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https://www.readbyqxmd.com/read/29683331/propargylation-of-ugi-amide-dianion-an-entry-into-pyrrolidinone-and-benzoindolizidine-alkaloid-analogues
#1
Alaa Zidan, Marie Cordier, Abeer M El-Naggar, Nour E A Abd El-Sattar, Mohamed Ali Hassan, Ali Khalil Ali, Laurent El Kaïm
Propargylation of Ugi adducts under the addition of excess sodium hydride in DMSO leads to direct formation of pyrrolidinone enamides, which are useful precursors of iminium intermediates and may be trapped by various nucleophiles. This approach has been applied to the formation of benzoindolizidine alkaloids with high diversity via a Ugi/propargylation/Pictet-Spengler cyclization.
April 23, 2018: Organic Letters
https://www.readbyqxmd.com/read/29676029/functionalized-spiroindolines-with-anticancer-activity-through-a-metal-free-post-ugi-diastereoselective-one-pot-cascade-reaction
#2
Zhi-Gang Xu, Shi-Qiang Li, Jiang-Ping Meng, Dian-Yong Tang, Liu-Jun He, Jie Lei, Hui-Kuan Lin, Hong-Yu Li, Zhong-Zhu Chen
A post-Ugi diastereoselective one-pot cascade reaction requiring no metal catalyst was developed. The reaction scope was wide with mild conditions and good yields. A collection of spiroindolines was prepared by the protocol and screening tests in several difficult-to-inhibit cancer cell lines were conducted. The relationship of structure and anticancer activities was promising and in the Huh7 cell lines compound 16 j is more potent than Vinbalstine. The cyclization design strategy could be applicable to other multicomponent reactions (MCRs) for synthesizing bioactive and drug-like heterocycles...
April 20, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29651145/multicomponent-reactions-provide-key-molecules-for-secret-communication
#3
Andreas C Boukis, Kevin Reiter, Maximiliane Frölich, Dennis Hofheinz, Michael A R Meier
A convenient and inherently more secure communication channel for encoding messages via specifically designed molecular keys is introduced by combining advanced encryption standard cryptography with molecular steganography. The necessary molecular keys require large structural diversity, thus suggesting the application of multicomponent reactions. Herein, the Ugi four-component reaction of perfluorinated acids is utilized to establish an exemplary database consisting of 130 commercially available components...
April 12, 2018: Nature Communications
https://www.readbyqxmd.com/read/29645306/angled-vortex-fluidic-mediated-multicomponent-photocatalytic-and-transition-metal-catalysed-reactions
#4
Keith A Stubbs, Colin Raston, Louisa Ho
The dynamic thin film which is formed in an angled rapidly rotating tube in a vortex fluidic device (VFD) is effective in facilitating multicomponent reactions (MCRs) as photocatalytic or metal-mediated processes. Here we demonstrate the utility of the VFD using two known MCRs, an Ugi-type three component and A3-coupling reactions. The Ugi-type reaction can be done in either confined or continuous flow modes of operation of the microfluidic platform whereas the A3-coupling reaction was optimised for the confined mode of operation...
April 12, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29623124/sequential-ugi-reaction-base-induced-ring-closing-iaac-protocol-toward-triazolobenzodiazepine-fused-diketopiperazines-and-hydantoins
#5
Robby Vroemans, Fante Bamba, Jonas Winters, Joice Thomas, Jeroen Jacobs, Luc Van Meervelt, Jubi John, Wim Dehaen
A practical three-step protocol for the assembly of triazolobenzodiazepine-fused diketopiperazines and hydantoins has been developed. The synthesis of these tetracyclic ring systems was initiated by an Ugi reaction, which brought together all necessary functionalities for further transformations. The Ugi adducts were then subjected to a base-induced ring closing and an intramolecular azide-alkyne cycloaddition reaction in succession to obtain highly fused benzodiazepine frameworks.
2018: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29620860/acid-promoted-one-pot-synthesis-of-substituted-furan-and-6-methylpyrazin-2-1h-one-derivatives-via-allene-intermediate-formed-in-situ
#6
Jie Lei, Zhi-Gang Xu, Dianyong Tang, Yong Li, Jia Xu, Hong-Yu Li, Jin Zhu, Zhong-Zhu Chen
Under the acidic conditions, substituted furans were constructed from γ alkynyl ketones through corresponding allene intermediates in one-pot. The methodolgy was also tailored to a series of the Ugi reaction products for the synthesis of 6-methylpyrazin-2(1H)-one derivatives. The current method offered significant advantages for the combinatorial applications of these chemcial scaffolds.
