- One-Pot Regioselective and Stereoselective Synthesis of C-Glycosyl Amides from Glycals Using Vinyl Azides as Glycosyl Acceptors
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The reaction of glycals containing good leaving groups with aromatic vinyl azides to give α-C-glycosyl amides in good yields is described. Various vinyl azides with different groups undergo the reaction smoothly. In these reactions, an iminodiazonium intermediate is generated by the attack of the vinyl azide onto the glycal under Lewis acid conditions. This undergoes Schmidt-type denitrogenative 1,2-migration to form a nitrilium ion, which, upon hydrolysis, gives the desired C-glycosyl amide.
- Rasool, Faheem,Ahmed, Ajaz,Hussain, Nazar,Yousuf, Syed Khalid,Mukherjee, Debaraj
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- Cu(OTf)2-Mediated Cross-Coupling of Nitriles and N-Heterocycles with Arylboronic Acids to Generate Nitrilium and Pyridinium Products**
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Metal-catalyzed C–N cross-coupling generally forms C?N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C–N cross-coupling that uses a dative N-ligand in the bond-forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a CuII complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative CuIII complex enables the oxidative C–N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp2) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.
- Bell, Nicola L.,Xu, Chao,Fyfe, James W. B.,Vantourout, Julien C.,Brals, Jeremy,Chabbra, Sonia,Bode, Bela E.,Cordes, David B.,Slawin, Alexandra M. Z.,McGuire, Thomas M.,Watson, Allan J. B.
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supporting information
p. 7935 - 7940
(2021/03/03)
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- Method for promoting acylation of amine or alcohol by carbon dioxide
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The invention relates to a method for promoting acylation of amine or alcohol by carbon dioxide, which comprises the following steps of: mixing an amine compound, carboxylate or thiocarboxylate compound and a reaction solvent under the action of carbon dioxide, and reacting to obtain an amide compound, or under the action of carbon dioxide, mixing the alcohol compound, the thiocarboxylate compound and the reaction solvent [gamma]-valerolactone, and reacting to obtain the ester compound. According to the invention, under the promotion action of carbon dioxide, carboxylate or thiocarboxylate is used as an acylation reagent, and amine and alcohol are converted into amide and ester compounds in the absence of a transition metal catalyst, so that acylation reagents such as acyl chloride or anhydride with irritation and corrosivity are avoided; and the method has the advantages of simple operation, mild reaction conditions, high tolerance of substrate functional groups, strong applicability and high yield, and provides an efficient, reliable and economical preparation method for synthesis of amide and ester compounds.
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Paragraph 0033-0034
(2021/05/29)
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- Direct para-Selective C-H Amination of Iodobenzenes: Highly Efficient Approach for the Synthesis of Diarylamines
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Iodine(III)-mediated synthesis of 4-iodo-N-phenylaniline from iodobenzene has been achieved, and the reaction can proceed under mild conditions. A variety of functional groups were well tolerated, providing the corresponding products in moderate to good yields. The remaining iodine group provides an effective platform for converting the products into several valuable asymmetric diphenylamines. Most importantly, this reaction can be easily scaled up to the ten-gram scale, highlighting its synthetic utility. The mechanistic study revealed that the in situ generated aryl hypervalent iodine intermediate is the key factor to realize this para-selective C-H amination reaction.
- Chen, Yujie,Huang, Zhibin,Jiang, Yaqiqi,Shu, Sai,Yang, Shan,Shi, Da-Qing,Zhao, Yingsheng
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p. 8226 - 8235
(2021/06/28)
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- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
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A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
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supporting information
p. 9204 - 9207
(2021/09/20)
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- Hybrid quinoline-thiosemicarbazone therapeutics as a new treatment opportunity for Alzheimer’s disease-synthesis, in vitro cholinesterase inhibitory potential and computational modeling analysis
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Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. The limited pharmacological approaches based on cholinesterase inhibitors only provide symptomatic relief to AD patients. Moreover, the adverse side effects such as nausea, vomiting, loss of appetite, muscle cramps, and headaches associated with these drugs and numerous clinical trial failures present substantial limitations on the use of medications and call for a detailed insight of disease heterogeneity and development of preventive and multifactorial therapeutic strategies on urgent basis. In this context, we herein report a series of quinoline-thiosemicarbazone hybrid therapeutics as selective and potent inhibitors of cholinesterases. A facile multistep synthetic approach was utilized to generate target structures bearing multiple sites for chemical modifications and establishing drug-receptor interactions. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, 1H- and 13C-NMR). In vitro inhibitory results revealed compound 5b as a promising and lead inhibitor with an IC50 value of 0.12 ± 0.02 μM, a 5-fold higher potency than standard drug (galantamine; IC50 = 0.62 ± 0.01 μM). The synergistic effect of electron-rich (methoxy) group and ethylmorpholine moiety in quinolinethiosemicarbazone conjugates contributes significantly in improving the inhibition level. Molecular docking analysis revealed various vital interactions of potent compounds with amino acid residues and reinforced the in vitro results. Kinetics experiments revealed the competitive mode of inhibition while ADME properties favored the translation of identified inhibitors into safe and promising drug candidates for pre-clinical testing. Collectively, inhibitory activity data and results from key physicochemical properties merit further research to ensure the design and development of safe and high-quality drug candidates for Alzheimer’s disease.
