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Brittain-DR-1965-Phd-Thesis.Pdf
POLYMETHYLENE PYRIDINES , A thesis submitted by David Robert Brittain in partial fulfilment of the requirements for the degree of DOCTOR OP PHILOSOPHY in the University of London Organic Chemistry Department, dune, 1965. Imperial College, LONDON, S.W.7. ABSTRACT This thesis describes a series of attempts to syn- thesise 2,5- and 1,4-polymethylene bridged pyridines. Nuclear magnetic resonance theory predicts that protons, which are held directly over an aromatic ring, will be abnormally shielded compared with protons in aliphatic straight-chain hydrocarbons. This prediction has been verified for the central methylene protons of paracyclo- phanes. The degree of shielding, expressed in terms of the distance from the aromatic ring, is a measure of the induced ring current and hence the aromaticity of the benzene ring. Similar measurements upon 2,5- or 1,4— polymethylene bridged pyridines would make it possible to determine the degree of aromaticity of the pyridine ring relative to benzene. A review of the subject of aromaticity is presented in which special reference has been made to its inter- pretation by nuclear magnetic resonance. The synthetic work has not been brougL.t to a truly satisfactory conclusion. However, the synthetic routes to 2,5-dialkylpyridines have been thoroughly investigated and a wide variety of such compounds prepared. The functional groups at the ends of the alkyl chains have been varied in an effort to produce a derivative which would cyclise to give a 2,5-bridged pyridine. The attempted intramolecular oxidative coupling of 2,5-dihex- 51 -ynylpyridine received much attention. In the attempts to obtain a 1,4-bridged pyridine, two tricyclic compounds, each containing two quaternised pyridine rings linked by polymethylene chains, were obtained. -
JUN 1 51998 Science
Efforts Toward the Syntheses of Natural Products: Part A: Paeoniflorin Part B: (+)-Taxusin A thesis presented by Rebecca J. Carazza B.S. Chemistry University of Massachusetts, Amherst, 1993 Submitted to the Department of Chemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry at the Massachusetts Institute of Technology June 1998 © 1998 Massachusetts Institute of Technology. All rights reserved. SinatureofAuthor: SignatureT- -~- -- .. -uof -Author: -- I- ----- D4pdrtment o('ihemistry May 26, 1998 Certified by: ,Scott C. Virgil Thesis Advisor Acceuted bv: Dietmar Seyferth Chairman, Departmental Committee on Graduate Students O-V .Z\ . JUN 1 51998 Science UR PAES This doctoral thesis has been examined by a committee of the Department of Chemistry as follows: Professor Rick L. Danheiser - Chairman Professor Scott C. Virgil / Th/sis Supervisor Professor Peter H. Seeberger Efforts Toward the Syntheses of Natural Products: Part A: Paeoniflorin Part B: (+)-Taxusin by Rebecca J. Carazza Submitted to the Department of Chemistry on May 26, 1998 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Chemistry Massachusetts Institute of Technology ABSTRACT Part A Efforts toward the synthesis of the monoterpene glycoside paeoniflorin (1) are discussed. Optimization of the previous synthetic route was successful. Synthesis of the key cc-diazo intermediate 30 was achieved and the construction of the carbocyclic frame was completed. Key reactions of the strategy involve a ring contraction via a Wolff rearrangement, and formation of the lactone 78 which undergoes diisobutylaluminum hydride reduction followed by acid catalyzed cyclization to the paeoniflorin ring system 80. A new synthetic strategy was initiated to prepare the key [3.2.1]bicyclooctanone 81 using a palladium mediated olefin cyclization of the acyloin substrate 82. -
Syntheses of Morphine and Codeine (1992 – 2002): Templates for Exploration of Synthetic Tools