April 5, 2018: ACS Combinatorial Science
https://www.readbyqxmd.com/read/29584639/synthesis-of-polyheterocyclic-pyrrolo-3-4-b-pyridin-5-ones-via-a-one-pot-ugi-3cr-aza-diels-alder-n-acylation-aromatization-s-n-2-process-a-suitable-alternative-towards-novel-aza-analogues-of-falipamil
#7
Angel Zamudio-Medina, Ailyn N García-González, Genesis K Herrera-Carrillo, Daniel Zárate-Zárate, Adriana Benavides-Macías, Joaquín Tamariz, Ilich A Ibarra, Alejandro Islas-Jácome, Eduardo González-Zamora
We describe the one-pot synthesis of twenty polyheterocyclic pyrrolo[3,4- b ]pyridin-5-ones via a cascade process (Ugi-3CR/aza Diels-Alder/ N -acylation/aromatization) in 20 to 95% overall yields, as well as four pharmacologically promising analogues via an improved cascade process (Ugi-3CR/aza Diels-Alder/ N -acylation/aromatization/SN 2): two piperazine-linked pyrrolo[3,4- b ]pyridin-5-ones in 33 and 34%, and a couple of Falipamil aza-analogues in 30 and 35% overall yields. It is worth highlighting the good substrate scope found, because final products are furnished with alkyl, aryl, and heterocyclic substituents...
March 27, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29577465/visible-light-activation-of-spin-silenced-fluorescence
#8
Matthias Eing, Bryan Tuten, James P Blinco, Christopher Barner-Kowollik
We introduce a self-reporting, profluorescent, visible light-induced release system. Fluorescence activation is enabled by a mild remote trigger signal that can be monitored with the naked-eye in real time. The light-responsive spin-silenced polymer is synthesized via an Ugi post-polymerization modification incorporating paramagnetic nitroxides and a light cleavable fluorophore moiety.
March 25, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29545578/exploring-ugi-azide-four-component-reaction-products-for-broad-spectrum-influenza-antivirals-with-a-high-genetic-barrier-to-drug-resistance
#9
Jiantao Zhang, Yanmei Hu, Christopher Foley, Yuanxiang Wang, Rami Musharrafieh, Shuting Xu, Yongtao Zhang, Chunlong Ma, Christopher Hulme, Jun Wang
Influenza viruses are respiratory pathogens that are responsible for seasonal influenza and sporadic influenza pandemic. The therapeutic efficacy of current influenza vaccines and small molecule antiviral drugs is limited due to the emergence of multidrug-resistant influenza viruses. In response to the urgent need for the next generation of influenza antivirals, we utilized a fast-track drug discovery platform by exploring multi-component reaction products for antiviral drug candidates. Specifically, molecular docking was applied to screen a small molecule library derived from the Ugi-azide four-component reaction methodology for inhibitors that target the influenza polymerase PAC -PB1N interactions...
March 15, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29536295/clinical-outcomes-of-intraoperative-manual-dilatation-of-pylorus-in-pylorus-preserving-gastrectomy-a-retrospective-analysis
#10
Chun-Chao Zhu, Tae-Han Kim, Felix Berlth, Shin-Hoo Park, Yun-Suhk Suh, Seong-Ho Kong, Hyuk-Joon Lee, Hui Cao, Han-Kwang Yang
BACKGROUND: Delayed gastric emptying is one of the most disturbing complications of pylorus-preserving gastrectomy (PPG) and it increases hospital stay. We investigated the clinical outcome of intraoperative manual dilatation of the pylorus as a preventive method of pyloric spasm after PPG. MATERIALS AND METHODS: We reviewed gastric cancer patients who underwent PPG between January 2014 and December 2016 at Seoul National University Hospital by a single surgeon...
