DOCSLIB.ORG

The Selective Oxidation of Beta-Cyclodextrin on the Secondary Face

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Selective Oxidation of Beta-Cyclodextrin on the Secondary Face W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1997 The Selective Oxidation of beta-Cyclodextrin on the Secondary Face Christine Evelyn Heath College of William & Mary - Arts & Sciences Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Physical Chemistry Commons Recommended Citation Heath, Christine Evelyn, "The Selective Oxidation of beta-Cyclodextrin on the Secondary Face" (1997). Dissertations, Theses, and Masters Projects. Paper 1539626108. https://dx.doi.org/doi:10.21220/s2-j6cv-jt95 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. The Selective Oxidation of {3-CycIodextrin on the Secondary Face A Thesis Presented to The Faculty of the Department of Chemistry The College of William and Mary In Partial Fulfillment of the Requirements for the Degree of Master of Arts by Christine Evelyn Heath August 1997 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts aUwAki , C hristine E. H eath Approved, August 1997 Christopher J. Ab^it, Ph. D. CL. C.^R&st Deborah C. Bebout, Ph. D. Robert J. Hinkle, Ph. D. TABLE OF CONTENTS ACKNOWLEDGMENTS...........................................................................................................iv LIST OF FIGURES.............................. v ABSTRACT...................................................................................................................................vi INTRODUCTION........................................................................................................................ 2 BACKGROUND.................................................................................................................... 6 Cydodextrins .....................................................................................................................6 p-Cyclodextrin in Photocatalysis ....................................................................................9 Benzylidene Methyl Glucoside ..................................................................................... 14 Epoxides ............................................................................................................................16 Phenyl Selenide ............................................................................................................... 19 Wittig Reaction................................................................................................................ 21 EXPERIMENTAL........................................................................................................................24 4,6-O-Benzylidene-a-D-methyl glucopyranoside .................................................... 24 Methyl-2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside .........................25 Methyl-3-deoxy-3-phenylseleno-4,6-0-benzylidene-a-D-altropyranoside... .25 Methyl-3-deoxy-3-phenylselenoxy-4,6-0-benzylidene-a-D-altropyranoside. .26 Methyl-4,6-0-benzylidene-3-deoxy-a-D-eri/f/zro-hexopyranosid-2-ulose 26 2-0-(p-Toluenesulfonyl)-p-cycIodextrin ................................................................... 27 2-0-(p-T oluenesulfonyl)-p-cydodextrin .......................... 28 2A,3A-Anhydro-p-cyclodextrin man no epoxide .............................................:... 28 S^Deoxy-S^phenylseleno-p-cydodextrin ............................................................... 29 SA-Deoxy-S^phenylselenoxy -p-cyclodextrin.......................................................... 29 3A-Deoxy-p-cydodextrin-2A-ulose ...............................................................................30 S^Deoxy-p-cydodextrin^A-p-nitrophenylhydrazone ............................................30 RESULTS....................................................................................................................................32 DISCUSSION............................................................................................................................ 38 CONCLUSION.......................................................................................................................... 43 APPENDIX OF SPECTRA............................ 44 REFERENCES............................................................................................................................54 VITA 57 ACKNOWLEDGMENTS The author wishes to express her gratitude to Dr. Christopher J. Abelt for allowing her to partake in this exploration of chemistry and all its wonders, especially for his patience in answering her many questions, and for his unfailing sense of humor. She would also like to thank Dr. Robert J. Hinkle and Dr. Deborah C. Bebout for their critique of this manuscript. She is especially grateful to everyone in Dr. Abelt's research group for their help and companionship. Last, she would like to acknowledge her friends and family for their support throughout this year. LIST OF FIGURES 1. General properties of cyclodextrins ............................................................................... 