Current Organic Synthesis, 2006, 3, 99-120 99 Syntheses of Morphine and Codeine (1992 – 2002): Templates for Exploration of Synthetic Tools L. M. Mascavage#, M. L. Wilson and D. R. Dalton* Department of Chemistry (016-00), Beury Hall, 13th and Norris Streets, Temple University, Philadelphia, PA 19122, USA and Department of Chemistry, Arcadia University, Glenside, PA, 19038, USA Abstract: Morphine (1) and its O-methylated analogue codeine (2), analgesic alkaloids of the opium poppy (Papaver Somniferium), have been targets of organic chemists engaged in synthetic activities for at least half a century. The “first” (Gates) and “most efficient” (Rice) syntheses of morphine (1) and codeine (2) are well known and have been reviewed and analyzed extensively numerous times. However, syntheses of the same two alkaloids that have been reported since 1992 and which have been used as devices to advance the art of organic synthesis are not as widely recognized and they have not been as thoroughly reviewed. Here they are analyzed in the spirit of the use of these two compounds as templates. Further, since both racemic and enantiospecific syntheses are important and since all eight (8) approaches (since 1992) are sufficiently different so as to warrant more tha n superficial examination, they are all considered. H HO 7 H 8 15 6 H H 6 14 N 5 CH3 H 13 NCH3 HO 14 13 9 16 9 O 16 12 15 10 O 10 4 4 11 1, R = H 2, R = CH 1 1 3 RO 3 RO 3 2 2 It is nearly two hundred years since the initial report the ubiquitous standard opium poppy or with cultivars that (1806) of the isolation of morphine (1, R = H) from the might be subsequently generated through genetic unripe seed pods of the opium poppy, Papever somniferum, manipulations so as to maximize production of these or by Friedrich Wihelm Adam Setürner [1], seventy five years related bases. -
Durham E-Theses
Durham E-Theses The synthesis and potential applications of asymmetric silacycles Matthews, Jennifer Louise How to cite: Matthews, Jennifer Louise (1994) The synthesis and potential applications of asymmetric silacycles, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/5504/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk The Synthesis and Potential Applications of Asymmetric Silacycles The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. Jennifer Louise Matthews, B.Sc. (Hons) Ph.D. Thesis University of Durham November 1994 COPYRIGHT The copyright of this work rests with the author. No quotation from it should be published without prior consent. Information derived from this thesis should be acknowledged. DECLARATION The work contained in this thesis was carried out in the Department of Chemistry at the University of Durham between October 1991 and September 1994. -
Advances in the Asymmetric Total Synthesis of Natural Products Using Chiral Secondary Amine Catalyzed Reactions of Α,Β-Unsaturated Aldehydes
molecules Review Advances in the Asymmetric Total Synthesis of Natural Products Using Chiral Secondary Amine Catalyzed Reactions of α,β-Unsaturated Aldehydes Zhonglei Wang 1,2 1 School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; [email protected] 2 School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China Academic Editor: Ari Koskinen Received: 12 August 2019; Accepted: 19 September 2019; Published: 19 September 2019 Abstract: Chirality is one of the most important attributes for its presence in a vast majority of bioactive natural products and pharmaceuticals. Asymmetric organocatalysis methods have emerged as a powerful methodology for the construction of highly enantioenriched structural skeletons of the target molecules. Due to their extensive application of organocatalysis in the total synthesis of bioactive molecules and some of them have been used in the industrial synthesis of drugs have attracted increasing interests from chemists. Among the chiral organocatalysts, chiral secondary amines (MacMillan’s catalyst and Jorgensen’s catalyst) have been especially considered attractive strategies because of their impressive efficiency. Herein, we outline advances in the asymmetric total synthesis of natural products and relevant drugs by using the strategy of chiral secondary amine catalyzed reactions of α,β-unsaturated aldehydes in the last eighteen years. Keywords: bioactive natural products; pharmaceuticals; asymmetric total synthesis; chiral secondary amines; α,β-unsaturated aldehydes 1. Introduction In 2000, the MacMillan group [1] first described the fundamental concept of LUMO-lowering iminium-ion activation. In 2005, the Jørgensen group [2,3] reported diarylprolinol silyl ether catalysts, which have also been used in iminium-ion catalysis. -
