- Design of enamides as new selective monoamine oxidase-B inhibitors
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Objectives: To develop of new class of selective and reversible MAO-B inhibitors from enamides. Methods: Syntheses of the titled derivatives (AD1–AD11) were achieved by reacting cinnamoyl chloride and various primary and secondary amines in basic medium. All eleven compounds were investigated for in vitro inhibitory activities against recombinant human MAO-A and MAO-B. The reversibilities of lead compound inhibitions were analysed by dialysis. MTT assays of lead compounds were performed using normal VERO cell lines. Key findings: Compounds AD3 and AD9 exhibited the greatest inhibitory activity against MAO-B with IC50 values of 0.11 and 0.10?μm, respectively, and were followed by AD2 and AD1 (0.51 and 0.71?μm, respectively). Most of the compounds weakly inhibited MAO-A, with the exceptions AD9 and AD7, which had IC50 values of 4.21 and 5.95?μm, respectively. AD3 had the highest selectivity index (SI) value for MAO-B (>363.6) and was followed by AD9 (SI 42.1). AD3 and AD9 were found to be competitive inhibitors of MAO-B with Ki values of 0.044?±?0.0036 and 0.039?±?0.0047?μm, respectively. Reversibility experiments showed AD3 and AD9 were reversible inhibitors of MAO-B; dialysis restored the activity of MAO-B to the reference level. MTT assays revealed AD3 and AD9 were non-toxic to normal VERO cell lines with IC50 values of 153.96 and 194.04?μg/ml, respectively. Computational studies provided hypothetical binding modes for AD3 and AD9 in the binding cavities of MAO-A and MAO-B. Conclusions: These results encourage further studies on the enamide scaffold as potential drug candidates for the treatment of Alzheimer's and Parkinson's diseases.
- Kavully, Fathima Sahla,Oh, Jong Min,Dev, Sanal,Kaipakasseri, Swafvan,Palakkathondi, Ashique,Vengamthodi, Ajeesh,Abdul Azeez, Rinshana Fathima,Tondo, Anna Rita,Nicolotti, Orazio,Kim, Hoon,Bijo
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Read Online
- Dialkylaminoacetonitrile Derivatives as Amide Synthons. A One-Pot Preparation of Heteroaryl Amides via a Strategy of Sequential SNAr Substitution and Oxidation
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Dialkylamino acetonitrile derivatives were utilized as alternative to cyanohydrin synthons for preparation of the corresponding heteroaryl dialkyl amides via a strategy of sequential base-mediated coupling and oxidation. The most advantageous oxidant, NiO2-H2O, can readily oxidize 2-substituted aminoacetonitriles to the corresponding amides under both basic and neutral conditions by forming cyanohydrins in situ.
- Zhang, Zhongxing,Yin, Zhiwei,Kadow, John F.,Meanwell, Nicholas A.,Wang, Tao
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Read Online
- Direct Amidation of Esters by Ball Milling**
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The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This direct synthesis platform has been applied to the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals as well as the gram-scale synthesis of an active pharmaceutical, all in the absence of a reaction solvent.
- Barreteau, Fabien,Battilocchio, Claudio,Browne, Duncan L.,Godineau, Edouard,Leitch, Jamie A.,Nicholson, William I.,Payne, Riley,Priestley, Ian
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supporting information
p. 21868 - 21874
(2021/09/02)
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- Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
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Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
- Liu, Xin,Werner, Thomas
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p. 1096 - 1104
(2020/12/31)
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- PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
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A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.
- Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
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p. 491 - 497
(2021/01/20)
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- Electron-Catalyzed Aminocarbonylation: Synthesis of α,β-Unsaturated Amides from Alkenyl Iodides, CO, and Amines
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Aminocarbonylation of alkenyl iodides with CO and amines proceeded under heating to produce α,β-unsaturated amides in good yields (23 examples, 71% average yield). This catalyst-free method exhibited good functional-group tolerance, and open a straightforward access to functionalized acrylamides, as illustrated by the synthesis of Ilepcimide. A hybrid radical/ionic mechanism involving chain electron transfer is proposed for this transformation.
- Picard, Baptiste,Fukuyama, Takahide,Bando, Takanobu,Hyodo, Mamoru,Ryu, Ilhyong
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supporting information
p. 9505 - 9509
(2021/12/09)
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- Mizoroki-Heck Reaction of Unstrained Aryl Ketones via Ligand-Promoted C-C Bond Olefination
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Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.
