The Click Reaction As an Efficient Tool for the Construction of Macrocyclic Structures
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On Conducting Polymer Coated Electrodes: a Versatile Platform for the Modification of Electrode Surfacesa
Full Paper http://www.paper.edu.cn ‘‘Click’’ on Conducting Polymer Coated Electrodes: A Versatile Platform for the Modification of Electrode Surfacesa Yan Li, Weixia Zhang, Jing Chang, Jinchun Chen, Guangtao Li,* Yong Ju* Two types of N-substituted pyrroles with azide and terminal alkyne groups have been synthesized and electropolymerized. ‘‘Click’’ chemistry, specifically Huisgen 1,3-dipolar cycloaddition, was used as a general method for functionalization of the polypyrrole films. Several model compounds, including redox active (quinone), bioactive (cholic acid) and recognition elements (carbohydrate and thymi- dine) could easily be attached onto the electrode surfaces without loss of functionality or the elec- troactivity of the underlying conducting polymers. The results suggest that the polypyrrole films are clickable and provide a novel biocompatible and versatile platform for efficient modifications on electrode surfaces. Introduction catalysis.[1,2] A key factor in such investigations and applications is the achievement of an efficient interface The immobilization of functional units, such as electro- between the functional groups and the conductive active, bioactive and biological recognition elements, onto surface.[3,4] conductive surfaces is of enormous interest, both in Compared to various protocols developed for confining studies of functional groups themselves and in numerous functional units onto solid surfaces, electrodeposition of applications ranging from disease diagnosis to electro- conducting polymers offers a simple and -
Heterocycles 2 Daniel Palleros
Heterocycles 2 Daniel Palleros Heterocycles 1. Structures 2. Aromaticity and Basicity 2.1 Pyrrole 2.2 Imidazole 2.3 Pyridine 2.4 Pyrimidine 2.5 Purine 3. Π-excessive and Π-deficient Heterocycles 4. Electrophilic Aromatic Substitution 5. Oxidation-Reduction 6. DNA and RNA Bases 7. Tautomers 8. H-bond Formation 9. Absorption of UV Radiation 10. Reactions and Mutations Heterocycles 3 Daniel Palleros Heterocycles Heterocycles are cyclic compounds in which one or more atoms of the ring are heteroatoms: O, N, S, P, etc. They are present in many biologically important molecules such as amino acids, nucleic acids and hormones. They are also indispensable components of pharmaceuticals and therapeutic drugs. Caffeine, sildenafil (the active ingredient in Viagra), acyclovir (an antiviral agent), clopidogrel (an antiplatelet agent) and nicotine, they all have heterocyclic systems. O CH3 N HN O O N O CH 3 N H3C N N HN N OH O S O H N N N 2 N O N N O CH3 N CH3 caffeine sildenafil acyclovir Cl S N CH3 N N H COOCH3 nicotine (S)-clopidogrel Here we will discuss the chemistry of this important group of compounds beginning with the simplest rings and continuing to more complex systems such as those present in nucleic acids. Heterocycles 4 Daniel Palleros 1. Structures Some of the most important heterocycles are shown below. Note that they have five or six-membered rings such as pyrrole and pyridine or polycyclic ring systems such as quinoline and purine. Imidazole, pyrimidine and purine play a very important role in the chemistry of nucleic acids and are highlighted. -
Combined Experimental and Theoretical Study of Poly(Aniline-Co-Pyrrole) Oligomer
ORE Open Research Exeter TITLE Combined experimental and theoretical study of poly(aniline-co-pyrrole) oligomer AUTHORS Kamran, Muhammad; Ullah, Habib; Shah, Anwar-ul-Haq A.; et al. JOURNAL Polymer DEPOSITED IN ORE 15 March 2016 This version available at http://hdl.handle.net/10871/20729 COPYRIGHT AND REUSE Open Research Exeter makes this work available in accordance with publisher policies. A NOTE ON VERSIONS The version presented here may differ from the published version. If citing, you are advised to consult the published version for pagination, volume/issue and date of publication Combined Experimental and Theoretical Study of Poly(Aniline-co-Pyrrole) Oligomer Habib Ullah*,a,b, Muhammad Kamranb, Salma Bibic, Anwar-ul-Haq A. Shah*,b, Asif A. Tahira, Khurshid Ayub*,d aEnvironment and Sustainability Institute (ESI), University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK bInstitute