- Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters
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A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.
- Nikitas, Nikolaos F.,Apostolopoulou, Mary K.,Skolia, Elpida,Tsoukaki, Anna,Kokotos, Christoforos G.
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p. 7915 - 7922
(2021/05/03)
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- The magnetic graphene oxide/NHC catalyzed aerobic direct amidation and cross-dehydrogenative coupling of aldehydes
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In this paper, the synthesis of a novel imidazolium based N-heterocyclic carbene (NHC) containing imidazopyridine substitutes using a three-component reaction is described. This compound was immobilized on magnetic graphene oxide (GO) to make a heterogeneous catalyst for the direct aerobic amidation of benzaldehyde derivatives under solvent-free conditions, as well as the intra-and intermolecular cross dehydrogenative coupling of aldehydes. In addition, the catalytic activity of the NHC catalyst was homogeneously studied in the presence of Fe3O4 nanoparticles under the same conditions, and showed good activity with lower yields than the heterogeneous catalyst.
- Sepahvand, Heshmatollah,Ghasemi, Elnaz,Sharbati, Mohammad,Mohammadi, Melika Sadat,Arshadi Pirlar, Maghsoud,Shahverdizadeh, Gholam Hossein
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p. 16555 - 16565
(2019/11/11)
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- Amidation and esterification of carboxylic acids with amines and phenols by N,N′-diisopropylcarbodiimide: A new approach for amide and ester bond formation in water
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The present study reports the successful synthesis of two important and abundant functional groups “ester and amide” by N,N′-diisopropylcarbodiimide (DIC) in water as a green solvent. A wide range of substrates could be employed with high functional group tolerance. The products were obtained in high yields after short reaction times. This method provides an efficient, economic, simple and very mild protocol for ester and amide bond formation in aqueous media. In addition, this work not only may lead to environmentally benign systems but also will provide a new aspect of organic chemistry in water.
- Fattahi, Nadia,Ayubi, Morteza,Ramazani, Ali
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p. 4351 - 4356
(2018/07/13)
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- Synthesis and anion recognition studies of new ureylbenzamide-based receptors
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A new group of ureylbenzamide-based receptors (1–4) has been synthesized; its binding affinity and capacity to form supramolecular complexes in solution with different anions have been investigated. For designing these receptors, it was considered a combination of the positions of the urea and amide groups (ortho and meta), and the chromophore groups naphthyl and nitrophenyl, yielding four receptors. The position and chromophore structure affected the acidity of the urea and amide hydrogens in the order 4>3>2>1. All the spectroscopic studies showed a significant change of 1 and 2 compared with 3 and 4 in the presence of different TBAX salts in acetonitrile. The 1H-NMR spectra show a preferential interaction of the anions with the urea group in receptors 1 and 2 due to the less steric hindrance, while there is a cooperative interaction of amide group in receptors 3 and 4 due to the closeness of both groups.
- Moreno-Valle, Bibiana,Aguilar-Martínez, Milagros,Ochoa-Terán, Adrián,Martínez-Quiroz, Marisela,Miranda-Soto, Valentín,García-Elías, José,Ochoa-Lara, Karen,Labastida-Galván, Victoria,Ordo?ez, Mario
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- Poly(methylhydrosiloxane) as a green reducing agent in organophosphorus-catalysed amide bond formation
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Development of catalytic amide bond formation reactions has been the subject of the intensive investigations in the past decade. Herein we report an efficient organophosphorus-catalysed amidation reaction between unactivated carboxylic acids and amines. Poly(methylhydrosiloxane), a waste product of the silicon industry, is used as an inexpensive and green reducing agent for in situ reduction of phosphine oxide to phosphine. The reported method enables the synthesis of a wide range of secondary and tertiary amides in very good to excellent yields.
