DOCSLIB.ORG

Controlling Transition Metal-Catalyzed Alkyne Annulations Utilizing Polarized Ynol Ethers

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Controlling Transition Metal-Catalyzed Alkyne Annulations Utilizing Polarized Ynol Ethers University of Denver Digital Commons @ DU Electronic Theses and Dissertations Graduate Studies 2020 Controlling Transition Metal-Catalyzed Alkyne Annulations Utilizing Polarized Ynol Ethers Brandon L. Coles-Taylor Follow this and additional works at: https://digitalcommons.du.edu/etd Part of the Organic Chemistry Commons Controlling Transition Metal-Catalyzed Alkyne Annulations Utilizing Polarized Ynol Ethers ______________ A Dissertation Presented to the Faculty of the College of Natural Sciences and Mathematics University of Denver ____________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy ____________ by Brandon L. Coles-Taylor June 2020 Advisor: Brian Michel, PhD ©Copyright by Brandon L. Coles-Taylor 2020 All Rights Reserved Author: Brandon L. Coles-Taylor Title: Controlling Transition Metal-Catalyzed Alkyne Annulations Utilizing Polarized Ynol Ethers Advisor: Brian Michel, PhD Degree Date: June 2020 Abstract Transition metal-catalyzed alkyne annulations have developed into incredibly powerful synthetic tools over there the past quarter century. These reactions provide rapid access to important organic scaffolds such as indole, quinoline, isoquinoline, indene, and isocoumarin scaffolds. Transition metal mediated alkyne annulations have proven invaluable in synthetic fields, such as natural product total synthesis, by offering efficient pathways to otherwise synthetically difficult to access substrates. Foundational works performed by chemist such as Larock, Ackermann, Satoh, and Miura have been established through relying upon the usage of symmetrical alkynes. When unsymmetrical alkynes are used in annulation processes mixtures of regioisomers are often isolated. While methodologies have been developed which regioselectively deliver annulation products, the regioselective nature of these reactions is often empirically determined and obtained with little synthetic design to impact the alkyne migratory insertion step of the catalytic cycle. In recent years few examples of polarized, unsymmetrical alkynes have been sparingly used in transition metal alkyne annulations. Still, these limited examples provide the roadmap for how to regioselectively control alkyne annulations. Researchers have displayed that one class of polarized alkynes, ynol ethers, exhibit the ability to react regioselectively in transition metal-catalyzed migratory insertion processes. There has been ii little research focused on expanding this regioselective nature of ynol ethers into transition metal-catalyzed alkyne annulations. This dissertation provides the work we have accomplished in efforts to bridge this gap. We have established the use of ynol ethers as compatible annulations partners in transition metal-catalyzed alkyne annulations. They have been utilized in the regioselective synthesis of diverse 4-oxy-substituted isoquinolinones. These substrates can be further functionalized into prolyl-4-hydroxylase domain inhibitor analogues. Ynol ethers were also employed to regioselectively facilitate the palladium catalyzed synthesis of complex indenol ethers. Through inhibiting the terminal step in this indene synthesis, -hydride elimination and intercepting the in-situ generated palladium intermediate, the isolation of an enantiomeric mixture of isomers was observed. To date we have partially optimized a regioselective, enantioselective, intermolecular Heck–Suzuki–Miyaura cascade reaction. Further investigation is necessary to fully understand regioselective transition metal- catalyzed ynol ether annulations, but the groundwork has been laid for this work to continue. iii Acknowledgements I would like to acknowledge Benjamin L. Taylor and Natalie M. Brierre, my father and mother, for all their love and support throughout the years. Even when times look bleak you are always in my corner. I am forever grateful. To Ryan S. Taylor, my brother, thanks for your constant support and encouragement throughout this program. You have seen me through some pretty steep hills and low valleys. I could not have asked for a more loving and supportive brother. To Justin A. Seyler, my reunited brother, thanks for keeping me sane through this insane process. I literally could not have done this without you. To my lab mates and other graduate students, of whom I have been blessed to cross paths within my time at the University of Denver, thank you for the knowledge you have imparted to me. I will always do my best to pay that kindness forward. To Virginia Pearl Schnur, my loving grandmother. Thank you for all the love, support, guidance, and the grit & determination you have modeled for me. Without every little thing you have done for my life I would not be where I am today. Thank you to those who have aided in the editing of this dissertation. Finally, to my loving, beautiful, supportive wife, Carolyn M. Coles-Taylor, a document of double the length of this dissertation could not fully to express what you have meant to the completion of this degree. You have been my rock, and I am excited to be yours as you embark on your own doctoral journey at the University of California, Irvine. To all of those who have profoundly impacted the trajectory of my life, I am forever grateful. Peace, Love, and Prosperity, Brandon L. Coles-Taylor iv Table of Contents Abstract ......................................................................................................................... ii Acknowledgements ....................................................................................................... iv Table of Contents ........................................................................................................... v List of Figures ............................................................................................................. vii Chapter One: Regioselectivity in Metal-Catalyzed Alkyne Annulations ...................... 