.H., Vinodh,Sulur G., Manjunatha,Sumathi, Shanmugam
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supporting information
p. 3799 - 3803
(2015/06/08)
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- An eco-friendly and highly efficient route for N-acylation under catalyst-free conditions
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An eco-friendly, simple, mild, chemoselective and highly efficient procedure for the acylation of primary and secondary amine function in various structurally and electronically aliphatic and aromatic compounds affording their corresponding N-Ac derivatives is developed. Mild conditions, simplicity and easier work-up are the main advantages of this method.
- Ouarna, Souad,K'tir, Hacène,Lakrout, Salah,Ghorab, Hamida,Amira, A?cha,Aouf, Zineb,Berredjem, Malika,Aouf, Nour-Eddine
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p. 913 - 919
(2015/10/28)
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- Magnetically separable γ-Fe2O3 nanoparticles: An efficient catalyst for acylation of alcohols, phenols, and amines using sonication energy under solvent free condition
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This paper reports a facile synthesis of magnetically separable iron oxide (γ-Fe2O3) nanoparticles using thermolysis method. The structural and morphological study of the synthesized γ-Fe2O3 nanoparticles was carried out using X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), energy dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) techniques. The electron microscopy reveals that the γ-Fe2O3 nanoparticles have spherical morphology with a particle size in the range of 40-100 nm. The XPS study confirmed the Fe is in +3 oxidation state. The synthesized γ-Fe2O3 nanoparticles have been used as an efficient heterogeneous catalyst for the organic transformation between phenols, alcohols, and amines with acetic anhydride under sonication using mild reaction conditions. Various electrons withdrawing and electrons donating substrates show an excellent yield of desired products with the advantage of magnetic separation and reusability of γ-Fe2O3 nanocatalyst.
- Bhosale, Manohar A.,Ummineni, Divya,Sasaki, Takehiko,Nishio-Hamane, Daisuke,Bhanage, Bhalchandra M.
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- An eco-benign and highly efficient procedure for N-acylation catalyzed by heteropolyanion-based ionic liquids using carboxylic acid under solvent-free conditions
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An eco-benign and highly efficient route for N-acylation of amines has been developed by treating amines with corresponding carboxylic acids in the presence of 2 mol % of heteropolyanion-based ionic liquids as catalysts under solvent-free conditions. This practical reaction could tolerate a wide range of substrates. Thus, various N-acylation products including N-acyl α-amino acid derivatives were obtained in moderate to excellent yields at 70 C to 120 C. Moreover, recycling studies revealed that heteropolyanion-based ionic liquids were easily reusable for this N-acylation. This method provides a green and much improved protocol over the existing methods.
- Chen, Zhikai,Fu, Renzhong,Chai, Wen,Zheng, Hao,Sun, Lin,Lu, Qiang,Yuan, Rongxin
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p. 2237 - 2245
(2014/03/21)
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- ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions
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A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhydride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with substrates having other functional groups and it is suitable for practical organic synthesis.
- Farhadi, Saeed,Jahanara, Kosar
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p. 368 - 375
(2014/04/03)
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- Synthesis, X-ray crystallography, and reactions of N-acyl and N-carbamoyl succinimides
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A collection of N-acyl and N-carbamoyl succinimides were prepared by acylation of succinimide with acyl chlorides or by ethylene dichloride (EDC) coupling of carboxylic acids. The x-ray crystal structures of N-benzoyl and N-p-nitrobenzoyl succinimides were determined. The N-acyl succinimides were effective in acylating primary amines, a secondary amine, and an aromatic amine. Copyright
- Goodman, Cassie A.,Eagles, Joel B.,Rudahindwa, Leandre,Hamaker, Christopher G.,Hitchcock, Shawn R.
