Constantinos G. Screttas
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( 12 ) United States Patent
US009981991B2 (12 ) United States Patent (10 ) Patent No. : US 9 , 981, 991 B2 Castillo et al. ( 45 ) Date of Patent: May 29 , 2018 ( 54 ) SYNTHESIS AND ISOLATION OF Hitchcock et al ., “ The first crystalline alkali metal salt of a CRYSTALLINE ALKALIMETAL ARENE benzenoid radical anion without a stabilizing substituent and of a RADICAL ANIONS related dimer: X - ray structures of the toluene radical anion and of the benzene radical anion dimer potassium -crown ether salts . ” J . ( 71 ) Applicants : Efrain Maximiliano Castillo , El Paso , Am . Chem . Soc . , vol . 123 , No . 1 , 2001 , pp . 189 - 190 . TX (US ) ; Skye Fortier , El Paso , TX Rainis et al ., “ Disproportionation of the lithium , sodium , and potassium salts of anthracenide and perylenide radical anions in (US ) DME and THF, ” J. Am . Chem . Soc. , vol. 96 , No. 9 , 1974 , pp . 3008 - 3010 . ( 72 ) Inventors : Efrain Maximiliano Castillo , El Paso , Krieck et al ., “ Rubidium -mediated birch - type reduction of 1 , 2 TX (US ) ; Skye Fortier , El Paso , TX diphenylbenzene in tetrahydrofuran .” J . Am . Chem . Soc . , vol. 133 , (US ) No . 18 , 2011, pp . 6960 - 6963. (73 ) Assignee : THE BOARD OF REGENTS OF Zabula , “ A main group metal sandwich : five lithium cations jammed between two corannulene tetraanion decks .” Science, vol. 333 , No . THE UNIVERSITY OF TEXAS 6045 , 2011, pp . 1008 - 1011. SYSTEM , Austin , TX (US ) Connelly et al ., “ Chemical Redox Agents for Organometallic Chem istry ." Chem . Rev. , vol . 96 , No . 2 , 1996 , pp . 877 - 910 . ( * ) Notice : Subject to any disclaimer , the term of this Kowalczuk et al. , “ New reactions of potassium naphthalenide with patent is extended or adjusted under 35 B - , y - and d - lactones : an efficient route to a -alkyl y - and 8 - lactones U . -
Open Thesis.Pdf
The Pennsylvania State University The Graduate School Department of Chemistry ALKYNYLIODONIUM SALTS IN ORGANIC SYNTHESIS. APPLICATION TOWARDS THE SYNTHESIS OF THE CORE OF (±)-HALICHLORNIE. and ATTEMPTS TOWARDS THE SYNTHESIS OF KINAMYCIN F. A Thesis in Chemistry by Angela Lyn Perkins © 2005 Angela Lyn Perkins Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2005 The thesis of Angela Lyn Perkins was reviewed and approved* by the following: Ken S. Feldman Professor of Chemistry Thesis Advisor Chair of Committee Blake R. Peterson Associate Professor of Chemistry Raymond L. Funk Professor of Chemistry Squire J. Booker Assistant Professor of Biochemistry and Molecular Biology Ayusman Sen Professor of Chemistry Head of the Department of Chemistry *Signatures are on file in the Graduate School iii ABSTRACT Alkynyliodonium salts are synthetically useful intermediates that serve as electrophilic acetylene equivalents due to the electron withdrawing nature of the hypervalent iodine. In one example, reaction of an alkynyliodonium salt with soft nucleophiles via conjugate addition, followed by loss of iodobenzene, generates alkylidenecarbenes. Alkylidenecarbenes are divalent, short lived intermediates capable of participating in a various bond-forming processes depending upon the functionality present within the molecule. Due to the wide variety of possible reactions, alkylidenecarbenes are useful reactive intermediates in natural product synthesis. The application of alkynyliodonium salts to generate alkylidenecarbenes is described in the first part of this thesis. Chapter 1 discusses the formation of alkynyliodonium salts and their application towards the generation of alkylidenecarbenes. The total synthesis of radermachol, a natural product target, was examined utilizing an alkylidenecarbene addition to a double bond as a key step. -
Adventures with Substances Containing Metals in Negative Oxidation States†
Inorg. Chem. 2006, 45, 3167−3186 Adventures with Substances Containing Metals in Negative Oxidation States† John E. Ellis* Department of Chemistry, UniVersity of Minnesota, Minneapolis, Minnesota 55455 Received December 9, 2005 A brief history of substances containing s,p- and d-block metals in negative oxidation states is described. A classification of these species and discussions of formal oxidation state assignments for low-valent transition metals in complexes are included, along with comments on the innocent and noninnocent character of ligands in metalates. Syntheses of highly reduced carbonyl complexes formally containing transition metals in their lowest known oxidation states of III− and IV− are discussed. Atmospheric-pressure syntheses of early-transition-metal carbonyls involving alkali-metal polyarene-mediated reductions of non-carbonyl precursors have been developed. In the absence of carbon monoxide, these reactions afford homoleptic polyarenemetalates, including the initial species containing three aromatic hydrocarbons bound to one metal. In several instances, these metalates function as useful synthons for “naked” spin-paired atomic anions of transition metals. Introduction The adventures1 to be described in this paper involve the synthesis and characterization of anionic carbonyls and related complexes of d-block elements that my students and I have carried out over the past 34+ years at the University of Minnesota. However, to properly set the stage for our efforts, it will be necessary to first consider pertinent aspects of the history of free and ligand-stabilized metal anions, including some recent exciting discoveries in this area. The anionic main-group species are of particular interest because they represent the first compounds to contain metals in negative oxidation states or valencies.2 Main-Group Metal Anions John Ellis was born in 1943 in San Pedro, CA. -