1 1.1 Transition Metal-Catalyzed Annulations of Unsymmetrical Alkynes................ 1 1.1.1 Rhodium .................................................................................................. 3 You and coworkers developed a N-assisted C–H General Information ..................... 10 1.1.2. Palladium .................................................................................................. 14 1.1.3 Ruthenium .................................................................................................. 20 1.1.4 Other Transition Metals ............................................................................. 26 1.1.5 Conclusion ................................................................................................. 37 Chapter Two: The Synthesis and Reactivity of Ynol Ethers ...................................... 40 2.1 Synthesis of Ynol Ethers ................................................................................... 40 2.1.1 -Elimination ............................................................................................. 41 2.1.2 -Elimination ............................................................................................. 55 2.1.3 Oxidation of Terminal Alkynes ................................................................. 57 2.2 Reactivity of Ynol Ethers.................................................................................. 59 2.2.1 Cycloadditions of Ynol Ethers: The Utility of Ketene Surrogates ............ 60 2.2.2 Metal Migratory Insertion Across Ynol Ethers ......................................... 67 2.3 Conclusions ....................................................................................................... 71 Chapter Three: Accessing 4-Oxy-Substituted Isoquinolinones via C–H Activation and Regioselective Migratory Insertion with Electronically Biased Ynol Ethers ................... 73 3.1 Introduction ....................................................................................................... 73 3.1.1 Synthesis of Isoquinolinones via Transition Metal-Catalyzed Alkyne Annulations ............................................................................................................... 74 3.1.2 Controlling Alkyne Migratory Insertion with Electronically Biased Alkynes ..................................................................................................................... 84 3.2 Results and Discussion ..................................................................................... 86 3.2.1 Optimization of Reaction Conditions ........................................................ 86 3.2.2 Synthesis of Isoquinolinones 288 .............................................................. 88 3.2.3 Synthesis of FG-4497 Analogue ................................................................ 92 3.3 Conclusions ....................................................................................................... 94 3.4 Experimental Procedures .................................................................................. 95 v 3.4.1 Synthesis of Alkylated Ynol Ethers 287b-d............................................... 96 3.4.2 Synthesis of Ynol ethers 287e and 287i ..................................................... 98 3.4.3 General Procedure for Rhodium Catalyzed Annulations......................... 100 3.5 NMR Spectra from Chapter 3 ......................................................................... 113 Chapter Four: Access to Substituted Indenol Ethers via Carbopalladation Heck Cascades ........................................................................................................................
Load more

Recommended publications
  • 1, 1, 1, 3, 3-Pentafluoropropane (HFC-245Fa) (CAS No. 460-73-1)
    1, 1, 1, 3, 3-Pentafluoropropane (HFC-245fa) (CAS No. 460-73-1) JACC Report No. 44 Brussels, June 2004 1, 1, 1, 3, 3-Pentafluoropropane (HFC-245fa) ECETOC JACC REPORT No. 44 © Copyright - ECETOC European Centre for Ecotoxicology and Toxicology of Chemicals 4 Avenue E. Van Nieuwenhuyse (Bte 6), B-1160 Brussels, Belgium. All rights reserved. No part of this publication may be reproduced, copied, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the copyright holder. Applications to reproduce, store, copy or translate should be made to the Secretary General. ECETOC welcomes such applications. Reference to the document, its title and summary may be copied or abstracted in data retrieval systems without subsequent reference. The content of this document has been prepared and reviewed by experts on behalf of ECETOC with all possible care and from the available scientific information. It is provided for information only. ECETOC cannot accept any responsibility or liability and does not provide a warranty for any use or interpretation of the material contained in the publication. ECETOC JACC No. 44 1, 1, 1, 3, 3-Pentafluoropropane (HFC-245fa) 1,1,1,3,3-Pentafluoropropane (HFC-245fa) (CAS No. 460-73-1) CONTENTS EXECUTIVE SUMMARY 1 THE ECETOC SCHEME FOR THE JOINT ASSESSMENT OF COMMODITY CHEMICALS 2 1. SUMMARY AND CONCLUSIONS 3 2. IDENTITY, PHYSICAL, AND CHEMICAL PROPERTIES, ANALYTICAL METHODS 5 2.1 Identity 5 2.2 EC classification and labelling 5 2.3 Physical and chemical properties 5 2.4 Conversion factors 6 2.5 Analytical methods 7 2.5.1 In air 7 2.5.2 In water 7 3.