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p. 2155 - 2164
(2013/07/25)
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- Immobilization of Candida cylindracea lipase on poly lactic acid, polyvinyl alcohol and chitosan based ternary blend film: Characterization, activity, stability and its application for N-a
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The ecofriendly ternary blend polymer film was prepared from the chitosan (CH), polylactic acid (PLA) and polyvinyl alcohol (PVA). Immobilization of Candida cylindracea lipase (CCL) was carried out on ternary blend polymer via entrapment methodology. The ternary blend polymer and immobilized biocatalyst were characterized by using N2 adsorption-desorption isotherm, SEM, FTIR, DSC, and (%) water content analysis through Karl Fischer technique. Biocatalyst was then subjected for the determination of practical immobilization yield, protein loading and specific activity. Immobilized biocatalyst was further applied for the determination of biocatalytic activity for N-acylation reactions. Various reaction parameters were studied such as effect of immobilization support (ratio of PLA:PVA:CH), molar ratio (dibutylamine:vinyl acetate), solvent, biocatalyst loading, time, temperature, and orbital speed rotation. The developed protocol was then applied for the N-acylation reactions to synthesize several industrially important acetamides with excellent yields. Interestingly, immobilized lipase showed fivefold higher catalytic activity and better thermal stability than the crude extract lipase CCL. Furthermore various kinetic and thermodynamic parameters were studied and the biocatalyst was efficiently recycled for four successive reuses. It is noteworthy to mention that immobilized biocatalyst was stable for period of 300 days.
- Badgujar, Kirtikumar C.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
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p. 1335 - 1347
(2013/09/12)
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- Application of H/D exchange to hydrogen bonding in small molecules
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Do you recognize me? A series of simple amides has been used to demonstrate the application of hydrogen/deuterium exchange in small-molecule hydrogen bonding. By comparison with similar controls, the degree of protection from H/D exchange can provide insight into the degree of hydrogen bonding (see scheme).
- Schneider, Tanya L.,Halloran, Kevin T.,Hillner, Julie A.,Conry, Rebecca R.,Linton, Brian R.
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supporting information
p. 15101 - 15104
(2013/11/06)
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- Isopropenyl acetate, a remarkable, cheap and acylating agent of amines under solvent- and catalyst-free conditions: A systematic investigation
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Isopropenyl acetate was proved to be an efficient reagent for acetylation of amine in the absence of solvent and catalyst. The corresponding acetamides were obtained in very high yields without any purification.
- Pelagalli, Romina,Chiarotto, Isabella,Feroci, Marta,Vecchio, Stefano
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supporting information; experimental part
p. 2251 - 2255
(2012/09/08)
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- Solvent free, highly chemoselective N and O-acylation on silica and silica magnesium oxide: A recyclable solid surface
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Silica or silica/magnesium oxide mixed surface mediates the N and O-acylation, benzoylation or sulfonylation of hosts of substrates under solvent free conditions at ambient temperature with high chemoselectivity.
- Ghosh, Pranab,Mandal, Amitava
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p. 261 - 268
(2012/10/29)
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- Novel double-SO3h functionalized ionic liquid for acetylation
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Novel double-SO3H functionalized ionic liquid (DFIL) was synthesized and its catalytic activities for acetylation studied. The result showed that the DFIL possess high acidity and was very efficient for the acetylation of alcohols, amines and phenols with good to excellent yields in short reaction times. Operational simplicity, stability to water and air, small amounts needed, low cost, high yields, high acidity, applicability to large-scale reactions and reusability are the key features of the DFIL, which indicated promising applications of DFIL in green chemical processes. Pleiades Publishing, Ltd., 2012.
- Zhu, Lili,Liang, Xuezheng
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p. 684 - 688
(2013/02/23)
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- Amorphous carbon-silica composites bearing sulfonic acid as solid acid catalysts for the chemoselective protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations
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Amorphous carbon-silica composites bearing sulfonic acid derived from inexpensive natural organic compounds (glucose, maltose, cellulose, chitosan and starch) were prepared by partial carbonization followed by sulfonation and their catalytic activity was evaluated for the protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations under solvent-free conditions. Different biomaterials have been chosen, with a view to select the most active solid acid catalyst. Carbon-silica composites were characterized by FTIR, XRD and elemental analysis. Sulfonated carbon-silica composite derived from starch was found to be the most active and could be recycled for several runs without loss of significant activity. It was also characterized by TGA, SEM and TEM.