- Alsaab, Hashem O.,Aqsa, Sehar,Asif, Tahira Tasneem,Ibrar, Aliya,Kausar, Naghmana,Khan, Imtiaz,Munir, Rubina,Shahid, Noorma,Younas, Muhammad Tayyab,Zaib, Sumera
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- Design, synthesis, kinetic, molecular dynamics, and hypoglycemic effect characterization of new and potential selective benzimidazole derivatives as Protein Tyrosine Phosphatase 1B inhibitors
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Protein-tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling pathway and has been validated as a therapeutic target for type 2 diabetes. A wide variety of scaffolds have been included in the structure of PTP1B inhibitors, one of them is the benzimidazole nucleus. Here, we report the design and synthesis of a new series of di- and tri- substituted benzimidazole derivatives including their kinetic and structural characterization as PTP1B inhibitors and hypoglycemic activity. Results show that compounds 43, 44, 45, and 46 are complete mixed type inhibitors with a Ki of 12.6 μM for the most potent (46). SAR type analysis indicates that a chloro substituent at position 6(5), a β-naphthyloxy at position 5(6), and a p-benzoic acid attached to the linker 2-thioacetamido at position 2 of the benzimidazole nucleus, was the best combination for PTP1B inhibition and hypoglycemic activity. In addition, molecular dynamics studies suggest that these compounds could be potential selective inhibitors from other PTPs such as its closest homologous TCPTP, SHP-1, SHP-2 and CDC25B. Therefore, the compounds reported here are good hits that provide structural, kinetic, and biological information that can be used to develop novel and selective PTP1B inhibitors based on benzimidazole scaffold.
- Campos-Almazán, Mara Ibeth,Flores-Ramos, Miguel,Hernández-Campos, Alicia,Castillo, Rafael,Sierra-Campos, Erick,Torgeson, Kristiane,Peti, Wolfgang,Valdez-Solana, Mónica,Oria-Hernández, Jesús,Méndez, Sara T.,Castillo-Villanueva, Adriana,Jiménez-de Jesús, Hugo,Avitia-Domínguez, Claudia,Téllez-Valencia, Alfredo
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- Z-Selective Fluoroalkenylation of (Hetero)Aromatic Systems by Iodonium Reagents in Palladium-Catalyzed Directed C?H Activation
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The direct and catalytic incorporation of fluorine containing molecular motifs into organic compounds resulting high-value added chemicals represents a rapidly evolving part of synthetic methodologies, thus this area is in the focus of pharmaceutical and agrochemical research. Herein we report a stereoselective procedure for direct fluorovinylation of aromatic and heteroaromatic scaffolds. This methodology development has been realized by palladium-catalyzed ortho C?H activation reaction of aniline derivatives featuring the regioselectivity via directing groups such as secondary of tertiary amides, ureas or ketones. The application of non-symmetrical aryl(fluoroalkenyl)-iodonium salts as fluoroalkenylating agents allowed mild reaction conditions in general for this transformation. The scope and limitations have been thoroughly investigated and the feasibility has been demonstrated by more than 50 examples.
- Bényei, Attila,Domján, Attila,Egyed, Orsolya,Gonda, Zsombor,Novák, Zoltán,Sályi, Gerg?,Tóth, Balázs L.
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supporting information
(2021/11/09)
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- Catalyst-free generation of acyl radicals induced by visible light in water to construct C-N bonds
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We describe herein a catalyst-free and redox-neutral photochemical strategy for the direct generation of acyl radicals from α-diketones, and its selective conversion of nitrosoarenes to hydroxyamides or amides with AcOH or NaCl as an additive. The reaction was carried out under mild conditions in water with purple LEDs as the light source. A broad scope of substrates was demonstrated. Mechanistic experiments indicate that α-diketones cleave to give acyl radicals, with hydroxyamides being further reduced to amides.
- Ran, Maogang,He, Jiaxin,Yan, Boyu,Liu, Wenbo,Li, Yi,Fu, Yunfen,Li, Chao-Jun,Yao, Qiuli
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supporting information
p. 1970 - 1975
(2021/03/16)
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- New half-sandwich (η6-p-cymene)ruthenium(II) complexes with benzothiazole hydrazone Schiff base ligand: Synthesis, structural characterization and catalysis in transamidation of carboxamide with primary amines
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Few half-sandwich (η6-p-cymene) ruthenium(II) complexes supported by benzothiazole hydrazone Schiff bases were synthesized. The new complexes possess the general formulae [Ru(η6-p-cymene)(L)Cl] (1-3) (L = salicyl((2-(benzothiazol-2-yl)hydrazono)methylphenol) (SAL-HBT), 2-((2-(benzothiazol-2-yl)hydrazono)methyl)-6 methoxyphenol) (VAN-HBT) or naphtyl-2-((2-(benzothiazol-2-yl)hydrazono)methyl phenol) (NAP-HBT). All compounds were fully studied by analytical, spectroscopic techniques (IR, NMR) and also by mass spectrometry. The solid state structure of the complex 3 reveals the coordination of p-cymene moieties with ruthenium(II) in a three-legged piano-stool geometry along with benzothiazole hydrazone Schiff base ligand in a monobasic bidentate fashion. The catalytic properties of the complexes were screened in transamidation of primary amide with amines after optimization with respect to solvent, substituents, time and catalyst loading. The results show that the complex 3 is the most efficient catalyst for the transamidation of carboxamides with amines.
- Vijayapritha, Subbarayan,Viswanathamurthi, Periasamy
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supporting information
(2020/10/18)
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- Aryne Precursors for Selective Generation of 3-Haloarynes: Preparation and Application to Synthetic Reactions
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The synthesis and reaction of new 3-haloaryne precursors 2a-2h were studied. The ortho-(trimethylsilyl)aryl triflate precursors 2a-2h were prepared by a simple procedure involving O-trimethylsilylation and migration of a trimethylsilyl group followed by triflation. The remarkable feature of new precursors is the selective generation of 3-haloarynes by suppressing the competitive thia-Fries rearrangement, which is the problem in the reaction using the well-known 3-haloaryne precursors. The advantage of new precursor 2a over a typical precursor 1 was confirmed by the direct comparisons in several reactions. The application of precursors 2a-2h to the syntheses of heterocycles was also reported.