3 2. Targeted modified cyclodextrin .......................................................................................5 3 . a-, p-, and y- cyclodextrins ................................................................................................ 6 4. Hydrogen bonding stabilization of p-CD C-2 alkoxide ..............................................7 5. Previous oxidations of p-CD on the primary face ..................................................... 9 6 . 9,10-Dicyanoanthracene .................................................................................................. 11 7. The 2-O-ether tether of DCA with p-CD ...................................................................13 8 . p-CD tethered with DCA using the Wittig reaction on the secondary face . .14 9. A one-glucose model for oxidation of the secondary face of p-CD .....................15 10. General scheme for ring epoxidation ............................................................................ 17 11. Dipole interactions for nucleophilic attack of epoxides ............................................18 1 2 . Syn-elimination of phenyl selenoxide to form allylic alcohols ............................ 2 0 13. General mechanism for the Wittig reaction ............................................................... 22 14. Resonance stabilization of the phosphorus ylide of DCA ...................................... 23 15. Proposed derivatization of p-CD on the secondary face using the Wittig reaction .............................................................................................................................23 16. Mechanism of attachment of the benzylidene group to methyl glucoside . .38 17. Mechanism for the Sn 2 tosylation of p-CD at the 2 position ................................39 18. Mechanism for the epoxidation of p-CD .................................................................. 40 19. Mechanism for the ring opening of p-CD manno epoxide ...................................40 2 0 . Mechanism of the sy«-elimination of the phenyl selenoxide of p-CD to form the 2-ulose........................................................................................................................ 42 21. 1H NMR spectrum of 4,6-O-benzylidene methyl glucoside in CDCI 3 ............... 45 22. NMR spectrum of methyl-2,3-anhydro-4,6-0-benzylidene-a-D- mannopyranoside in CDCI 3 .......................................................................................46 23. NMR spectrum of methyl-3-deoxy-3-phenylseleno-4,6-0-benzylidene-a-D- altropyranoside in CDCI 3 ........................................................................................... 47 24. 1H NMR spectrum of methyl-3-deoxy-4,6-0-benzylidene-a-D-eryf/zro- hexopyranosid-2-ulose in CDCI 3 ...............................................................................48 25. 'H NMR spectrum of 2-0-(p-toluenesulfonyl)-p-cydodextrin in DMSO .... 49 26. NMR spectrum of 2A,3A-anhydro-p-cydodextrin manno epoxide in D 2O.5 O 27. NMR spectrum of SA-deoxy-S^phenylseleno-p-cydodextrin in DMSO .. 51 28. *H NMR spectrum of crude S^deoxy-p-cyclodextrin^-^-ulose in D 2O ............ 52 29. *H NMR spectrum of the possible SA-deoxy-p-cyclodextrin^A-p- nitrophenylhydrazone in D 2 O ...................................................................................53 v ABSTRACT The selective oxidation of p-cydodextrin at C-2 on one glucose residue was attempted. The oxidation pathway involved forming the 2,3 -manno epoxide, opening the epoxide with phenyl selenide anion selectively at the 3-position, oxidizing to the phenyl selenoxide, and finally, eliminating to the enol, which tautomerizes to the desired ketone. Due to the size and complexity of the cyclodextrin molecule, the proposed pathway was first attempted on a model compound, benzylidene methyl glucoside, and then applied to p-cyclodextrin. Data from thin-layer chromatography and proton NMR are consistent with successful oxidation to the 3-deoxy-2-uIose of both the model compound and the cyclodextrin. The oxidized cyclodextrin is a useful precursor for the Wittig reaction. This procedure is of interest in tethering p-cydodextrin to dicyanoanthracene with the intent
Load more

Recommended publications
  • Selenium Stabilized Carbanions. Preparation of A-Lithio Selenides and Applications to the Synthesis of Olefins by Reductive Elim
