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Pyrylium Salt Chemistry Emerging As a Powerful Approach for the Cite This: Chem
Chemical Science View Article Online PERSPECTIVE View Journal | View Issue Over one century after discovery: pyrylium salt chemistry emerging as a powerful approach for the Cite this: Chem. Sci., 2020, 11, 12249 All publication charges for this article construction of complex macrocycles and metallo- have been paid for by the Royal Society of Chemistry supramolecules Yiming Li, ab Heng Wanga and Xiaopeng Li *a Over one century after its discovery, pyrylium salt chemistry has been extensively applied in preparing light emitters, photocatalysts, and sensitizers. In most of these studies, pyrylium salts acted as versatile precursors for the preparation of small molecules (such as furan, pyridines, phosphines, pyridinium salts, thiopyryliums and betaine dyes) and poly(pyridinium salt)s. In recent decades, pyrylium salt chemistry has emerged as a powerful approach for constructing complex macrocycles and metallo-supramolecules. In this perspective, we attempt to summarize the representative efforts of synthesizing and self-assembling Received 20th August 2020 large, complex architectures using pyrylium salt chemistry. We believe that this perspective not only Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Accepted 13th October 2020 highlights the recent achievements in pyrylium salt chemistry, but also inspires us to revisit this chemistry DOI: 10.1039/d0sc04585c to design and construct macrocycles and metallo-supramolecules with increasing complexity and rsc.li/chemical-science desired function. 1. Introduction pyrylium salt with perchlorate as the counterion was reported in 1911 by Baeyer;7 however, since the discovery of pyrylium salts, Pyrylium salts are a type of six-membered cationic heterocycles such salts have been underappreciated for about a half-century. -
Rodd's Chemistry of Carbon Compound S
RODD'S CHEMISTRY OF CARBON COMPOUND S A modern comprehensive treatis e SECOND EDITIO N Edited by S . COFFE Y M.Sc. (London), D.Sc. (Leyden), F .R.I.C. formerly of I.C.I. Dyestuffs Division, Blackley, Manchester VOLUME II PART C POLYCARBOCYCLIC COMPOUNDS , EXCLUDING STEROIDS PREFACE VII OFFICIAL PUBLICATIONS ; SCIENTIFIC JOURNALS AND PERIODICALS X V LIST OF COMMON ABBREVIATIONS AND SYMBOLS USED XV I Chapter 9. Polycarbocyclic Compounds with Separate Ring Systems , and Spiro Compounds N. A . J . RoGERs 1. General introduction to polycarbocyclic compounds ; classification and nomenclature a. Classification I b. Nomenclature 2 (i) Ring-systems joined directly or through a carbon chain, 3 - (ii) Spir o compounds, 3 - (iii) Fused and bridged ring-systems, 4 2 . Compounds with rings joined directly or through a carbon chain 5 a. General methods of synthesis 6 b. Polycyclopropyl compounds 6 c. Polycyclobutyl compounds 9 d. Polycyclopentyl compounds 9 e. Cyclopropylcyclopentane compounds 1 3 f. Cyclopropylcyclohexane compounds 1 3 g. Cyclobutylcyclohexane compounds 13 h. Cyclopentylcyclohexane compounds 14 i. Polycyclohexyl compounds 1 4 (i) Hydrocarbons, r4 - (ii) Hydroxy and amino derivatives, 15 - (iii) Ketones, 16 - (iv) Carboxylic acids, I q j. Cyclopentylcycloheptane compounds 1 7 k. Cyclohexylcycloheptane compounds 1 8 1. Bicycloheptyl and its derivatives 1 8 m . Bicyclo-octyl and related compounds 1 8 3. Spiro compounds ; spiranes 20 a. The spiro[z .z]pentane group 2 1 b. The spiro[2 .3]hexane group 22 c. The spiro[z .4]heptane group 23 d. The spiro[2 .5]octane group 24 e. The spiro[2,6]nonane group 2 5 f. -
Direct, Catalytic, Intermolecular Anti