    [Show full text]
  • Quantum Chemical Study of the Mechanism of the Catalytic
    ISSN 00231584, Kinetics and Catalysis, 2013, Vol. 54, No. 2, pp. 157–167. © Pleiades Publishing, Ltd., 2013. Original Russian Text © D.E. Zavelev, G.M. Zhidomirov, R.A. Kozlovskii, 2013, published in Kinetika i Kataliz, 2013, Vol. 54, No. 2, pp. 166–176. Quantum Chemical Study of the Mechanism of the Catalytic Oxyethylation of Ethylene Glycol on PhosphorusDoped Titanium Dioxide: The Role of the Surface Phosphoryl and Hydroxyl Groups of the Catalyst D. E. Zaveleva,*, G. M. Zhidomirovb,c, and R. A. Kozlovskiid a Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, 119991 Russia b Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia c Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia d Mendeleev University of Chemical Technology of Russia, Moscow, 125047 Russia *email: [email protected] Received June 25, 2012 Abstract—DFT calculations of the oxyethylation pathways of monoethylene glycol (MEG) and diethylene glycol (DEG) were performed on a model fragment of phosphorusdoped titanium dioxide (anatase). It was shown that the surface hydroxyl group of titanium dioxide, whose proton initiates C–O bond cleavage in the ethylene oxide molecule, plays the key role in the activation of the molecule. At the same time, the phospho ryl group –P(OH)2O activates the reactant molecule R (MEG, DEG, etc.) and carries out the synchronous proton transfer from R to the hydroxyl oxygen atom of titanium dioxide, thus restoring the catalyst structure and closing the catalytic cycle. This restructuring occurs synchronously in one step. The substitution of the catalyst hydroxyl groups by alkoxyl groups can influence oxyethylation occurring via the bimolecular nucleo philic substitution mechanism and can poison the catalyst in some cases.
    [Show full text]
  • 1 Vita Peter J. Stang Personal Data
    VITA PETER J. STANG PERSONAL DATA: BORN: November 17, 1941, Nurnberg, Germany CITIZENSHIP: U.S.A. (Naturalized, June, 1962) MARRIED: 1969, Christine M.E. Schirmer CHILDREN: Antonia (b. 1973); B.S. Brown Univ. 1995; M.D. and MBA McGill Univ. 2001 Alexandra (b. 1977); Honors B.S. Univ. of Utah 2000 ADDRESS: 1406 S Chancellor Way, Salt Lake City, Utah 84108 Chemistry Department, 315 S 1400 E, Rm. 2020, University of Utah, Salt Lake City, Utah 84112 PHONE: Office – (801) 581-8329; Home – (801) 581-9749; FAX: Office – (801) 581-8433 EDUCATION B.S. Chemistry, 1963, DePaul University, Chicago, Illinois (Magna Cum Laude) Ph.D., Chemistry, 1966, University of California, Berkeley (NIH Fellow, with A. Streitwieser) Postdoctoral, 1966-68, Princeton University (NIH Fellow, with P.v.R. Schleyer) ACADEMIC EXPERIENCE David P. Gardner Chair of Chemistry, 2014-present Distinguished Professor of Chemistry, University of Utah, 1992-present Dean, College of Science, University of Utah, 1997-2007 Chairperson, Department of Chemistry, University of Utah, 1989-1995 Professor, University of Utah, 1979-1992 Honorary Professor of Chemistry, CAS Institute of Chemistry, Beijing, China Honorary Professor, Zhejiang Univ., East China Normal Univ. and East China Univ. of Science and Technology, Soochow University, Nanjing Normal University, University of Science & Technology of China Senior Fellow, Loker Hydrocarbon Research Inst., U. of Southern Calif. 1991-Present Visiting Scientist, MIT, Cambridge, Mass., 1978 Associate Professor, University of Utah, 1975-79 Assistant Professor, University of Utah, 1969-75 Instructor, Princeton University, 1968-69 RESEARCH INTERESTS Molecular Architecture via Coordination: Formation of discrete supramolecular species with well defined geometries and shapes via self-assembly (molecular triangles, squares, rectangles, pentagons, hexagons, 3D assemblies).
