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New Cyclophanes As Supramolecular Scaffolds: the Synthesis of Tribenzo-1,4,7-Triazacyclononatriene
Loyola University Chicago Loyola eCommons Dissertations Theses and Dissertations 2010 New Cyclophanes as Supramolecular Scaffolds: The Synthesis of Tribenzo-1,4,7-Triazacyclononatriene. Andria M. Panagopoulos Loyola University Chicago Follow this and additional works at: https://ecommons.luc.edu/luc_diss Part of the Biochemistry Commons Recommended Citation Panagopoulos, Andria M., "New Cyclophanes as Supramolecular Scaffolds: The Synthesis of Tribenzo-1,4,7-Triazacyclononatriene." (2010). Dissertations. 88. https://ecommons.luc.edu/luc_diss/88 This Dissertation is brought to you for free and open access by the Theses and Dissertations at Loyola eCommons. It has been accepted for inclusion in Dissertations by an authorized administrator of Loyola eCommons. For more information, please contact [email protected]. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. Copyright © 2010 Andria M. Panagopoulos LOYOLA UNIVERSITY CHICAGO NEW CYCLOPHANES AS SUPRAMOLECULAR SCAFFOLDS: THE SYNTHESIS OF TRIBENZO-1,4,7-TRIAZACYCLONONATRIENE A DISSERTATION SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY PROGRAM IN CHEMISTRY BY ANDRIA M. PANAGOPOULOS CHICAGO, ILLINOIS AUGUST 2010 Copyright by Andria M. Panagopoulos, 2010 All rights reserved ACKNOWLEDGEMENTS I would like to sincerely thank my advisor, Daniel P. Becker, Ph.D. for all his support and guidance throughout the years. I have learned so much from you, not only about chemistry, but about myself and for that I thank you. I would also like to thank my friends and family. You guys have stood by my side, encouraged me and supported me. I could not have completed this without your love and support. -
Organic Chemistry
Wisebridge Learning Systems Organic Chemistry Reaction Mechanisms Pocket-Book WLS www.wisebridgelearning.com © 2006 J S Wetzel LEARNING STRATEGIES CONTENTS ● The key to building intuition is to develop the habit ALKANES of asking how each particular mechanism reflects Thermal Cracking - Pyrolysis . 1 general principles. Look for the concepts behind Combustion . 1 the chemistry to make organic chemistry more co- Free Radical Halogenation. 2 herent and rewarding. ALKENES Electrophilic Addition of HX to Alkenes . 3 ● Acid Catalyzed Hydration of Alkenes . 4 Exothermic reactions tend to follow pathways Electrophilic Addition of Halogens to Alkenes . 5 where like charges can separate or where un- Halohydrin Formation . 6 like charges can come together. When reading Free Radical Addition of HX to Alkenes . 7 organic chemistry mechanisms, keep the elec- Catalytic Hydrogenation of Alkenes. 8 tronegativities of the elements and their valence Oxidation of Alkenes to Vicinal Diols. 9 electron configurations always in your mind. Try Oxidative Cleavage of Alkenes . 10 to nterpret electron movement in terms of energy Ozonolysis of Alkenes . 10 Allylic Halogenation . 11 to make the reactions easier to understand and Oxymercuration-Demercuration . 13 remember. Hydroboration of Alkenes . 14 ALKYNES ● For MCAT preparation, pay special attention to Electrophilic Addition of HX to Alkynes . 15 Hydration of Alkynes. 15 reactions where the product hinges on regio- Free Radical Addition of HX to Alkynes . 16 and stereo-selectivity and reactions involving Electrophilic Halogenation of Alkynes. 16 resonant intermediates, which are special favor- Hydroboration of Alkynes . 17 ites of the test-writers. Catalytic Hydrogenation of Alkynes. 17 Reduction of Alkynes with Alkali Metal/Ammonia . 18 Formation and Use of Acetylide Anion Nucleophiles . -
Biocatalytic Process Design and Reaction Engineering* This Work Is Licensed Under a ** Creative Commons Attribution 4.0 R