- Gupta, Princy,Paul, Satya
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experimental part
p. 2365 - 2372
(2011/10/31)
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- Metal acetate/metal oxide in acetic acid: An efficient reagent for the chemoselective N-acetylation of amines under green conditions
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The use of catalytic amount of metal acetate or metal oxide in acetic acid is a new and highly efficient acetylating system for chemoselective N-acetylation of primary and secondary amines in excellent yields under reflux condition. No other solvent is required. The noted features of this method include mild reaction conditions, use of innocuous reagents, excellent yields, convenient work-up, and reuse of catalyst.
- Brahmachari, Goutam,Laskar, Sujay,Sarkar, Sajal
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experimental part
p. 288 - 295
(2010/10/18)
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- HYDRATE INHIBITORS
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The present invention relates to compounds for controlling gas hydrate formation of the formula (I) and (II) and plugging of gas hydrate forming fluids wherein R1 is selected from the group consisting of H, acetyl and carbonyl derivative; R2 is H, -OR3 or -NR4R5, where: R3 is H, C1-6-alkyl or carbonyl derivative, R4, R5 are selected from the group consisting of H, C1-18-alkyl, alkanol, alkoxy, cyclic/aromatic or alkylene. The invention further comprises compositions and method of producing the compounds of formula (I) and (II), method for controlling gas hydrate formation and plugging of gas hydrate forming fluids, and use of compounds of formula (I) and (II).
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Page/Page column 36
(2010/09/18)
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- Synthesis and application of a microgel-supported acylating reagent by coupled ring-opening metathesis polymerization and activators Re-Generated by electron transfer for atom transfer radical polymerization
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A novel microgel-supported acylating reagent (MGAR) was prepared by combining ring-opening metathesis polymerization (ROMP) and Activators Re-Generated by Electron Transfer for Atom Transfer Radical Polymerization (ARGET ATRP): (1) synthesis of an ATRP macroinitiator 3 by living ROMP of oxanorbornene-based activated ester 1, derived from Af-hydroxysuccinimide, using the Grubbs initiator RuCl2(PCy3)2(=CHPh) and (Z)-but-2-ene-l,4-diyl bis(2-bromopropanoate) (BDBP) as a terminating agent; (2) synthesis of MGAR 4 by ARGET ATRP of styrene (S) and divinylbenzene (DVB) using the prepared macroinitiator 3, a CuCI2ZMe6TREN (tris[2-(dimethylamino)ethyl]amine) catalyst system, a Sn(Oct)2 [tin(II)2ethylhexanoate] reducing agent. The synthesized microgels 4 exhibit excellent acyl (acetyl, benzoyl, phenylsulfonyl) transfer properties for primary and secondary amines (n-BuNH2, Et2NH, morpholine, etc.) under mild conditions (25 °C, 13.5-14 h) affording N-acylamines with high yield (95.6-100%) and purity (94.1-96.0%).
- Li, Hong,Pang, Zi-Bo,Jiao, Zhi-Feng,Lin, Fei
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experimental part
p. 255 - 259
(2010/09/03)
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- Spinel-type zinc aluminate (ZnAl2O4) nanoparticles prepared by the co-precipitation method: A novel, green and recyclable heterogeneous catalyst for the acetylation of amines, alcohols and phenols under solvent-free conditions
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Zinc aluminate (ZnAl2O4) nanoparticles with an average particle size of about 8 nm were easily prepared by the co-precipitation method using aqueous ammonia solution as the precipitating agent. This nanosized spinel-type oxide was characterized by TGA, XRD, FT-IR, TEM, and surface area measurement and used as the heterogeneous catalyst for the acetylation reaction. Efficient acetylation of various amines, alcohols and phenols was carried out over ZnAl2O4 nanoparticles using acetic anhydride and/or acetyl chloride as the acetylating agents at room temperature without the use of a solvent. The method is highly selective, allowing the alcoholic hydroxyl group to be protected while the phenolic hydroxyl group remains intact, and the amine group can be acetylated in the presence of the hydroxyl group. This method is fast and has a high yield. It is also clean, safe, cost effective, compatible with substrates that have other functional groups and very suitable for practical organic synthesis. In addition, the catalyst can be reused without significant loss of activity. Indeed, the catalytic activity of the ZnAl2O4 nanoparticles is higher than that of bulk ZnAl2O4.