    [Show full text]
  • Lewis Acid Catalyzed Intramolecular Condensation of Ynol Ether-Acetals
    ORGANIC LETTERS 2012 Lewis Acid Catalyzed Intramolecular Vol. 14, No. 23 Condensation of Ynol Ether-Acetals. 6100–6103 Synthesis of Alkoxycycloalkene Carboxylates Vincent Tran and Thomas G. Minehan* Department of Chemistry and Biochemistry, California State University, Northridge 18111 Nordhoff Street, Northridge, California 91330, United States [email protected] Received November 3, 2012 ABSTRACT Treatment of ynol ether-tethered dialkyl acetals with catalytic quantities of scandium triflate in CH3CN gives rise to five-, six-, and seven-membered alkoxycycloalkene carboxylates in good to excellent yields. Tri- and tetrasubstituted carbocyclic and heterocyclic alkenes may be formed by this method, and the products obtained may serve as useful intermediates for natural product synthesis. Alkoxycycloalkene carboxylates are highly useful trialkyl phosphonacetate.5 Since the efficiency of this proto- starting materials for organic synthesis (Figure 1). col is often low, the development of an alternative method for Stereoselective introduction of carbon substituents the preparation of cycloalkenol carboxylates of varying ring β to the ester functional group may be accomplished sizes would clearly be of value for natural product synthesis. by allylic substitution or Michael addition reactions, Here we report our efforts toward the realization of this goal as shown by Villieras et al.1 Ogasawara has prepared and detail a novel Lewis acid catalyzed condensation of ynol the nitraria alkaloids (þ)-nitramine, (þ)-isonitramine, and ether-acetals
    [Show full text]
  • HHS Public Access Author Manuscript
    HHS Public Access Author manuscript Author Manuscript Author ManuscriptTetrahedron Author Manuscript Lett. Author Author Manuscript manuscript; available in PMC 2017 January 20. Published in final edited form as: Tetrahedron Lett. 2016 January 20; 57(3): 415–419. doi:10.1016/j.tetlet.2015.12.041. A Single-Flask Synthesis of α-Alkylidene and α-Benzylidene Lactones from Ethoxyacetylene, Epoxides/Oxetanes, and Carbonyl Compounds Kevin Nga, Vincent Trana, and Thomas Minehana,* aDepartment of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, CA 91330, USA Abstract Low temperature treatment of (ethoxyethynyl)lithium with epoxides or oxetanes in the presence of BF3•OEt2, followed by addition of aldehydes or ketones and warming to room temperature, affords structurally diverse five- and six-membered α-alkylidene and α-benzylidene lactones (5) in good to excellent yields. This one-pot process, in which three new carbon-carbon bonds and a ring are formed, affords substituted α,β-unsaturated lactones of predominantly Z-configuration. The reaction likely occurs via alkyne-carbonyl metathesis of a hydroxy-ynol ether intermediate, acid-promoted alkene E- to Z-isomerization, and lactonization. Graphical abstract Keywords Ynol ethers; α-alkylidene lactones; α-benzylidene lactones; tandem reactions; BF3•OEt2 promotion The α–alkylidene lactone moiety is found in numerous synthetically challenging and biologically important natural products, many of which possess anticancer, antimalarial, antibacterial, antifungal, antiviral, and/or anti-inflammatory activities.1 Of particular significance are the numerous members of the α-methylene-γ-butyrolactone family of sesquiterpenes, to which belong the germacranolides, (pseudo)guaianolides, eudesmanolides, and the cembranolides.2 Recently, synthetic attention has also been *Corresponding author.
