The Experts below are selected from a list of 11238 Experts worldwide ranked by ideXlab platform
Brenno A D Neto - One of the best experts on this subject based on the ideXlab platform.
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synthetic enzyme catalyzed Multicomponent Reaction for isoxazol 5 4h one syntheses their properties and biological application why should one study mechanisms
Organic and Biomolecular Chemistry, 2021Co-Authors: Gabriela H C Oliveira, Luciana M Ramos, Raissa Kelly Correa De Paiva, Saulo T A Passos, Marina M Simoes, Fabricio Machado, Jose R Correa, Brenno A D NetoAbstract:In this work, we describe the application of a synthetic enzyme (synzyme) as the catalyst to promote the Multicomponent synthesis of isoxazol-5(4H)-one derivatives. The catalytic system could be used up to 15 times without any notable loss of its activity. Some derivatives showed fluorescence and their photophysical data were evaluated. The mechanism of the Reaction was, for the first time, investigated and, among the three Reaction pathway possibilities, only one was operating under the developed conditions. ESI-MS(/MS) allowed for both the simultaneous monitoring of the Multicomponent Reaction (MCR) and the proposition of a kinetic model to explain the transformation. The kinetic model pointed firmly to only one Reaction pathway and helped to discard the other two possibilities. The antimicrobial abilities of all synthesized derivatives against Gram-positive and Gram-negative strains were also evaluated. The abilities of functional chromophores (fluorescent compounds) as live cell-imaging probes were verified and one of the Multicomponent adducts could stain early endosomes selectively in bioimaging experiments.
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combined role of the asymmetric counteranion directed catalysis acdc and ionic liquid effect for the enantioselective biginelli Multicomponent Reaction
Journal of Organic Chemistry, 2018Co-Authors: Haline G O Alvim, Danielle L J Pinheiro, Valter H Carvalhosilva, Mariana Fioramonte, Fabio C Gozzo, Wender A Silva, Giovanni W Amarante, Brenno A D NetoAbstract:This work describes new chiral task-specific ionic liquids bearing chiral anions as the catalysts for the enantioselective Multicomponent Biginelli Reaction. For the first time, the combined role of asymmetric counteranion-directed catalysis (ACDC) and ionic liquid effect (ILE) for the chiral induction in the Biginelli Multicomponent Reaction is demonstrated. The chiral induction arises from a supramolecular aggregate where the anion and the cation of the catalyst are alongside with a key cationic intermediate of the Reaction. Each component of the new catalyst had a vital role for the chiral induction success. The mechanism of an asymmetric version of this Multicomponent Reaction is in addition demonstrated for the first time using electrospray (tandem) mass spectrometry, ESI-MS(/MS). The analyses indicated the Reaction takes place preferentially and exclusively through the iminium mechanism. Unprecedented supramolecular aggregates were detected by ESI-MS and characterized by ESI-MS/MS. No intermediate of the other two possible Reactions pathways could be detected. Theoretical calculations shed light on the transition state of the transformation during the key step of the chiral induction and helped to elucidate the roles of the chiral anion (ACDC contribution) and of the imidazolium-containing nonchiral cation derivative (ILE contribution) in the molecular Reaction process.
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insights on the petasis borono mannich Multicomponent Reaction mechanism
RSC Advances, 2015Co-Authors: Roberto Y Souza, Giovana A Bataglion, Davi A C Ferreira, Claudia C Gatto, Marcos N Eberlin, Brenno A D NetoAbstract:A joint experimental and theoretical investigation on the mechanism of the Petasis Borono–Mannich Reaction is described. Using the charge-tag strategy for mass spectrometry ion monitoring in solution, unprecedented key intermediates were intercepted and characterized. A key intermediate was also isolated from the Reaction solution and its structure could be deduced from single crystal X-ray diffraction. A mechanism further consolidated by DFT calculations that reconciles the present and all available data on this important Multicomponent Reaction is presented.
Alexander Dömling - One of the best experts on this subject based on the ideXlab platform.