- Wang, Mei-Ling,Xu, Hui,Li, Han-Yuan,Ma, Biao,Wang, Zhen-Yu,Wang, Xing,Dai, Hui-Xiong
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p. 2147 - 2152
(2021/04/05)
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- Simple Synthesis of Amides via Their Acid Chlorides in Aqueous TPGS-750-M
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The technology of surfactant chemistry is employed for amide bond construction via the reaction of acyl chlorides with amines in 2 wt % TPGS-750-M aqueous solution. Specifically, this highly efficient method enables a chromatography-free scalable process and recycling of the TPGS-750-M solution.
- Shi, Min,Ye, Ning,Chen, Wei,Wang, Hui,Cheung, Chiming,Parmentier, Michael,Gallou, Fabrice,Wu, Bin
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supporting information
p. 1543 - 1548
(2020/11/23)
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- Catalytic α-Hydroarylation of Acrylates and Acrylamides via an Interrupted Hydrodehalogenation Reaction
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The palladium-catalyzed, α-selective hydroarylation of acrylates and acrylamides is reported. Under optimized conditions, this method is highly tolerant of a wide range of substrates including those with base sensitive functional groups and/or multiple enolizable carbonyl groups. A detailed mechanistic study was undertaken, and the high selectivity of this transformation was shown to be enabled by the formation of a [PdII(Ar)(H)] intermediate, which performs selective hydride insertion into the β-position of α,β-unsaturated carbonyl compounds.
- Cherney, Emily C.,Engle, Keary M.,Gurak, John A.,Joe, Candice L.,Vasquez, Alena M.
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supporting information
p. 10477 - 10484
(2020/08/07)
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- Copper(I)-Catalyzed Asymmetric 1,4-Conjugate Hydrophosphination of α,β-Unsaturated Amides
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A catalytic asymmetric conjugate hydrophosphination of α,β-unsaturated amides is accomplished by virtue of the strong nucleophilicity of copper(I)-PPh2 species, which provides an array of chiral phosphines bearing an amide moiety in high to excellent yields with excellent enantioselectivity. Furthermore, the dynamic kinetic resolution of unsymmetrical diarylphosphines (HPAr1Ar2) is successfully carried out through the copper(I)-catalyzed conjugate addition to α,β-unsaturated amides, which affords P-chiral phosphines with good-to-high diastereoselectivity and high enantioselectivity. 1H NMR studies show that the precoordination of HPPh2 to copper(I)-bisphosphine complex is critical for the efficient deprotonation by Barton's Base. Moreover, the relative stability of the copper(I)-(R,RP)-TANIAPHOS complex in the presence of excessive HPPh2, confirmed by 31P NMR studies, is pivotal for the high asymmetric induction, as the ligand exchange between bisphosphine and HPPh2 would significantly reduce the enantioselectivity. At last, a double catalytic asymmetric conjugate hydrophosphination furnishes the corresponding product in high yield with high diastereoselectivity and excellent enantioselectivity, which is transformed to a chiral pincer palladium complex in moderate yield. This chiral palladium complex is demonstrated as an excellent catalyst in the asymmetric conjugate hydrophosphination of chalcone.
- Li, Yan-Bo,Tian, Hu,Yin, Liang
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supporting information
p. 20098 - 20106
(2021/01/01)
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- Metal-Free Transamidation of Secondary Amides by N-C Cleavage
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Transamidation reactions represent a fundamental chemical process involving conversion of one amide functional group into another. Herein, we report a facile, highly chemoselective method for transamidation of N-tert-butoxycarbonylation (N-Boc) activated secondary amides that proceeds under exceedingly mild conditions in the absence of any additives. Because this reaction is performed in the absence of metals, oxidants, or reductants, the reaction tolerates a large number of useful functionalities. The reaction is compatible with diverse amides and nucleophilic amines, affording the transamidation products in excellent yields through direct nucleophilic addition to the amide bond. The utility of this methodology is highlighted in the synthesis of Tigan, a commercial antiemetic, directly from the amide bond. We expect that this new metal-free transamidation will have broad implications for the development of new transformations involving direct nucleophilic addition to the amide bond as a key step.
- Rahman, Md. Mahbubur,Li, Guangchen,Szostak, Michal
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p. 12091 - 12100
(2019/10/11)
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- Radical α,β-Dehydrogenation of Saturated Amides via α-Oxidation with TEMPO under Transition Metal-Free Conditions
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A transition metal-free radical process for the selective α,β-dehydrogenation of saturated amides under mild conditions is developed. Utilizing radical activation strategy, the challenging issue associated with the low α-acidity of amides is resolved. For the first time, α,β-unsaturated Weinreb amides and acrylamides could be efficiently prepared directly from corresponding saturated amides. Mechanistic studies confirm the radical nature of this transformation. Two gram scale α,β-dehydrogenation have also been performed to demonstrate the utility of this method.