DIRECT, CATALYTIC, INTERMOLECULAR ANTI-MARKOVNIKOV HYDROACETOXYLATIONS OF ALKENES ENABLED VIA PHOTOREDOX CATALYSIS, AND INVESTIGATIONS INTO THE MECHANISM OF THE POLYMERIZATION OF 4-METHOXYSTYRENE INITIATED BY PYRYLIUM SALTS Andrew Perkowski A dissertation submitted to the faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry. Chapel Hill 2014 Approved by: David A Nicewicz Erik Alexanian Marcey Waters Maurice Brookhart Joseph Templeton © 2014 Andrew Perkowski ALL RIGHTS RESERVED ii ABSTRACT Andrew Perkowski: Direct, Catalytic, Intermolecular Anti-Markovnikov Hydroacetoxylations of Alkenes Enabled via Photoredox Catalysis, and Investigations into the Mechanism of the Polymerization of 4-Methoxystyrene Initiated by Pyrylium Salts (Under the Direction of David A. Nicewicz) I. Intermolecular Anti-Markovnikov Addition of Oxygen Nucleophiles to Alkenes: Direct and Indirect Catalytic Methods to Address a Fundamental Challenge Markovnikov versus anti-Markovnikov functionalization of alkenes is discussed, as well as the inherent challenge in overcoming Markovnikov selectivity. Stoichiometric and catalytic methods for anti-Markovnikov functionalization are discussed and appraised. II. Anti-Markovnikov Addition of Oxygen Nucleophiles to Alkene Cation Radical Intermediates The formation of alkene cation radicals is disccused, as well as examples of anti- Markovnikov nucleophilic addition to alkene cation radicals. III. The Direct Anti-Markovnikov -
ABSTRACT Synthesis of New Chiral Pyrylium Salts, the Corresponding
ABSTRACT Synthesis of New Chiral Pyrylium Salts, the Corresponding Phosphinine and Pyridine Derivatives and the Kinetic Studies of the Epimerization of Pyrylium Salts Nelson A. van der Velde, Ph.D. Mentor: Charles M. Garner, Ph.D. Despite the versatility of pyrylium salts as precursors to many heteroaromatic systems, chiral pyrylium salts are almost unknown in the literature. One reason for this scarcity is that pyrylium salts are often involved as intermediates rather than as isolated and characterized materials. Another is that many pyrylium salts preparations tend to result in non-characterizable black solid due to polymerization reactions. We have developed the synthesis of several new chiral pyrylium salts and their conversion to the corresponding pyridines and phosphinines. This work almost triples the number of reported chiral pyrylium salts, and also represents the first racemizable/epimerizable pyrylium salts. The derived phosphinines and pyridines represent rare alpha-chiral ligands for transition metals. Interestingly, only a few examples of chiral phosphinines have been reported in the literature. Incorporation of chirality directly (i.e., alpha to aromatic ring) onto these planar ring systems has proven to be difficult. From our pyrylium salts we have synthesized new phosphinines with the chirality as close as possible to the phosphorus center. Two known pyridinium salts were also prepared with the thiosemicarbazone moiety. The cytotoxicity and inhibition of cruzain were evaluated and found to be non-actives. Our interest in chiral pyrylium salts led us to investigate the configurational stability of chiral centers alpha to the pyrylium ring. Although no epimerizable (or even racemizable) pyrylium salts have been reported, deuterium exchange at ortho and especially para benzylic positions is well-known, suggesting that epimerization is possible. -
By M. TICHY Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, Prague (Received October 10, 1975)
CHEMISTRY OF TWISTANE SYSTEM AND ITS USE IN STEREOCHEMISTRY* By M. TICHY Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, Prague (Received October 10, 1975) The aim of the present review is to show the chemistry of twistane system and the various ways in which it can be used as a stereochemical model of great utility. Many of the stereochemical appli- cations mentioned are the result of investigations made in the author's Laboratory. Twistane — tricyclo(4,4,0,03,8)decane (I) — belongs to the great family of adamantane isomers** of the formula C10H16. It is composed solely of six-membered rings, twisted in the same sense. The parent hydrocarbon has three two-fold rota- tional axes of symmetry (D2) and exists in two enantiomeric forms which differ in the sense of twist: according to the CAHN—INGOLD—PRELOG nomenclature [11] the enantiomer (la) has P-helicity whereas the other (lb) M-helicity. la lb • * This review is based on a lecture presented at A. Jôzsef University, Szeged, and on the review in Chem. Listy 69, 45 (1975). »* For reviews on adamantane chemistry see [1—3], adamantane isomers other than twistane are studied e.g. in ref. [4—10]. 158 M. TICHY There are three groups of sterically analogous carbon atoms in this system: carbons 1,3,6,8, carbons 4,5,9,10 and carbons 2 and 7. Whereas the two bonds at C(2) and C(7) in the parent hydrocarbon are sterically equivalent, the bonds in positions 4,5,9 and 10 are non-equivalent and therefore substitution in these positions affords two diastereoisomeric (monosubstituted) derivatives (Formulae A and B). -