    6638 Journal of the American Chemical Society / 101:22 / October 24, I979 Selenium Stabilized Carbanions. Preparation of a-Lithio Selenides and Applications to the Synthesis of Olefins by Reductive Elimination of ,&Hydroxy Selenides and Selenoxide Syn Elimination Hans J. Reich,** Flora Chow, and Shrenik K. Shah Contribution from the Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706. Received May 10, 1979 Abstract: The deprotonation of several alkyl aryl selenides with lithium amide bases has been studied. The kinetic acidity of methyl m-trifluoromethylphenyl selenide was found to be 1/33 that of the sulfur analogue. The introduction of a m-trifluoro- methyl substituent into methyl phenyl sulfide increased the kinetic acidity by a factor of 22.4. A variety of @-hydroxy selenides have been prepared by the reduction of a-phenylseleno ketones and the addition of a-lithio selenides (prepared by deprotona- tion of benzyl phenyl selenide, bis(phenylseleno)methane, methoxymethyl m-trifluoromethylphenyl selenide, and phenylsele- noacetic acid, and by n-butyllithium cleavage of bis(pheny1seleno)methane) to carbonyl compounds. These @-hydroxyselen- ides are converted to olefins on treatment with rnethanesulfonyl chloride and triethylamine. This reductive elimination pro- ceeds exclusively or predominantly with anti stereochemistry. Simple olefins, styrenes, cinnamic acids, vinyl ethers, and vinyl selenides have been prepared using this technique. Attempts to carry out the syn reductive elimination of @-hydroxyselenox-
    [Show full text]
  • Green Synthesis of Carboxylic Acids and Esters
    Molecules 2015, 20, 10496-10510; doi:10.3390/molecules200610496 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Selenium Catalyzed Oxidation of Aldehydes: Green Synthesis of Carboxylic Acids and Esters Luca Sancineto 1,†, Caterina Tidei 1,†, Luana Bagnoli 1, Francesca Marini 1, Eder J. Lenardão 2 and Claudio Santi 1,* 1 Group of Catalysis and Organic Green Chemistry, Department of Pharmaceutical Sciences, University of Perugia, Via del Liceo 1, Perugia 06100, Italy; E-Mails: [email protected] (L.S.); [email protected] (C.T.); [email protected] (L.B.); [email protected] (F.M.) 2 Laboratório de Síntese Orgânica Limpa (LASOL), Centro de Ciências Químicas, Farmacêuticas e de Alimentos (CCQFA), Universidade Federal de Pelotas (UFPel), P.O. Box 354, Pelotas 96010-900, Brazil; E-Mail: [email protected] † These authors contributed equally to this work. * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +39-75-585-5102; Fax: +39-75-585-5116. Academic Editor: Thomas G. Back Received: 30 April 2015 / Accepted: 3 June 2015 / Published: 8 June 2015 Abstract: The stoichiometric use of hydrogen peroxide in the presence of a selenium-containing catalyst in water is here reported as a new ecofriendly protocol for the synthesis of variously functionalized carboxylic acids and esters. The method affords the desired products in good to excellent yields under very mild conditions starting directly from commercially available aldehydes. Using benzaldehyde as a prototype the gram scale synthesis of benzoic acid is described, in which the aqueous medium and the catalyst could be recycled at last five times while achieving an 87% overall yield.
    [Show full text]
  • Stereoselective Reactions of Organoselenium Compounds
    Organoselenium Chemistry Authors: Fateh V. Singh, Thomas Wirth Address: VIT University, Chennai Campus, Vandalur-Kelambakkam Road, Chennai-600127, Tamil Nadu, India Cardiff University, School of Chemistry, Main Building, Park Place, Cardiff CF10 3AT, United Kingdom Email: [email protected] 1 1. Introduction Organoselenium chemistry has been established as valuable research area in synthetic and medicinal chemistry.1-11 After the discovery of the selenoxide elimination reaction in early 1970s,12-14 organoselenium reagents received the great success in organic synthesis including asymmetric synthesis.15-18 More commonly, synthetic transformations such as selenenylations, selenocyclizations and 2,3-sigmatropic rearrangements have been successfully achieved using these reagents under mild reaction conditions.19-33 The application of these reagents in catalysis makes them more suitable reagents in organic synthesis.34-39 Several books,1-7, 41-43 book chapters8-11, 44-48 and review articles49-64 have been published to explain the utility of organoselenium reagents in synthesis. This chapter highlights the application of organoselenium reagents in organic synthesis including asymmetric synthesis. 2. Organoselenium Reagents As Electrophiles Organoselenium reagents play different roles in organic reactions but mainly known for their electrophilic behaviour. The electrophilic selenium species can be generated by the cleavage of the Se-Se bond of diselenides and can be used to activate the olefinic double bonds. Due to their electrophilic character, selenium electrophiles react with olefinic double bonds to form three membered seleniranium ion intermediate. Furthermore, the seleniranium ion intermediate can be employed to achieve various selenenylation reactions with different nucleophiles. 2.1. Selenenylation Reactions 2 Selenium electrophiles have been successfully used to achieve various selenylation reactions such as selenylation of olefins, arenes and other organic species.