- Wang, Mei-Mei,Sui, Guo-Hui,Cui, Xian-Chao,Wang, Hui,Qu, Jian-Ping,Kang, Yan-Biao
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p. 8267 - 8274
(2019/06/27)
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- Visible-light-promoted oxidation/condensation of benzyl alcohols with dialkylacetamides to cinnamides
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Oxidative cross-coupling reactions of benzyl alcohols with N,N-dialkylacetamides were developed only employing oxygen as the terminal oxidant, efficiently providing a new, novel protocol for the construction of multifunctionalized cinnamides with the synergistic effects of KOH, organic photocatalyst eosin Y, and visible light irradiation at room temperature. A broad substrate scope and mild reaction conditions are the prominent features of this transformation.
- Yang, Tianlong,Lu, Maojian,Lin, Zhaowei,Huang, Mingqiang,Cai, Shunyou
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supporting information
p. 449 - 453
(2019/01/24)
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- Synthesis, evaluation, and molecular properties prediction of substituted cinnamoylpiperazine derivatives as potential antinociceptive and anticonvulsive agents
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A series of novel cinnamoylpiperazine derivatives (5a–5l) were synthesized as potential antinociceptive, and anticonvulsive agents. Various heterocyclic systems like piperidine, morpholine, piperazine, and N-arylpiperazine were combined with cinnamoyl or methylenedioxy cinnamoyl moieties to obtain a series of constrained analogs of cinnamides. Of these, compound 5e possessing 4-fluorophenyl substitution on the piperazine ring exhibited good antinociceptive activity in capsaicin and formalin-induced nociception methods, and also significant anticonvulsant activity in pentylenetetrazole and maximal electroshock-induced seizure methods. Further, all the derivatives were studied for molecular and preadmet properties. The activities of compound 5e were supported by molecular and preadmet properties for its in silico oral bioavailability and drug-likeness.
- Prasanthi, Gummalla,Prasad, Kvsrg,Bharathi, Koganti
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p. 1599 - 1608
(2018/04/12)
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- Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
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A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
- Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
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p. 6659 - 6662
(2018/09/29)
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- An efficient procedure for chemoselective amidation from carboxylic acid and amine (ammonium salt) under mild conditions
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Presented here is an efficient one-pot and catalyst-free procedure for the synthesis of amides starting from carboxylic acids and amine/ammonium salts using 2,2-dichloro-1,3-diisopropylimidazolidine-4,5-dione as the coupling agent. Reactions can proceed smoothly even with those bearing thermosensitive group(s) at ambient temperature, and the corresponding products of primary, secondary and tertiary amides can be afforded in moderate to excellent yields of up to 96%.
- Li, Jianhui,He, Shaopo,Fu, Haiqing,Chen, Xin,Tang, Min,Zhang, Dela,Wang, Bo
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p. 2289 - 2303
(2017/12/26)
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- Fragmentation pattern of amides by EI and HRESI: Study of protonation sites using DFT-3LYP data
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Amides are important natural products which occur in a few plant families. Piplartine and piperine, major amides in Piper tuberculatum and P. nigrum, respectively, have shown a typical N-CO cleavage when analyzed by EI-MS or HRESI-MS. In this study several synthetic analogs of piplartine and piperine were subjected to both types of mass spectrometric analysis in order to identify structural features influencing fragmentation. Most of the amides showed an intense signal of the protonated molecule [M + H]+ when subjected to both HRESI-MS and EI-MS conditions, with a common outcome being the cleavage of the amide bond (N-CO). This results in the loss of the neutral amine or lactam and the formation of aryl acylium cations. The mechanism of N-CO bond cleavage persists in α,β-unsaturated amides because of the stability caused by extended conjugation. Computational methods determined that the protonation of the piperamides and their derivatives takes place preferentially at the amide nitrogen supporting the dominant the N-CO bond cleavage.