- Kakigi, Kengo,Kawasaki, Yuichi,Miyabe, Hideto,Miyoshi, Shouta,Yoshioka, Eito
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p. 13544 - 13556
(2020/12/15)
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- Nitromethane as a nitrogen donor in Schmidt-type formation of amides and nitriles
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The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.
- Jiao, Ning,Liu, Jianzhong,Qiu, Xu,Song, Song,Wei, Jialiang,Wen, Xiaojin,Zhang, Cheng,Zhang, Ziyao
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supporting information
p. 281 - 285
(2020/01/28)
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- An organocatalytic C-C bond cleavage approach: A metal-free and peroxide-free facile method for the synthesis of amide derivatives
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A facile organocatalytic approach has been devised towards the synthesis of amide derivatives using 1,3-dicarbonyls as easily available acyl-sources under peroxide-free reaction conditions. This transformation was accomplished by the cleavage of the C-C bond in the presence of TEMPO as an organocatalyst and excludes the use of transition-metals and harsh reaction conditions. A broad range of substrates with diverse functional groups were well tolerated and delivered the products in high yields.
- Vodnala, Nagaraju,Gujjarappa, Raghuram,Polina, Saibabu,Satheesh, Vanaparthi,Kaldhi, Dhananjaya,Kabi, Arup K.,Malakar, Chandi C.
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supporting information
p. 20940 - 20944
(2020/12/31)
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- Iodine and Br?nsted acid catalyzed C–C bond cleavage of 1,3-diketones for the acylation of amines
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A metal-free N-acylation method of anilines with 1,3-diketones has been developed, by using iodine and p-toluene sulfonic acid as the co-catalysts. The reaction can proceed in 1,4-dioxane at elevated temperature to produce the corresponding amides with 48–89% yields. Further, the gram-scale experiment was carried out under the standard conditions and the possible mechanism was proposed.
- Zhou, Xiao-Yu,Chen, Xia,Yang, Dan
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supporting information
p. 177 - 184
(2019/11/26)
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- Synthesis of diverse libraries of carboxamides via chemoselective N-acylation of amines by carboxylic acids employing Br?nsted acidic IL [BMIM(SO3H)][OTf]
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Chemoselective N-acylation of amines with carboxylic acids as acyl electrophiles and Br?nsted acidic IL [BMIM(SO3H)][OTf] as promoter is reported under both thermal and microwave irradiation to produce libraries of carboxamides in good to excellent yields after a simple workup. The protocol is compatible with structurally diverse 1° and 2° amines and works in the presence of sensitive functional groups such as thiols and phenols. The potential for recycling and reuse of the IL is also demonstrated.
- Savanur, Hemantkumar M.,Malunavar, Shruti S.,Prabhala, Pavankumar,Sutar, Suraj M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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supporting information
(2019/09/30)
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- SMALL MOLECULE INHIBITORS OF GALECTIN-3
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The present disclosure relates to compounds of formula I, which inhibit Gal-3, and include pharmaceutically acceptable salts, compositions comprising such compounds, and methods using and making such compounds and compositions.
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Page/Page column 286-287
(2019/04/26)
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- Antimicrobial activity of quinoline-based hydroxyimidazolium hybrids
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Eight quinoline-based hydroxyimidazolium hybrids 7a-h were prepared and evaluated in vitro against a panel of clinically important fungal and bacterial pathogens, including mycobacteria. Hybrid compounds 7c-d showed remarkable antifungal activity against Cryptococcus neoformans with a minimum inhibitory concentration (MIC) value of 15.6 μg/mL. Against other opportunistic fungi such as Candida spp. and Aspergillus spp., these hybrids showed MIC values of 62.5 μg/mL. Regarding their antibacterial activity, all the synthetic hybrids demonstrated little inhibition of Gram-negative bacteria (MIC ≥50 μg/mL), however, hybrid 7b displayed >50% inhibition against Klebsiella pneumoniae at 20 μg/mL and full inhibition at 50 μg/mL. Moreover, this hybrid was shown to be a potent anti-staphylococcal molecule, with a MIC value of 2 μg/mL (5 μM). In addition, hybrid 7h also demonstrated inhibition of Staphylococcus aureus at 20 μg/mL (47 μM). Hybrids 7a and 7b were the most potent against Mycobacterium tuberculosis H37Rv with MIC values of 20 and 10 μg/mL (46 and 24 μM), respectively. The 7b hybrid demonstrated high selectivity in killing S. aureus and M. tuberculosis H37Rv in comparison with mammalian cells (SI >20), and thus it can be considered a hit molecule for mechanism of action studies and the exploration of related chemical space.
- Abonia, Rodrigo,Bernal, Anthony,Guzman, Juan,Insuasty, Braulio,Insuasty, Daniel,Marquez, Edgar,Puerto, Gloria,Quiroga, Jairo,Svetaz, Laura,Vidal, Oscar,Zacchino, Susana
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- SO2F2-Activated Efficient Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
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A novel, mild and practical protocol for the efficient activation of the Beckmann rearrangement utilizing the readily available and economical sulfuryl fluoride (SO2F2 gas) has been developed. The substrate scope of the operationally simple methodology has been demonstrated by 37 examples with good to nearly quantitative isolated yields (over 90 % yield in most cases) in a short time, including B(OH)2, COOH, NH2, and OH substituted substrates. A tentative mechanism was proposed involving formation and elimination of key intermediate, sulfonyl ester.