Strategic Applications of Named Reactions in Organic Synthesis
Strategic Applications of Named Reactions in Organic Synthesis Strategic Applications of Named Reactions in Organic Synthesis Background and Detailed Mechanisms by László Kürti and Barbara Czakó UNIVERSITY OF PENNSYLVANIA 250 Named Reactions AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD • PARIS SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO iii Senior Publishing Editor Jeremy Hayhurst Project Manager Carl M. Soares Editorial Assistant Desiree Marr Marketing Manager Linda Beattie Cover Printer RR Donnelley Interior Printer RR Donnelley Elsevier Academic Press 30 Corporate Drive, Suite 400, Burlington, MA 01803, USA 525 B Street, Suite 1900, San Diego, California 92101-4495, USA 84 Theobald's Road, London WC1X 8RR, UK This book is printed on acid-free paper. Copyright © 2005, Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (+44) 1865 843830, fax: (+44) 1865 853333, e-mail: [email protected]. You may also complete your request on-line via the Elsevier homepage (http://elsevier.com), by selecting “Customer Support” and then “Obtaining Permissions.” Library of Congress Cataloging-in-Publication Data Application Submitted British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN: 0-12-429785-4 For all information on all Elsevier Academic Press Publications visit our Web site at www.books.elsevier.com Printed in the United States of America 05 06 07 08 09 10 9 8 7 6 5 4 3 2 1 iv This book is dedicated to Professor Madeleine M. -
An Umpolung Strategy to React Catalytic Enols with Nucleophiles
ARTICLE https://doi.org/10.1038/s41467-019-13175-5 OPEN An umpolung strategy to react catalytic enols with nucleophiles Amparo Sanz-Marco 1, Samuel Martinez-Erro 1, Martin Pauze 1,2, Enrique Gómez-Bengoa 2 & Belén Martín-Matute 1* The selective synthesis of α-functionalized ketones with two similar enolizable positions can be accomplished using allylic alcohols and iridium(III) catalysts. A formal 1,3-hydrogen shift 1234567890():,; on allylic alcohols generates catalytic iridium-enolates in a stereospecific manner, which are able to react with electrophiles to yield α-functionalized ketones as single constitutional isomers. However, the employment of nucleophiles to react with the nucleophilic catalytic enolates in this chemistry is still unknown. Herein, we report an umpolung strategy for the selective synthesis of α-alkoxy carbonyl compounds by the reaction of iridium enolates and alcohols promoted by an iodine(III) reagent. Moreover, the protocol also works in an intra- molecular fashion to synthesize 3(2H)-furanones from γ-keto allylic alcohols. Experimental and computational investigations have been carried out, and mechanisms are proposed for both the inter- and intramolecular reactions, explaining the key role of the iodine(III) reagent in this umpolung approach. 1 Department of Organic Chemistry, Stockholm University, Stockholm SE-10691, Sweden. 2 Departamento de Química Orgánica I, Universidad del País Vasco/UPV-EHU, Manuel de Lardizabal 3, Donostia – San Sebastián 20018, Spain. *email: [email protected] NATURE COMMUNICATIONS | (2019) 10:5244 | https://doi.org/10.1038/s41467-019-13175-5 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-13175-5 mpolung reactions represent a powerful approach for the halogen and oxygen-based electrophilic species. -
Copyrighted Material