    [Show full text]
  • 53 Chapter 3 Progress Towards the Total Synthesis Of
    53 C h a p t e r 3 Progress Towards the Total Synthesis of Cylindrocyclophane F. Investigations into a Novel B-alkyl Suzuki Cross-Coupling. I. Introduction to the Cylindrocyclophanes. i. Isolation and structure determination. The [7.7]paracyclophanes were isolated in 1990 by Moore and co-workers from two species of terrestrial blue-green algae, Cylindrospermum licheniforme Kutzing and Nostoclickia (Roth) Bornet.1 The cylindrocyclophanes were found to be the major cytotoxic component in three different strains of Cylindrospermum licheniforme; cylindrocyclophane A exhibited moderate toxicity against KB and LoVo tumor cell limes (IC50 = 0.5 mg/mL). In fact, all of the cyclophanes have an IC50 between 0.5–5.0 mg/mL but they are not selective for human solid tumor cell lines in the Corbett assay.2 The structurally similar chlorinated nostocyclophanes3 were found to be the major cytotoxic component of Nostoclickia (Fig. 1). 1 Moore, B. S.; Chen, J.-L.; Patterson, G. M.; Moore, R. M.; Brinen, L. S.; Kato, Y.; Clardy, J. J. Am. Chem. Soc. 1990, 112, 4061. 2 LoRusso, P.; Wozniak, A. J.; Polin, L.; Capps, D.; Leopold, W. R.; Werbel, L. M.; Biernat, L.; Dan, M. E.; Corbett, T. N. Cancer Res. 1990, 50, 4900. 3 Chen, J. L.; Moore, R. E.; Patterson, G. M. L. J. Org. Chem. 1992, 56, 4360. 54 R 3 R R R R 1 2 3 1 Me Cylindrocyclophanes A OH OH Me HO OH B OH OAc Me C OH H Me HO OH D OAc OAc Me Me E OAc H Me R2 F H H Me R3 R 1 Me Cl HO R3 Nostocyclophane A OMe b-D-glu b-D-glu B OMe OH b-D-glu C OH OH OH R2 OH Cl Me D OMe OH OH OMe Figure 1.
    [Show full text]
  • Novel Synthesis of Partially Fluorinated Ethers
    Issue in Honor of Prof. Sukh Dev ARKIVOC 2003 (iii) 104-119 Alkylation of in situ generated fluorinated alkoxides: novel synthesis of partially fluorinated ethers G. K. Surya Prakash*, Jinbo Hu and George A. Olah Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, CA 90089-1661 E-mail: [email protected] Dedicated to Professor Sukh Dev on the occasion of his 80th birthday (received 07 Jan 03; accepted 24 Feb 03; published on the web 27 Feb 03) Abstract Fluorinated ethers RfCF2OR were prepared from acyl chlorides RfCOCl, alkylating agents (such as dimethyl sulfate, alkyl triflates, alkyl mesylates and tosylates, etc.) and potassium fluoride in diglyme at 80~100 oC. The success and the efficiency of the reaction are affected by two factors: the stability and nucleophilicity of the fluorinated alkoxide generated in situ; and the other is the electrophilicity of the alkylating agents used. Keywords: Fluoroethers, fluoroacyl halides, fluoride ion, alkylation Introduction In general, carbon-fluorine bonds (C-F, ~116 kcal/mol) are stronger than carbon-hydrogen bonds (C-H, ~99 kcal/mol).1 However, not all organofluorine compounds are more stable than their non-fluorinated analogs, and sometimes they are even less stable. For instance, if a partially or fully fluorinated organic compounds contains an acidic hydrogen at the β position, HF elimination is observed. This is the main reason that α-fluoro alcohols are thermally unstable and 2 difficult to be synthesized or isolated. Formation of fluoromethanol (FCH2OH) from ethyl fluoroformate and from formyl fluoride was first reported by Olah and Pavlath3 in 1953, and Weinmayer4 in 1963 claimed the formation of fluoromethanol (25-30% in equilibrium) from a solution of paraformaldehyde in excess hydrogen fluoride.