- Hamstra, Daan F. J.,Lenstra, Danny C.,Koenders, Tjeu J.,Rutjes, Floris P. J. T.,Mecinovi?, Jasmin
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supporting information
p. 6426 - 6432
(2017/08/10)
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- Design, Synthesis, and Evaluation of the Highly Selective and Potent G-Protein-Coupled Receptor Kinase 2 (GRK2) Inhibitor for the Potential Treatment of Heart Failure
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A novel class of therapeutic drug candidates for heart failure, highly potent and selective GRK2 inhibitors, exhibit potentiation of β-adrenergic signaling in vitro studies. Hydrazone derivative 5 and 1,2,4-triazole derivative 24a were identified as hit compounds by HTS. New scaffold generation and SAR studies of all parts resulted in a 4-methyl-1,2,4-triazole derivative with an N-benzylcarboxamide moiety with highly potent activity toward GRK2 and selectivity over other kinases. In terms of subtype selectivity, these compounds showed enough selectivity against GRK1, 5, 6, and 7 with almost equipotent inhibition to GRK3. Our medicinal chemistry efforts led to the discovery of 115h (GRK2 IC50 = 18 nM), which was obtained the cocrystal structure with human GRK2 and an inhibitor of GRK2 that potentiates β-adrenergic receptor (βAR)-mediated cAMP accumulation and prevents internalization of βARs in β2AR-expressing HEK293 cells treated with isoproterenol. Therefore, 115h appears to be a novel class of therapeutic for heart failure treatment.
- Okawa, Tomohiro,Aramaki, Yoshio,Yamamoto, Mitsuo,Kobayashi, Toshitake,Fukumoto, Shoji,Toyoda, Yukio,Henta, Tsutomu,Hata, Akito,Ikeda, Shota,Kaneko, Manami,Hoffman, Isaac D.,Sang, Bi-Ching,Zou, Hua,Kawamoto, Tetsuji
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p. 6942 - 6990
(2017/09/07)
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- Transamidation of carboxamides with amines over nanosized zeolite beta under solvent-free conditions
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A highly efficient approach to transamidation of carboxamides with amines over nanosized zeolite beta under solvent-free conditions has been successfully demonstrated. Transamidation of a variety of amides with amines produced the respective N-alkyl amides in moderate to excellent yields.
- Durgaiah, Chevella,Naresh, Mameda,Swamy, Peraka,Srujana, Kodumuri,Rammurthy, Banothu,Narender, Nama
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- Ce(III) immobilised on aminated epichlorohydrin-activated agarose matrix - "green" and efficient catalyst for transamidation of carboxamides
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The present study reports the preparation and characterisation of Ce(III) immobilised on an aminated epichlorohydrin-activated agarose matrix (CAEA) as a "green" catalyst. The catalyst was synthesised by the reaction of the epichlorohydrin-activated agarose matrix with ammonia solution, which was then treated with Ce(NO3)3 · 6H2O. The catalyst (CAEA) was characterised by FT-IR, far IR, CHN, XRD, TGA, and ICP techniques. CAEA is shown to be an effective and reusable heterogeneous catalyst for the transamidation of carboxamides with amines under solventfree conditions. The catalyst was successfully applied to the synthesis of a wide range of aromatic and aliphatic amides. High efficiency, mild reaction conditions, easy work-up, simple separation and also reusability are important advantages of this catalyst.
- Zarei, Zeinab,Akhlaghinia, Batool
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p. 1421 - 1437
(2015/09/15)
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- Radical-Induced Metal and Solvent-Free Cross-Coupling Using TBAI-TBHP: Oxidative Amidation of Aldehydes and Alcohols with N-Chloramines via C-H Activation
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A solvent-free cross-coupling method for oxidative amidation of aldehydes and alcohols via a metal-free radial pathway has been demonstrated. The proposed methodology uses the TBAI-TBHP combination which efficiently induces metal-free C-H activation of aldehydes under neat conditions at 50 °C or ball-milling conditions at room temperature.
- Achar, Tapas Kumar,Mal, Prasenjit
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p. 666 - 672
(2015/08/19)
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- Transformation of Contact-Explosives Primary Amines and Iodine(III) into a Successful Chemical Reaction under Solvent-Free Ball Milling Conditions
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Any synthetic transformation using contact-explosives primary amines and hypervalent iodine(III) (phenyliodine diacetate) in constrained media (extreme conditions) is practically impossible. Herein, we report a method of controlling the explosion into a successful chemical reaction using the acid-salt NaHSO4. As a proof-of-concept, we considered mechanochemical (ball-milling) cross dehydrogenative coupling (CDC) reaction for the amidation of aldehydes via C-H activation. An isothermal titration calorimetric (ITC) study was helpful to understand the enthalpy changes during the reactions before and after addition of NaHSO4.