Radical Anions, Radicals and Anions
AN ABSTRACTOF THE THESISOF DOCTOR OF PHILOSOPHY Larry Lee Hutchinsonfor the degree of September 21, 1976 in CHEMISTRY presented on THE FORMA- Title:RADICAL ANIONS,RADICALS AND ANIONS. TION ANDSTEREOCHEMISTRY OFALKYL LITHIUM REAGENTS FROMLITHIUM 4,4'-DI-TERT-BUTYLBIPHENYL AND ALKYL HALIDES. ,Redacted for Privacy. Abstract approved: Peter K. Freeman The reactions of alkylhalides with metals andradical anion solutions were investigated. The reaction of exo-and endo-anti-3-chlorotricyclo , deuteroly- [3.2. 1.024joct-6-ene with magnesium inTHF followed by sis gave syn:antideuteriation ratios of 2.2and 0.42, respectively, Analysis of the exohydro- with 85% monodeuteriumincorporation. shift reagent study with carbon involvedepoxidation followed by a 4 chloro-exo-tricyclo[3. 2. 1.02,'octane Eu(fod)3.Reaction of anti-3- -78° in THF with a rate with lithium naphthalenedianion proceeded at lithium constant of 5.5 x10-21V11 min1, while under identical conditions -1 -1. naphthalene exhibited arate constant of1.0 Mmin Deuterolysis incorporation of the dianionsolution gave a syn toanti deuterium with greater than 50.In contrast,7-chloronorcarane in reacting lithium naphthalene in THF at-78° exhibited a rate constant of -1 0. 035 Mmin-1. Deuterolys is of the dianion solution gave a syn to anti deuterium incorporation greaterthan 50.In contrast, 7-chloro- norcarane in reactingwith lithium naphthalene in THE at-78° -1min-1 exhibited a rate constant of 0. 035M for the anti compound while the syn had a rate constantof 0.063. Upon deuterolysis, the deuterium incorporation was75%, with an anti:syn ratio of 7. naphthalene with Mg Brin THF Reaction of sodium or lithium 2 gave a dark precipitatewith properties expected for magnesium metal.Reaction of sodium anthracene withmagnesium bromide in THF, or reaction of magnesiummetals with anthracene in THF gave a yellow solutionof the sparingly soluble magnesiuma.nthracene dianion.Purification and crystallization gave an orangecrystalline solid with a composition of MgA3THF. -
UCLA Electronic Theses and Dissertations
UCLA UCLA Electronic Theses and Dissertations Title Reduction Chemistry of Rare-Earth Metal Complexes: Toward New Reactivity and Properties Permalink https://escholarship.org/uc/item/0m7803zq Author Huang, Wenliang Publication Date 2013 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA Los Angeles Reduction Chemistry of Rare-Earth Metal Complexes: Toward New Reactivity and Properties A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Chemistry by Wenliang Huang 2013 ABSTRACT OF THE DISSERTATION Reduction Chemistry of Rare-Earth Metal Complexes: Toward New Reactivity and Properties by Wenliang Huang Doctor of Philosophy in Chemistry University of California, Los Angeles, 2013 Professor Paula L. Diaconescu, Chair Rare-earths are a group of metals with fascinating physical properties and intriguing chemical reactivity. Organometallic rare-earth chemistry is of particular interest because of the increasing number of their applications in industry and consumer goods as well as the importance of understanding their physical and chemical properties. Despite the dominance of the trivalent oxidation state, recently, low-valent organometallic rare-earth compounds were characterized and showed interesting reactivity toward various molecules. The theme of this thesis is the reduction chemistry of rare-earth metal complexes. By utilizing an electronically and TBS t geometrically flexible ferrocene diamide -
Rare Earth Arene-Bridged Complexes Obtained by Reduction Of
Rare Earth Arene-bridged Complexes Obtained by Reduction of Organometallic Precursors Wenliang Huang and Paula L. Diaconescu* Department of Chemistry & Biochemistry, University of California, Los Angeles, California 90095 ABSTRACT Rare earth chemistry has witnessed remarkable advances in recent years. In particular, ancillary ligands other than cyclopentadienyl derivatives have been introduced to the organometallic chemistry and their complexes exhibit distinct reactivity and properties compared to the metallocene or half-sandwiched analogues. The present chapter reviews arene-bridged rare earth complexes with an emphasis on those compounds obtained by reduction reactions. A particular emphasis is placed on rare earth complexes supported by 1,1′-ferrocenediyl diamides since they show the most diverse chemistry with arenes: fused arenes, such as naphthalene and anthracene, formed inverse-sandwiched complexes, in which the arene is dianionic; weakly conjugated arenes, such as biphenyl, p-terphenyl, and 1,3,5-triphenylbenzene, were unexpectedly reduced by four electrons and led to 6-carbon, 10- electron aromatic systems; on the contrary, (E)-stilbene, which has a carbon-carbon double bond between the two phenyl rings, could only be reduced by two electrons, which were located on the carbon-carbon double bond instead of the phenyl rings. The reactivity of some rare earth arene-bridged complexes is also discussed with noticeable examples being the activation of white phosphorus (P4) by rare earth naphthalene complexes. 4- 3- Stoichiometric P4 activation led to polyphosphide (P8 or P7 ), which could then be transferred to phosphorus-containing organic molecules. 1 Table of Content 1. INTRODUCTION 1.1 General Remarks about the Organometallic Chemistry of Rare Earths This review summarizes recent advances in arene rare earth chemistry with an emphasis on complexes obtained by reduction and supported by non-cyclopentadienyl ancillary ligands.