- A Concise Total Synthesis of Dictyodendrins F, H, and i Using Aryl Ynol Ethers as Key Building Blocks
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We report a concise total synthesis of dictyodendrin F and the first total syntheses of dictyodendrins H and I in six steps. In these syntheses, aryl ynol ethers were employed as the key building blocks to introduce aryl and heteroaryl rings in the dictyodendrins. This rapid synthesis utilized a novel hetero-[2 + 2]-cycloaddition reaction between two aryl ynol ethers to yield a cyclobutenone ring. The cyclobutenone was sequentially converted into a highly substituted carbazole via a retro-4π/6π-electrocyclization-N-acylation cascade reaction to provide the dictyodendrin core. Consecutive intramolecular oxidative coupling and deprotection gave dictyodendrins F, H, and I.
- Zhang, Wenhan,Ready, Joseph M.
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- Copper-catalyzed transformation of alkyl nitriles to N -arylacetamide using diaryliodonium salts
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This work reports a simple and efficient method for the copper-catalyzed redox-neutral transformation of alkyl nitriles using eco-friendly diaryliodonium salts and leading to N-arylacetamides. The method features high efficiency, broad substrate scope and good functional group tolerance.
- Sallio, Romain,Payard, Pierre-Adrien,Pakulski, Pawe?,Diachenko, Iryna,Fabre, Indira,Berteina-Raboin, Sabine,Colas, Cyril,Ciofini, Ilaria,Grimaud, Laurence,Gillaizeau, Isabelle
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p. 15885 - 15889
(2021/05/19)
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- Solvent- and transition metal-free amide synthesis from phenyl esters and aryl amines
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A general, economical, and environmentally friendly method of amide synthesis from phenyl esters and aryl amines was developed. This new method has significant advantages compared to previously reported palladium-catalyzed approaches. The reaction is performed transition metal- and solvent-free, using a cheap and environmentally benign base, NaH. This approach enabled us to obtain target amides in high yields with high atom economy.
- Rzhevskiy, Sergey A.,Ageshina, Alexandra A.,Chesnokov, Gleb A.,Gribanov, Pavel S.,Topchiy, Maxim A.,Nechaev, Mikhail S.,Asachenko, Andrey F.
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p. 1536 - 1540
(2019/01/24)
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- Ruthenium-Catalyzed Oxidative Amidation of Alkynes to Amides
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Complex CpRuCl(PPh3)2 catalyzes reactions of terminal alkynes with 4-picoline N-oxide and primary and secondary amines to afford the corresponding amides. The reactions occur in chlorinated solvent and aqueous medium, showing applications in peptide chemistry. Stoichiometric studies reveal that the true catalysts of the processes are the vinylidene cations [CpRu(=C=CHR)(PPh3)2]+ which are oxidized to the Ru(η2-CO)-ketenes by the N-oxide. Finally, nucleophilic additions of primary and secondary amines to the free ketenes yield the corresponding amides.
- álvarez-Pérez, Andrea,Esteruelas, Miguel A.,Izquierdo, Susana,Varela, Jesús A.,Saá, Carlos
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supporting information
p. 5346 - 5350
(2019/07/08)
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- [Co(MeTAA)] Metalloradical Catalytic Route to Ketenes via Carbonylation of Carbene Radicals
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An efficient synthetic strategy towards beta-lactams, amides, and esters involving “in situ” generation of ketenes and subsequent trapping with nucleophiles is presented. Carbonylation of carbene radical intermediates using the cheap and highly active cobalt(II) tetramethyltetraaza[14]annulene catalyst [Co(MeTAA)] provides a convenient one-pot synthetic protocol towards substituted ketenes. N-tosylhydrazones are used as carbene precursors, thereby bridging the gap between aldehydes and ketenes. Activation of these carbene precursors by the metalloradical cobalt(II) catalyst affords CoIII-carbene radicals, which subsequently react with carbon monoxide to form ketenes. In the presence of a nucleophile (imine, alcohol, or amine) in the reaction medium the ketene is immediately trapped, resulting in the desired products in a one-pot synthetic protocol. The β-lactams formed upon reaction with imines are produced in a highly trans-selective manner.
- Chirila, Andrei,van Vliet, Kaj M.,Paul, Nanda D.,de Bruin, Bas
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p. 2251 - 2258
(2018/04/09)
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- Palladium-catalyzed carbonylation of benzylic ammonium salts to amides and esters: Via C-N bond activation
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An efficient palladium-catalyzed carbonylation reaction of readily available quaternary ammonium salts with CO is reported for the first time to afford arylacetamides and arylacetic acid esters via benzylic C-N bond cleavage. This protocol features mild reaction conditions under atmospheric pressure of CO, a redox-neutral process without an additional oxidant, and a broad substrate scope for various kinds of amines, alcohols and phenols.