R. Wohlgemuth, Biocatalytic Process Design and Reaction Engineering, Chem. Biochem. Eng. Q., 31 (2) 131–138 (2017) 131 Biocatalytic Process Design and Reaction Engineering* This work is licensed under a ** Creative Commons Attribution 4.0 R. Wohlgemuth International License Sigma-Aldrich, Member of Merck Group, doi: 10.15255/CABEQ.2016.1029 Industriestrasse 25, CH-9470 Buchs, Switzerland Review Received: November 2, 2016 Accepted: May 31, 2017 Biocatalytic processes occurring in nature provide a wealth of inspiration for manu- facturing processes with high molecular economy. The molecular and engineering as- pects of bioprocesses converting available raw materials into valuable products are there- fore of much industrial interest. Modular reaction platforms and straightforward working paths, from the fundamental understanding of biocatalytic systems in nature to the design and reaction engineering of novel biocatalytic processes, have been important for short- ening development times. Building on broadly applicable reaction platforms and tools for designing biocatalytic processes and their reaction engineering are key success factors. Process integration and intensification aspects are illustrated with biocatalytic processes to numerous small-molecular weight compounds, which have been prepared by novel and highly selective routes, for applications in the life sciences and biomedical sciences. Key words: molecular economy, retrosynthetic analysis, route selection, biocatalytic asymmetric synthesis, biocatalysts, biocatalytic process assembly, -
Stereochemistry, Alkyl Halide Substitution (SN1 & SN2)
Chem 261 Assignment & Lecture Outline 3: Stereochemistry, Alkyl Halide Substitution (SN1 & SN2) Read Organic Chemistry, Solomons, Fryle & Snyder 12th Edition (Electronic) • Functional Group List – Learn to recognize – Please see Green Handout – also p 76 of text • Periodic Table – Inside Front Cover - know 1st 10 elements (up through Neon) • Relative Strength of Acids and Bases – Inside Front cover (reference only) • Chapter 5 – Stereochemistry • Chapter 6 –Ionic Reactions: Nucleophilic Substitution of Alkyl Halides Problems: Do Not turn in, answers available in "Study Guide Student Solutions Manual " Solomons, Fryle, Snyder • Chapter 5: 5.1 to 5.15; 5.18 to 5.21; 5.26; 5.28; 5.33a-d; 5.46 • Chapter 6: 6.1 to 6.5; 6.7 to 6.10; 6.13; 6.20; 6.26; 6.27 Lecture Outline # 3 I. Comparison of 2 Structures: Same Molecular Formula ? -> If Yes, Possibly Isomers or Identical Same Arrangement (Sequence) of Groups ? If No -> Structural Isomers If Yes -> Superposable? If Yes -> Identical Structures If No -> Stereoisomers Non-Superposable Mirror Images ? If NO -> Diastereomers If Yes -> Enantiomers II. Chirality and Stereoisomers A. The Concept of Chirality 1. Identification of chiral objects a) achiral = not chiral b) planes of symmetry within a molecule 2. Types of stereoisomers – enantiomers and diastereomers B. Location of stereogenic (chiral) centres – 4 different groups on tetrahedral atom 1. Enantiomers & diastereomers 2. Meso compounds - chiral centers with plane of symmetry within molecule 3. Molecules with more than one chiral centre 4. Recognition of chiral centers in complex molecules - cholesterol - 8 chiral centres Drawing the enantiomer of cholesterol and its potential 255 stereoisomers 5. -
II. Stereochemistry 5
B.Sc.(H) Chemistry Semester - II Core Course - III (CC-III) Organic Chemistry - I II. Stereochemistry 5. Physical and Chemical Properties of Stereoisomers Dr. Rajeev Ranjan University Department of Chemistry Dr. Shyama Prasad Mukherjee University, Ranchi 1 Syllabus & Coverage Syllabus II Stereochemistry: Fischer Projection, Newmann and Sawhorse Projection formulae and their interconversions. Geometrical isomerism: cis–trans and syn-anti isomerism, E/Z notations with Cahn Ingold and Prelog (CIP) rules for determining absolute configuration. Optical Isomerism: Optical Activity, Specific Rotation, Chirality/Asymmetry, Enantiomers, Molecules with two or more chiral-centres, Distereoisomers, Meso structures, Racemic mixture. Resolution of Racemic mixtures. Relative and absolute configuration: D/L and R/S designations. Coverage: 1. Types of Isomers : Comparing Structures 2. Optical Activity 3. Racemic Mixtures : Separation of Racemic Mixtures 4. Enantiomeric Excess and Optical Purity 5. Relative and Absolute Configuration 6. Physical and Chemical Properties of Stereoisomers 2 Stereochemistry Types of Isomers Dr. Rajeev Ranjan 3 Stereochemistry Determining the Relationship Between Two Non-Identical Molecules