DOCSLIB.ORG

Signature of Author

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Signature of Author NEW METHODS FOR THE FORMATION OF CARBON-CARBON BONDS VIA ORGANOMETALLIC COMPOUNDS by BRIAN SCOTT BRONK B.A. (High Honors), Colgate University (1989) SUBMITTED TO THE DEPARTMENT OF CHEMISTRY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 1995 © Massachusetts Institute of Technology, 1995 Signature of Author.. ........................................................... Department of Chemistry September 19, 1994 /' I . N 'N Certified by....................... ......... .. ........................................ Certifiedby Rick L. Danheiser Thesis Supervisor Certified by ......... ... ...................................... Stephen J. Lippard A Thesis Supervisor // . Accepted by.................. .................... /../.!.............................................. Dietmar Seyferth Departmental Committee on Graduate Studies I:;. .i., . : .1'_I_ , This doctoral thesis has been examined by a committee of the Department of Chemistry as follows: n An Professor Stephen L. Buchw ald ....... ............................. m L. BcChairman Professor Rick L. Danheiser . ................... Thesis Supervisor Professor Stephen J. Lippard ........... ........ .................... Thesis Supervisor Professor Dietmar Seyferth ............ .......... -.... 2 ACKNOWLEDGMENTS After writing a thesis totaling over 300 pages, the task of writing one final page would seem quite simple. Unfortunately, I am left with a single page to express my gratitude to :l who have made this journey successful. First, I must thank my entire family for their constant support and encouragement. I would also like to thank Professor John C. Cochran for introducing me to the joy of research. I will never know what caused him to see any potential in a freshman struggling to survive his Organic Chemistry class. He is a great mentor and friend. A great deal of credit for my professional development must go to both Rick L. Danheiser and Stephen J. Lippard. The opportunity they provided me for my graduate studies was truly unique and I have enjoyed it immensely. Although their styles of leading a research group are different, they share the quest for discovery and truth in science. Both are excellent teachers and researchers, and I have been very fortunate to have had the opportunity to work so closely with two excellent scientists. The members of both the Danheiser and Lippard groups were the people who had to put up with me on a daily basis, and for that I must thank you all. Brian Dixon was always willing to discuss the finer points of life, usually over a prudent choice of beer. In addition to being one of the brightest people I have known, it was always nice to know that he would be right there during any hockey altercations. Jennifer Dixon also deserves credit for putting up with me, as well as making sure I got at least one good meal every week. John Kane and I probably spent more time together than was healthy for either one of us, however, his camaraderie made life more enjoyable and was invaluable during the interview season. He was also the first person to point out that I resembled a traffic cone on the ice, although I must remind him that I did win the overall scoring title. John Protasiewicz was a wonderful mentor when I changed projects. His skills as a teacher are unquestionable and are only matched by his abilities as an angler. There is a group of people who are not only friends, but could also be counted on for an Outreach trip. Sandy Gould, a very bright and insightful chemist, was always good company on long trips, as was Kathy Lee -- her positive spirit always cheered me up. Annie Helgason was always entertaining, regardless of the setting. Certain people at MIT have always managed to bring a smile to my face, although with varying tactics. Joanne Yun was always willing to share a story with me to bring my spirits to a higher level, as well as introduce me to colors that I had never before seen. Steve Dunham and I shared more fishing stories than fishing trips, but it was still quite enjoyable. Rob Niger was always ready with an inappropriate comment, often at the expense of Jennifer Loebach or Anne Valentine, both of whom I enjoyed talking to when Niger was not present. I have left the hockey team to Michael Lawlor and I look forward to hearing about their success in the future, as well as his quest for that JJ look. Steve Tardivo was always willing to chat during those trips to the stockroom, as well as make sure that I always