- Zhang, Guofu,Zhao, Yiyong,Xuan, Lidi,Ding, Chengrong
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supporting information
p. 4911 - 4915
(2019/07/31)
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- Visible Light-Promoted Beckmann Rearrangements: Separating Sequential Photochemical and Thermal Phenomena in a Continuous Flow Reactor
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The Beckmann rearrangement of oximes to amides typically requires strong acids or highly reactive, hazardous electrophiles and/or elevated temperatures to proceed. A very attractive alternative is the in situ generation of Vilsmeier–Haack reagents, by means of photoredox catalysis, as promoters for the thermal Beckmann rearrangement. Investigation of the reaction parameters for this light-induced method using a one-pot strategy has shown that the reaction is limited by the different temperatures required for each of the two sequential steps. Using a continuous flow reactor, the photochemical and thermal processes have been separated by integrating a flow photoreactor unit at low temperature for the electrophile generation with a second reactor unit, at high temperature, where the rearrangement takes place. This strategy has enabled excellent conversions and yields for a diverse set of oximes, minimizing the formation of side products obtained with the original one-pot method.
- Chen, Yuesu,Cantillo, David,Kappe, C. Oliver
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supporting information
p. 2163 - 2171
(2019/03/14)
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- Copper-Catalyzed Site-Selective Oxidative C?C Bond Cleavage of Simple Ketones for the Synthesis of Anilides and Paracetamol
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A copper-catalyzed approach for the N-acylation of anilines with acetone and acetophenones via C?C bond cleavage is described. Under the developed conditions both CHCl3 and CH2Cl2 were identified as potential C1-source to promote the transformation. The reaction features a site selective C?C bond cleavage to install the amide moieties with high functional-group compatibility and wide substrate scope. The developed method avoids the use of sensitive and narcotic agents. The method also represents an excellent complement to the previous protocols with lower E-factor (13.91 mg/1 mg) than current industrially used method (E-factor 17.54 mg/1 mg). The developed approach has also been extended for the effective preparation of pyridine derivatives and paracetamol in gram scale. The course of the reaction was monitored by 1H NMR as a preliminary investigation of the reaction mechanism. (Figure presented.).
- Vodnala, Nagaraju,Gujjarappa, Raghuram,Hazra, Chinmoy K.,Kaldhi, Dhananjaya,Kabi, Arup. K.,Beifuss, Uwe,Malakar, Chandi C.
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supporting information
p. 135 - 145
(2018/12/05)
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- Synthesis of acetamides from aryl amines and acetonitrile by diazotization under metal-free conditions
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An efficient and metal-free coupling reaction has been developed that affords acetamides from the corresponding aryl amines and acetonitrile. This method tolerates a wide range of functional groups and is selective toward aryl amines. Preliminary mechanistic studies were conducted.
- Duan, Pan,Guo, Yu,Kang, Huan,Li, Yi-Na,Wen, Xianghao,Xiao, Fang,Zeng, Yao-Fu,Zhang, Na-Na
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supporting information
p. 2169 - 2172
(2019/11/25)
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- Selective cleavage of the N-propargyl group from sulfonamides and amides under ruthenium catalysis
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The selective cleavage of the N-propargyl group from sulfonamides and amides under ruthenium catalysis is described. The reaction tolerates a broad range of functional groups, and the desired products were obtained in 10–95% yield.
- Wang, Jingjing,Li, Feng,Pei, Wenlong,Yang, Mixue,Wu, Yidan,Ma, Danyang,Zhang, Furong,Wang, Jianhui
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supporting information
p. 1902 - 1905
(2018/04/19)
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- Environmentally sustainable route to SiO2@Au-Ag nanocomposites for biomedical and catalytic applications
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A facile, sustainable, operationally simple and mild method for the synthesis of SiO2@Au-Ag nanocomposites (NCs) using Nephrolepis cordifolia tuber extract is described and its catalytic, antibacterial and cytotoxic properties were investigated. The fabricated SiO2@Au-Ag NCs were well characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) to determine the optical activity, size and morphology, elemental composition, functional groups present, crystallinity, thermal stability and chemical state respectively. The obtained SiO2@Au-Ag NCs exhibited spherical shape SiO2 decorated with Au and Ag nanoparticles. The diameter of the SiO2 nanoparticles ranges from 200-246 with average 3 nm diameter of Au and Ag NPs. Synthetic utility of this protocol has been demonstrated by exploring its effective catalytic activities for the solvent-free amidation of carboxylic acid with a primary amine with excellent yields. Moreover, the synthesized nanocomposite exhibited as noticeable antibacterial effect against Gram negative and Gram positive bacteria and better bio-compatibility against human keratinocytes. Thus, additive free SiO2@Au-Ag NCs display the potential for catalysis and biomedical applications.
- Sapkota, Kanti,Chaudhary, Prerna,Han, Sung Soo
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p. 31311 - 31321
(2018/09/25)
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- Flower-like AgNPs@m-MgO as an excellent catalyst for CO2 fixation and acylation reactions under ambient conditions
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Synthesis of fine chemicals from the chemical fixation of CO2 is one of the attractive research areas of today to utilise greenhouse gas CO2 in a greener pathway. A flower-like silver nanoparticle grafted mesoporous magnesium oxide (AgNPs@m-MgO) nanocomposite has been prepared by a facile in situ pathway. The materials are characterised by XRD, FTIR, UV-vis, TG-DTA, FESEM, HR-TEM and N2 adsorption-desorption studies. This AgNPs@m-MgO material showed a mesoporous nature with good surface area. It indicated brilliant catalytic activity for both the carboxylation of terminal alkynes by chemical fixation of CO2 (1 atm) and the acylation of various amines by utilizing acetic acid as a reagent in solvent-free conditions showing yields up to 98% and 99% of the propiolic acid and acetamide products, respectively. The reusability of this catalyst has also been verified and it showed high recycling efficiency for both the reactions together with no considerable catalyst deactivation.