Dr. Rajeev Ranjan 4 Stereochemistry Comparing Structures: Are the structures connected the same? yes no Are they mirror images? Constitutional Isomers yes no Enantiomers Enantiomers Is there a plane of symmetry? All chiral centers will be opposite between them. yes no Meso Diastereomers superimposable Dr. Rajeev Ranjan 5 Stereochemistry Optical Activity: • The chemical and physical properties of two enantiomers are identical except in their interaction with chiral substances. • The physical property that differs is the behavior when subjected to plane-polarized light ( this physical property is often called an optical property). • Plane-polarized (polarized) light is light that has an electric vector that oscillates in a single plane. -
Synthesis of Axially Chiral Biaryl Compounds by Asymmetric Catalytic Reactions with Transition Metals Pauline Loxq, E
Synthesis of axially chiral biaryl compounds by asymmetric catalytic reactions with transition metals Pauline Loxq, E. Manoury, Rinaldo Poli, Éric Deydier, A. Labande To cite this version: Pauline Loxq, E. Manoury, Rinaldo Poli, Éric Deydier, A. Labande. Synthesis of axially chiral biaryl compounds by asymmetric catalytic reactions with transition metals. Coordination Chemistry Re- views, Elsevier, 2016, 308, Part 2, pp.131-190. 10.1016/j.ccr.2015.07.006. hal-01929757 HAL Id: hal-01929757 https://hal.archives-ouvertes.fr/hal-01929757 Submitted on 1 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Synthesis of axially chiral biaryl compounds by asymmetric catalytic reactions with transition metals Pauline Loxq, a,b Eric Manoury,a,b Rinaldo Poli,a,b,c Eric Deydier a,b,d,* and Agnès Labande a,b,* a CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France. b Université de Toulouse, UPS, INPT, F-31077 Toulouse Cedex 4, France. c Institut Universitaire de France, 103, bd Saint-Michel, 75005 Paris, France. d IUT A Paul Sabatier, Departement de Chimie, Avenue Georges Pompidou, CS 20258, F- 81104 Castres Cedex, France Dedicated to the memory of our colleague and friend Guy Lavigne (1947-2015). -
Arenechromium Tricarbonyl Complexes: Conformational
η6 – ARENECHROMIUM TRICARBONYL COMPLEXES: CONFORMATIONAL ANALYSIS, STEREOCONTROL IN NUCLEOPHILIC ADDITION AND APPLICATIONS IN ORGANIC SYNTHESIS by HARINANDINI PARAMAHAMSAN Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Thesis Advisor: Prof. Anthony J. Pearson Department of Chemistry CASE WESTERN RESERVE UNIVERSITY May 2005 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the dissertation of Harinandini Paramahamsan candidate for the Ph.D. degree*. (signed) Prof. Philip P. Garner (Chair of the Committee, Department of Chemistry, CWRU) Prof. Anthony J. Pearson (Department of Chemistry, CWRU) Prof. Fred L. Urbach (Department of Chemistry, CWRU) Dr. Zwong-Wu Guo (Department of Chemistry, CWRU) Dr. Stuart J. Rowan (Department of Macromolecular Science and Engineering, CWRU) Date: 14th January 2005 *We also certify that written approval has been obtained for any propriety material contained therein. To Amma, Naina & all my Teachers Table of Contents List of Tables………………………………………………………………………..……iv List of Figures…………………………………………………………………….…........vi List of Schemes…………………………………………………………………….….….ix List of Equations………………………………………………………...……….……….xi Acknowledgements………………………………………………………….…..……….xii List of Abbreviations……………………………………………………………………xiv Abstract………………………………………………………………………………….xvi CHAPTER I........................................................................................................................ 1 I.1 Structure and Bonding ........................................................................................... -
Chapter 8. Chiral Catalysts José M