had a coffee mug from which to drink. Fari Firooznia and Alex Huboux, fellow classmates, were always around to discuss the impending hurdle that had been placed before us. Tricia Takahara and Andrew Feig helped make the transition downstairs that much easier, and Linda Doerrer was always there to keep things on a somewhat even keel. I have also had the opportunity to work with a variety of wonderful visiting scientists. Toshi Takahashi proved to be a hilarious baymate and the Japanese lessons provided by he and Kazu Takahashi will never be forgotten. More recently, I have had the opportunity to work with Tomoaki Tanase, who, along with Laura Pence and Steve Watton, has helped me through the crystallography experience. Finally, I must stress that because one is not mentioned does not mean one is forgotten. 3 To Karen, whose love, patience and understanding have guided me through 4 NEW METHODS FOR THE FORMATION OF CARBON-CARBON BONDS VIA ORGANOMETALLIC COMPOUNDS by Brian Scott Bronk Submitted to the Department of Chemistry on September 19, 1994 in partial fulfillment of the requirements for the Degree of Doctor of Philosophy ABSTRACT A novel strategy for achieving intramolecular conjugate addition reactions with nonstablized carbanion derivatives has been developed. This general strategy relies on the formation of an organozinc intermediate from the corresponding alkyl iodide and activated zinc metal, and can be employed in the synthesis of a variety of five and six-membered ring products. Mechanistic studies suggest that, at most, only a small fraction of the cyclization product can arise from a radical-mediated pathway. Finally, the addition of electrophilic reagents permits in situ synthetic elaboration of the product enolate. The reductive coupling reaction of two carbon monoxide ligands on a Group V metal center has been extended to include electrophilic reagents other than the commonly employed silyl reagents. The coupling reaction was found to be successful with a variety of carbon-based electrophiles from the intermediate carbyne, while direct coupling from the dicarbonyl precursor was successful with the tantalum complex and acetyl chloride. Mechanistic studies on the conversion of the carbyne to the coupled product have provided a new series of compounds that readily undergo the reductive coupling transformation. Methods to remove the newly formed ligand, both as an acetylene and an olefin, as well as employing the organic fragment in synthetic transformations, were explored. Thesis Supervisors: Rick L. Danheiser and Stephen J. Lippard Titles: Professor of Chemistry 5 TABLE OF CONTENTS Part I Intramolecular Conjugate Addition Reactions via Organozinc Compounds 8 Chapter 1 Introduction and Background 9 Chapter 2 Substrate Synthesis 22 Chapter 3 Intramolecular Conjugate Addition Reactions via Organozinc Compounds 34 Chapter 4 Studies on the Mechanism of the Zinc-Promoted Cyclization Reaction 47 Chapter 5 Intramolecular Conjugate Addition With Subsequent Enolate Elaboration 59 Chapter 6 Experimental Section 71 6 Part II Reductive Coupling of Carbon Monoxide on Group V Metal Centers 149 Chapter 1 Introduction and Background 150 Chapter 2 Studies on the Mechanism of Reductive Coupling 163 Chapter 3 Reductive Coupling Promoted by Carbon-Based Electrophiles 188 Chapter 4 Studies on the Synthetic Elaboration of the Group V Coupled Products 213 Chapter 5 Experimental Section 230 Appendix I Complete Tables of Bond Distances and Angles from X-Ray Crystallography Studies 295 7 Part I Intramolecular Conjugate Addition Reactions Via Organozinc Compounds 8 CHAPTER 1 Introduction and Background The conjugate addition reaction, defined as the addition of a nucleophile to a carbon-carbon ir-bond conjugated with an electron withdrawing group, has played an important role in the field of organic chemistry. In spite of the enormous utility of the conjugate addition reaction as a synthetic method, there remains one area in which the reaction is not very successful. Namely, a general method to effect the intramolecular conjugate addition of non-stabilized carbanions remains a difficult task, despite significant research in this area. The goal of this project, therefore, was to develop a system that would allow for the success of such a transformation with a wide variety of substrates. The original aim of this study was to explore the feasibility of tandem zinc oxidative addition and transmetalation as the basis of our proposed general strategy. In order to fully appreciate the genesis of our proposal, however, a brief review of the conjugate addition reaction, as well as the chemistry of organozinc compounds will be presented. The Michael Reaction The first examples of the conjugate addition reaction employed stabilized carbanions as the nucleophilic species, and included reactions such as the addition of diethyl sodiomalonate (1) to diethyl ethylidenemalonate (2), which was first reported in 1883 (eq 1).1 The reactions involving stabilized carbanions