- Fokoue,Marques,Correia,Yamaguchi,Qu,Aires-De-Sousa,Scotti,Lopes,Kato
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p. 21407 - 21413
(2018/06/26)
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- Synthesis of piplartine analogs and preliminary findings on structure–antimicrobial activity relationship
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In this work it is described the synthesis, characterization and antimicrobial and toxicity evaluation of a series of analogs of piplartine, a piperamide found in Piper sp. The compounds structures were confirmed by infrared spectroscopy, 1H, 13C nuclear magnetic resonance, high resolution mass spectroscopy and were evaluated against strains of Candida spp., Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Derivative 24 was almost four-fold more potent (IC50: 48.83 μM) and five-fold less toxic (SI > 3) than piplartine (IC50: 189.2 μM; SI: 0.21) against Candida krusei, as well as two-fold more potent than fluconazole (IC50: 104.48 μM). This compound was also active against Candida tropicalis at 97.67 μM. Benzoyl derivative 17 was three-fold more potent (IC50: 85.2 μM) and more than five-fold less toxic (CC50: 231.71 μM) than piplartine (IC50: 315.33 μM and CC50: 41.14 μM) against Staphylococcus aureus. Given these findings, we have found analogs of piplartine which can be assumed as prototypes for the optimization and the development of new antimicrobial (compounds 24 and 17) agents.
- Fregnan, Antonio Maciel,Brancaglion, Guilherme Andrade,Galv?o, Alexandre Francisco Cerqueira,D’Sousa Costa, Cinara Oliveira,Moreira, Diogo Rodrigo Magalh?es,Soares, Milena Botelho Pereira,Bezerra, Daniel Pereira,Silva, Naiara Chaves,de Souza Morais, Stella Maria,Oliver, Josidel Concei??o,Dias, Amanda Latercia Tranches,Coelho, Luiz Felipe Leomil,Carvalho, Diogo Teixeira,Dias, Danielle Ferreira,de Souza, Thiago Belarmino
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p. 603 - 614
(2017/02/15)
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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 0115-0117
(2017/09/21)
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- Amide α,β-Dehydrogenation Using Allyl-Palladium Catalysis and a Hindered Monodentate Anilide
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A practical and direct method for the α,β-dehydrogenation of amides is reported using allyl-palladium catalysis. Critical to the success of this process was the synthesis and application of a novel lithium N-cyclohexyl anilide (LiCyan). The reaction conditions tolerate a wide variety of substrates, including those with acidic heteroatom nucleophiles.
- Chen, Yifeng,Turlik, Aneta,Newhouse, Timothy R.
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supporting information
p. 1166 - 1169
(2016/02/18)
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- Chloroform as a Carbon Monoxide Precursor: In or Ex Situ Generation of CO for Pd-Catalyzed Aminocarbonylations
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Conditions for the rapid hydrolysis of chloroform to carbon monoxide (CO) using heterogeneous CsOH·H2O are described. CO and 13CO can be generated cleanly and rapidly under mild conditions and can be captured either in or ex situ in palladium-catalyzed aminocarbonylation reactions. Utilizing only 1-3 equiv of CO allows for the aminocarbonylation of aryl, vinyl, and benzyl halides with a wide variety of primary and secondary amines giving amide products in good to excellent yields. (Chemical Equation Presented).
- Gockel, Samuel N.,Hull, Kami L.
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supporting information
p. 3236 - 3239
(2015/07/15)
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- Methylaluminoxane (MAO)-assisted direct amidation of esters
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Aliphatic and aromatic esters are efficiently transformed into amides in good to excellent yields, under mild conditions using methylaluminoxane (MAO). This reaction can be performed either at room temperature or by applying microwave irradiation.
- Desrat, Sandy,Ducousso, Aline,Gapil, Shelly,Remeur, Camille,Roussi, Fanny
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p. 385 - 387
(2015/02/19)
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- Size of gold nanoparticles driving selective amide synthesis through aerobic condensation of aldehydes and amines
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Metal nanoparticles (NPs) have attracted much attention in many fields due to their intrinsic characteristics. It is generally accepted that smaller NPs (1.5-3 nm) are more active than larger NPs, and reverse cases are very rare. We report here the direct aerobic oxidative amide synthesis from aldehydes and amines catalyzed by polymer-incarcerated gold (Au) NPs. A unique correlation between imine/amide selectivity and size of NPs was discovered; Au-NPs of medium size (4.5-11 nm) were found to be optimal. High yields were obtained with a broad range of substrates, including primary amines. Au-NPs of medium size could be recovered and reused several times without loss of activity, and they showed good activity and selectivity in amide formation from alcohols and amines. Superior activity and selectivity of gold nanoparticles (Au-NPs) of medium size (4.5-11 nm) were found for the direct and selective aerobic oxidative amide synthesis from various combinations of aldehydes and amines. This is an example of an unusual correlation between the size of NPs and their activity/selectivity. These catalysts could be recovered and reused several times without loss of activity.