of Chemical Sciences, University of Peshawar, 25120 Peshawar, Pakistan cNational Centre of Excellence in Physical Chemistry, University of Peshawar, 25120 Peshawar, Pakistan. dDepartment of Chemistry, COMSATS Institute of Information Technology, University Road, Tobe Camp, 22060 Abbottabad, Pakistan * To whom corresponding should be addressed Email: [email protected] Abstract Quantum mechanical calculations are performed to establish the structure of an oligomer of aniline and pyrrole [Poly(Ani-co-Py)], through comparison of experimental and theoretically calculated properties, including conductivity. The copolymer was synthesized through chemical oxidative polymerization and then confirmed from the experimental IR, UV-vis, mass spectra, elemental, XRD, TGA, and SEM analysis. Quantum mechanical calculations are performed at Density Functional Theory (DFT) and Time dependent DFT (TD-DFT) methods for the electronic and spectroscopic properties of the oligomer. -
Read the Book of Abstracts
2o21 ONLINE May 10- 12 2021 International Symposium on SupraBiomolecular Systems 2021 Table of Contents TBD 1 Prof. Andreas Herrmann TBD 2 Prof. Rachel O’Reilly Tackling challenges in nanomedicine with responsive supramolecular polymers and advanced mi- croscopy 3 Dr. Silvia Pujals, Mr. Edgar Fuentes, Dr. Lorenzo Albertazzi Water Soluble Nanotubular Architectures from Amphiphilic Dinucleobases 4 Dr. Fatima Aparicio, Ms. Paula Blue Chamorro, Dr. Raquel Chamorro, Prof. David Gonzalez-Rodriguez Glyconucleolipids as new drug delivery systems for Parkinson’s disease treatment 5 Mr. Anthony Cunha, Dr. Alexandra Gaubert, Prof. Philippe Barthélémy, Dr. Benjamin Dehay, Dr. Laurent Latxague Membraneless compartments based on intrinsically disordered proteins: from biology towards new pro- tein materials 6 Prof. Paolo Arosio Low Molecular Weight Oleogel formation via unique keto-enol-type nucleolipid supramolecular assembly 8 Mr. Arthur KLUFTS-EDEL, Ms. Bérangère Dessane, Dr. Aladin Hamoud, Dr. Geoffrey Prévot, Dr. Antoine Lo- quet, Dr. Brice Kauffmann, Prof. Philippe Barthélémy, Prof. Sylvie Crauste-Manciet, Dr. Valérie Desvergnes Multi-responsive supramolecular fibers from peptide-based amphiphiles 9 Mr. Edgar Fuentes, Dr. Marieke Gerth, Dr. Jose Augusto Berrocal, Dr. Carlo Matera, Prof. Pau Gorostiza, Prof. Ilja Voets, Dr. Silvia Pujals, Dr. Lorenzo Albertazzi Electrostatic Protein Assemblies Towards Biohybrid Photoactive Materials 10 Dr. Eduardo Anaya-Plaza, Prof. Mauri Kostiainen Exploring Polyoxometalates as Non-destructive Staining Agents for Contrast-Enhanced Microfocus Com- puted Tomography of Biological Tissues 11 Ms. Sarah Vangrunderbeeck, Mr. Sébastien De Bournonville, Mrs. Hong Giang T. Ly, Prof. Wim De Borggraeve, Prof. Tatjana Parac-Vogt, Prof. Greet Kerckhofs Hydrogels with Photo-Switchable Stiffness: A Tool to Mimic Extra Cellular Matrix 13 Prof. -
Synthesis of Organometallic PNA Oligomers by Click Chemistry
Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2008 1 Supporting Information: Synthesis of organometallic PNA oligomers by click chemistry Gilles Gasser, Nina Hüsken, S. David Köster and Nils Metzler-Nolte* Department of Inorganic Chemistry I – Bioinorganic Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum Universitätsstrasse 150; 44801 Bochum, Germany Fax: +49 (0)234 – 32 14378; E-Mail: [email protected] Table of contents I. Experimental Section a) Materials 2 b) Instrumentation and methods 2 c) Peptide Nucleic Acid synthesis 2 d) Synthesis, characterisation and NMR spectra of Fmoc-1-OtBu, Fmoc-1-OH, Fmoc-2-OtBu and 3 3 e) Characterisation of PNA1-4 10 f) Synthesis and characterisation of Fc-PNA1-3 and Fc2-PNA4 10 II. MALDI-TOF Spectra a) Figure 5: MALDI-TOF mass spectrum of Fc-PNA1 11 b) Figure 6: MALDI-TOF mass spectrum of Fc-PNA2 12 c) Figure 7: MALDI-TOF mass spectrum of Fc-PNA3 12 d) Figure 8: MALDI-TOF mass spectrum of Fc2-PNA4 13 III. References 13 Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2008 2 I. Experimental Section a) Materials. All chemicals were of reagent grade quality or better, obtained from commercial suppliers and used without further purification. Solvents were used as received or dried over 4 Å molecular sieves. b) Instrumentation and methods. 1H and 13C NMR spectra were recorded in deuterated solvents on a Bruker DRX 400 spectrometer at 30°C. The chemical shifts, δ, are reported in ppm (parts per million). -