March 13, 2018: Gastric Cancer
https://www.readbyqxmd.com/read/29529499/an-access-to-a-library-of-novel-triterpene-derivatives-with-a-promising-pharmacological-potential-by-ugi-and-passerini-multicomponent-reactions
#11
Jana Wiemann, Lucie Heller, René Csuk
The promising combination of natural product leads and their derivatization by isocyanide-based multicomponent reactions (IMCRs) has gained interest in accessing diversity-oriented libraries with auspicious pharmacological potential. Therefore, a set of 34 Ugi and 3 Passerini products was successfully synthesized starting from naturally occurring triterpenoids, i.e. oleanolic acid (OA) and maslinic acid (MA), followed by a biological evaluation of the novel α-acylamino carboxamides and the α-acyloxy carboxamides in colorimetric SRB assays to determine their cytotoxic potential...
February 21, 2018: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29517821/an-unprecedented-retro-mumm-rearrangement-revealed-by-esi-ms-ms-irmpd-spectroscopy-and-dft-calculations
#12
Claudio Iacobucci, Samantha Reale, Massimiliano Aschi, Jos Oomens, Giel Berden, Francesco De Angelis
Brønsted acids and protic solvents mediate acyl transfer, known as Mumm rearrangement, from imidates to the corresponding acylamides. This represents a key step in several reactions, e.g. the Ugi-four component reaction (U-4CR) and Passerini-three component reaction (P-3CR). Herein we report an unprecedented break of the non-reversibility of the Mumm rearrangement. A combination of electrospray tandem mass spectrometry (ESI-MS/MS), infrared multiphoton dissociation (IRMPD) ion spectroscopy and theoretical calculations demonstrates the occurrence of the retro-Mumm rearrangement of protonated isopeptides in the gas-phase...
March 8, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29516397/efficacy-of-postoperative-upper-gastrointestinal-series-ugi-and-computed-tomography-ct-scan-in-bariatric-surgery-a-meta-analysis-on-7516-patients
#13
Mario Musella, Valeria Cantoni, Roberta Green, Wanda Acampa, Nunzio Velotti, Paola Maietta, Alberto Cuocolo
BACKGROUND: To demonstrate the lack of utility and efficacy of routine early postoperative upper gastrointestinal study (UGI) in obese patients undergoing bariatric surgery and to show the higher efficacy of CT scan in cases of clinical suspicion of a leakage, a meta-analysis was performed. MATERIALS AND METHODS: A literature search including articles published in last 18 years was performed. For both UGI and CT scan, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated...
March 7, 2018: Obesity Surgery
https://www.readbyqxmd.com/read/29507869/endoscopic-ultrasound-assessment-of-gastrointestinal-polypoid-lesions-of-indeterminate-morphology-in-patients-with-portal-hypertension
#14
Dimitrios E Sigounas, Amanullah Shams, Peter C Hayes, John N Plevris
Background and study aims:  Polypoid lesions found during upper gastrointestinal endoscopy (UGIE) are occasionally found in patients with portal hypertension (PH). This study aimed to assess the true nature of such polypoid lesions using endoscopic ultrasound (EUS) and determine the accuracy of UGIE in differentiating between vascular and non-vascular lesions in PH. Patients and methods:  We retrospectively assessed all patients with PH referred for EUS due to polypoid lesions of unknown nature at UGIE over a 7-year period...
March 2018: Endoscopy International Open
https://www.readbyqxmd.com/read/29505240/a-multifunctional-polypeptide-via-ugi-reaction-for-compact-and-biocompatible-quantum-dots-with-efficient-bioconjugation
#15
Hang Zhang, Jinlong Chen, Chunsheng Xiao, Youhua Tao, Xianhong Wang
The growing application of quantum dots (QDs) in biomedical research necessitates, in turn, continuous development of surface functionalizing ligands to optimize their performance for ever more challenging and diverse biological applications. Here, we demonstrate the novel multifunctional polypeptide ligands for compact and biocompatible QDs. The target ligand preparation exploits the efficient, activating agent-free Ugi reaction of four functional components to incorporate lipoic acid, pyridine, zwitterion motifs, and reactive functionalities in a one-pot procedure under mild conditions...