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Multicomponent Reaction derived covalent inhibitor space
Science Advances, 2021Co-Authors: Fandi Sutanto, Shabnam Shaabani, Constantinos G Neochoritis, Tryfon Zarganestzitzikas, Pravin Patil, Ehsan Ghonchepour, Alexander DömlingAbstract:The area of covalent inhibitors is gaining momentum due to recently introduced clinical drugs, but libraries of these compounds are scarce. Multicomponent Reaction (MCR) chemistry is well known for its easy access to a very large and diverse chemical space. Here, we show that MCRs are highly suitable to generate libraries of electrophiles based on different scaffolds and three-dimensional shapes and highly compatible with multiple functional groups. According to the building block principle of MCR, acrylamide, acrylic acid ester, sulfurylfluoride, chloroacetic acid amide, nitrile, and α,β-unsaturated sulfonamide warheads can be easily incorporated into many different scaffolds. We show examples of each electrophile on 10 different scaffolds on a preparative scale as well as in a high-throughput synthesis mode on a nanoscale to produce libraries of potential covalent binders in a resource- and time-saving manner. Our operational procedure is simple, mild, and step economical to facilitate future covalent library synthesis.
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Glutarimide Alkaloids Through Multicomponent Reaction Chemistry
European Journal of Organic Chemistry, 2018Co-Authors: Markella Konstantinidou, Katarzyna Kurpiewska, Justyna Kalinowska-tluscik, Alexander DömlingAbstract:A concise four step synthetic route for glutarimide alkaloids of high biological interest is presented. The scaffold is accessed via an Ugi four component Reaction, hereby introducing two points of variation. This is followed by a hydrolysis, a cyclization under mild conditions, and an amine deprotection. The diastereomers of the cyclized intermediate can be easily separated, thus leading to optically pure alkaloids. By this route, four natural products and ten derivatives were synthesized. The scope and limitations of the synthetic methodology were investigated.
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The Gewald Multicomponent Reaction
Molecular Diversity, 2011Co-Authors: Yijun Huang, Alexander DömlingAbstract:The Gewald Reaction of sulfur, cyanoacetic acid derivatives, and oxo-component (G-3CR) yielding highly substituted 2-aminothiophene derivatives has seen diverse applications in combinatorial and medicinal chemistry. Its products are of great use in pharmaceutical industry mainly as small molecular weight inhibitors. We herein review synthetic scope and variations, usage, and structural biology of Gewald products.
Xian Huang - One of the best experts on this subject based on the ideXlab platform.
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a novel Multicomponent Reaction of arynes β keto sulfones and michael type acceptors a direct synthesis of polysubstituted naphthols and naphthalenes
ChemInform, 2007Co-Authors: Xian Huang, Jian XueAbstract:A novel Multicomponent Reaction of arynes, beta-keto sulfones, and Michael-type acceptors is presented, providing an efficient method for the synthesis of polysubstituted naphthols and polysubstituted naphthalenes. Further investigation suggests that the tandem Reaction may proceed via a sequential nucleophilic attack to arynes, intramolecular nucleophilic substitution followed by a Michael addition, and a ring closure-elimination process.
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a novel Multicomponent Reaction of arynes β keto sulfones and michael type acceptors a direct synthesis of polysubstituted naphthols and naphthalenes
Journal of Organic Chemistry, 2007Co-Authors: Xian HuangAbstract:A novel Multicomponent Reaction of arynes, β-keto sulfones, and Michael-type acceptors is presented, providing an efficient method for the synthesis of polysubstituted naphthols and polysubstituted naphthalenes. Further investigation suggests that the tandem Reaction may proceed via a sequential nucleophilic attack to arynes, intramolecular nucleophilic substitution followed by a Michael addition, and a ring closure−elimination process.
Mikhail Krasavin - One of the best experts on this subject based on the ideXlab platform.
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convenient access to novel functionalized pyrazino 1 2 b isoquinolin 6 one and diazepino 1 2 b isoquinolin 7 one scaffolds via the cushman Multicomponent Reaction followed by post condensation
ChemInform, 2014Co-Authors: Pakornwit Sarnpitak, Mikhail KrasavinAbstract:The synthesis is based on Cushman Multicomponent Reaction, wherein aryl glyoxals are used as the carbonyl component for the first time.
