DOCSLIB.ORG

Diboron(4) Compounds: from Structural Curiosity to Synthetic Workhorse Emily C

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Diboron(4) Compounds: from Structural Curiosity to Synthetic Workhorse Emily C This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. Review pubs.acs.org/CR Diboron(4) Compounds: From Structural Curiosity to Synthetic Workhorse Emily C. Neeve,† Stephen J. Geier,§ Ibraheem A. I. Mkhalid,‡ Stephen A. Westcott,*,§ and Todd B. Marder*,† † Institut für Anorganische Chemie, Julius-Maximilians-UniversitatWü ̈rzburg, Würzburg 97074, Germany § Mount Allison University, Department of Biochemistry and Chemistry, Sackville, New Brunswick E4L 1G8, Canada ‡ Department of Chemistry, King Abdulaziz University, Jeddah 21413, Saudi Arabia ABSTRACT: Although known for over 90 years, only in the past two decades has the chemistry of diboron(4) compounds been extensively explored. Many interesting structural features and reaction patterns have emerged, and more importantly, these compounds now feature prominently in both metal-catalyzed and metal-free methodologies for the formation of B−C bonds and other processes. CONTENTS 4. Boryl Addition (Hydroboration) Reactions 9115 4.1. α,β-Unsaturated Carbonyls, Imines, and 1. Introduction 9092 Related Compounds 9115 2. Synthesis, Structure, and Bonding of Diboron(4) 4.2. Alkynes 9119 Compounds 9093 4.3. Alkenes 9121 2.1. B2X4 Compounds 9093 4.4. Dienes, Enynes, and Allenes 9122 2.2. B2H4 Chemistry 9094 4.5. Aldehydes and Imines 9123 2.3. B2(NR2)4 Compounds 9094 4.6. Ring-Opening Reactions 9123 2.4. B2(alkyl)n Compounds 9095 4.7. Borylative Cyclizations and Related Intermo- 2.5. B2(OR)4 Compounds 9095 lecular Reactions 9124 2.5.1. Synthesis of B2(OR)4 9095 4.8. Boron-Element Additions Across Mutiple 2.5.2. Adducts of B2(OR)4 Compounds 9096 Bonds 9125 2.6. Three-Membered Aromatic Heterocycles − 4.9. Diagram Summarizing Section 4 9126 Containing B B Bonds 9098 5. Boryl Substitutions 9126 2.7. Diboryl Groups as Ligands 9098 5.1. Coupling Reactions 9126 2.8. [2]-Borametalloarenophanes 9098 − 5.2. Allylic and Propargylic Substitutions 9127 2.9. B B Bonding 9099 5.3. Alkyl Substitutions 9130 3. 1,2- and 1,4-Diborations 9101 5.4. Alkenyl Substitutions 9131 3.1. Mechanistic Studies of 1,2-Diboration Pro- 5.5. Aromatic Substitutions 9131 cesses 9101 5.5.1. Aryl Halides 9131 3.2. Alkynes 9104 5.5.2. Aryl C−O Electrophiles 9135 3.3. Alkenes (Aliphatic) 9105 5.5.3. Aryl C−N Bonds 9136 3.4. Alkenes (Vinyl Arenes) 9107 5.5.4. Aryl Nitriles 9136 3.5. Alkenyl and Alkynyl Boronate Esters 9108 5.6. Diagram Summarizing Section 5 9137 3.6. Dienes 9109 6. Conclusion 9137 3.7. Allenes 9110 Author Information 9137 3.8. Carbonyls and Thiocarbonyls 9112 Corresponding Authors 9137 3.9. Imines 9113 3.10. Other Substrates 9113 3.11. Unsaturated Carbonyls 9114 3.12. Diagram Summarizing Section 3 9115 Received: March 22, 2016 Published: July 19, 2016 © 2016 American Chemical Society 9091 DOI: 10.1021/acs.chemrev.6b00193 Chem. Rev. 2016, 116, 9091−9161 Chemical Reviews Review Figure 1. Diboron compounds. Notes 9137 1b).11 This compound was arduously prepared by the slow Biographies 9137 passage of B5H9, in an atmosphere of dihydrogen, through an Acknowledgments 9138 electric discharge between copper electrodes. Not surprisingly, References 9138 while several theoretical and physical studies have focused on − this complex,12 22 its complicated synthesis has limited the synthetic potential of this unique diboron compound, and its ff 1. INTRODUCTION chemistry remains largely unexplored. A di erent structural − isomer of B10H16, also bearing a central B B bond where The advent of diboron(4) compounds in 1925 introduced a neither boron atom bears a terminal hydride, was prepared by new group of reagents that would eventually prove to be very Sneddon and co-workers through the dehydrocoupling of versatile and extremely