Load more

Recommended publications
  • 239 Subpart K—Indirect Discharge Point Sources
    Environmental Protection Agency § 414.111 BAT effluent limita- streams contain significant amounts of tions and NSPS 1 the pollutants identified above. Any such streams designated as metal or Effluent characteristics Maximum Maximum for cyanide bearing must be treated inde- for any monthly one day average pendently of other metal or cyanide bearing waste streams unless the con- 1,1,1-Trichloroethane ........................ 59 22 1,1,2-Trichloroethane ........................ 127 32 trol authority determines that the Trichloroethylene ............................... 69 26 combination of such streams, prior to Vinyl Chloride .................................... 172 97 treatment, with the Appendix A waste 1 All units are micrograms per liter. streams will result in substantial re- 2 Total Zinc for Rayon Fiber Manufacture that uses the vis- cose process and Acrylic Fibers Manufacture that uses the duction of these pollutants. This deter- zinc chloride/solvent process is 6,796 μg/l and 3,325 μg/l for mination must be based upon a review maximum for any one day and maximum for monthly average, respectively. of relevant engineering, production, and sampling and analysis information. [52 FR 42568, Nov. 5, 1987, as amended at 58 1 FR 36893, July 9, 1993] PSES and PSNS Maximum Effluent characteristics Maximum for any Subpart K—Indirect Discharge for any monthly Point Sources one day average Acenaphthene ................................... 47 19 SOURCE: 58 FR 36893, July 9, 1993, unless Anthracene ........................................ 47 19 otherwise noted. Benzene ............................................ 134 57 Bis(2-ethylhexyl) phthalate ................ 258 95 Carbon Tetrachloride ......................... 380 142 § 414.110 Applicability; description of Chlorobenzene .................................. 380 142 the subcategory of indirect dis- Chloroethane ..................................... 295 110 charge point sources. Chloroform ........................................
    [Show full text]
  • EI-ICHI NEGISHI Herbert C
    MAGICAL POWER OF TRANSITION METALS: PAST, PRESENT, AND FUTURE Nobel Lecture, December 8, 2010 by EI-ICHI NEGISHI Herbert C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, U.S.A. Not long ago, the primary goal of the synthesis of complex natural products and related compounds of biological and medicinal interest was to be able to synthesize them, preferably before anyone else. While this still remains a very important goal, a number of today’s top-notch synthetic chemists must feel and even think that, given ample resources and time, they are capable of synthesizing virtually all natural products and many analogues thereof. Accepting this notion, what would then be the major goals of organic synthesis in the twenty-first century? One thing appears to be unmistakably certain. Namely, we will always need, perhaps increasingly so with time, the uniquely creative field of synthetic organic and organometallic chemistry to prepare both new and existing organic compounds for the benefit and well-being of mankind. It then seems reasonably clear that, in addition to the question of what compounds to synthesize, that of how best to synthesize them will become increasingly important. As some may have said, the primary goal would then shift from aiming to be the first to synthesize a given compound to seeking its ultimately satisfactory or “last synthesis”. If one carefully goes over various aspects of organic synthetic methodology, one would soon note how primitive and limited it had been until rather recently, or perhaps even today. For the sake of argument, we may propose here that the ultimate goal of organic synthesis is “to be able to synthesize any desired and fundamentally synthesizable organic compounds (a) in high yields, (b) efficiently (in as few steps as possible, for example), (c) selectively, preferably all in t98–99% selectivity, (d) economically, and (e) safely, abbreviated hereafter as the y(es)2 manner.” with or without catalyst R1M + R2X R1R2 + MX R1, R2: carbon groups.