Reactions of Pyrrole, Imidazole, and Pyrazole with Ozone
Environmental Science Water Research & Technology View Article Online PAPER View Journal | View Issue Reactions of pyrrole, imidazole, and pyrazole with † Cite this: Environ. Sci.: Water Res. ozone: kinetics and mechanisms Technol., 2020, 6,976 Agnes Tekle-Röttering,‡a Sungeun Lim, ‡bc Erika Reisz,d Holger V. Lutze,efgj Mohammad Sajjad Abdighahroudi, e Sarah Willach,e Winfried Schmidt,af Peter R. Tentscher,h Daniel Rentsch, i Christa S. McArdell, b Torsten C. Schmidt *efg and Urs von Gunten*bc Five-membered nitrogen-containing heterocyclic compounds (azoles) belong to potential moieties in com- plex structures where transformations during ozonation can occur. This study focused on the azole–ozone chemistry of pyrrole, imidazole, and pyrazole as model compounds. Reaction kinetics and ozonation products were determined by kinetic and analytical methods including NMR, LC-HRMS/MS, HPLC-UV, and IC-MS. 1 Analyses of reactive oxygen species ( O2, ˙OH, H2O2), quantum chemical computations (Gibbs energies), and kinetic simulations were used to further support the proposed reaction mechanisms. The species-specific 6 −1 Creative Commons Attribution-NonCommercial 3.0 Unported Licence. second-order rate constants for the reactions of ozone with pyrrole and imidazole were (1.4 ± 1.1) × 10 M −1 5 −1 −1 s and (2.3 ± 0.1) × 10 M s , respectively. Pyrazole reacted more slowly with ozone at pH 7 (kapp =(5.6± 0.9) × 101 M−1 s−1). Maleimide was an identified product of pyrrole with a 34% yield. Together with other prod- ucts,formate,formamide,andglyoxal,CandNmassbalancesof∼50% were achieved. Imidazole reacted with ozone to cyanate, formamide, and formate (∼100% yields per transformed imidazole, respectively) with a closed mass balance. -
CONCISE STUDY NOTES for BG 4Th Semester (UNIT: Amines and Heterocyclic Compounds)
CONCISE STUDY NOTES FOR BG 4th Semester (UNIT: Amines and Heterocyclic Compounds) Syllabus Amines: Classification and factors affecting basicity of amines. Mechanistic details (wherever applicable) of methods of formation of alkyl and arylamines through reduction of nitro compounds and nitriles. Gabriel-Phthalamide reaction and Hofmann rearrangement. Mechanisms involved in the formation and reactions of arenediazonium salts including Azo coupling. Heterocyclic compounds bearing one nitrogen atom: Stuctural features of pyrrole, pyrrolidine, pyridine and piperidine and comparative account of their basic strength. Aromaticity and electrophilic substitution reactions of pyrrole and their comparison with those of furan and thiophene.Mechanisms involved in the preparations of Indole and quinoline using Fischer-Indole and Bishlier-Napierlaski syntheses. Amines: Their classification Alkyl, aryl and ar-alkyl derivatives of ammonia are known as amines General formula is RNH2, R2NH, R3NH, where R can be any alkyl, aryl or aralkyl group. Amines are classified in to primary, secondary and tertiary amines depending upon the number of Hydrogen atoms in ammonia replaced by alkyl or aryl group. If one of hydrogen atom in NH3 is replaced by alkyl or aryl group, the derivative of ammonia so obtained is known as primary amine, if two hydrogen atoms in ammonia are replaced by alkyl, aryl or ar-alkyl groups, the derivative obtained is known as secondary amine, while as if all H atoms in ammonia are replaced by alkyl aryl or aralkyl groups, a tertiaty amine is obtained as shown below: The R groups can be alkyl, aryl or aralkyl groups. Further a secondary or tertiary amine may contain same or different R groups. -
Heterocyclic Chemistrychemistry
HeterocyclicHeterocyclic ChemistryChemistry Professor J. Stephen Clark Room C4-04 Email: [email protected] 2011 –2012 1 http://www.chem.gla.ac.uk/staff/stephenc/UndergraduateTeaching.html Recommended Reading • Heterocyclic Chemistry – J. A. Joule, K. Mills and G. F. Smith • Heterocyclic Chemistry (Oxford Primer Series) – T. Gilchrist • Aromatic Heterocyclic Chemistry – D. T. Davies 2 Course Summary Introduction • Definition of terms and classification of heterocycles • Functional group chemistry: imines, enamines, acetals, enols, and sulfur-containing groups Intermediates used for the construction of aromatic heterocycles • Synthesis of aromatic heterocycles • Carbon–heteroatom bond formation and choice of oxidation state • Examples