- Farhadi, Saeid,Panahandehjoo, Somayeh
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scheme or table
p. 293 - 302
(2010/09/04)
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- N1,N3-Diacyl-3,4-dihydropyrimidin-2(1H)-ones: neutral acyl group transfer reagents
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Readily available N1,N3-diacyl-3,4-dihydropyrimidin-2(1H)-ones efficiently acylate ammonia, primary and secondary amines to furnish primary, secondary and tertiary amides in good to excellent yields. The wide applicability of the procedure is demonstrated
- Singh, Kamaljit,Singh, Kawaljit
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experimental part
p. 10395 - 10399
(2010/02/28)
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- Candida antarctica lipase B-catalyzed synthesis of acetamides using [BMIm(PF6)] as a reaction medium
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An efficient protocol has been developed for synthesis of acetamides using Candida antarctica lipase B (CaL B) in [BMIm(PF6)] as a greener reaction medium. The reaction is applicable to a wide variety of aliphatic esters/acetic acid and amines providing excellent yields of corresponding acetamide. The catalyst exhibits remarkable activity and is reusable for up to four consecutive cycles.
- Dhake, Kishor P.,Qureshi, Ziyauddin S.,Singhal, Rekha S.,Bhanage, Bhalchandra M.
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experimental part
p. 2811 - 2814
(2009/09/30)
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- Microwave-assisted preparation of amides using a stable and reusable mesoporous carbonaceous solid acid
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An efficient and green microwave assisted protocol to prepare amides from amines via N-acylation using acidic polysaccharide derived mesoporous materials provides quantitative yields of amides in short reaction times.
- Luque, Rafael,Budarin, Vitaly,Clark, James H.,MacQuarrie, Duncan J.
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experimental part
p. 459 - 461
(2010/04/22)
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- One-portion synthesis of 2-acetoxy carbonyl compounds from aldehydes by using an acetylated masked acyl cyanide
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α-Acetoxy esters or amides were synthesized directly and in one portion from aldehydes and alcohols or amines by one-carbon homologation using a masked acyl cyanide reagent bearing an acetyl group. Georg Thieme Verlag Stuttgart.
- Nemoto, Hisao,Kawamura, Tomoyuki,Kitasaki, Kyoko,Yatsuzuka, Kenji,Kamiya, Masaki,Yoshioka, Yasuko
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scheme or table
p. 1694 - 1702
(2009/12/25)
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- Metal-triflate ionic liquid systems immobilized onto mesoporous MS41 materials as new and efficient catalysts for N-acylation
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Two kinds of MS41-immobilized ionic liquids (ILs) based on dihydroimidazolium and pyridinium cation were prepared using a grafting method. The second immobilization of triflate salts on these materials led to the immobilization of metal-triflate complexes into ILs. The materials thus obtained were characterized by 1H NMR, XRD, N2-sorption measurements, TG-DTA, DRIFT, XPS, TEM, and ICP-AES. The catalysts were tested in acylation of amines and sulfonamides and proved highly active and selective. For both aromatic and aliphatic amines, acylation with carboxylic acids was possible. For sulfonamides, acylation was possible only with anhydrides. Recycling the catalysts was not accompanied by any leaching of ILs or metal triflate.
- Coman, Simona M.,Florea, Mihaela,Parvulescu, Vasile I.,David, Victor,Medvedovici, Andrei,De Vos, Dirk,Jacobs, Pierre A.,Poncelet, George,Grange, Paul
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p. 359 - 369
(2008/03/13)
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- Catalytic metathesis of simple secondary amides
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(Chemical Equation Presented) Trading places: The metathesis of secondary amides through a transacylation mechanism has been achieved by employing catalytic quantities of an organic imide and a Bronsted base (see scheme). Equilibrium-controlled exchange between various amide pairs is demonstrated for substrates bearing N-alkyl and N-aryl substituents.
- Bell, Christen M.,Kissounko, Denis A.,Gellman, Samuel H.,Stahl, Shannon S.