    [Show full text]
  • Recent Progress in the Use of Pd-Catalyzed C-C Cross-Coupling Reactions in the Synthesis of Pharmaceutical Compounds
    http://dx.doi.org/10.5935/0103-5053.20140255 J. Braz. Chem. Soc., Vol. 25, No. 12, 2186-2214, 2014. Printed in Brazil - ©2014 Sociedade Brasileira de Química 0103 - 5053 $6.00+0.00 Review Recent Progress in the Use of Pd-Catalyzed C-C Cross-Coupling Reactions in the Synthesis of Pharmaceutical Compounds André F. P. Biajoli, Cristiane S. Schwalm, Jones Limberger, Thiago S. Claudino and Adriano L. Monteiro* Laboratory of Molecular Catalysis, Institute of Chemistry, UFRGS, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre-RS, Brazil A grande capacidade do paládio de formar ligações carbono-carbono entre substratos apropriadamente funcionalizados permitiu que os químicos orgânicos efetuassem transformações antes impossíveis ou alcançáveis somente através de rotas muito longas. Neste contexto, uma das mais elegantes e importantes aplicações das reações de acoplamento cruzado catalisadas por paládio é a síntese de compostos de interesse farmacêutico. A presente revisão tem por objetivo apresentar uma visão geral do uso de acoplamentos cruzados na síntese de componentes de medicamentos (ou de candidatos a medicamentos), independentemente da escala, compreendendo o período de 2011 até o final de julho de 2014. The impressive ability of palladium to assemble C-C bonds between appropriately functionalized substrates has allowed synthetic organic chemists to perform transformations that were previously impossible or only possible using multi-step approaches. In this context, one of the most important and elegant applications of the Pd-catalyzed C-C coupling reactions currently is the synthesis of pharmaceuticals. This review is intended to give a picture of the applications of Pd-catalyzed C-C cross-coupling reactions for the synthesis of drug components or drug candidates regardless of the scale from 2011 through to the end of July, 2014.
    [Show full text]
  • The 2010 Chemistry Nobel Prize: Pd(0)-Catalyzed Organic Synthesis
    GENERAL ARTICLE The 2010 Chemistry Nobel Prize: Pd(0)-Catalyzed Organic Synthesis Gopalpur Nagendrappa and Y C Sunil Kumar The 2010 Nobel Prize in Chemistry was awarded to three scientists, R F Heck, E-I Negishi and A Suzuki, for their work on “Palladium – Catalyzed Cross Couplings in Organic Syn- (left) G Nagendrappa thesis”. It pertains to research done over a period of four was a Professor of decades. The synthetic procedures embodied in their work Organic Chemistry at enable construction of C–C bond selectively between complex Bangalore University, molecules as in simple ones at desired positions without and Head of the Department of Medici- disturbing any functional groups at other parts of the reacting nal Chemistry, Sri molecules. The work finds wide applications in the synthesis Ramachandra (Medical) of pharmaceuticals, agricultural chemicals, and molecules for University, Chennai. electronics and other applications. It would not have been He is currently in Jain University, Bangalore. possible to synthesize some of the complex natural products or He continues to teach synthetic compounds without using these coupling reactions and do research. His in one or more steps. work is in the area of organosilicon chemis- Introduction try, synthetic and mechanistic organic In mythical stories and folk tales we come across characters that, chemistry, and clay- catalysed organic while uttering some manthras (words of charm), throw a pinch or reactions (Green fistful of a magic powder, and suddenly there appears the object Chemistry). or person they wished for or an event happens the way they want. (right) Sunil Kumar is A large number of movies have been made with such themes and a PhD from Mysore characters that would be depicted as ‘scientists’.