    [Show full text]
  • Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis Christopher K
    Review pubs.acs.org/CR Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis Christopher K. Prier, Danica A. Rankic, and David W. C. MacMillan* Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States References 5360 1. INTRODUCTION CONTENTS A fundamental aim in the field of catalysis is the development 1. Introduction 5322 of new modes of small molecule activation. One approach 2+ toward the catalytic activation of organic molecules that has 2. Photochemistry of Ru(bpy)3 5323 3. Net Reductive Reactions 5324 received much attention recently is visible light photoredox 3.1. Reduction of Electron-Poor Olefins 5324 catalysis. In a general sense, this approach relies on the ability of 3.2. Reductive Dehalogenation 5326 metal complexes and organic dyes to engage in single-electron- 3.3. Reductive Cleavage of Sulfonium and transfer (SET) processes with organic substrates upon Sulfonyl Groups 5328 photoexcitation with visible light. 3.4. Nitrogen Functional Group Reductions 5329 Many of the most commonly employed visible light 3.5. Radical Cyclizations 5330 photocatalysts are polypyridyl complexes of ruthenium and iridium, and are typified by the complex tris(2,2′-bipyridine) 3.6. Reductive Epoxide and Aziridine Opening 5331 2+ 3.7. Reduction-Labile Protecting Groups 5331 ruthenium(II), or Ru(bpy)3 (Figure 1). These complexes 4. Net Oxidative Reactions 5332 4.1. Functional Group Oxidations 5332 4.2. Oxidative Removal of the PMB Group 5334 4.3. Oxidative Biaryl Coupling 5335 4.4. Oxidative Generation of Iminium Ions 5335 4.5. Azomethine Ylide [3 + 2] Cycloadditions 5338 4.6.
    [Show full text]
  • Part I Α,Β‑Dehydrogenation of Carbonyl Compounds Via Selenium Reagents Elimination Part II Indium Catalyzed Cyclization Reaction of Acrylate
    This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. Part I α,β‑dehydrogenation of carbonyl compounds via selenium reagents elimination Part II Indium catalyzed cyclization reaction of acrylate Zhang, Qiuchi 2019 Zhang, Q. (2019). Part I α,β‑dehydrogenation of carbonyl compounds via selenium reagents elimination Part II Indium catalyzed cyclization reaction of acrylate. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/83381 https://doi.org/10.32657/10220/47601 Downloaded on 23 Sep 2021 15:44:23 SGT PART I: DEHYDRO OF THIOESTERS PART II: INDIUM CATALYZED CYCLIZATION. CYCLIZATION. CATALYZED II: INDIUM THIOESTERS PART I: DEHYDRO OF PART PART I: DEHYDROGENATION OF CARBONYL COMPOUNDS VIA SELENIUM REAGENTS ELIMINATION. PART II: INDIUM CATALYZED CYCLIZATION REACTION OF ACRYLATE. ZHANG QIUCHI ZHANG QIUCHI 2018 SCHOOL OF PHYSICAL ANDMATHEMATICAL SCIENCES 2019 i PART I: α,β-DEHYDROGENATION OF CARBONYL COMPOUNDS VIA SELENIUM REAGENTS ELIMINATION. PART II: INDIUM CATALYZED CYCLIZATION REACTION OF ACRYLATE. ZHANG QIUCHI School of Physical and Mathematical Sciences A thesis submitted to the Nanyang Technological University in partial fulfillment of the requirement for the degree of Doctor of Philosophy 2019 ii Statement of Originality I hereby certify that the work embodied in this thesis is the result of original research, is free of plagiarised materials, and has not been submitted for a higher degree to any other University or Institution. 3 Supervisor Declaration Statement I have reviewed the content and presentation style of this thesis and declare it is free of plagiarism and of sufficient grammatical clarity to be examined.