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p. 761 - 763
(2007/10/03)
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- Part 148 in the series "studies on novel synthetic methodologies:" Selective acetylation of alcohols, phenols and amines and selective deprotection of aromatic acetates using silica-supported phosphomolybdic acid
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An environmentally friendly silica-supported phosphomolybdic acid was found to be a highly efficient catalyst for the selective acetylation of alcohols, phenols and amines in the absence of any solvent and also for the chemoselective deprotection of aromatic acetates under very mild conditions. This method has been used for the protection of the hydroxy groups as well as for the deprotection of the acetates of several naturally occurring bioactive phenolic compounds. The catalyst can be easily recovered and reused.
- Das, Biswanath,Thirupathi, Ponnaboina,Kumar, Rathod Aravind,Laxminarayana, Keetha
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p. 2677 - 2683
(2008/09/19)
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- Deuterium exchange as an indicator of hydrogen bond donors and acceptors
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Hydrogen-deuterium exchange has been used to determine the hydrogen bonding preferences of a select group of small peptides in organic solvents. This kinetic analysis permitted comparison of hydrogen bond strengths in relation to controls and also indicated the identity of both hydrogen bond donors and hydrogen bond acceptors. Copyright
- Steffel, Lauren R.,Cashman, Timothy J.,Reutershan, Michael H.,Linton, Brian R.
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p. 12956 - 12957
(2008/09/17)
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- Silica sulfuric acid as a reusable catalyst for the conversion of ketones into amides by a Schmidt reaction under solvent-free conditions
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Silica sulfuric acid is a highly efficient reagent for the conversion of a variety of ketones into the corresponding amides by a Schmidt reaction under solvent-free conditions. Cyclic, aliphatic and aromatic ketones with electron-donating or withdrawing substituents may be converted easily in excellent yield. The major advantages of this method are: operational simplicity, the ready availability of the reagent, selectivity, general applicability, mild reaction conditions, short reaction times and high yields. The recovered catalyst could be used in new attempts without any purification.
- Eshghi, Hossein,Hassankhani, Asadollah,Mosaddegh, Elaheh
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p. 218 - 219
(2007/10/03)
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- Catalysis of aminolysis of p-nitrophenyl acetate by 2-pyridones
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The influence of a series of alkyl-substituted 3-cyano-2-pyridones on the kinetics of the reaction of p-nitrophenyl acetate (10) with n-butylamine (9) was studied. The reactions were monitored under pseudo-first-order conditions using an excess of n-butyl
- Fischer, Christian B.,Steininger, Harald,Stephenson, David S.,Zipse, Hendrik
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p. 901 - 907
(2007/10/03)
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- Novel catalytic effects in ester aminolysis in chlorobenzene
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The mechanism of glyme catalyzed ester aminolysis in chlorobenzene should be modified by including a new reaction pathway that shows a first-order dependence on the concentration of the phase transfer catalyst and a second-order dependence on butylamine.
- Basilio, Nuno,Garcia-Rio, Luis,Leis, J. Ramon,Mejuto, Juan C.,Perez-Lorenzo, Moises
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p. 3817 - 3819
(2007/10/03)
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- Photochemical desulfonylation of N-tosyl amides by 2-phenyl-N,N′- dimethylbenzimidazoline (PDMBI)
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Photoinduced electron transfer reaction between N-tosyl amides and 2-phenyl-N,N′-dimethylbenzimidazoline (PDMBI) provides an efficient approach for the desulfonylation of N-tosyl amides. Georg Thieme Verlag Stuttgart.
- Liu, Qiang,Liu, Zhengang,Zhou, Yu-Lu,Zhang, Wei,Yang, Li,Liu, Zhong-Li,Yu, Wei
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p. 2510 - 2512
(2007/10/03)
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- Zinc oxide (ZnO) as a new, highly efficient, and reusable catalyst for acylation of alcohols, phenols and amines under solvent free conditions
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Zinc oxide (ZnO) is a highly efficient catalyst for the acylation of a variety of alcohols, phenols and amines with acid chlorides or acid anhydrides under solvent free conditions. Primary, secondary, tertiary, allylic and benzylic alcohols, diols and phenols with electron donating or withdrawing substituents can be easily acylated in good to excellent yield.
- Hosseini Sarvari, Mona,Sharghi, Hashem
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p. 10903 - 10907
(2007/10/03)
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