    [Show full text]
  • Zinc Chloride Catalyzed Multicomponent Synthesis of Pyrazolopyridocoumarin Scaffolds
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ePrints@Bangalore University J. Chem. Sci. (2019) 131:29 © Indian Academy of Sciences https://doi.org/10.1007/s12039-019-1610-0 REGULAR ARTICLE Zinc chloride catalyzed multicomponent synthesis of pyrazolopyridocoumarin scaffolds DEVADAS SHAMALAa, KALEGOWDA SHIVASHANKARa,∗ , CHANDRAb and MADEGOWDA MAHENDRAb aP. G. Department of Chemistry, Bangalore University, Central College Campus, Bangalore, Karnataka 560 001, India bDepartment of Studies In Physics, Manasagangotri, University of Mysore, Mysore, Karnataka 570 006, India E-mail: [email protected] MS received 4 October 2018; revised 20 February 2019; accepted 27 February 2019; published online 22 March 2019 Abstract. An efficient synthesis of a series of pyrazolopyridocoumarins is reported by condensation of 4- hydroxycoumarin, benzaldehydes and 1-alkyl-5-amino-pyrazoles in the presence of 10 mol% zinc chloride in ethanol under reflux conditions through one-pot reaction. The significant attraction of this protocol is being a simple procedure, mild reaction condition, and excellent yield. The molecular structure of the compound (4e) is established by single crystal X-ray structure determination. Keywords. Coumarins; pyridine; pyrazole; zinc chloride; multicomponent reactions; one-pot synthesis. 1. Introduction have been developed for the preparation of pyra- zolopyridocoumarin derivatives with the use of various Multicomponent reactions (MCRs) efficiently combine catalysts such as n-tetrabutylammonium tribromide, 28 29 30 three or more reactants simultaneously in one pot that do Zn(OTf)2, glacial acetic acid, piperidine in acetic not need the isolation, purification and characterization acid, 31 and iodine. 19,32 However, these methodologies of intermediate products.
    [Show full text]
  • MICROREVIEW Reactivity of Polar Organometallic Compounds In
    MICROREVIEW Reactivity of Polar Organometallic Compounds in Unconventional Reaction Media: Challenges and Opportunities Joaquin García-Álvarez,*[a] Eva Hevia,*[b] and Vito Capriati*[c] This paper is gratefully dedicated to the memory of Dr. Guy Lavigne Abstract: Developing new green solvents in designing chemical chemicals in chemical transformations is, indeed, solvents used products and processes or successfully employing the already as reaction media, which account for 80–90% of mass utilization existing ones is one of the key subjects in Green Chemistry and is in a typical pharmaceutical/fine chemical operational process. especially important in Organometallic Chemistry, which is an Thus, the solvent itself is often a critical parameter especially in interdisciplinary field. Can we advantageously use unconventional drug product manufacturing and is as well responsible for most reaction media in place of current harsh organic solvents also for waste generated in the chemical industries and laboratories.[3] polar organometallic compounds? This Microreview critically Following these considerations, some of the most critical analyses the state-of-the-art on this topic and showcases recent and intriguing questions that arise are: Can we get traditional developments and breakthroughs which are becoming new research organic solvents out of organometallic reactions?[4] Can we use directions in this field. Because metals cover a vast swath of the protic, recyclable, biodegradable, and cheap unconventional periodic table, the content is organised into three Sections solvents also for highly reactive organometallic compounds? discussing the reactivity of organometallic compounds of s-, p- and Answering these questions would not only mean to break new d-block elements in unconventional solvents.
