3278-14-6Relevant academic research and scientific papers
Direct carbodiimide-mediated conjugation of carboxylates using pyridinium p-toluenesulfonate and tertiary amines as additives
Ficht, Simon,R?glin, Lars,Ziehe, Matthias,Breyer, David,Seitz, Oliver
, p. 2525 - 2528 (2004)
The use of carboxylates in the carbodiimide-mediated coupling to amines was investigated. The addition of pyridinium p-toluenesulfonate (PPTS) and a tertiary amine was found to significantly improve acylation yields by up to 70%.
Fluorous-tethered amine bases for organic and parallel synthesis: Scope and limitations
Lindsley, Craig W,Zhao, Zhijian,Leister, William H,Strauss, Kimberly A
, p. 6319 - 6323 (2002)
The synthesis of fluorous-tethered amine bases is described. These novel fluorous-tethered reagents promote reactions, remove acidic by-products, and scavenge electrophiles. They are readily separated from the reaction mixture by solid phase extraction on a novel mixed sorbent SPE (SCX/fluorous silica gel) delivering products in high yields and purities.
Synthesis, characterization and cytotoxic evaluation of inclusion complexes between Riparin A and β-cyclodextrin
Araújo, éverton José Ferreira de,Silva, Oskar Almeida,Rezende-Júnior, Luís Mário,Sousa, Ian Jhemes Oliveira,Araújo, Danielle Yasmin Moura Lopes de,Carvalho, Rusbene Bruno Fonseca de,Pereira, Sean Telles,Gutierrez, Stanley Juan Chavez,Ferreira, Paulo Michel Pinheiro,Lima, Francisco das Chagas Alves
, p. 84 - 91 (2017)
This study performed a physicochemical characterization of the inclusion complex generated between Riparin A and β-cyclodextrin (Rip A/β-CD) and compared the cytotoxic potential of the incorporated Rip A upon Artemia salina larvae. Samples were analyzed by phase solubility diagram, dissolution profile, differential scanning calorimetry, X-ray diffraction, infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy and artemicidal action. Riparin A/β-cyclodextrin complexes presented increased water solubility, AL type solubility diagram and Kst constant of 373?L/mol. Thermal analysis demonstrated reduction of the melt peak of complexed Rip A at 116.2?°C. Infrared spectroscopy confirmed generation of inclusion complexes, 1H NMR pointed out the interaction with H-3 of β-CD cavities, alterations in the crystalline natures of Rip A when incorporated within β-CD were observed and inclusion complexes presented higher cytotoxic on A.?salina nauplii, with CL50 value of 117.2 (84.9–161.8) μg/mL. So, Rip A was incorporated into β-CDs with high efficiency and water solubility of Rip A was improved. Such solubility was corroborated by cytotoxic evaluation and these outcomes support the improvement of biological properties for complexes between Riparin A/β-cyclodextrin.
Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous-Flow
Chen, Xiangyang,Houk, Kendall N.,Mo, Jia-Nan,Su, Junqi,Umanzor, Alexander,Zhang, Zheng,Zhao, Jiannan
supporting information, (2022/01/06)
Phosphine-mediated deoxygenative nucleophilic substitutions, such as the Mitsunobu reaction, are of great importance in organic synthesis. However, the conventional protocols require stoichiometric oxidants to trigger the formation of the oxyphosphonium i
Allenone-Mediated Racemization/Epimerization-Free Peptide Bond Formation and Its Application in Peptide Synthesis
Wang, Penghui,Wang, Xuewei,Wang, Zhengning,Zhao, Junfeng
supporting information, p. 10374 - 10381 (2021/07/26)
Allenone has been identified as a highly effective peptide coupling reagent for the first time. The peptide bond was formed with an α-carbonyl vinyl ester as the key intermediate, the formation and subsequent aminolysis of which proceed spontaneously in a racemization-/epimerization-free manner. The allenone coupling reagent not only is effective for the synthesis of simple amides and dipeptides but is also amenable to peptide fragment condensation and solid-phase peptide synthesis (SPPS). The robustness of the allenone-mediated peptide bond formation was showcased incisively by the synthesis of carfilzomib, which involved a rare racemization-/epimerization-free N to C peptide elongation strategy. Furthermore, the successful synthesis of the model difficult peptide ACP (65-74) on a solid support suggested that this method was compatible with SPPS. This method combines the advantages of conventional active esters and coupling reagents, while overcoming the disadvantages of both strategies. Thus, this allenone-mediated peptide bond formation strategy represents a disruptive innovation in peptide synthesis.
Visible Light-Driven Efficient Synthesis of Amides from Alcohols using Cu?N?TiO2 Heterogeneous Photocatalyst
Singha, Krishnadipti,Ghosh, Subhash Chandra,Panda, Asit Baran
, p. 657 - 662 (2021/02/02)
Amides were synthesized from alcohols and amines in high yields using an in situ generated active ester of N-hydroxyimide with our developed Cu?N?TiO2 catalyst at room temperature using oxygen as a sole oxidant under visible light. The catalyst can be easily prepared, robust, and recycled four times without a considerable change in catalytic activity. This developed protocol applies to a wide substrate scope and has good functional group tolerance. The application of this amidation reaction has been successfully demonstrated for the synthesis of moclobemide, an antidepressant drug, and an analog of the itopride drug on a gram scale.