- Chowdhury, Arpita Hazra,Ghosh, Swarbhanu,Islam, Sk. Manirul
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p. 14194 - 14202
(2018/08/28)
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- Sulfonium Salts as Alkylating Agents for Palladium-Catalyzed Direct Ortho Alkylation of Anilides and Aromatic Ureas
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A novel method for the ortho alkylation of acetanilide and aromatic urea derivatives via C-H activation was developed. Alkyl dibenzothiophenium salts are considered to be new reagents for the palladium-catalyzed C-H activation reaction, which enables the transfer of methyl and other alkyl groups from the sulfonium salt to the aniline derivatives under mild catalytic conditions.
- Simkó, Dániel Cs.,Elekes, Péter,Pázmándi, Vivien,Novák, Zoltán
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supporting information
p. 676 - 679
(2018/02/09)
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- Direct synthesis of N-arylamides via the coupling of aryl diazonium tetrafluoroborates and nitriles under transition-metal-free conditions
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The direct synthesis of N-arylamides via the coupling of aryl diazonium tetrafluoroborates and nitriles under transition-metal-free conditions has been developed. The reported protocol is practical and represents an efficient method to produce functionalized amides in moderate to good yields.
- Xiong, Biquan,Wang, Gang,Xiong, Tao,Wan, Liming,Zhou, Congshan,Liu, Yu,Zhang, Panliang,Yang, Changan,Tang, Kewen
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supporting information
p. 3139 - 3142
(2018/07/13)
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- A to aryl diazonium tetrafluoroborate salts with a nitrile preparation machine acid radical amine compounds (by machine translation)
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The invention provides a high-efficiency, high-selective synthesis of different substituted functional group containing organic amide compound, it adopts the cuprous iodide as a catalyst, in order to aryl diazonium tetrafluoroborate salts compounds and organic nitrile compound as the reaction substrate, the reaction system by adding the organic solvent, water and alkali. The advantage of this method: cheap and easily obtained catalyst; the substrate has a high applicability; mild reaction conditions, safe and reliable; the resulting target product selectivity is close to 100%, yield is as high as 90% or more. The method solves the traditional synthetic organic amide compound of rigorous reaction conditions, the reaction selectivity is poor, the experimental procedure is complicated, the productivity is low and needs to be used for the environment of a harmful reagent and the like, it has good industrial application prospect. The invention also provides a corresponding different substituted functional group containing organic amide compound. (by machine translation)
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Paragraph 0038
(2018/06/04)
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- Imidazolium chloride: An efficient catalyst for transamidation of primary amines
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A highly efficient and convenient protocol of imidazolium chloride (30 mol %) catalyzed amidation of amines with moderate to excellent yields was reported. The protocol shows broad substrate scope for aromatic, aliphatic, and heterocyclic primary amines.
- Tian, Qingqiang,Gan, Zongjie,Wang, Xuetong,Li, Dan,Luo, Wen,Wang, Huajun,Dai, Zeshu,Yuan, Jianyong
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supporting information
(2018/09/10)
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- A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes
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A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with inexpensive N-chlorosuccinimide (NCS) was achieved in MeCN in the presence of 10 mol% of l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under mild conditions, yielding a variety of aryl chlorides in excellent yields. This method proved to be tolerant of a broad range of functional groups and particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient without copper catalysis. This heterogeneous copper catalyst can be recovered by a simple filtration of the reaction solution and recycled for at least 10 times without any decreases in activity.
- He, Wen,Zhang, Rongli,Cai, Mingzhong
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p. 764 - 770
(2017/01/13)
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- Combining Eosin y with Selectfluor: A Regioselective Brominating System for Para-Bromination of Aniline Derivatives
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A mild, metal-free, and absolutely para-selective bromination of aniline derivatives has been developed in excellent yields, wherein the organic dye Eosin Y is employed as the bromine source in company with Selectfluor. Neither air nor moisture sensitive, this facile reaction proceeds smoothly at room temperature and completes within a short time. Mechanistic studies indicate a radical pathway; therefore, the existence of an in situ generated brominating reagent, "Selectbrom", is postulated, which may reasonably account for the unique regioselectivity for the para-bromination of N-acyl- as well as N-sulfonylanilines.
- Huang, Binbin,Zhao, Yating,Yang, Chao,Gao, Yuan,Xia, Wujiong
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supporting information
p. 3799 - 3802
(2017/07/26)
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- Efficient Heterogeneous Gold(I)-Catalyzed Direct C(sp2)–C(sp) Bond Functionalization of Arylalkynes through a Nitrogenation Process to Amides
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The first heterogeneous gold(I)-catalyzed direct C(sp2)–C(sp) bond functionalization of arylalkynes through a nitrogenation process to amides has been achieved by using an ordered mesoporous silica (MCM-41)-immobilized phosphine gold(I) complex [MCM-41-PPh3-AuCl] as catalyst and silver carbonate (Ag2CO3) as cocatalyst with trimethylsilyl azide (TMSN3) as a nitrogen source, yielding a variety of amides in moderate to excellent yields under mild conditions. This heterogeneous phosphine gold(I) complex shows the same turnover numbers as the homogeneous chloro(triphenylphosphine)gold(I) (Ph3PAuCl) and can easily be recovered by simple filtration of the reaction solution and recycled at least eight times without significant loss of activity, providing a novel, efficient, practical and economic method for the synthesis of amides from alkynes. (Figure presented.).