    [Show full text]
  • A Novel Strategy for the Manufacture of Idelalisib: Controlling the Formation
    RSC Advances View Article Online PAPER View Journal | View Issue A novel strategy for the manufacture of idelalisib: controlling the formation of an enantiomer† Cite this: RSC Adv.,2018,8, 15863 Nagaraju Mekala,ab Srinivasa Rao Buddepu,ab Sanjay K. Dehury,a Krishna Murthy V. R. Moturu, *a Sunil Kumar V. Indukuri,a Umamaheswara Rao Vasireddia and Atchuta R. Parimib A novel and scalable synthesis of 5-fluoro-3-phenyl-2-[(1S)-1-(9H-purin-6-ylamino)propyl]-4(3H)- Received 15th January 2018 quinazolinone, idelalisib 1, has been developed. This strategy controls the desfluoro impurity of 13 during Accepted 13th April 2018 reduction of nitro intermediate 4, and also arrests the formation of the enantiomer during cyclisation of DOI: 10.1039/c8ra00407b diamide 17, without affecting the neighbouring chiral centre. This process is demonstrated on a larger rsc.li/rsc-advances scale in the laboratory and achieved good chemical and chiral purities coupled with good yields. Introduction have received at least one prior therapy and as rst line treat- Creative Commons Attribution 3.0 Unported Licence. ment in the presence of 17p depletion. Quinazolinones are fused heterocyclic alkaloids and have As part of our research programme on the development of attracted many scientists working in organic and medicinal a series of anticancer drugs, herein we disclose a novel strategy chemistry due to their substantial and extensive range of ther- for the synthesis of idelalisib, 1. Our approach has resulted not apeutic activities. The remarkable therapeutic activities1 such as only in achieving almost total control of undesired enantiomer antiinammatory, anticonvulsant, antidiabetic, anticancer, of 1, but also enhanced the yields tremendously during the antitussive, antibacterial, analgesic, hypnotic, and sedative cyclisation step when compared to known related reports in the 5–7 activities coupled with exotic structural features have impelled literature.
    [Show full text]
  • Right to Know
    Right to Know Hazardous Substance Fact Sheet Common Name: ZINC CHLORIDE Synonyms: Butter of Zinc; Tinning Flux; Zinc Dichloride CAS Number: 7646-85-7 Chemical Name: Zinc Chloride (ZnCl2) RTK Substance Number: 2030 Date: December 2000 Revision: January 2010 DOT Number: UN 2331 Description and Use EMERGENCY RESPONDERS >>>> SEE LAST PAGE Zinc Chloride is an odorless, white, crystalline (sand-like) Hazard Summary granule or powder. It is used in soldering flux and iron Hazard Rating NJDOH NFPA galvanizing, as a screening smoke for crowd control and wood HEALTH 3 - preservative, and in making agricultural chemicals, FLAMMABILITY 0 - pharmaceuticals, and textiles. REACTIVITY 0 - CORROSIVE POISONOUS GASES ARE PRODUCED IN FIRE Reasons for Citation f Zinc Chloride is on the Right to Know Hazardous Substance List because it is cited by OSHA, ACGIH, DOT, Hazard Rating Key: 0=minimal; 1=slight; 2=moderate; 3=serious; 4=severe NIOSH, IRIS and EPA. f This chemical is on the Special Health Hazard Substance f Zinc Chloride can affect you when inhaled. List. f Zinc Chloride is a CORROSIVE CHEMICAL and contact can severely irritate and burn the skin and eyes with possible eye damage. f Exposure to Zinc Chloride can irritate the nose and throat. f Inhaling Zinc Chloride can irritate the lungs causing SEE GLOSSARY ON PAGE 5. coughing and/or shortness of breath. Higher exposures may cause a build-up of fluid in the lungs (pulmonary edema), a FIRST AID medical emergency, with severe shortness of breath. f Zinc Chloride can cause nausea, vomiting, diarrhea and Eye Contact abdominal pain. f Immediately flush with large amounts of water for at least 30 minutes, lifting upper and lower lids.