Dulaneyspr15.Pdf (409.1Kb)
Adventures in Organophosphorus Chemistry James W. Dulaney, III (Faculty Mentor: David E. Lewis) Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, WI 54702-4004 Background Challenges with the Mitsunobu reaction What is required in a replacement to make the reaction Azodicarboxylates, an important component of the re- “green”? Organophosphorus compounds have been an increasingly important part of organic synthesis since the discovery action, are very hazardous: of the Arbuzov rearrangement in 1905. In the century that followed this discovery, the applications of phosphorus- O Green? based reagents in synthesis has grown to incorporate the Wittig and Horner-Wadsworth-Emmons reactions for OEt • They are highly explosive (especially diethyl azodi- N alkene formation, as well as the Mitsunobu inversion reaction, which is used to convert alcohols to a wide range carboxylate). N Green reactions are run under more environmentally sustainable conditions with a view to of products with inversion of configuration. O minimizing environmental impact: • They are highly toxic (especially diethyl azodicar- OEt boxylate). diethyl azodicarboxylate • They are highly regulated. (DEAD) • Wherever possible, renewable sources are used • Wherever possible, hazardous materials are eliminated completely or replaced by The Wittig reaction Ph Ph Ph BuLi Ph less hazardous materials P R P R Regulations have been put into place by the DOT that O Ph Ph O-i-Pr • Wherever possibler, catalytic reactions are used Reaction between an ylide and an aldehyde or ketone to give an alkene. make azodicarboxylic esters even more difficult to ob- N • Hazardous waste is minimized wherever possible (e.g. organic solvents can be re- Reaction gives mainly the Z isomer with aldehydes O tain and use. -
Catalytic Synthesis of 1,3,5-Triphenylbenzenes, Β
J. Mex. Chem. Soc. 2006, 50(3), 114-118 Article © 2006, Sociedad Química de México ISSN 1870-249X Catalytic Synthesis of 1,3,5-Triphenylbenzenes, β-Methylchalcones and 2,4,6-Triphenyl Pyrylium Salts, Promoted by a Super Acid Triflouromethane Sulfonic Clay from Acetophenones Rosario Ruíz-Guerrero,1 Jorge Cárdenas,1 Lorena Bautista,1 Marina Vargas,1,3 Eloy Vázquez-Labastida2 and Manuel Salmón*1 1 Instituto de Química de la Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán 04510, México D. F. [email protected] 2 Escuela Superior de Ingeniería Química e Industrias Extractivas del Instituto Politécnico Nacional, Edificio 7, Unidad Profesional, Zacatenco, Col. La Escalera, México 07038, D. F. 3 Departamento de Química, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Estado de México, México 54740. Dedicated to Professor Pedro Joseph-Nathan on the occasion of his 65th birthday. Recibido el 9 de marzo del 2006; aceptado el 31 de mayo del 2006 Abstract. A montmorillonite clay from the State of Durango, Resumen. Una arcilla de montmorilonita del estado de Durango se Mexico, was used as catalyst. The clay was activated with trifluo- empleó como catalizador. La arcilla fue activada con ácido trifluoro- romethane sulfonic acid and used to study the condensation of differ- metansulfónico y usada para estudiar la condensación de diferentes ent acetophenones in refluxing benzene to produce triphenylben- acetofenonas en benceno a reflujo para producir trifenilbencenos, β- zenes, β-methylchalcones and pyrylium salts. This catalytic proce- metilchalconas y sales de pirilio. Este proceso catalítico produjo un dure afforded a new simple one-step method for the synthesis of com- nuevo método en una sola etapa para la síntesis de moléculas comple- plex organic molecules through the C-C bonds formation and the jas a través de la formación de enlaces C-C con el contraión del ácido counter ion for the pyrylium salt. -