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convenient access to novel functionalized pyrazino 1 2 b isoquinolin 6 one and diazepino 1 2 b isoquinolin 7 one scaffolds via the cushman Multicomponent Reaction followed by post condensation
Tetrahedron Letters, 2014Co-Authors: Pakornwit Sarnpitak, Mikhail KrasavinAbstract:Abstract Post-Multicomponent Reaction modifications of Cushman Reaction-derived 1,2,3,4-tetrahydroisoquinolin-4-carboxylic acids turned out to be a surprisingly underdeveloped strategy in scaffold-oriented synthesis. In this Letter, we describe a concise synthesis of hitherto unreported pyrazino- and diazepino-fused isoquinolones in two chemical operations. The synthesis involves the use, for the first time, of aryl glyoxals as carbonyl components for the Cushman Multicomponent Reaction.
Yen Wei - One of the best experts on this subject based on the ideXlab platform.
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facile fabrication of organic dyed polymer nanoparticles with aggregation induced emission using an ultrasound assisted Multicomponent Reaction and their biological imaging
Journal of Colloid and Interface Science, 2018Co-Authors: Ruming Jiang, Meiying Liu, Liucheng Mao, Hongye Huang, Xiaoyong Zhang, Qiang Huang, Yuanqing Wen, Qianyong Cao, Jianwen Tian, Yen WeiAbstract:Abstract Ultrasound as a powerful technique has increasingly been used in both industry and academia in recent years. Herein, an efficient approach to the ultrafast preparation of cross-linked fluorescent copolymers (PEGMA-AEMA-TPE) with aggregation-induced emission (AIE) via an ultrasound-assisted Multicomponent Reaction (MCR) is described. A number of characterization techniques were carried out to certify the successful preparation of these AIE-active copolymers. Due to the introduction of a hydrophilic PEG fragment and a hydrophobic AIE-active dye, the obtained fluorescent copolymers showed amphiphilic properties and could assemble into organic dyed polymer nanoparticles (ODPNs) with great water dispersibility. The final PEGMA-AEMA-TPE ODPNs demonstrated intense fluorescence, strong photostability, a low critical micelle concentration (CMC) of 0.007 mg mL−1 and high biocompatibility. More importantly, the PEGMA-AEMA-TPE ODPNs show obvious AIE characteristics, which could elegantly overcome the quenching effect caused by the aggregation of ODPNs based on conventional organic dyes. Considered the above results, we believe that these AIE-active ODPNs should be promising candidates for biological imaging and other biomedical applications.
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preparation of pegylated polymeric nanoprobes with aggregation induced emission feature through the combination of chain transfer free radical polymerization and Multicomponent Reaction self assembly characterization and biological imaging applications
Materials Science and Engineering: C, 2017Co-Authors: Qing Wan, Meiying Liu, Liucheng Mao, Ruming Jiang, Hongye Huang, Yanfeng Dai, Fengjie Deng, Xiaoyong Zhang, Yen WeiAbstract:Abstract Self-assembly of amphiphilic luminescent copolymers is a general route to fabricate fluorescent polymeric microparticles (FPMs). In this work, the FPMs with aggregation-induced emission (AIE) feature were fabricated via the combination of the chain transfer free radical polymerization and “one-pot” Multicomponent Reaction, which conjugated the aldehyde-containing AIE active dye AIE (CHO-An-CHO) and amino-terminated hydrophilic polymer (ATPPEGMA) using mercaptoacetic acid (MTA) as the “lock” molecule. The structure, chemical compositions, optical properties as well as biological properties of the PPEGMA-An-PPEGMA FPMs were characterized and investigated by means of a series of techniques and experiments in detail. We demonstrated the final copolymers showed amphiphilic properties, strong yellow fluorescence and high water dispersibility. Biological evaluation suggested that PPEGMA-An-PPEGMA FPMs possess low cytotoxicity and can be used for cell imaging. More importantly, many other AIE active FPMs are expected to be fabricated using the similar strategy because of the good substrate and monomer applicability of the Multicomponent Reaction and chain transfer living radical polymerization. Therefore, we could conclude that the strategy described in this work should be of great interest for fabrication of multifunctional AIE active nanoprobes for biomedical applications.