Chapter 8. Chiral Catalysts José M. Fraile, José I. García, José A. Mayoral 1. The Origin of Enantioselectivity in Catalytic Processes: the Nanoscale of Enantioselective Catalysis. Enantiomerically pure compounds are extremely important in fields such as medicine and pharmacy, nutrition, or materials with optical properties. Among the different methods to obtain enantiomerically pure compounds, asymmetric catalysis1 is probably the most interesting and challenging, in fact one single molecule of chiral catalyst can transfer its chiral information to thousands or even millions of new chiral molecules. Enantioselective reactions are the result of the competition between different possible diastereomeric reaction pathways, through diastereomeric transition states, when the prochiral substrate complexed to the chiral catalyst reacts with the corresponding reagent. The efficiency of the chirality transfer, measured as enantiomeric excess [% ee = (R−S)/(R+S) × 100], depends on electronic and steric factors in a very subtle form. A simple calculation shows that differences in energy of only 2 kcal/mol between these transition states are enough to obtain more than 90% ee, and small changes in any of the participants in the catalytic process can modify significantly this difference in energy. Those modifications may occur in the near environment of the catalytic centre, at less than 1 nm scale, but also at longer distances in the catalyst, substrate, reagent, solvent, or support in the case of immobilized catalysts. This is the reason because asymmetric -
Tetrazinebox: a Structurally Transformative Toolbox Qing-Hui Guo, Jiawang Zhou, Haochuan Mao, Yunyan Qiu, Minh T
pubs.acs.org/JACS Article TetrazineBox: A Structurally Transformative Toolbox Qing-Hui Guo, Jiawang Zhou, Haochuan Mao, Yunyan Qiu, Minh T. Nguyen, Yuanning Feng, Jiaqi Liang, Dengke Shen, Penghao Li, Zhichang Liu, Michael R. Wasielewski, and J. Fraser Stoddart* Cite This: J. Am. Chem. Soc. 2020, 142, 5419−5428 Read Online ACCESS Metrics & More Article Recommendations *sı Supporting Information ABSTRACT: Synthetic macrocycles capable of undergoing allosteric regulation by responding to versatile external stimuli are the subject of increasing attention in supramolecular science. Herein, we report a structurally transformative tetracationic cyclophane containing two 3,6-bis(4-pyridyl)-l,2,4,5-tetrazine (4-bptz) units, which are linked together by two p-xylylene bridges. The cyclophane, which possesses modular redox states and structural post-modifications, can undergo two reversibly consecutive two-electron reductions, affording first its bisradical dicationic counterpart, and then subsequently the fully reduced species. Furthermore, one single-parent cyclophane can afford effectively three other new analogs through box- to-box cascade transformations, taking advantage of either reductions or an inverse electron-demand Diels−Alder (IEDDA) reaction. While all four new tetracationic cyclophanes adopt rigid and symmetric box-like conformations, their geometries in relation to size, shape, electronic properties, and binding affinities toward polycyclic aromatic hydrocarbons can be readily regulated. This structurally transformative tetracationic cyclophane performs a variety of new tasks as a result of structural post-modifications, thus serving as a toolbox for probing the radical properties and generating rapidly a range of structurally diverse cyclophanes by efficient divergent syntheses. This research lays a solid foundation for the introduction of the structurally transformative tetracationic cyclophane into the realm of mechanically interlocked molecules and will provide a toolbox to construct and operate intelligent molecular machines. -
Transcription 11.12.07
Lab 17A • 12/07/11 [lab quiz] Nomenclature of alkenes The first molecule that I want to look at is this one, where we have the two methyl groups on one side, two hydrogens on the other side. Would it be appropriate to use cis or trans, or E or Z, or both, or neither? One carbon of the double bond versus the other, those are the two different sides of the double, then the top versus the bottom are the two faces of the double bond. If we notice, on both the top face and the bottom face, we have a methyl group that is pointed the same way as a hydrogen. There is a steric factor as far as what alkene would prefer to form thermodynamically, so there is an importance that there’s some interaction there. That methyl group with one hydrogen is exactly the same interaction as you’d have the methyl group and the other hydrogen pointed the opposite way – meaning that if you were to switch the two hydrogens, you’d end up with exactly the same molecule again. The only reason that we use the term cis or trans or E or Z is to describe that it is one configuration versus another, but since there’s only one configuration possible, there’s therefore no term that should be used. It would, in fact, be wrong to call this cis, trans, E, or Z. When an alkene has two of the same substituent on the same side, there is only one unique configuration of that alkene, and so it cannot be called cis, trans, E, or Z. -