of commonly used strategies for heterocycle synthesis Pyridines • General properties, electronic structure • Synthesis of pyridines • Electrophilic substitution of pyridines • Nucleophilic substitution of pyridines • Metallation of pyridines Pyridine derivatives • Structure and reactivity of oxy-pyridines, alkyl pyridines, pyridinium salts, and pyridine N-oxides Quinolines and isoquinolines • General properties and reactivity compared to pyridine • Electrophilic and nucleophilic substitution quinolines and isoquinolines 3 • General methods used for the synthesis of quinolines and isoquinolines Course Summary (cont) Five-membered aromatic heterocycles • General properties, structure and reactivity of pyrroles, furans and thiophenes • Methods and strategies for the synthesis of five-membered heteroaromatics -
Professor of Chemistry
Bruce C. Gibb FRSC Professor of Chemistry Department of Chemistry Tulane University New Orleans, LA 70118, USA Tel: (504) 862 8136 E-mail: [email protected] Website: http://www.gibbgroup.org Twitter: @brucecgibb Research Interests: Aqueous supramolecular chemistry: understanding how molecules interact in water: from specific ion- pairing and the hydrophobic effect, to protein aggregation pertinent to neurodegenerative disorders. Our research has primarily focused on: 1) novel hosts designed to probe the hydrophobic, Hofmeister, and Reverse Hofmeister effects, and; 2) designing supramolecular capsules as yocto-liter reaction vessels and separators. Current efforts to probe the hydrophobic and Hofmeister effects include studies of the supramolecular properties of proteins. Professional Positions: Visiting Professor, Wuhan University of Science and Technology as a Chair Professor of Chutian Scholars Program (2015-2018) Professor of Chemistry, Tulane University, New Orleans, USA (2012-present). University Research Professor, University of New Orleans, USA (2007-2011). Professor of Chemistry, University of New Orleans, USA (2005-2007). Associate Professor of Chemistry, University of New Orleans, USA (2002-2005). Assistant Professor of Chemistry, University of New Orleans, USA, (1996-2002). Education: Postdoctoral Work Department of Chemistry, New York University. Synthesis of Carbonic Anhydrase (CA) mimics with Advisor: Prof. J. W. Canary, (1994-1996). Department of Chemistry, University of British Columbia, Canada De Novo Protein development. Advisor: Prof. J. C. Sherman (1993-1994). Ph.D. Robert Gordon’s University, Aberdeen, UK. Synthesis and Structural Examination of 3a,5-cyclo-5a- Androstane Steroids. Advisors: Dr. Philip J. Cox and Dr. Steven MacManus (1987-92) . B.Sc. with Honors in Physical Sciences Robert Gordon’s University, Aberdeen, UK. -
N-Methylprotoporphyrin IX: Chemical Synthesis and Identification
Proc. Nati. Acad. Sci. USA Vol. 78, No. 3, pp. 1490-1494, March 1981 Biochemistry N-Methylprotoporphyrin IX: Chemical synthesis and identification as the green pigment produced by 3,5-diethoxycarbonyl-1,4- dihydrocollidine treatment (N-alkyl porphyrins/porphyrin synthesis/ferrochelatase inhibitor/NMR) PAUL R. ORTIZ DE MONTELLANO, HAL S. BEILAN, AND KENT L. KUNZE Department of Pharmaceutical Chemistry, School of Pharmacy, and Liver Center, University of California, San Francisco, California 94143 Communicated by Rudi Schmid, November 24, 1980 ABSTRACT The hepatic pigment accumulated in 3,5-di- mitochondrial ferrochelatase (13, 14). The differential physio- ethoxycarbonyl-1,4-dihydrocollidine-treated rats, which has been logical effects of AIA and DDC are thus related, at least in part, reported to inhibit ferrochelatase, has been isolated and purified. to differences in the structures of the accompanying The pigment has been resolved into one major, one minor, and hepatic two trace components, all of which appear to be isomeric por- pigments. In concert with our efforts to define the structure of phyrins. The major fraction has been unambiguously identified the abnormal porphyrins due to AIA and other unsaturated byspectroscopic methods as the isomer of N-methyprotopor- agents (9, 10, 15, 16), we have undertaken a structural inves- phyrin IX (isolated as the dimethyl ester) in which vinyl-substituted tigation of the DDC-induced pigment. We report here un- pyrrole ring A is methylated. The minor product appears to be an ambiguous spectroscopic identification of the DDC pigment isomer of the same porphyrin with the N-methyl group on pro- as N-methylprotoporphyrin IX (dimethyl ester), confirmation pionic acid-substituted ring C, and the trace components have the same high-pressure liquid chromatography retention times as the of this structural assignment by chemical synthesis of the four other two possible isomers of the porphyrin. -