JWST960-SUBIND JWST960-Smith October 25, 2019 9:5 Printer Name: Trim: 254mm × 178mm SUBJECT INDEX The vast use of transition metal catalysts in organic chemistry makes the citation of every individual metal impractical, so there are limited citations of individual metals. Palladium is one exception where individual citations are common, in keeping with the widespread use of that metal. However, in most cases, the term metal catalyst, or catalyst, metal is used as a heading, usually representing transition metals. A-SE2 mechanism 893 and the steering wheel model acceleration of Diels-Alder reactions 487 151–152 reactions, high pressure A1 mechanism, acetal hydrolysis and universal NMR database 1038 487 155 hydrogen-bonding 1038 A1,3-strain 196 Cahn-Ingold-Prelog system hydrophobic effect 1038 A2 mechanism, acetal hydrolysis 149–152 in water 1038 487 determination 152 ionic liquids 1038 ab initio calculations 36 D/L nomenclature 149 micellular effects 1038 and acidity 346 Kishi’s NMR method 155 microwave irradiation 1038 and antiaromaticity 71 sequence rules 149–152 phosphate 1039 and nonclassical carbocations absolute hardness 64, 359, 361 solid state 1038 427 table 361 ultracentrifuge 1038 norbornyl carbocation 436 absorbents, chiral 168 ultrasound 1038 ab initio studies 248 absorption, and conjugation 317 zeolites 1038 1,2-alkyl shifts in alkyne anions differential, and diastereomers acceleration, Petasis reaction 1349 168 1202 and cubyl carbocation 413 differential, and resolution 169 acenaphthylene, reaction with and SN2 408–409 abstraction, -
Gong Ph.D. Thesis Final
MULTICOMPONENT CYCLIZATION REACTIONS: A GENERAL APPROACH TO DIBENZOCYCLOOCTADIENE LIGNAN NATURAL PRODUCTS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Wei Gong Graduate Program in Chemistry The Ohio State University 2012 Dissertation Committee: Professor T. V. RajanBabu Professor Jovica Badjic Professor Anita Mattson Copyright by Wei Gong 2012 Abstract Aiming at finding a general and broadly applicable route to dibenzocyclooctadiene (DBCOD) lignans, an important class of natural products with wide-ranging biological activities, we applied Pd-catalyzed bis-metallative cyclizations mediated by a [B-Sn] reagent, 1-trimethylstannyl-2,5-dimethyl-2,5-diazaborolidine, to access the core DBCOD systems. 2,2’-Dipropargyl biphenyls are suitable precursors of [B-Sn] reagent mediated cyclizations and their acetylene moieties can be installed by addition of lithium acetylides to 2’-substituted biphenyl aldehydes. Most of these acetylide additions are highly stereoselective and chelating models have been proposed to rationalize their stereochemical results. The viability of the [B-Sn]-mediated cyclizations of these dipropargyl biphenyls depends on the chirality of the biphenyl scaffolding and the configuration of the propargylic center. Models based on steric arguments can be used to rationalize the stereochemical outcomes in successful cyclizations, and the reluctance in others to undergo the cyclization. A racemic synthesis of steganone was achieved from a 1,2-bisalkylidenecyclooctadiene prepared via the [B-Sn]-mediated cyclization. A novel AD-mix mediated tandem process quickly led to the formation of the key lactone, which was converted to steganone after three steps. ii Eight fully substituted DBCOD lignans, including compounds such as kadsuralignan B, tiegusanin D, and schizanrin F, with a tertiary center at C7, were first synthesized using an intermediate prepared by the [B-Sn]-mediated cyclization. -
Enzyme Catalyzed Cross Acyloin Reactions Via C-C Bond Cleavage