- Yu, Weijie,Yang, Shuwu,Xiong, Fei,Fan, Tianxiang,Feng, Yan,Huang, Yuanyuan,Fu, Junkai,Wang, Tao
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p. 3099 - 3103
(2018/05/22)
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- Methods for preparing amide compounds using alkynes and methods for preparing peptides using the same
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The present invention relates to a method for preparing an amide compound, which comprises a step of agitating an alkyne and an N-hydroxy compound in an organic solvent in the presence of a transition metal catalyst to form an amide bond, and a method for preparing a peptide using the same. According to the present invention, the amidation reaction does not depend on polar reactivity, such as the conventional simple nucleophilicity and electrophilicity, but is based on a reaction derived from coordination reactivity between an alkyne and a transition metal, and thus shows excellent chemical selectivity. In addition, the method does not require a consumptive step such as attachment and detachment of a protecting group but includes a simple process during the synthesis of a peptide. Thus, the method is very effective for preparing a polypeptide compound. The method also has 100% of atomic economic efficiency since the starting materials are not lost during the reaction.COPYRIGHT KIPO 2017
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Paragraph 0107-0109; 0172-0174; 0184-0186
(2017/09/21)
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- Novel green acylamide synthesis method through quaternary ammonium salt C-N bond fracture
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The invention provides a novel green acylamide synthesis method through quaternary ammonium salt C-N bond fracture. The structure of the compound is expressed by methods such as H NMR, C, NMR and HRMS and is confirmed. A series of phenmethyl quaternary ammonium salts and aminated compounds are used; under the catalysis effect of PdCl2(dppf), PPh3 is used as a ligand, Na2CO3 is used as the alkali, and corresponding amide compounds are generated in the 100-DEG C CO atmosphere in a pHMe/DMSO mixed solvent. The method has the advantages that the efficiency is high; the toxicity is low; the conditions are mild; the application range of the substrate is wide; the yield is high; the product purity is high; the separation is convenient; the method can be applicable to large-scale preparation; the application prospects are wide.
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Paragraph 0024-0026
(2017/04/19)
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- Modular Synthesis of Arylacetic Acid Esters, Thioesters, and Amides from Aryl Ethers via Rh(II)-Catalyzed Diazo Arylation
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One-pot formation of arylacetic acid esters, thioesters, and amides via Rh(II)-catalyzed arylation of a Meldrum's acid-derived diazo reagent with electron-rich arenes is described. The methodology was used to efficiently synthesize an anticancer compound.
- Best, Daniel,Jean, Micka?l,Van De Weghe, Pierre
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p. 7760 - 7770
(2016/09/12)
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- Metal-free hydration of ynamides: Convenient approach to amides
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The trifluoroacetic acid (TFA) mediated hydration of ynamides was developed, which is an efficient approach for the synthesis of N-monosubstituted amides. This convenient method is effective with a wide range of substrates under room temperature condition, and the products are obtained in high to excellent yields through an easy work-up process.
- Huang, Hai,Tang, Luning,Xi, Yang,He, Guangke,Zhu, Hongjun
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p. 1873 - 1876
(2016/04/19)
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- Nitrogen enriched mesoporous organic polymer anchored copper(ii) material: An efficient and reusable catalyst for the synthesis of esters and amides from aromatic systems
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A new copper-grafted mesoporous poly-melamine-formaldehyde (Cu-mPMF) has been synthesized from melamine and paraformaldehyde in DMSO medium, followed by grafting of Cu(ii) at its surface. Cu-mPMF has been characterized by elemental analysis, powder XRD, HR TEM, FE-SEM, N2 adsorption study, FT-IR, UV-vis DRS, TGA-DTA, EPR spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The Cu-grafted mesoporous material showed very good catalytic activity in methyl esterification of benzylic alcohols and amidation of nitriles. Moreover, the catalyst is easily recoverable and can be reused seven times without appreciable loss of catalytic activity in the above reactions. The highly dispersed and strongly bound Cu(ii) sites in the Cu-grafted mesoporous polymer could be responsible for the observed high activities of the Cu-mPMF catalyst. Due to strong binding with the functional groups of the polymer, no evidence of leached copper from the catalyst during the course of reaction emerged, suggesting true heterogeneity in the catalytic process. This journal is
- Molla, Rostam Ali,Iqubal, Md. Asif,Ghosh, Kajari,Kamaluddin,Islam, Sk. Manirul
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p. 6546 - 6559
(2015/04/14)
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- Chemoselective Reductive Deoxygenation and Reduction of α-Keto Amides by using a Palladium Catalyst
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A palladium catalyst is used to synthesize 2,N-diphenylacetamides and α-hydroxy amides from readily available α-keto amides by chemoselective reductive deoxygenation and chemoselective reduction using polymethylhydrosiloxane (PMHS). This methodology has t
- Mamillapalli, N. Chary,Sekar, Govindasamy
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p. 3273 - 3283
(2015/11/03)
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- An efficient protocol for the preparation of amides by copper-catalyzed reactions between nitriles and amines in water
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The reactions between nitriles and amines catalyzed by Cu(OAc)2 and 2-piperidinecarboxylic acid were carried out in pure water without any other additives. A variety of substituted amides can be obtained in moderate to good yields up to 90%.