- Miyamura, Hiroyuki,Min, Hyemin,Soulé, Jean-Fran?ois,Kobayashi, Shu
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supporting information
p. 7564 - 7567
(2015/06/25)
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- PhICl2 and wet DMF: An efficient system for regioselective chloroformyloxylation/a-chlorination of alkenes/a,β-unsaturated compounds
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PhICl2 in wet DMF was found to form an efficient system for realizing difunctionalization of various alkenes and olefinic derivatives possessing a wide range of functional groups. This novel methodology provides convenient access to either regioselective chloroformyloxylated products or a-chlorinated olefinic products, depending on the type of structure of the original unsaturated starting material. The mechanism of the reaction is proposed and discussed.
- Liu, Le,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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supporting information
p. 436 - 439
(2014/04/03)
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- Metal-free tandem oxidative aryl migration and C-C bond cleavage: Synthesis of α-ketoamides and esters from acrylic derivatives
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A novel tandem metal-free oxidative aryl migration/C-C bond-cleavage reaction, mediated by hypervalent iodine reagent, has been discovered. The presented transformation provided straightforward access to important α-ketoamide and α-ketoester derivatives from readily available acrylic derivatives via a concerted process of 1,2-aryl shift concomitant with C-C bond cleavage.
- Liu, Le,Du, Liang,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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supporting information
p. 5772 - 5775
(2015/02/19)
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- Oxidative coupling of alkenes with amides using peroxides: Selective amide C(sp3)-H versus C(sp2)-H functionalization
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A new oxidative coupling of unactivated terminal alkenes with amides using peroxides is described, in which mono- and difunctionalization of alkenes are selectively achieved. In this reaction with amides, the chemoselectivity toward the functionalization of the C(sp3)-H bonds adjacent to the nitrogen atom or the functionalization of the carbonyl C(sp2)-H bonds across alkenes relies on the reaction conditions. This journal is
- Yang, Xu-Heng,Wei, Wen-Ting,Li, Hai-Bing,Song, Ren-Jie,Li, Jin-Heng
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supporting information
p. 12867 - 12869
(2014/12/11)
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- A novel one-step synthesis of benzo[b]furo[3,2-b]pyridines having an amino group at the 4-position from benzo[b]furo[3,2-d][1,3]oxazine
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A novel one-step synthesis of benzo[b]furo[3,2-b]pyridines having an amino group at the 4-position from benzo[b]furo[3,2-d][1,3]oxazine by treatment of various amines is described.
- Tabuchi, Yukako,Kakumoto, Yusa,Uchimoto, Hitomi,Kawasaki, Ikuo,Ohishi, Yoshitaka,Nishide, Kiyoharu
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p. 177 - 191
(2013/03/13)
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- Amide formation using in situ activation of carboxylic acids with [Et 2NSF2]BF4
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The formation of amides through the in situ activation of carboxylic acids with [Et2NSF2]BF4 is presented. A wide range of carboxylic acids and amines were used to produce the corresponding amides in up to 99 % yield. The reaction of hindered amines was also possible in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under slightly modified conditions. An enantiopure carboxylic acid and amine were both shown to react without racemization. Copyright
- Mahe, Olivier,Desroches, Justine,Paquin, Jean-Francois
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p. 4325 - 4331
(2013/07/26)
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- Copper-catalyzed oxidative coupling of carboxylic acids with formamides for the synthesis of α,β-unsaturated amides
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A novel and efficient protocol for the synthesis of α,β- unsaturated amides has been developed using catalytic amount of Cu(OAc) 2 and TBHP as an available oxidant. Oxidative coupling of various unsaturated carboxylic acids with N,N-disubstituted formamides was examined to furnish the desired products in good yields.
- Li, Huamin,Pan, Changduo,Cheng, Yixiang,Zhu, Chengjian
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supporting information
p. 6679 - 6681
(2013/11/19)
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- The aminocyclodextrin/Pd(OAc)2 complex as an efficient catalyst for the Mizoroki-Heck cross-coupling reaction
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An aminocyclodextrin/Pd(OAc)2 complex is used as an efficient, reusable catalyst in the Mizoroki-Heck reaction of aryl halides/triflates with olefins to give carbon-carbon-coupled products in good to excellent yields. This simple, efficient catalytic system is applicable to a wide range of aryl and heteroaryl halides/triflates and olefins. This environmentally benign procedure is less hazardous, milder, uses a catalytic amount of ligand and Pd(OAc) 2, avoids an inert atmosphere, and catalyst recovery and reusability are achieved. Copyright
- Kanagaraj, Kuppusamy,Pitchumani, Kasi
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supporting information
p. 14425 - 14431
(2013/11/06)
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- Aerobic oxidative amidation of aromatic and cinnamic aldehydes with secondary amines by CuI/2-pyridonate catalytic system
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A simple and convenient CuI/2-pyridonate catalytic system for the oxidative amidation of aldehydes with secondary amines has been developed. With this system, a variety of useful arylamides have been synthesized in moderate to good yields in the presence of small amount of copper catalyst and the pyridonate ligand, generating only water as a coproduct. Synthesis of cinnamamides was also achieved by the reactions of cinnamaldehydes with secondary amines in moderate yields. Air was successfully employed as a green oxidant in this catalytic system, achieving a safe and atom-efficient system for the synthesis of amides.