March 5, 2018: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/29498845/lewis-acid-catalyzed-diastereoselective-synthesis-of-multisubstituted-n-acylaziridine-2-carboxamides-from-2h-azirines-via-joulli%C3%A3-ugi-three-component-reaction
#16
Anikó Angyal, Andras Demjen, Edit Wéber, Anita K Kovacs, Janos Wolfling, Laszlo G Puskas, Ivan Kanizsai
A ZnCl2-catalyzed diastereoselective Joullié-Ugi three-component reaction from 2H-azirines, isocyanides and carboxylic acids has been established. The protocol allows the preparation of highly and diversely functionalized N-acylaziridine-2-carboxamide derivatives in up to 82% isolated yields. Moreover,the applicability of N-acylaziridines is demonstrated through a variety of transformations.
March 2, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29466017/aza-riley-oxidation-of-ugi-azide-and-ugi-3cr-products-toward-vicinal-tricarbonyl-amides-two-step-mcr-oxidation-methodology-accessing-functionalized-%C3%AE-%C3%AE-diketoamides-and-%C3%AE-%C3%AE-diketotetrazoles
#17
Christopher Foley, Arthur Shaw, Christopher Hulme
Direct oxidative deamination of glyoxal-derived Ugi-azide and Ugi three-component reaction products readily affords vicinal tricarbonyls (α,β-diketoamides) and α,β-diketotetrazoles with two diversity elements. This significant extension of our previously described multicomponent reaction-oxidative deamination methodology is proposed to proceed through a mechanistically distinct SeO2 -mediated C-N oxidation derived from an active enol of α-amino-β-ketone systems, effectively an aza-Riley oxidation. This methodology accesses diverse VTC systems from prototypical amines, glyoxaldehydes, and isocyanide building blocks in a mere two steps...
February 21, 2018: Organic Letters
https://www.readbyqxmd.com/read/29457887/synthesis-of-highly-substituted-imidazole-uracil-containing-molecules-via-ugi-4cr-and-passerini-3cr
#18
Rudrakshula Madhavachary, Tryfon Zarganes-Tzitzikas, Pravin Patil, Katarzyna Kurpiewska, Justyna Kalinowska-Tłuścik, Alexander Dömling
The synthesis of uracil/thymine containing tetra/tri-substituted imidazoles were demonstrated using Ugi/Passerini-reaction fol-lowed by a post-cyclization reaction sequence. The approach enables the one-pot facile construction of diverse compounds in moderate to excellent yields (47-82%). The 5-fluorouracil and 5-methyluracil moieties afford potentially bioactive molecules with drug-like properties. These scaffolds are being utilized in the screening deck of the European Lead Factory.
February 19, 2018: ACS Combinatorial Science
https://www.readbyqxmd.com/read/29457732/total-synthesis-of-plusbacin-a3-and-its-dideoxy-derivative-using-a-solvent-dependent-diastereodivergent-joulli%C3%A3-ugi-three-component-reaction
#19
Akira Katsuyama, Fumika Yakushiji, Satoshi Ichikawa
Full details of our synthetic studies toward plusbacin A3 (1), which is a depsipeptide with antibacterial activity, and its dideoxy derivative are described. To establish an efficient synthetic route of 1, a solvent-dependent diastereodivergent Joullié-Ugi three-component reaction (JU-3CR) was used to construct trans-Pro(3-OH) in a small number of steps. Two strategies were investigated toward the total synthesis. In the first synthetic strategy, the key steps were the trans-selective JU-3CR and a macrolactonization at the final stage of the synthesis...
February 19, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29457731/synthesis-of-structurally-diverse-emissive-molecular-rotors-with-four-component-ugi-stators
#20
Ma Carmen García-González, Andres Aguilar-Granda, Angel Zamudio-Medina, Luis D Miranda, Braulio Rodríguez-Molina
The use of the multicomponent Ugi reaction to rapidly prepare a library of dumbbell-like molecular rotors is highlighted here. The synthetic strategy consisted on the atom-economic access to fifteen bulky and structurally-diverse iodinated stators, which were cross coupled to the 1,4-diethynylphenylene rotator. From those experiments, up to six rotors 1a-c and 1l-n were obtained, with yields ranging from 35 to 69 % per coupled C-C bond. In addition to the frameworks diversity, five of these compounds showed Aggregate-Enhanced Emission properties thanks to their conjugated 1,4-bis-[(phenyl)ethynyl]benzene cores, a property that rises by increasing the water fraction (fw) in their THF solutions...
February 19, 2018: Journal of Organic Chemistry
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