    [Show full text]
  • Fluoro-Silane As a Functional Monomer for Protein Conformational Imprinting
    Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2011 Fluoro-Silane as a Functional Monomer for Protein Conformational Imprinting Yun Peng Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Biomedical Engineering and Bioengineering Commons Recommended Citation Peng, Yun, "Fluoro-Silane as a Functional Monomer for Protein Conformational Imprinting" (2011). All Graduate Theses and Dissertations. 906. https://digitalcommons.usu.edu/etd/906 This Dissertation is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. FLUORO-SILANE AS A FUNCTIONAL MONOMER FOR PROTEIN CONFORMATIONAL IMPRINTING by Yun Peng A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Biological Engineering Approved: David W. Britt, Ph.D. Timothy E. Doyle, Ph.D. Major Professor Committee Member Marie K. Walsh, Ph.D. Soonjo Kwon, Ph.D. Committee Member Committee Member Jixun Zhan, Ph.D. Byron Burnham Committee Member Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2011 ii Copyright © Yun Peng 2011 All Rights Reserved iii ABSTRACT Fluoro-silane as a Functional Monomer for Protein Conformational Imprinting by Yun Peng, Doctor of Philosophy Utah State University, 2011 Major Professor: Dr. David W. Britt Department: Biological Engineering By using the technology of molecularly imprinted polymer (MIP), we propose to synthesize a protein conformational imprint that also acts as a plastic enzyme, inducing protein structural transitions.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,501,891 B2 Nozue Et Al
    US008501891B2 (12) United States Patent (10) Patent No.: US 8,501,891 B2 NOZue et al. (45) Date of Patent: Aug. 6, 2013 (54) ETHYLENE-o-OLEFIN COPOLYMER AND (56) References Cited MOLDED ARTICLE U.S. PATENT DOCUMENTS (75) Inventors: Yoshinobu Nozue, Ichihara (JP); 5,962,615 A 10/1999 Kojoh et al. Yasutoyo Kawashima, Ichihara (JP); 2002/0143124 A1 10/2002 Ogane 2003/0060579 A1 3/2003 Oshima et al. Naoko Ochi, Chiba (JP) 2006, OO89476 A1 4/2006 Iseki et al. 2006/O199925 A1 9/2006 Matsuura et al. (73) Assignee: Sumitomo Chemical Company, 2007/0093.627 A1 4/2007 Iseki et al. Limited, Tokyo (JP) FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this CN 1765943. A 5, 2006 CN 1939.943. A 4/2007 patent is extended or adjusted under 35 EP O339571 A1 11, 1989 U.S.C. 154(b) by 423 days. JP 1-292009 A 11, 1989 JP O7-238114 A 9, 1995 (21) Appl. No.: 12/745,178 JP 08-0597O6 A 3, 1996 JP 2003-0961.25 A 4/2003 JP 2003-171412 A 6, 2003 (22) PCT Filed: Nov. 27, 2008 JP 2005-2333 A 1, 2005 JP 2005-206777 A 8, 2005 (86). PCT No.: PCT/UP2008/072000 JP 2005-24.8013. A 9, 2005 JP 2005-281541. A * 10, 2005 S371 (c)(1), JP 2006-233208 A 9, 2006 (2), (4) Date: Jul. 16, 2010 OTHER PUBLICATIONS (87) PCT Pub. No.: WO2009/069823 Mino et al., (JP 2005-281541) Oct. 13, 2005; abstract and translation in English.* PCT Pub.
    [Show full text]
  • Reactive Chlorine Compounds in the Atmosphere
    CHAPTER 1 Reactive Bromine Compounds O.N.Singh 1 · P.Fabian 2 1 Department of Applied Physics, Institute of Technology, Banaras Hindu University, Varanasi- 221 005, India. E-mail: [email protected] 2 University of Munich, Lehrstuhl für Bioklimatologie und Immissionsforschung, Am Hochanger 13, D-85354 Freising-Weihenstephan, Germany. E-mail: [email protected] Bromine, a minor constituent in the Earth’s atmosphere – with its 50-fold higher efficiency of ozone destruction compared to chlorine – contributes significantly to the ozone hole formation and wintertime stratospheric ozone depletion over northern mid and high latitudes.In addition ozone episodes observed in the Arctic during polar sunrise are solely due to atmospheric bromine.CH3Br, CH2Br2 and CHBr3 are the major brominated gases in the atmosphere, of which CH3Br being most abundant, contributes about 50% and CH2Br2 around 7 to 10% of the total organic stratospheric bromine.Bromocarbons with shorter lifetimes like CHBr3 ,CH2BrCl, CHBr2Cl, CHBrCl2 and CH2BrI decompose before reaching the stratosphere, and are responsible for the ozone episodes.But for 3CHBr, which has also significant anthropogenic sources, all the aforementioned bromocarbons are mostly of marine origin.Halons (H-1211, H-1301, H-2402, H-1202) are solely anthropogenic and are far more stable.They decompose only after reaching the stratosphere.It is estimated that 39% of the stratospheric organic bromine (ª 7 pptv) loading is due to these halons.Increa- ses are being still registered in the atmospheric abundance of halons in spite of production restrictions.Though extensively investigated,the existing knowledge with regard to the pro- duction and degradation of atmospheric bromine gases, is not commensurate with its importance.