- Kumarachar, Tapas,Mal, Prasenjit
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p. 3977 - 3985
(2016/01/25)
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- A One-Pot, fast, and efficient amidation of carboxylic acids, α-amino acids and sulfonic acids using pph3/n-chlorobenzotriazole system
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Triphenylphosphine (PPh3)/N-chlorobenzotriazole (NCBT), and amine (primary and secondary aliphatic amines and also substituted anilines) in CH2Cl2 efficiently converted carboxylic acids, α-amino acids, and sulfonic acids to the corresponding amides and sulfonamides at room temperature. Good to excellent yields, inexpensive, and fast reaction conditions are the important features of this procedure.
- Rouhi-Saadabad, Hamed,Akhlaghinia, Batool
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p. 1703 - 1714
(2015/09/15)
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- An azobenzene-containing metal-organic framework as an efficient heterogeneous catalyst for direct amidation of benzoic acids: Synthesis of bioactive compounds
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An azobenzene-containing zirconium metal-organic framework was demonstrated to be an effective heterogeneous catalyst for the direct amidation of benzoic acids in tetrahydrofuran at 70°C. This finding was applied to the synthesis of several important, representative bioactive compounds.
- Hoang, Linh T. M.,Ngo, Long H.,Nguyen, Ha L.,Nguyen, Hanh T. H.,Nguyen, Chung K.,Nguyen, Binh T.,Ton, Quang T.,Nguyen, Hong K. D.,Cordova, Kyle E.,Truong, Thanh
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supporting information
p. 17132 - 17135
(2015/12/04)
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- A mild and clean method for oxidative formation of amides from aldehydes and amines
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A metal-free direct oxidative formation of amides from aldehydes and amines using a hypervalent iodine(III) reagent or an ion-supported hypervalent iodine(III) reagent as a recyclable oxidant under mild conditions is reported. Georg Thieme Verlag Stuttgart.
- Fang, Chen,Qian, Weixing,Bao, Weiliang
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experimental part
p. 2529 - 2531
(2009/04/12)
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- Tagged phosphine reagents to assist reaction work-up by phase-switched scavenging using a modular flow reactor
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The use of three orthogonally tagged phosphine reagents to assist chemical work-up via phase-switch scavenging in conjunction with a modular flow reactor is described. These techniques (acidic, basic and Click chemistry) are used to prepare various amides
- Smith, Christopher D.,Baxendale, Ian R.,Tranmer, Geoffrey K.,Baumann, Marcus,Smith, Stephen C.,Lewthwaite, Russell A.,Ley, Steven V.
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p. 1562 - 1568
(2008/02/07)
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- Oxidation of N-benzylaldimines to N-benzylamides by MCPBA and BF3·OEt2
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N-Benzylamides were obtained from the corresponding N-benzylaldimines in high yields. N-Benzylaldimines are readily prepared from the corresponding aldehydes with benzylamine. This procedure involves the oxidation of N-benzylaldimines with MCPBA with BF3·OEt2. In this reaction, the reaction presumably follows an internal hydrogen abstraction to provide only N-benzylamide.
- An, Gwang-Il,Rhee, Hakjune
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p. 876 - 878
(2007/10/03)
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- GUANIDINE DERIVATIVES USEFUL IN THERAPY
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Guanidine derivatives of formulanidine derivatives of formula I, wherein R8 represents hydrogen, halogen, alkyl C1 to 6, nitro, trifluoromethyl, thioalkyl C1 to 6, hydroxy, alkoxy C1 to 6, or a group selected from NR4R5, -O(CH2)pQ, -(CH2)mOQ, -(CH2)mNR1R2, -O(CH2)mNR1R2, -NHCO(CH2)mNH(CH2)nQ or -(CH2)pCONR1R2, or R8 represents the group A-CO-B; R9 represents hydrogen, halogen, alkyl C1 to 6, nitro or trifluoromethyl; and R1, R2, R4, R5, n, m, p, Q, A, B, and W are as defined in the specification, are described together with processes for their manufacture and compositions containing them. Compounds of formula I are useful in therapy
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- Potential Central Nervous System Active Agents. 1. Synthesis of Aromatic N-Benzyl Amides
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The preparation and spectral properties (IR, MS, NMR) are given for 18 aromatic N-benzyl amides, variously substituted on the acyl part, including four new ones and an (E)-cinnamide derivative.The amides were prepared by heating the appropriate N-benzylammonium salt in o-xylene, or from the reaction of the corresponding acid chloride with benzylamine.The occurrence of an intense peak in their mass spectra, which corresponds to the loss of the N-acyl substituent without hydrogen transfer, is reported.
- Agwada, Vincent C.
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p. 479 - 481
(2007/10/02)
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