    [Show full text]
  • Selenides and Diselenides: a Review of Their Anticancer and Chemopreventive Activity
    molecules Review Selenides and Diselenides: A Review of Their Anticancer and Chemopreventive Activity Mónica Álvarez-Pérez 1 ID , Wesam Ali 2,3, Małgorzata Anna Mar´c 3, Jadwiga Handzlik 3 and Enrique Domínguez-Álvarez 1,* 1 Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas (IQOG, CSIC), Juan de la Cierva 3, 28006 Madrid, Spain; [email protected] 2 Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B2 1, D-66123 Saarbruecken, Germany; [email protected] 3 Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland; [email protected] (M.A.M.); [email protected] (J.H.) * Correspondence: [email protected]; Tel.: +34-912587590 Received: 3 January 2018; Accepted: 9 March 2018; Published: 10 March 2018 Abstract: Selenium and selenocompounds have attracted the attention and the efforts of scientists worldwide due to their promising potential applications in cancer prevention and/or treatment. Different organic selenocompounds, with diverse functional groups that contain selenium, have been reported to exhibit anticancer and/or chemopreventive activity. Among them, selenocyanates, selenoureas, selenoesters, selenium-containing heterocycles, selenium nanoparticles, selenides and diselenides have been considered in the search for efficiency in prevention and treatment of cancer and other related diseases. In this review, we focus our attention on the potential applications of selenides and diselenides in cancer prevention and treatment that have been reported so far. The around 80 selenides and diselenides selected herein as representative compounds include promising antioxidant, prooxidant, redox-modulating, chemopreventive, anticancer, cytotoxic and radioprotective compounds, among other activities.
    [Show full text]
  • A Mechanistic Investigation of the Reactions of Diselenides with Biological Oxidants
    A mechanistic investigation of the reactions of diselenides with biological oxidants Kelly Gardiner Faculty of Medicine (Sydney Medical School) The University of Sydney A thesis submitted to fulfil the requirements for the degree of Doctor of Philosophy 2019 Declaration This is to certify that, to the best of my knowledge, the content of this thesis is my own work. This thesis has not been submitted for any degree or other purpose. I certify that the intellectual content of this thesis is the product of my own work and that all the assistance received in preparing this thesis and sources have been acknowledged. Signed, Kelly Gardiner, BBiomedSc (Hons) ii Table of Contents Abstract ...................................................................................................................................ix Acknowledgements .................................................................................................................xi List of Abbreviations ............................................................................................................xii List of Figures ......................................................................................................................xvii List of Tables ........................................................................................................................xxv Publications Arising from this Thesis ..............................................................................xxvi 1. Introduction ........................................................................................................................1
    [Show full text]
  • Studies on Performance Improvements of Thiourethane-Based Material for Ophthalmic Lenses and Indirect Electroreductions
    Studies on Performance Improvements of Thiourethane-based Material for Ophthalmic Lenses and Indirect Electroreductions Masahiko Kusumoto September 2013 Graduate School of Natural Science and Technology OKAYAMA UNIVERSITY CONTENTS Part I Studies on Performance Improvements of Thiourethane-based Material for Ophthalmic Lenses Chapter 1 Introduction and General Summary Chapter 2 Search for the Stabilizer of the Isocyanate Compounds Chapter 3 Search for the Internal Mold Release Agent Added in the Polymerization Process of the Thiourethane-based Material Chapter 4 Synthesis of Selenium-containing Thiol Compound and Evaluation of Tthiourethane-based Material for Ophthalmic Lenses Parat II Study on Indirect Electroreductions Using Selenium and Tellurium Reagents Chapter 1 Introduction and General Summary Chapter 2 Electroreductive Ring Opening of α,β-Epoxy Carbonyl Compounds and Their Homologues Chapter 3 Selective Dehalogenation of α,α-Dihalolactones and α,α-Dihalolactams by Indirect Electroreduction Chapter 4 A New Relay Reaction by (PhSe)2/Sacrificial Anode System for Indirect Electroreduction of α,β-Epoxy Carbonyl Compounds to β-Hydroxy Derivatives in an Undivided Cell Part I Studies on Performance Improvements of Thiourethane-based Material for Ophthalmic Lenses -1 - -2 - Chapter 1 Introduction and General Summary -3 - -4 - 1.1 Introduction About seventy millions people are wearring glasses in Japan, and more than one billion people are wearing them worldwide. We can not lead our lives without a pair of glasses. Optical materials including ophthalmic lenses have been originally made of glass. Crown glass used in standard ophthalmic lenses has a refractive index of 1.523, Abbe number of 53, and specific gravity of 2.54. Glass lenses having a high refractive index have been developed in order to make the lenses thinner.