    [Show full text]
  • New Preparations and Reactions of Salt Stabilized Organozinc Reagents For
    Dissertation zur Erlangung des Doktorgrades der Fakultät für Chemie und Pharmazie der Ludwig-Maximilians-Universität München NEW PREPARATIONS AND REACTIONS OF SALT STABILIZED ORGANOZINC REAGENTS FOR THE FUNCTIONALIZATION OF AROMATICS, HETEROAROMATICS, AND ALLYLIC COMPOUNDS von Mario Ferdinand Ellwart aus München 2016 ERKLÄRUNG Diese Dissertation wurde im Sinne von § 7 der Promotionsordnung vom 28. November 2011 von Herrn Prof. Dr. Paul Knochel betreut. EIDESSTATTLICHE VERSICHERUNG Diese Dissertation wurde eigenständig und ohne unerlaubte Hilfe erarbeitet. München, ………………………. ………….……………………………… (Mario F. Ellwart) Dissertation eingereicht am: 07.10.2016 1. Gutachter: Prof. Dr. Paul Knochel 2. Gutachter: Prof. Dr. Oliver Trapp Mündliche Prüfung am: 06.12.2016 This work was carried out from January 2014 to October 2016 under the guidance of Prof. Dr. Paul Knochel at the Department of Chemistry of the Ludwig-Maximilians-Universität, Munich. Firstly, I would like to express my appreciation to Prof. Dr. Paul Knochel for giving me the great opportunity to do my Ph.D. in his group and for his guidance in the course of my scientific research. I am also very grateful to Prof. Dr. Oliver Trapp for agreeing to be the second reviewer of this thesis, as well as Prof. Dr. Manfred Heuschmann, Prof. Dr. Klaus T. Wanner, Prof. Dr. Konstantin Karaghiosoff, and Prof. Dr. Regina de Vivie-Riedle for their interest shown in this manuscript by accepting to be referees. I also would like to thank Michael Eisold, Marthe Ketels, Meike Simon, and Dr. Benedikt S. Soller for the careful correction of this manuscript. I thank all past and present co-workers I have met in the Knochel group for their kindness and their help.
    [Show full text]
  • Growth and Characterization of a New Non-Linear Optical Crystal: Urea Thiourea Zinc Chloride
    Asian Journal of Chemistry Vol. 20, No. 7 (2008), 5067-5070 Growth and Characterization of a New Non-Linear Optical Crystal: Urea Thiourea Zinc Chloride G. MADHURAMBAL† and M. MARIAPPAN* Department of Chemistry, R.V.S. College and Technology Kallikuppam, Thiruvettakudi Post, Karaikal-609 609, India E-mail: [email protected]; [email protected] Urea thiourea zinc chloride (UTZC) a new semi-organic non-linear optical material has been synthesized. Single crystals of UTZC have been grown by slow evaporation of saturated aqueous solution at room temperature. The spectral bands have been compared with urea, thiourea, bis thiourea zinc chloride (BTZC). Key Words: Urea thiourea zinc chloride crystals, Non- linear optical material. INTRODUCTION Non-linear optics playing a vital role in the emerging photoelectronic technologies. New non-linear optical (NLO) frequency conversion materials have a significant impact on laser technology, optical communication and optical data storage. The search for new and efficient NLO materials has resulted in the development of a new class of materials called semi-organics. These materials have the potential for combining the high optical non- linearity and chemical flexibility of organic materials with the thermal stability and mechanical robustness of inorganic NLO materials1. Thiourea possess a large dipole moment and it forms a number of co-ordination compounds like bis thiourea cadmium chloride (BTCC)2 and tris thiourea zinc sulphate (ZTS)3, antimony thiourea bromide monohydrate (ATBM)4 which are potential materials for frequency doubling of the near IR laser radiation. Single crystals of these materials have very high laser damage threshold5. In general crystals of the type M[tu]2X2, where M = Cd, Co, Hg, Pb, Ti, Zn; tu = thiourea and X = halogen, have been found to exhibit good NLO proper- ties6.