- Zhu, Mingwen,Fujita, Ken-Ichi,Yamaguchi, Ryohei
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p. 9102 - 9109,8
(2012/12/11)
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- NHC-catalyzed C-O or C-N bond formation: Efficient approaches to α,β-unsaturated esters and amides
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Simple and efficient NHC-catalyzed transformations of bromoenal or α,β-dibromoenal into α,β-unsaturated esters or amides with high stereoselectivity through C-O or C-N bond formation have been demonstrated. The NHC-catalyzed processes occur under mild con
- Zhang, Bo,Feng, Peng,Cui, Yuxin,Jiao, Ning
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p. 7280 - 7282
(2012/07/28)
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- Stereoselective olefination of N-sulfonyl imines with stabilized phosphonium ylides for the synthesis of electron-deficient alkenes
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An unprecedented protocol has been developed for thestereoselective synthesis of structurally diverse electron-deficient alkenes in moderate to excellent yields from readily accessible N-sulfonyl imines and stabilized phosphonium ylides. Significantly, the olefination reaction of N-sulfonylimines with nitrile-stabilized phosphonium ylides affords an array of α,β-unsaturated nitriles with high Z selectivity, and the reactions with ester-, amide-, and ketone-stabilized phosphonium ylides afford α,β-unsaturated esters, amides, and ketones with high E selectivity, respectively. Spectroscopic analysis of the reaction mixtures and trapping of the intermediates allow plausible mechanisms to be proposed. Initialimine/ylide addition leads to the formation of betaines that cyclize to form 1,2-azaphosphetanes that subsequently eliminate iminophosphoranes to yield alkenes. For the synthesis of electron-deficient 1,2-disubstituted alkenes, the presence of an electron-withdrawing group in the betaine allows rapid interconversion between its two diastereomers through proton transfer. The Z/E selectivity for alkene synthesis is determined by the different rates at which the two betaine diastereomers form the corresponding 1,2-azaphosphetane diastereomers. In contrast, the Z/E selectivity for the synthesis of electron-deficient trisubstituted alkenes originates from the diastereoselective addition of stabilized phosphonium ylides to N-sulfonyl imines.
- Fang, Fan,Li, Yuan,Tian, Shi-Kai
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experimental part
p. 1084 - 1091
(2011/04/15)
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- Stereoseleetive synthesis of polysubstituted alkenes through a phosphine-mediated three-component system of aldehydes, α-halo carbonyl compounds, and terminal alkenes
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A study was conducted to demonstrate stereoselective synthesis of polysubstituted alkenes through a phosphine-mediated three-component system of aldehydes, α-halo carbonyl compounds, and terminal alkenes. Triphenylphosphine, α-halo carbonyl compounds, and methyl acrylate were added to a solution of aldehyde in chloroform or 1-propanol under nitrogen at room temperature. The resulting mixture was stirred at the specified temperature until transformation was completely observed by thin layer chromatography (TLC) analysis. The mixture was cooled to room temperature and purified by column chromatography on silica gel, eluting with petroleum ether/ethyl acetate. The study demonstrated that the first one-pot and three-component reaction of aldehydes, α-haloacetates, and terminal alkenes was developed in the presence of phenylphosphine to produce a wide range of trisubstituted alkenes with significant stereoselectivity.
- Liu, Da-Neng,Tian, Shi-Kai
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supporting information; experimental part
p. 4538 - 4542
(2009/12/25)
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- Stereoselective olefination reactions promoted by Rieke manganese
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A study of the advantages of using manganese, an inexpensive and nontoxic metal, to perform stereoselective β-elimination reactions and to promote sequential olefination reactions of aldehydes to obtain α,β- unsaturated esters and amides is presented. Various elimination reactions, all of them characterized by occurring with complete stereoselectivity and in high yields, were performed using active manganese (Mn*) as metalating agent. This ability of manganese has been applied to develop a novel and direct synthesis of (E)-α,β-unsaturated esters or amides and (Z)-α,β-unsaturated α-halo esters and α-choroamides through a Mn*-mediated sequential olefination protocol of aldehydes with dichloro esters or amides and trihalo esters or trichloroamides, respectively. Georg Thieme Verlag Stuttgart.