    [Show full text]
  • University Microfilms, Inc., Ann Arbor, Michigan OXIDIZING PROPERTIES of SELENIUM COMPOUNDS
    OXIDIZING PROPERTIES OF SELENIUM COMPOUNDS Item Type text; Dissertation-Reproduction (electronic) Authors White, Joe Wade, 1940- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 25/09/2021 07:39:00 Link to Item http://hdl.handle.net/10150/284855 This dissertation has been ~ microfilmed exactly as received 67-11,365 WHITE, Joe Wade, 1940- OXIDIZING PROPERTIES OF SELENIUM COMPOUNDS. University of Arizona, Ph.D., 1967 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan OXIDIZING PROPERTIES OF SELENIUM COMPOUNDS by Joe Wade White A Dissertation Submitted to the Faculty of the DEPARTMENT OF CHEMISTRY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 19 6 7 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE I hereby recommend that this dissertation prepared under my direction by Joe Wade White entitled Oxidizing Properties of Selenium Compounds be accepted as fulfilling the dissertation requirement of the degree of Doctor of Philosophy Dissertation DirectorDire Date After inspection of the dissertation, the following members of the Final Examination Committee concur in its approval and recommend its acceptance:* *//s/ 7 —r—/ is- is? ll S a-/3 -(-7 » -/S-4 7 *This approval and acceptance is contingent on the candidate's adequate performance and defense of this dissertation at the final oral examination. The inclusion of this sheet bound into the library copy of the dissertation is evidence of satisfactory performance at the final examination.
    [Show full text]
  • Aspects of Organoselenium Chemistry
    Aspects of Organoselenium Chemistry A thesis presented for the degree of Doctor of Philosophy by Virginia R. Ward B.Sc. (Hons) School of Chemistry and Physics November 2012 TABLE OF CONTENTS ABSTRACT iii STATEMENT OF ORIGINALITY v ACKNOWLEDGEMENTS vi ABBREVIATIONS vii 1 INTRODUCTION 1 1.1 SELENIUM 1 1.2 ORGANOSELENIUM CHEMISTRY 5 1.2.1 Selenium dioxide 5 1.2.2 Electrophilic Selenium Reagents 7 1.2.3 Nucleophilic Selenium Reagents 15 1.2.4 Radical Chemistry of Organoselenium Compounds 21 1.2.5 The Selenoxide syn-Elimination 26 1.2.5 Biotransformation of Organoselenium Compounds 29 2 THE AMIDOSELENATION OF ALKENES 32 2.1 INTRODUCTION 32 2.2 INVESTIGATION OF THE FORMATION OF THE trans-OXAZOLINE (2.9) 34 2.3 ONE-POT PREPARATION OF -AMIDO SELENIDES 40 2.4 ALTERNATIVE SOLVENTS FOR THE AMIDOSELENATION REACTION 46 2.5 TWO-STEP PREPARATION OF -AMIDO SELENIDES 49 2.6 PREPARATION OF THE trans-OXAZOLINE (2.9) 56 3 CYCLISATION OF -AMIDOALKYL PHENYL SELENIDES 59 3.1 INITIAL ATTEMPTS TO OPTIMISE THE FORMATION OF N-ACYLAZIRIDINES 59 3.2 CYCLISATION OF -AMIDO SELENIDES AT LOW TEMPERATURE 67 3.3 SUMMARY OF RESULTS FROM THE CYCLISATION OF -AMIDO SELENIDES 76 3.4 FACTORS DETERMINING THE FORMATION OF 3- VERSUS 5-MEMBERED RINGS 77 3.5 OCCURRANCE AND UTILITY OF N-ACYLAZIRIDINES 79 4 AMIDOSELENATION via ADDITION OF ‘PHENYLSELENENYL PERCHLORATE’ 83 4.1 INTRODUCTION 83 4.2 PREPARATION OF -(PHENYLSELANYL)CYCLOHEXYL AMIDES 86 4.3 ALTERNATIVES TO THE -AMIDO SUBSTITUENT 88 5 CLOSER EXAMINATION OF A SELENOXIDE AND A SELENONE 92 5.1 PREPARATION OF N-[2-(PHENYLSELENINYL)CYCLOHEXYL]BENZAMIDE