- Li, Xiaoya,Li, Zhengkai,Deng, Hang,Zhou, Xiangge
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supporting information
p. 2212 - 2216
(2013/05/09)
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- Rhodium-catalyzed oxygenative addition to terminal alkynes for the synthesis of esters, amides, and carboxylic acids
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A gem of a couple: The title reaction of terminal alkynes with O and Nnucleophiles proceeds in the presence of [Rh(cod)Cl}2], P(4-FC 6H4)3, and 4-picoline N-oxide. Alcohols, amines, and water add to the terminal alkynes to give esters, amides, and carboxylic acids, respectively. The reaction involves formation of a rhodium vinylidene, oxidation to a ketene by oxygen transfer, and nucleophilic addition.
- Kim, Insu,Lee, Chulbom
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supporting information
p. 10023 - 10026
(2013/10/01)
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- Carbene radicals in cobalt(II)-porphyrin-catalysed carbene carbonylation reactions; A catalytic approach to ketenes
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One-pot radicals: Cobalt(III)-carbene radicals, generated by metallo-radical activation of diazo compounds and N-tosylhydrazone sodium salts with cobalt(II) complexes of porphyrins, readily undergo radical addition to carbon monoxide, allowing the catalytic production of ketenes. These ketenes subsequently react with various amines, alcohols and imines in one-pot tandem transformations to produce differently substituted amides, esters and β-lactams in good isolated yields. Copyright
- Paul, Nanda D.,Chirila, Andrei,Lu, Hongjian,Zhang, X. Peter,Debruin, Bas
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supporting information
p. 12953 - 12958
(2013/10/01)
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- A straightforward synthesis of N-monosubstituted α-keto amides via aerobic benzylic oxidation of amides
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An efficient sodium bicarbonate promoted aerobic oxidation reaction to prepare N-monosubstituted α-keto amides in the presence of n-tetrabutylammonium hydrogensulfate (TBAHS) was described. This reaction provides a very simple and convenient synthetic route to N-monosubstituted α-keto amides from easily available aryl- or heteroarylacetamides in good to high yields without using toxic reagents and harsh conditions.
- Shao, Jun,Huang, Xiaomei,Wang, Siyuan,Liu, Bingxin,Xu, Bin
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p. 573 - 579
(2012/01/13)
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- Pd-catalyzed carbonylation of diazo compounds at atmospheric pressure: A catalytic approach to ketenes
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The carbonylation of carbenes through catalytic cycles is highly desirable due to the importance of ketene-mediated reactions in organic synthesis. In this investigation, a highly efficient and mild catalytic approach toward ketene intermediates has been developed based on Pd-catalyzed carbonylation of diazo compounds with CO. When α-diazocarbonyl compounds or N-tosylhydrazone salts are heated in the presence of a palladium catalyst under atmospheric pressure of CO, ketene intermediates are formed in situ, where they undergo further reactions with various nucleophiles such as alcohols, amines, or imines. The Pd-catalyzed tandem carbonylation-Staudinger cycloaddition gives β-lactam derivatives in good yields with excellent trans diastereoselectivity. The results from DFT calculation on the reaction mechanism suggest that Pd is involved in the [2 + 2] cycloaddition process and affects the diastereoselectivity of the β-lactam products by assisting isomerization of the addition intermediate. On the other hand, the acylketenes generated from the Pd-catalyzed carbonylation of α-diazoketones react with imines in a formal [4 + 2] cycloaddition manner to afford 1,3-dioxin-4-one derivatives. This straightforward carbonylation provides a new approach toward highly efficient catalytic generation of ketene species under mild conditions.
- Zhang, Zhenhua,Liu, Yiyang,Ling, Lin,Li, Yuxue,Dong, Yian,Gong, Mingxing,Zhao, Xiaokun,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 4330 - 4341
(2011/06/21)
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- Antiimplantation Agents: Part II - 1,2-Diaryl-1,2,3,4-tetrahydroisoquinolines
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1,2-Diaryl-3,4-dihydroisoquinolinium derivatives (5) have been synthesised from N-aryl-N-aroyl-β-phenethylamines (4) and found to exhibit no antiimplantation activity in the rat whereas many of the corresponding tetrahydroisoquinolines (6) are active.Structure-activity relationships have also been studied. 1-(p-Fluorophenyl)-6-methoxy-2-phenyl-1,2,3,4-tetrahydroisoquinoline (6u) and its nor derivative (6v) are very potent, while the ortho (6g) and the meta (6n) fluoro analogues as well as the des-fluoro derivative (6d) are quite active.Extensive biological tests have been carried out on 6g.The enantiomers (+)-6p*HCl and (-)-6q*HCl of 6n have similar activity profiles as that of 6n showing no separation of antiimplantation and estrogenic properties.Diastereomeric 2-(2-methyl-2-phenethyl)-1-phenyl-1,2,3,4-tetrahydroisoquinolines (13a and 13b) show similar properties, while the tetracyclic derivative 19 is inactive. 2-Phenoxyethyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline (26) shows moderate activity, but 1-(β-phenethyl)-2-phenyl-1,2,3,4-tetrahydroisoquinoline 29 is inactive.
- Nagarajan, K.,Talwalker, P. K.,Kulkarni, C. L.,Shah, R. K.,Shenoy, S. J.,Prabhu, S. S.
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