Working with Hazardous Chemicals
A Publication of Reliable Methods for the Preparation of Organic Compounds Working with Hazardous Chemicals The procedures in Organic Syntheses are intended for use only by persons with proper training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011; the full text can be accessed free of charge at http://www.nap.edu/catalog.php?record_id=12654). All chemical waste should be disposed of in accordance with local regulations. For general guidelines for the management of chemical waste, see Chapter 8 of Prudent Practices. In some articles in Organic Syntheses, chemical-specific hazards are highlighted in red “Caution Notes” within a procedure. It is important to recognize that the absence of a caution note does not imply that no significant hazards are associated with the chemicals involved in that procedure. Prior to performing a reaction, a thorough risk assessment should be carried out that includes a review of the potential hazards associated with each chemical and experimental operation on the scale that is planned for the procedure. Guidelines for carrying out a risk assessment and for analyzing the hazards associated with chemicals can be found in Chapter 4 of Prudent Practices. The procedures described in Organic Syntheses are provided as published and are conducted at one's own risk. Organic Syntheses, Inc., its Editors, and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein. -
Boronic Acids
Boronic Acids Boronic Acids www.alfa.com INCLUDING: • Boronic Esters • Oxazaborolidine Reagents • Coupling and Hydroboration Catalysts • Phosphine Ligands • Borylation Reagents www.alfa.com Where Science Meets Service Quality Boronic Acids from Alfa Aesar Alfa Aesar is known worldwide for a variety of chemical compounds used in research and development. Recognized for purity and quality, our products and brands are backed by technical and sales teams dedicated to providing you the best service possible. In this catalog, you will find details on our line of boronic acids, esters and related compounds, which are manufactured to the same exacting standards as our full offering of over 33,000 products. Also included in this catalog is a 28-page introduction to boronic acids, their properties and applications. This catalog contains only a selection of our wide range of chemicals and materials. Also included is a selection of novel coupling catalysts and ligands. Many more products, including high purity metals, analytical products, and labware are available in our main catalog or online at www.alfa.com. Table of Contents About Us _____________________________________________________________________________ II How to Order/General Information ____________________________________________________ III Introduction __________________________________________________________________________ 1 Alkenylboronic acids and esters _____________________________________________________ 29 Alkylboronic acids and esters ________________________________________________________ -
Organic Synthesis Using Carbon Dioxide As Phosgene-Free Carbonyl Reagent*
Pure Appl. Chem., Vol. 84, No. 3, pp. 581–602, 2012. http://dx.doi.org/10.1351/PAC-CON-11-05-04 © 2011 IUPAC, Publication date (Web): 1 September 2011 Organic synthesis using carbon dioxide as phosgene-free carbonyl reagent* An-Hua Liu, Yu-Nong Li, and Liang-Nian He‡ State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China Abstract:CO2 is very attractive as a typical renewable feedstock for manufacturing com- modity chemicals, fuel, and materials since it is an abundant, nontoxic, nonflammable, and easily available C1 resource. The development of greener chemical methodologies for replac- ing the utility of hazardous and environmentally undesirable phosgene largely relies on ingenious activation and incorporation of CO2 into valuable compounds, which is of para- mount importance from a standpoint of green chemistry and sustainable development. Great efforts have been devoted to constructing C–C, C–O, and C–N bond on the basis of CO2 acti- vation through molecular catalysis owing to its kinetic and thermodynamic stability. The aim of this