Supramolecular Chirality: Solvent Chirality Transfer in Molecular Chemistry and Polymer Chemistry
Symmetry 2014, 6, 677-703; doi:10.3390/sym6030677 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Review Supramolecular Chirality: Solvent Chirality Transfer in Molecular Chemistry and Polymer Chemistry Michiya Fujiki Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0036, Japan; E-Mail: [email protected]; Tel.: +81-743-72-6040 Received: 15 July 2014; in revised form: 7 August 2014 / Accepted: 7 August 2014 / Published: 13 August 2014 Abstract: Controlled mirror symmetry breaking arising from chemical and physical origin is currently one of the hottest issues in the field of supramolecular chirality. The dynamic twisting abilities of solvent molecules are often ignored and unknown, although the targeted molecules and polymers in a fluid solution are surrounded by solvent molecules. We should pay more attention to the facts that mostly all of the chemical and physical properties of these molecules and polymers in the ground and photoexcited states are significantly influenced by the surrounding solvent molecules with much conformational freedom through non-covalent supramolecular interactions between these substances and solvent molecules. This review highlights a series of studies that include: (i) historical background, covering chiral NaClO3 crystallization in the presence of D-sugars in the late 19th century; (ii) early solvent chirality effects for optically inactive chromophores/fluorophores in the 1960s–1980s; and (iii) the recent development of mirror symmetry breaking from the corresponding achiral or optically inactive molecules and polymers with the help of molecular chirality as the solvent use quantity. Keywords: optically active; chiral; achiral; supramolecules; polymers; solvent; circular dichroism; circularly polarized luminescence; homochirality; molecular chirality 1. -
Enantiomeric Resolution and Absolute Configuration of a Chiral Δ-Lactam
molecules Article Enantiomeric Resolution and Absolute Configuration of a Chiral δ-Lactam, Useful Intermediate for the Synthesis of Bioactive Compounds 1, 1, 1 1 Roberta Listro y, Giacomo Rossino y, Serena Della Volpe , Rita Stabile , Massimo Boiocchi 2 , Lorenzo Malavasi 3, Daniela Rossi 1,* and Simona Collina 1 1 Department of Drug Sciences, University of Pavia, via Taramelli 12, 27100 Pavia, Italy; [email protected] (R.L.); [email protected] (G.R.); [email protected] (S.D.V.); [email protected] (R.S.); [email protected] (S.C.) 2 Centro Grandi Strumenti, University of Pavia, via Bassi 21, 27100 Pavia, Italy; [email protected] 3 Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy; [email protected] * Correspondence: [email protected] These authors contributed equally to this work. y Academic Editor: Józef Drabowicz Received: 2 December 2020; Accepted: 18 December 2020; Published: 19 December 2020 Abstract: During the past several years, the frequency of discovery of new molecular entities based on γ- or δ-lactam scaffolds has increased continuously. Most of them are characterized by the presence of at least one chiral center. Herein, we present the preparation, isolation and the absolute configuration assignment of enantiomeric 2-(4-bromophenyl)-1-isobutyl-6-oxopiperidin-3-carboxylic acid (trans-1). For the preparation of racemic trans-1, the Castagnoli-Cushman reaction was employed. (Semi)-preparative enantioselective HPLC allowed to obtain enantiomerically pure trans-1 whose absolute configuration was assigned by X-ray diffractometry. Compound (+)-(2R,3R)-1 represents a reference compound for the configurational study of structurally related lactams.