- Nie, Quan,Yi, Feiyan,Huang, Bin,Cai, Mingzhong
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p. 3968 - 3976
(2017/11/20)
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- Nickel-(II)-Catalyzed N-Formylation and N-Acylation of Amines
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A highly efficient protocol of Ni(II) metal complex, [Ni(quin)2], catalyzing N-formylation and N-acylation of amines with moderate to excellent yields, using N,N-dimethylformamide and N,N-dimethylacetamide in the presence of imidazole, is described here. The protocol shows broad substrate scope for aliphatic, aromatic, and heterocyclic amines.
- Sonawane, Rahul B.,Rasal, Nishant K.,Jagtap, Sangeeta V.
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supporting information
p. 2078 - 2081
(2017/04/28)
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- AIBN-promoted amidation of anilines with 1, 3-diketones via oxidative cleavage of C–C bond under aerobic conditions
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N-Acylation of anilines with 1, 3-diketones promoted by AIBN (2-2′-azoisobutyronitrile) under metal-free and peroxide-free conditions in the presence of molecular oxygen as oxidant has been described. This protocol proceeds by the oxidative cleavage of C–C bond with simultaneous intermolecular C–N bond formation under mild conditions.
- Rao, Sadu Nageswara,Mohan, Darapaneni Chandra,Adimurthy, Subbarayappa
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p. 4889 - 4894
(2016/07/18)
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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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- Photo-Fries rearrangement of aryl acetamides: Regioselectivity induced by the aqueous micellar green environment
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Photochemical reactions tend to give more than one photoproduct. However, such a reaction can be a powerful synthetic tool when it is possible to conduct it in regioselective conditions yielding a single photoproduct. Water-surfactant solutions as reaction media can be considered as an approach in this context because they show products with different features than those from isotropic solutions. Here we describe results obtained from studying the effect on the prototypical photoreaction, known as the photo-Fries reaction of several substituted acetanilides and α-naphthyl acetamide within surfactant micelles (ionic and non-ionic micelles). This reaction involves homolytic cleavage of a C-N bond to yield a singlet radical pair. The surfactant micelles control the rotational and translational mobility of the radical pair, resulting in noticeable photoproduct selectivity.
- Iguchi, Daniela,Erra-Balsells, Rosa,Bonesi, Sergio M.
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p. 105 - 116
(2016/01/20)
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- Fragmentation of Protonated N-(3-Aminophenyl)Benzamide and Its Derivatives in Gas Phase
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An ion of m/z 110.06036 (ion formula [C6H8NO]+; error: 0.32 mDa) was observed in the collision induced dissociation tandem mass spectrometry experiments of protonated N-(3-aminophenyl)benzamide, which is a rearrangement product ion purportedly through nitrogen-oxygen (N–O) exchange. The N–O exchange rearrangement was confirmed by the MS/MS spectrum of protonated N-(3-aminophenyl)-O18-benzamide, where the rearranged ion, [C6H8NO18]+ of m/z 112 was available because of the presence of O18. Theoretical calculations using Density Functional Theory (DFT) at B3LYP/6-31?g(d) level suggest that an ion-neutral complex containing a water molecule and a nitrilium ion was formed via a transition state (TS-1), followed by the water molecule migrating to the anilide ring, eventually leading to the formation of the rearranged ion of m/z 110. The rearrangement can be generalized to other protonated amide compounds with electron-donating groups at the meta position, such as, –OH, –CH3, –OCH3, –NH(CH3)2, –NH-Ph, and –NHCOCH3, all of which show the corresponding rearranged ions in MS/MS spectra. However, the protonated amide compounds containing electron-withdrawing groups, including –Cl, –Br, –CN, –NO2, and –CF3, at the meta position did not display this type of rearrangement during dissociation. Additionally, effects of various acyl groups on the rearrangement were investigated. It was found that the rearrangement can be enhanced by substitution on the ring of the benzoyl with electron-withdrawing groups. [Figure not available: see fulltext.]
- Zu, Chengli,Mukhopadhyay, Sukrit,Hanley, Patrick S.,Xia, Shijing,Bell, Bruce M.,Grigg, David,Gilbert, Jeffrey R.,O’Brien, John P.
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p. 917 - 926
(2016/05/02)
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- Mild and efficient palladium-catalyzed direct trifluoroethylation of aromatic systems by C-H activation
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The introduction of trifluoroalkyl groups into aromatic molecules is an important transformation in the field of organic and medicinal chemistry. However, the direct installation of fluoroalkyl groups onto aromatic molecules still represents a challenging and highly demanding synthetic task. Herein, a simple trifluoroethylation process that relies on the palladium-catalyzed C-H activation of aromatic compounds is described. With the utilization of a highly active trifluoroethyl(mesityl)iodonium salt, the developed catalytic method enables the first highly efficient and selective trifluoroethylation of aromatic compounds. The robust catalytic procedure provides the desired products in up to 95 % yield at 25 °C in 1.5 to 3 hours and tolerates a broad range of functional groups. The utilization of hypervalent reagents opens new synthetic possibilities for direct alkylations and fluoroalkylations in the field of transition-metal-catalyzed C-H activation.
- T?th, Balázs L.,Kovács, Szabolcs,Sályi, Gerg?,Novák, Zoltán
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supporting information
p. 1988 - 1992
(2016/02/18)
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- Palladium-Catalyzed C-H Activation and Cyclization of Anilides with 2-Iodoacetates and 2-Iodobenzoates: An Efficient Method toward Oxindoles and Phenanthridones
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A concise approach to the synthesis of oxindoles and phenanthridones from anilides is described. In the presence of catalytic amount of Pd(OAc)2, 2-iodoacetates and 2-iodobenzoates can be used to functionalize ortho C-H bond of anilides, which subsequently undergo intramolecular cyclization to give the products. A possible reaction mechanism that involves a PdII/PdIV catalytic cycle is proposed with the support of detailed mechanistic studies.