- Concellon, Jose M.,Rodriguez-Solla, Humberto,Del Amo, Vicente,Diaz, Pamela
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experimental part
p. 2634 - 2645
(2009/12/06)
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- SmI3-catalyzed addition of amines to α,β-unsaturated N-acylbenzotriazoles
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The addition of amines to α,β-unsaturated N-acylbenzotriazoles could be catalyzed by samarium triiodide (SmI3) at ambient temperature. α,β-Unsaturated aliphatic N-acylbenzotriazoles afforded bis-addition products (β-amino amides), whereas N-cinnamoylbenzo
- Wang, Xiaoxia,He, Liang,Li, Zhifang,Wang, Wencun,Liu, Junhua
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experimental part
p. 819 - 829
(2009/08/08)
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- Thio FCMA intermediates as strong acyl donors: A general solution to the formation of complex amide bonds
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(Chemical Equation Presented) Novel methodology for the formation of amide bonds under neutral conditions is described. Evidence is presented that the active acyl donors are thio FCMA intermediates, generated from the reactions of thioacids with isonitril
- Rao, Yu,Li, Xuechen,Danishefsky, Samuel J.
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supporting information; experimental part
p. 12924 - 12926
(2009/12/07)
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- Features and applications of reactions of α,β-unsaturated N-acylbenzotriazoles with amino compounds
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Promoted by triethylamine, α,β-unsaturated N-acylbenzotriazoles reacted with amino compounds in a variety of ways. Thus, N-cinnamoylbenzotriazoles reacting with aromatic amines afforded novel addition products β-benzotriazolyl amides 3, which might be normally formed from the alternative but unknown 1,4-addition of benzotriazole to N-cinnamoylamides. The type 3 compounds could also result from the reaction between N-crotonoylbenzotriazole and aliphatic amines. However, normal 1,4-addition could occur between α,β-unsaturated aliphatic N-acylbenzotriazoles and aromatic amines, leading to β-amino N-acylbenzotriazoles 4 in good yields. In addition, exclusive 1,2-addition of aliphatic amines to N-cinnamoylbenzotriazoles gave excellent yields of cinnamides 5. Accordingly, three possible routes were proposed to rationalize the formation of compounds 3-5. Finally, with o-phenylenediamine and o-aminothiophenol as the substrates, the 1,4- and 1,2-addition to α,β-unsaturated N-acylbenzotriazoles could take place concurrently and the corresponding heterocycles 1,5-benzodiazepine-2-one and 1,5-benzothiazepine-4-one were constructed, respectively.
- Wang, Xiaoxia,Li, Zhifang,Zhu, Xiangming,Mao, Hui,Zou, Xuefei,Kong, Lichun,Li, Xinsheng
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p. 6510 - 6521
(2008/09/21)
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- Sequential reactions promoted by manganese: Completely stereoselective synthesis of (E)-α,β-unsaturated amides, ketones, aldehydes, and carboxylic acids
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(Chemical Equation Presented) A complete E-selective synthesis of α,β-unsaturated amides through a sequential reaction of a range of dichloroamides with a variety of aldehydes promoted by Rieke manganese (Mn*) is reported. A mechanism based on a sequential aldol-type reaction and a completely stereoselective β-elimination is proposed to explain these results. The unsaturated amides obtained are readily and efficiently transformed into α,β-unsaturated ketones, aldehydes, or carboxylic acids without loss of the diastereoisomeric purity of the C-C double bond.
- Concellon, Jose M.,Rodriguez-Solla, Humberto,Diaz, Pamela
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p. 7974 - 7979
(2008/02/13)
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- Stereospecific cyclopropanation of highly substituted C-C double bonds promoted by CrCl2. Stereoselective synthesis of cyclopropanecarboxamides and cyclopropyl ketones
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We describe herein a CrCl2-promoted cyclopropanation of α,β-unsaturated amides. This reaction can be carried out on (E)- or (2)-α,β-enamides in which the C-C double bond is di-, tri-, or tetrasubstituted. In all cases the process is completely stereospecific and only a single diastereoisomer is obtained. In addition, cyclopropyl ketones were readily prepared by reaction of the cyclopropanecarboxamides (derived from morpholine) obtained with a range of organolithium compounds. A mechanism has been proposed to explain the cyclopropanation reaction.
- Concellon, Jose M.,Rodriguez-Solla, Humberto,Mejica, Carmen,Blanco, Elena G.