Strecker Degradation Products of Aspartic and Glutamic Acids and Their Amides
Czech J. Food Sci. Vol. 19, No. 2: 41–45 Strecker Degradation Products of Aspartic and Glutamic Acids and their Amides JAN RÖSSNER, JAN VELÍEK, FRANTIEK PUDIL and JIØÍ DAVÍDEK Institute of Chemical Technology Department of Food Chemistry and Analysis, Prague, Czech Republic Abstract RÖSSNER J., VELÍEK J., PUDIL F., DAVÍDEK J. (2001): Strecker degradation products of aspartic and glutamic acids and their amides. Czech J. Food Sci., 19: 4145. Aspartic and glutamic acids, asparagine and glutamine were oxidised with either potassium peroxodisulphate or glyoxal. Non- volatile products were derivatised and analysed by GC/FID and GC/MS. Volatile reaction products were isolated and analysed by the same methods. It was found that the degradation reactions of amino acids are complex. Amino acids are principally degraded via the corresponding α-keto acids to Strecker aldehydes (aspartic acid to oxalacetic and 3-oxopropionic acids and glutamic acid to α-ketoglutaric and 4-oxobutyric acids), which are unstable and decomposed by decarboxylation to the corresponding alde- hydes. Aspartic acid also eliminates ammonia and yields fumaric acid whereas glutamic acid gives rise to an imine, pyroglutamic acid. A recombination of free radicals leads to dicarboxylic acids (succinic acid from aspartic acid, succinic, glutaric and adipic acids from glutamic acid). The major volatile products (besides the aldehydes) are lower carboxylic acids (acetic acid from aspartic acid and propionic acid acid from glutamic acid) that can at least partly arise by radical reactions. In both quality and quantity terms, a higher amount of degradation products arises by oxidation of amino acids by peroxodisulphate. Keywords: Strecker degradation; Strecker aldehydes; amino acids; glyoxal; sodium peroxodisulphate; aspartic acid; glutamic acid; asparagine; glutamine; radicals The reaction of an α-amino acid with an oxidation re- asparagine (Asn) and glutamine (Gln). -
Comparative Analysis of Click Chemistry Mediated Activity-Based Protein Profiling in Cell Lysates
Molecules 2013, 18, 12599-12608; doi:10.3390/molecules181012599 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Communication Comparative Analysis of Click Chemistry Mediated Activity-Based Protein Profiling in Cell Lysates Yinliang Yang, Xiaomeng Yang and Steven H. L. Verhelst * Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany; E-Mails: [email protected] (Y.Y.); [email protected] (X.Y.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +49-8161-713505; Fax: +49-8161-714404. Received: 26 June 2013; in revised form: 7 August 2013 / Accepted: 26 September 2013 / Published: 11 October 2013 Abstract: Activity-based protein profiling uses chemical probes that covalently attach to active enzyme targets. Probes with conventional tags have disadvantages, such as limited cell permeability or steric hindrance around the reactive group. A tandem labeling strategy with click chemistry is now widely used to study enzyme targets in situ and in vivo. Herein, the probes are reacted in live cells, whereas the ensuing detection by click chemistry takes place in cell lysates. We here make a comparison of the efficiency of the activity-based tandem labeling strategy by using Cu(I)-catalyzed and strain-promoted click chemistry, different ligands and different lysis conditions. Keywords: activity-based probes; cathepsins; click chemistry; proteases; protein modification 1. Introduction Within chemical biology, site specific protein modification by covalent small molecule probes is a powerful and often used technique to interrogate biomolecular interactions and protein function. The introduction of covalent small molecule probes can be based on different types of chemistries: probes may be incorporated by the use of exogenous or endogenous enzymes [1,2], or they can contain an intrinsic reactivity such as an electrophile or photocrosslinker that by itself forms a covalent bond to the target proteins [3–5].