- Gandeepan, Parthasarathy,Rajamalli, Pachaiyappan,Cheng, Chien-Hong
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p. 1872 - 1879
(2016/06/15)
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- Synthesis and antimicrobial activity of azetidin-2-one fused 2-chloro-3-formyl quinoline derivatives
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Azetidin-2-one fused 2-chloro-3-formyl quinolines derivatives, 3-chloro-4-(2-chloro-8/7/6-methoxyquinolin-3-yl)-1-(2,4-dinitro/4-nitro phenylamino)azetidin-2-one,3-chloro-4-(2-chloro-8/7/6-chloroquinolin-3-yl)-1-(2,4-dinitro/4-nitro phenylamino)azetidin-2-one, 3-chloro-4-(2-chloro-8/7/6-methylquinolin-3-yl)-1-(2,4-dinitro/4-nitrophenylamino) azetidin-2-one were synthesized by four steps, respectively from N-arylacetamides, 2-chloro-3-formyl quinolines, 2,4-dinitro/4-nitro phenyl hydrazine reflux with chloroacetyl chloride and triethyl amine. However yields of quinolines having electron donating groups in all cases. The structures of the synthesized compounds have been established on the basis of physical and spectral data. The antibacterial and antifungal activity of these compounds was tested by filter paper disc method against Staphylococcus aureus (MTCC96), Escherichia coli (MTCC722) and Candida albicans (MTCC183). The results showed that azetidin-2-one fused 2-chloro-3-formyl quinolines derivatives are better in inhibiting the growth of both types of organisms. Compounds AZT b2, AZT b3 to AZT g2, AZT g3 were found to be more potent compared to standard drug.
- Nayak, Govind,Shrivastava, Birendra,Singhai, Akhlesh Kumar
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p. 1977 - 1982
(2016/10/24)
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- A metal-free approach for transamidation of amides with amines in aqueous media
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An efficient, environmentally benign and a mild protocol for transamidation of amides with a variety of amines in the presence of K2S2O8 using stoichiometric quantity in aqueous conditions has been established. This method works under conventional thermal conditions and in microwave irradiation as well. A series of amides have been prepared using this reaction and this is a greener protocol for transamidation, which offers a diverse kind of substrate scope with exclusive product formation (yields 90-98%).
- Srinivas, Mahesuni,Hudwekar, Abhinandan D.,Venkateswarlu, Vunnam,Reddy, G. Lakshma,Kumar, K. A. Aravinda,Vishwakarma, Ram A.,Sawant, Sanghapal D.
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supporting information
p. 4775 - 4779
(2015/07/20)
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- An attractive route to transamidation catalysis: Facile synthesis of new o-aryloxide-N-heterocyclic carbene ruthenium(II) complexes containing trans triphenylphosphine donors
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Well-defined robust ruthenium(II) complexes 3a-d bearing o-aryloxide-N-heterocyclic carbene ligands with different wingtip substituents (3a (R = Me), 3b (R = Ph), 3c (R = iPr) and 3d (R = Mes)) in the imidazole ring were synthesized in good yields by the reaction of imidazolium proligands with metal precursor [RuHCl(CO)(PPh3)3] by transmetallation from the corresponding silver carbene complexes. All the Ru(II)-NHC complexes have been characterized by elemental analyses, spectroscopic methods as well as ESI mass spectrometry. The molecular structure of the complex 3a was identified by means of single-crystal X-ray diffraction analysis, which revealed that the complexes possess a distorted octahedral geometry. In order to explore the catalytic potential of the synthesized complexes, all the four [Ru-NHC] complexes [3a-d] were tested as catalysts for transamidation of carboxamides with amines. Notably, the complex 3a was found to be very efficient and versatile catalyst toward transamidation of a wide range of amides with amines.
- Nirmala, Muthukumaran,Prakash, Govindan,Viswanathamurthi, Periasamy,Malecki, Jan Grzegorz
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- Cleavage of C-N bonds in guanidine derivatives and its relevance to efficient C-N bonds formation
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Efficient nonenzymatic decomposition of guanidine derivatives with high structural and functional diversity into anilide products is achieved in the presence of PdII/Cu(II) carboxylates/CO, relying on a dual C-N bonds cleavage strategy. In this decomposition process, the cooperative action of PdII species, Cu(II) carboxylates, and CO provides not only the N-acylating agents but also an initiator to trigger this C-N bonds cleavage sequence. The current results indicate that PdII/Cu(II) carboxylates/CO system provides a convenient and practical method for highly selective cleavage of unreactive C-N single bonds.
- Chang, Denghu,Zhu, Dan,Zou, Peng,Shi, Lei
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p. 1684 - 1693
(2015/03/30)
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- Synthesis and Herbicidal Activity of Triketone-Quinoline Hybrids as Novel 4-Hydroxyphenylpyruvate Dioxygenase Inhibitors
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4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) is one of the most important targets for herbicide discovery. In the search for new HPPD inhibitors with novel scaffolds, triketone-quinoline hybrids were designed and subsequently optimized on the basis of the structure-activity relationship (SAR) studies. Most of the synthesized compounds displayed potent inhibition of Arabidopsis thaliana HPPD (AtHPPD), and some of them exhibited broad-spectrum and promising herbicidal activity at the rate of 150 g ai/ha by postemergence application. Most promisingly, compound III-l, 3-hydroxy-2-(2-methoxy-7-(methylthio)quinoline-3-carbonyl)cyclohex-2-enone (Ki = 0.009 ~M, AtHPPD), had broader spectrum of weed control than mesotrione. Furthermore, compound III-l was much safer to maize at the rate of 150 g ai/ha than mesotrione, demonstrating its great potential as herbicide for weed control in maize fields. Therefore, triketone-quinoline hybrids may serve as new lead structures for novel herbicide discovery.