    [Show full text]
  • Selective Selenoxide Elimination on the Secondary Face of Beta- Cyclodextrin
    W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1998 Selective Selenoxide Elimination on the Secondary Face of beta- Cyclodextrin Ahmed M. Hafez College of William & Mary - Arts & Sciences Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Organic Chemistry Commons Recommended Citation Hafez, Ahmed M., "Selective Selenoxide Elimination on the Secondary Face of beta-Cyclodextrin" (1998). Dissertations, Theses, and Masters Projects. Paper 1539626167. https://dx.doi.org/doi:10.21220/s2-40pe-w331 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. LIBRARY College of William and Mary SELECTIVE SELENOXIDE ELIMINATION ON THE SECONDARY FACE OF p-CYCLODEXTRIN A Thesis Presented to The Faculty of the Department of Chemistry The College of William and Mary in Virginia In Partial Fulfillment Of the Requirements for the Degree of Master of Arts by Ahmed M. Hafez August 1998 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts JlJA MS ' Ahmed M. H a ^ / Approved, August 1998 Christopher J. Abeu/Ph. D Robert J: Hinkle, Ph. D. ’athleen M. Morgan, IJh. D TABLE OF CONTENTS ACKNOWLEDGMENTS................................................................................
    [Show full text]
  • Selenium Reagents As Catalysts
    This is an Open Access document downloaded from ORCA, Cardiff University's institutional repository: http://orca.cf.ac.uk/119210/ This is the author’s version of a work that was submitted to / accepted for publication. Citation for final published version: Singh, Fateh Veer and Wirth, Thomas 2019. Selenium reagents as catalysts. Catalysis Science & Technology 9 (5) , pp. 1073-1091. 10.1039/C8CY02274G file Publishers page: http://dx.doi.org/10.1039/C8CY02274G <http://dx.doi.org/10.1039/C8CY02274G> Please note: Changes made as a result of publishing processes such as copy-editing, formatting and page numbers may not be reflected in this version. For the definitive version of this publication, please refer to the published source. You are advised to consult the publisher’s version if you wish to cite this paper. This version is being made available in accordance with publisher policies. See http://orca.cf.ac.uk/policies.html for usage policies. Copyright and moral rights for publications made available in ORCA are retained by the copyright holders. Selenium Reagents as Catalysts a b Fateh V. Singh,* Thomas Wirth* Organoselenium chemistry is now become an important tool in synthetic and medicinal chemistry. Organoselenium reagents are more commonly known as electrophiles but there are few organic transformations where they act as nucleophiles. These reagents have been successfully employed to achieve number of synthetically important transformations such as oxyselenenylations, selenocyclisation and selenoxide eliminations etc. In past two decades, another episode of their success is introduced as they have developed as potential catalysts in organic synthesis. Various selenium-catalysed approaches such as oxidation, reduction, cyclisation, rearrangement and stereoselective reactions have been successfully investigated.
    [Show full text]