article is to demonstrate the versatile use of CO2 in organic synthesis as the alterna- tive carbonyl source of phosgene, with the main focus on utilization of CO2 as phosgene replacement for the synthesis of value-added compounds such as cyclic carbonates, oxa - zolidinones, ureas, isocyanates, and polymers, affording greener pathways for future chemi- cal processes. Keywords: atom economy; aziridines; carbon dioxide; carbonylation; catalysis; green chemistry; ionic liquids; organic carbonate; phosgene-free process; urea. INTRODUCTION CO2 as an abundant, nontoxic, easily available, and typical renewable C1 source as well as an impor- tant “greenhouse” gas has been drawing more and more attention in line with the need for development of green chemistry and a sustainable society. -
Diethyl Azodicarboxylate, Conventionally Abbreviated As DEAD and Sometimes As DEADCAT, Is an Organic Compound with the Structural Formula
DBU • 1,5-Diazabicyclo[5.4.0]undec-7-ene, or more commonly DBU, is a chemical compound and belongs to the class of amidine compounds. • It is used in organic synthesis as a catalyst, a complexing ligand, and a non-nucleophilic base. • . It is also used as a curing agent for epoxy. • It is used in fullerene purification with trimethylbenzene (it reacts with C 70 and higher fullerenes, but not to C 60 fullerenes) • It is also used as a catalyst in polyurethane production. • It has a strong catalyst effect for the reactions of alicyclic and aliphatic isocyanates. • It also exhibited its dual character (base and nucleophile) in the synthesis of aryl- and styryl-terminal acetylenes. DEAD • Diethyl azodicarboxylate, conventionally abbreviated as DEAD and sometimes as DEADCAT, is an organic compound with the structural formula CH3CH2O2CN=NCO2CH2CH3. Its molecular structure consists of a central azo functional group, RN=NR, flanked by two ethyl ester groups. • It is an oxidising agent • This orange-red liquid is a valuable reagent but also quite dangerous and explodes upon heating. • Therefore, commercial shipment of pure diethyl azodicarboxylate is prohibited in the United States and is carried out either in solution or on polystyrene particles. • DEAD is an aza-dienophile and an efficient dehydrogenating agent, converting alcohols to aldehydes, thiols to disulfides and hydrazo groups to azo groups; it is also a good electron acceptor. • DEAD dissolves in most common organic solvents, such as toluene, chloroform, ethanol, tetrahydrofuran and dichloromethane but has low solubility in water or carbon tetrachloride; the solubility in water is higher for the related azo compound dimethyl azodicarboxylate. -
Dimethyldioxirane in TCF Bleaching Sequences
Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 4-1999 Dimethyldioxirane in TCF Bleaching Sequences Nayereh Mahdavi Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Wood Science and Pulp, Paper Technology Commons Recommended Citation Mahdavi, Nayereh, "Dimethyldioxirane in TCF Bleaching Sequences" (1999). Master's Theses. 4934. https://scholarworks.wmich.edu/masters_theses/4934 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. DIMETHYLDIOXIRANE IN TCF BLEACHING SEQUENCES by Nayereh Mahdavi A Thesis Submitted to the Faculty of The Graduate College in partial fulfilmentof the requirements forthe Degree of Master of Science Department of Paper and Printing Science and Engineering Western Michigan University Kalamazoo, Michigan April 1999 Copyright by Nayereh Mahdavi 1999 ACKNOWLEDGEMENTS I thank gratefullyDr. Raja Aravamuthan, my advisor and committee chairperson, forhis valuable guidance, and his continuous support, encouragement, and advice. I also wish to thank my committee member Dr. Peterson. I thank the NCASI and pilot plant fortheir assistance and forthe privilege of using their resources. I also wish to thank the Consolidated Paper Company forproviding the pulp formy research. My familyand friends have been my best support. I am deeply gratefulto each of them, especially to Mehdi, Lori, and Barbara. I would like to dedicate my thesis to my late mother for her loving, sensitive support, and continuing involvement in my lifeand education.