ENZYME CATALYZED CROSS ACYLOIN REACTIONS VIA C-C BOND CLEAVAGE A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY GÖKÇİL BİLİR IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN CHEMISTRY DECEMBER 2015 Approval of the thesis ENZYME CATALYZED CROSS ACYLOIN REACTIONS VIA C-C BOND CLEAVAGE submitted by GÖKÇİL BİLİR in partial fulfillment of the requirements for the degree of Master of Science in Chemistry Department, Middle East Technical University by, Prof. Dr. Gülbin Dural Ünver Dean, Graduate School of Natural and Applied Sciences Prof. Dr. Cihangir Tanyeli Head of Department, Chemistry Assist. Prof. Salih Özçubukçu Supervisor, Chemistry Dept., METU Examining Committee Members: Prof. Dr. Cihangir Tanyeli Dept. of Chemistry, METU Assist. Prof. Dr. Salih Özçubukçu Dept. of Chemistry, METU Prof. Dr. Özdemir Doğan Dept. of Chemistry METU Assist. Prof. Dr. Yunus Emre Türkmen Dept. of Chemistry, Bilkent University Assist. Prof. Dr. Ferdi Karadaş Dept. of Chemistry, Bilkent University Date: I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last name: Gökçil Bilir Signature iv ABSTRACT ENZYME CATALYZED CROSS ACYLOIN REACTIONS VIA C-C BOND CLEAVAGE Bilir, Gökçil M.Sc., Department of Chemistry Supervisor: Assist. Prof. Dr. Salih Özçubukçu December 2015, 67 pages Enzyme-catalysis is an effective tool for asymmetric synthesis under environmentally-friendly conditions, with an increasing number of examples at industrial scale. -
All-Carbon Spirocycles.Pptx
Spirocycles Containing All-Carbon Quaternary Centers Baran Group Meeting Emily Cherney Alkylations Continued Suresh- Synthesis (2008) v. 7, 1065-1068 Ficini- Tetrahedron Lett. (1981) v. 22, 629-632 O CO2Me O Me Me DME, rt H Me Me Me Me Me N H 44% N Ph N CO Me O 2 O MeO2C MgBr2, ACN, 70 °C O O O MeO2C 60-70% O O Ph N O Gravel- Org. Lett. (2010) v. 12, 5772-5775 • Me single diast. "Domino Stetter-Aldol-Aldol reaction" N Ph Br Me O O Et N S (30 mol %) H DBU (1 eq), Tanner- Tetrahedron (1989) v 45, 4309-4316 Me (CH2)2OH Me H H DCM, rt, NaH, DMF, Me 20 min TsHN Ts TsN Ts Stetter 0 to 50 °C O O (2 eq) TfO 71% Me O O O O Me nBuLi, THF, (±)-acoradiene H H HMPA, -20 °C O Aldol O 69% O Ts O HO HN Na(Hg), NaH2PO4, MeOH HO TsN H (+)-nitramine 74% OH O Aldol/ Sum it up! Common Akylation Strategies: J. Chem. Soc., Chem. Commun. (1995) 955-956 Elimination O 1 - double alkylation of bis-halide or other bis- O electrophile !- to ketone, malonate, etc. BF3•OEt2, DCM 2 - intramolecular cyclizations onto epoxides, O halides, or other electrophiles OH 3 - intramolecular Michael or Aldol reactions to HO Me O form quaternary centers 85% ee O 4- intramolecular Sakurai allylations to form OH O quaternary centers 86% 5- use of chiral amines to form chiral enamines for diastereoselective Aldol and Michael 71% reactions 6-I didn't cover oxidative dearom/intramolecular dr 1:1 Prins-type closure. -
This Item Was Submitted to Loughborough University As a Phd Thesis by the Author and Is Made Available in the Institutional Repo
This item was submitted to Loughborough University as a PhD thesis by the author and is made available in the Institutional Repository (https://dspace.lboro.ac.uk/) under the following Creative Commons Licence conditions. For the full text of this licence, please go to: http://creativecommons.org/licenses/by-nc-nd/2.5/ Novel methods for allylic amination by an intramolecular nitroso ene reaction by Duncan Atkinson Doctoral Thesis Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University 2nd Aug 2013 ©by Duncan Atkinson 2013 1 Disclaimer I, Duncan Atkinson, confirm that the work presented in this thesis is my own, and has not been submitted as part of the conditions for the award of any previous degree. Where work has been derived from other sources, I confirm that this has been indicated in the thesis. 2 Abstract. C-H functionalisation reactions aim for the selective cleavage of C-H bonds, and formation of a new carbon or heteroatom bond, often with the use of a transition metal catalyst. These reactions offer potential for functionalisation of hydrocarbons in fewer steps than conventional methods, and with high atom efficiency. They are therefore a subject of intense research in organic synthesis. Carbon- heteroatom bond forming reactions are particularly sought after, and useful in the efficient synthesis of many biologically significant groups such as oxazolidinone rings, 1,2 or 1,3 amino alcohols and amino acid analogues.1, 2, 3, 4, 5, 6 An efficient, cheap and robust method for C-H amination would also be adaptable to varied syntheses of important large molecules.