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p. 2981 - 2984
(2008/02/09)
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- Efficient syntheses of β-amino-N-acylbenzotriazoles and cinnamides through regioselective 1,4- or 1,2-addition of amines to N- cinnamoylbenzotriazoles
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Amines react with N-cinnamoylbenzotriazoles to afford either β-amino-N-acylbenzotriazoles or cinnamides depending on the structure of the amines. Aromatic amines react with N-cinnamoylbenzotriazoles via 1,4-addition to give β-amino-N-acyl-benzotriazoles in good yields. For o-phenylenediamine, the 1,4-addition products were further acylated to provide a facile route to substituted 1,3,4,5-tetrahydro-1,5-benzodiazepine-2-ones. Aliphatic amines, however, react exclusively through the 1,2-addition pathway to produce cinnamides in good yields. Georg Thieme Verlag Stuttgart.
- Wang, Xiaoxia,Zou, Xuefei,Li, Jian,Hu, Qinghong
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p. 3042 - 3046
(2007/10/03)
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- Mild one-pot conversion of carboxylic acids to amides or esters with Ph3P/trichloroisocyanuric acid
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The reaction of trichloroisocyanuric acid (TCICA) and triphenylphosphine in the presence of a carboxylic acid results in the in situ formation of the corresponding acid chloride under mild conditions. Subsequent addition of amines or alcohols, in the presence of a tertiary amine affords the corresponding amides, or esters, in good to excellent yields. The methodology was applied to the synthesis of a dipeptide.
- Rodrigues, Rogério Da C.,Barros, Igor M. A.,Lima, Edson L. S.
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p. 5945 - 5947
(2007/10/03)
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- Esters, amides and substituted derivatives of cinnamic acid: Synthesis, antimicrobial activity and QSAR investigations
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A series of esters (Ia-k), substituted derivatives (II a-d) and amides (IIIa-q) of cinnamic acid were synthesized and evaluated as antibacterial and antifungal agents. All the derivatives belonging to the series I, II and III showed antimicrobial activity comparable to the standard. Compounds If and IIc proved to be the most effective compounds. Quantitative structure-activity relationship (QSAR) investigation with multiple linear regression analysis was applied to find a correlation between different calculated physicochemical parameters of the compounds and biological activity. The quantitative models relating the structural features of cinnamic acid derivatives Ia-k, II a-d and IIIa-q and their antimicrobial activity showed that Gram negative Escherichia coli and Candida albicans (fungus) were the most sensitive microorganisms.
- Narasimhan, Balasubramanian,Belsare, Deepak,Pharande, Devayani,Mourya, Vishnukant,Dhake, Avinash
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p. 827 - 834
(2007/10/03)
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- Superacidic activation of α,β-unsaturated amides and their electrophilic reactions
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The electrophilic reactivity of α,β-unsaturated amides towards weak nucleophiles such as arenes and cyclohexane, initiated either with triflic acid (CF3SO3H) or with excess AlCl3, has been studied. The amides generally condense readily with aromatics in the presence of AlCl3 to give 3-arylpropionamides and related compounds in excellent yields, while some amides also undergo selective ionic hydrogenation with cyclohexane to give saturated amides. The proposed mechanism of these reactions involves dicationic intermediates (superelectrophiles). The direct observation of a dicationic species (by low-temperature NMR) is reported. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Koltunov, Konstantin Yu.,Walspurger, Stephane,Sommer, Jean
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p. 4039 - 4047
(2007/10/03)
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- Addition of organocerium reagents to morpholine amides: synthesis of important pheromone components of Achaea janata.
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Readily preparable morpholine amides hitch in good yields with organocerium reagents to produce ketones. Even in the presence of substrates and reagents with high steric hindrance, the organometallic compounds prepared from dry cerium(III) chloride and organomagnesium or organolithium compounds at -78 degrees C add cleanly to morpholine amides. The low cost of starting materials makes this new scheme of synthesis very interesting for the preparation of biologically important pheromones.
- Badioli, Michele,Ballini, Roberto,Bartolacci, Massimo,Bosica, Giovanna,Torregiani, Elisabetta,Marcantoni, Enrico
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p. 8938 - 8942
(2007/10/03)
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- The conversion of carboxylic acids into amides via NCS/triphenylphosphine
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Amides can be generated in very high yields under mild conditions from the corresponding carboxylic acid and amine in the presence of equivalent amounts of triphenylphosphine and N-halosuccinimides, e.g., NCS or NBS.
- Froyen
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p. 959 - 968
(2007/10/02)
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