    [Show full text]
  • SAFETY DATA SHEET 113690-Zinc Chloride
    SAFETY DATA SHEET (in accordance with Regulation (EU) 2015/830) 113690-Zinc chloride Version: 2 Page 1 of 9 Revision date: 20/04/2016 Print date: 20/04/2016 SECTION 1: IDENTIFICATION OF THE SUBSTANCE AND OF THE COMPANY/UNDERTAKING. 1.1 Product identifier. Product Name: Zinc chloride Product Code: 113690 Chemical Name: Zinc chloride Index No: 030-003-00-2 CAS No: 7646-85-7 EC No: 231-592-0 Registration No: 01-2119472431-44-XXXX 1.2 Relevant identified uses of the substance and uses advised against. For manufacturing, processing, laboratory or repacking use only Uses advised against: Uses other than those recommended. 1.3 Details of the supplier of the safety data sheet. Company: DC FINE CHEMICALS Ltd. Address: Hill Top, 88 City: NW11 6DY London (United Kingdom) Telephone: +44 (20) 7586 6800 Fax: +44 (20) 7504 1701 E-mail: [email protected] Web: www.dcfinechemicals.com 1.4 Emergency telephone number: (Only available during office hours) SECTION 2: HAZARDS IDENTIFICATION. 2.1 Classification of the substance. In accordance with Regulation (EU) No 1272/2008: Acute Tox. 4 : Harmful if swallowed. Aquatic Chronic 1 : Very toxic to aquatic life with long lasting effects. Skin Corr. 1B : Causes severe skin burns and eye damage. 2.2 Label elements. Labelling in accordance with Regulation (EU) No 1272/2008: Pictograms: -Continued on next page.- SAFETY DATA SHEET (in accordance with Regulation (EU) 2015/830) 113690-Zinc chloride Version: 2 Page 2 of 9 Revision date: 20/04/2016 Print date: 20/04/2016 P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing.
    [Show full text]
  • Pyridines Using Catalytic Zinc Chloride Amanda L
    Tetrahedron Letters 48 (2007) 4079–4082 Multicomponent synthesis of imidazo[1,2-a]pyridines using catalytic zinc chloride Amanda L. Rousseau,* Pulane Matlaba and Christopher J. Parkinson Discovery Chemistry, Biosciences, CSIR, Private Bag X2, Modderfontein 1645, South Africa Received 1 March 2007; revised 26 March 2007; accepted 4 April 2007 Available online 11 April 2007 Abstract—The novel use of zinc chloride to catalyze the one-pot, three component synthesis of imidazo[1,2-a]pyridines from a range of substrates using either conventional heating or microwave irradiation is described. This methodology affords a number of imidazo[1,2-a]pyridines in reasonable yields and short reaction times without any significant optimization of the reaction conditions. Ó 2007 Elsevier Ltd. All rights reserved. Imidazo[1,2-a]pyridines 1 and the related imidazo[1,2-a]- approach involves the coupling of 2-aminopyridines pyrimidines 2 (Fig. 1) have received significant atten- with a-halocarbonyl compounds.1 However, this tion from the pharmaceutical industry owing to their approach does not readily lend itself to a diversity interesting biological activities displayed over a broad oriented synthesis. range of therapeutic classes,1 exhibiting antibacterial,2 antifungal,3 antiviral,4 and anti-inflammatory5 proper- A more versatile approach uses a three component ties. They have also been shown to be selective cyclin coupling (3CC) involving the condensation of alde- dependant kinase inhibitors,6 GABA,7 and benzodiaze- hydes, 2-aminopyridine, and isocyanides (Scheme 1).10 8 pine receptor agonists, and bradykinin B2 receptor This robust approach allows for the preparation of a antagonists.9 Drug formulations containing imid- diverse range of products and suited our requirements azo[1,2-a]pyridines currently available on the market in the continuation of a synthetic program aimed at include alpidem 3 (anxiolytic), zolpidem 4 (hypnotic), kinase inhibitors.
    [Show full text]