- Wang, Da-Wei,Lin, Hong-Yan,Cao, Run-Jie,Chen, Tao,Wu, Feng-Xu,Hao, Ge-Fei,Chen, Qiong,Yang, Wen-Chao,Yang, Guang-Fu
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p. 5587 - 5596
(2015/06/25)
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- The convenient aqueous synthesis and biological evaluation of ortho-(3,4,5-trimethoxybenzoyl)-acetanilides as novel anti-cancer agents
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A series of new ortho-(3,4,5-trimethoxybenzoyl)-acetanilides were synthesised by the cross-coupling reaction catalyzed with Pd catalyst in aqueous medium, with polyethylene glycol as additive under very mild conditions. The evaluation of these compounds as tubulin polymerization inhibitors indicated that most of these compounds were potential anti-cancer agents. Among them, compound 13, 2-hydroxy-N-(5-methoxy-2-(3,4,5-trimethoxy benzoyl)phenyl) acetamide exhibited excellent antiproliferative activity against various human cancer cell lines (GI50= 71 nM for human HeLa cell line), and good activity for inhibiting tubulin polymerization (IC50= 2.94 μM). The mechanism study indicated that compound 13 could arrest cell-cycle progression at the mitosis phase, block the formation of cdc2/cyclin B1 complex, down-regulate the p-Cdc 25C and the anti-apoptotic proteins Bcl-2 and Bcl-XL, and up-regulate the pro-apoptotic proteins Bax and Bad. This journal is
- Sheng, Jianfei,Mao, Fei,Yan, Jun,Huang, Ling,Li, Xingshu
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p. 41510 - 41520
(2014/12/11)
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- Tris(pentafluorophenyl)borane catalyzed acylation of alcohols, phenols, amines, and thiophenols under solvent-free condition
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The acylation of alcohols, phenols, amines, and thiophenols was accomplished with 0.5 mol % of tris(pentafluorophenyl)borane [B(C 6F5)3] at ambient temperature under solvent-free condition. Major advantages of this method include high yield, short reaction time, simple procedure, compatibility with sensitive protecting groups as well as other functional groups, absence of racemization of optical active compounds, and epimerization of sugars.
- Prajapti, Santosh Kumar,Nagarsenkar, Atulya,Babu, Bathini Nagendra
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p. 1784 - 1787
(2014/03/21)
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- A one-pot process for palladium catalyzed direct C-H acylation of anilines in water using a removable ortho directing group
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A new mild, practical method for the synthesis of aminobenzophenone derivatives through a three step one-pot reaction sequence involving acylation of anilines, palladium catalyzed cross-dehydrogenative coupling of the formed anilides and the hydrolytic cleavage is reported. The full reaction sequence was performed under aqueous conditions.
- Szabo, Fruzsina,Simko, Daniel,Novak, Zoltan
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p. 3883 - 3886
(2014/01/06)
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- Novel quinoline-imidazolium adducts via the reaction of 2-oxoquinoline-3-carbaldehyde and quinoline-3-carbaldehydes with 1-butyl-3-methylimidazolium chloride [BMIM][Cl]
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A library of hydroxyquinolin-3-ylmethylimidazolium adducts were prepared in high yields from the reaction of [BMIM][Cl] with various substituted quinoline-3-carbaldehydes and 2-oxoquinoline-3-carbaldehydes under mild conditions by using sodium acetate in MeCN under ultrasound irradiation. The use of sodium acetate and imidazolium chloride was crucial for the success of these CC bond forming reactions. Attempted coupling with thiazolium bromide led instead to quinoline-3-carboxylic acid.
- Laali, Kenneth K.,Insuasty, Daniel,Abonia, Rodrigo,Insuasty, Braulio,Bunge, Scott D.
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supporting information
p. 4395 - 4399
(2014/07/22)
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- Schmidt reaction of ketones in dme solution in a continuous-flow microreactor
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The Schmidt reaction, the treatment with hydroazoic acid in the presence of a strong acid, converts ketones to amides directly and has been broadly applied in organic synthesis. In this communication, the Schmidt reaction of ketones was carried out in DME solution in a continuous-flow microreactor and gave the amide products. The enclosed small-volume feature of the microreactor made this reaction safe, fast, and cost-effective.
- Chen, Yuesu,Liu, Binjie,Liu, Xiaofeng,Yang, Yongtai,Ling, Yun,Jia, Yu
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supporting information
p. 1589 - 1592
(2015/02/19)
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- L-Proline: An efficient catalyst for transamidation of carboxamides with amines
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In the presence of a catalytic amount of l-proline (10 mol %), transamidations of carboxamides with amines were achieved under solvent-free conditions. The transamidation process is compatible with a wide range of amines.
- Rao, Sadu Nageswara,Mohan, Darapaneni Chandra,Adimurthy, Subbarayappa
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supporting information
p. 1496 - 1499
(2013/06/27)
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- Recyclable, highly efficient and low cost nano-MgO for amide synthesis under SFRC: A convenient and greener 'NOSE' approach
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A clean synthesis of amide derivatives has successfully been accomplished utilizing reusable nano-MgO under 'SFRC' (solvent free reaction condition). The 'green-ness' of this protocol makes it a benign alternative for the large scale synthesis.
- Das, Vijay Kumar,Devi, Rashmi Rekha,Thakur, Ashim Jyoti
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p. 118 - 125
(2013/06/26)
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