    [Show full text]
  • MALDI Matrix and MALDI Method
    (19) & (11) EP 2 060 919 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 20.05.2009 Bulletin 2009/21 G01N 33/68 (2006.01) H01J 49/04 (2006.01) (21) Application number: 07120550.4 (22) Date of filing: 13.11.2007 (84) Designated Contracting States: (72) Inventors: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR • Wuijckhuijse, Arjan Laurens HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE 3331 GP Zwijndrecht (NL) SI SK TR • Kientz, Charles Eliza Designated Extension States: 2611 Gl Delft (NL) AL BA HR MK RS (74) Representative: Hatzmann, Martin (71) Applicant: Nederlandse Organisatie voor Vereenigde Toegepast- Johan de Wittlaan 7 Natuurwetenschappelijk Onderzoek TNO 2517 JR Den Haag (NL) 2628 VK Delft (NL) (54) MALDI matrix and MALDI method (57) The invention is directed to a matrix material for wherein X is chosen from S, O or N, and wherein R1 and MALDI mass spectrometry, to a matrix composition for R2 are independently chosen from hydrogen, methyl, MALDI mass spectrometry, in particular for aerosol MAL- methoxy, ethoxy, and propoxy, or wherein R1 and R2 are DI mass spectrometry, to a MALDI mass spectrometry taken together to form an optionally substituted aromatic method, in particular an aerosol MALDI mass spectrom- ring structure, optionally comprising one or more heter- etry method, to the use of a specific compound as a MAL- oatoms, DI matrix material, and to the use of a MALDI matrix com- or a tautomeric form thereof. position in a gas phase coating method.
    [Show full text]
  • Downloaded for Personal Use Only
    People,SYNFORM Trends and Views in Synthetic Organic Chemistry 2015/01 SynSTorIES Synthesis of (Carbo)nucleoside An Enolate-Mediated Organo ca - Analogues by [3+2] Annulation of tal ytic Azide–Aldehyde [3+2]-Cyclo - Aminocyclopropanes addition Reaction: General Method for the High-Yielding Regioselective Synthesis of 1,4-Disubstituted 1,2,3-Triazoles Young Career Focus: Dr. Birgit Esser (Rheinische Friedrich-Wilhelms- Universität Bonn, Germany) The Ketene-Surrogate Coupling: Catalytic Conversion of Aryl Iodides ConTACT is Synform into Aryl Ketenes through Ynol Your opinion about This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Ethers welcome, please correspond if you like: [email protected] Thieme Synform A2 Dear readers, In THIS ISSUE This Editorial marks a landmark change SynSTorIES for Synform: from now onwards all the articles will be individually pu - The Ketene-Surrogate Coupling: Catalytic blished in advance on the Synform Conversion of Aryl Iodides into Aryl Ketenes website (https://www.thieme.de/en/ through Ynol Ethers . A3 thieme-chemistry/journals-synform- 54850.htm) as soon as they become available, thus ensuring An Enolate-Mediated Organocatalytic Azide– a much quicker online publication of SynSTorIES covering Aldehyde [3+2]-Cycloaddition Reaction: current literature, Young Career Focus, and all the other General Method for the High-Yielding Regio - Synform articles. Publication of the monthly issues in pdf selective Synthesis of 1,4-Disubstituted 1,2,3- format, such as this one, will continue but Synform Triazoles . A6 becomes more dynamic and more in line with the way we are used to reading news and articles on the web nowadays.
    [Show full text]