Sustainable triazine-based dehydro-condensation agents for amide synthesis
Sole, Roberto,Gatto, Vanessa,Conca, Silvia,Bardella, Noemi,Morandini, Andrea,Beghetto, Valentina
, (2021/04/26)
Conventional methods employed today for the synthesis of amides often lack of economic and environmental sustainability. Triazine-derived quaternary ammonium salts, e.g., 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM(Cl)), emerged as promising dehydro-condensation agents for amide synthesis, although suffering of limited stability and high costs. In the present work, a simple protocol for the synthesis of amides mediated by 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and a tert-amine has been described and data are compared to DMTMM(Cl) and other CDMT-derived quaternary ammonium salts (DMT-Ams(X), X: Cl? or ClO4?). Different tert-amines (Ams) were tested for the synthesis of various DMT-Ams(Cl), but only DMTMM(Cl) could be isolated and employed for dehydro-condensation reactions, while all CDMT/tert-amine systems tested were efficient as dehydro-condensation agents. Interestingly, in best reaction conditions, CDMT and 1,4-dimethylpiperazine gave N-phenethyl benzamide in 93% yield in 15 min, with up to half the amount of tert-amine consumption. The efficiency of CDMT/tert-amine was further compared to more stable triazine quaternary ammonium salts having a perchlorate counter anion (DMT-Ams(ClO4)). Overall CDMT/tert-amine systems appear to be a viable and more economical alternative to most dehydro-condensation agents employed today.
Method for click construction of amido bond by using pyrimidine condensing agent and application of amido bond in synthesis of amide and polypeptide
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Paragraph 0160-0163; 0207-0208, (2021/05/29)
The invention discloses a method for click construction of an amido bond by using a pyrimidine condensing agent and an application of the amido bond in synthesis of amide and polypeptide. The amido bond construction method comprises the following steps: adding an organic solvent dissolved with organic alkali into a carboxylic acid component and an amine component, stirring for reaction, adding an organic solvent dissolved with a pyrimidine condensing agent, continuously stirring for reaction, concentrating, separating and purifying to obtain an amide or polypeptide product. According to the amido bond construction method, the use amount of the condensing agent is small, and the condensing agent is safe, odorless and easy to store and has good atom economy. The amido bond construction reaction time is only several seconds to ten minutes, and the amide or polypeptide synthesis time is greatly shortened. Besides, the amido bond construction reaction can also be quickly carried out in an organic phase-water phase biphasic system and in the organic phase-water phase biphasic system under the condition that alkali is not added, so that a mild and feasible path is provided for the amido bond construction reaction in an alkali-sensitive biological system.
Method for preparing amide from carboxylic acid under irradiation of blue light by taking iridium and cobalt complexes as catalysts
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Paragraph 0073-0074, (2021/05/12)
The invention relates to a method for preparing amide from carboxylic acid under the irradiation of blue light by taking iridium and cobalt complexes as catalysts, and belongs to the field of chemistry. The method comprises the following step of: by taking R substituted carboxylic acid and R1' and R2' substituted amines as raw materials, triphenylphosphine as a deoxidizing agent, [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 as a photocatalyst and Co(dmgH)(dmgH2)Cl2 as a metal complex catalyst, reacting in dichloromethane in an inert atmosphere and under the irradiation of blue light to obtain an amide compound, wherein R is an aryl group, a heteroaryl group, a protected amino group, a substituted alkyl group, a substituted aryl group or a substituted protected amino group, R1' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and R2' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group.
Synthesis of Amidation Agents and Their Reactivity in Condensation Reactions
Sole, Roberto,Agostinis, Lodovico,Conca, Silvia,Gatto, Vanessa,Bardella, Noemi,Morandini, Andrea,Buranello, Chiara,Beghetto, Valentina
supporting information, p. 1672 - 1682 (2021/02/01)
Nowadays, the development of new approaches which smartly bypass the use of harsh reaction conditions and hazardous chemicals covers a pivotal role. In this research paper the synthesis, characterization, and application of novel libraries of triazine bis-quaternary ammonium salts, employed as coupling agents to produce amides is reported. Full characterization of the novel compounds by 1H and 13C NMR, FT-IR spectroscopy, ESI-HRMS, and elemental analysis is provided. Furthermore, a comparison in terms of activity of the preformed triazine compounds versus in situ formulations has been evaluated for the formation of amides in the presence of phenylethylamine and different aliphatic or aromatic acids. A possible correlation between the chemical structure of the triazine and their reactivity for the formation of the triazine bis-quaternary ammonium salts is also reported. Moreover, best performing condensation agents have been further tested for the cross-linking of collagen powder as possible wet white tanning systems, for sustainable and environmentally friendly leather tanning.