useful in many synthetic pathways to B H .23 form a range of valuable natural products, pharmaceutical 5 9 1 Brown further extended research on diboron compounds by intermediates, and biologically active compounds. Further- developing a pantheon of alkyl- and dialkylboranes by the more, organic compounds containing boron are ideal addition of BH ·LB (where LB = Lewis base, such as THF or candidates for green chemistry as they are generally considered 3 SMe2) to alkenes. For example, the addition of borane to nontoxic to plants, mammals, and other complex life forms and ff 2 cyclooctadiene a ords 9-borabicyclo[3.3.1]nonane (9-BBN, are therefore environmentally benign. The past few decades 24 Figure 1c), which has found extensive use in hydroboration have seen remarkable progress in both inorganic and organic reactions, wherein the B−H bond of the borane adds to an boron chemistry, with several people awarded the Nobel Prize − unsaturated organic fragment to generate the corresponding for their ground-breaking research in these emerging areas.3 5 organoborane. In the absence of a Lewis base, dialkylboranes William Lipscomb and Herbert Brown were awarded the usually exist as dimers, in which the two boron fragments are Nobel Prize in 1976 and 1979, respectively, for their once again connected by two three-center, two-electron B−H− contributions to the field of boron chemistry. Lipscomb’s main contribution in this field came from deducing the nature B bridges. In 2010, the Nobel Prize was awarded to Professor Akira of chemical bonding in boranes, such as B2H6, diborane(6), and clusters (Figure 1a), although he also made significant Suzuki for his outstanding work on cross-coupling reactions contributions to both nuclear magnetic resonance spectroscopy and the corresponding organoborane products and boronate reagents that have all but usurped the role of their more toxic and in the chemistry of large biomolecules. Using X-ray 5,25 crystallography as a method of structural determination, tin counterparts. − − Lipscomb and others6 9 were able to assess the nature of The Suzuki Miyaura reaction uses organoboranes (primarily “ ” aryl boronic acids, ArB(OH)2, and their boronate ester B2H6, where the two BH3 fragments were connected to one another through two B−H−B interactions with a pair of derivatives, ArB(OR)2) and organic halides (ArX or RX), in electrons shared among the three atoms. No significant boron− the presence of a catalyst, to generate organic products − boron interaction is believed to occur in these three-center two- containing a new C C bond (Scheme 1a and 1b). Although electron bonds, and the chemistry of diborane(6) proceeds aryl boronic acid derivatives have traditionally been prepared primarily via cleavage, either homolytically or heterolytically, of using Grignard and organolithium reagents, alternative − − borylation reactions using dialkoxyboranes or diboron(4) the two B H B bonds. 26 27,28 Furthering the understanding of boron chemistry, Nobel compounds, such as B2cat2 (cat = 1,2-O2C6H4), B2pin2 29 Prize laureate Roald Hoffmann was a doctoral student in (pin =1,2-O2C2Me4, Figure 1d), and B2neop2 (neop = Lipscomb’s laboratory and later responsible, in part, for OCH2CMe2CH2O, Figure 1e), have been developed (Scheme developing the extended Hückel method for calculating 1c). These diboron(4) compounds are relatively stable and easy molecular orbitals, the fragment molecular orbital (FMO) to handle and are increasingly utilized in all aspects of approach, and for developing the isolobal analogy well beyond chemistry. Indeed, it is now difficult to keep pace with the latest the boron cluster field.10 Other notable boron chemists that developments using these tetraalkoxydiboron(4) compounds, including tetrahydroxydiboron, as their full potential is still worked with Lipscomb included M. Frederick Hawthorne, − pioneer in the synthesis of boron and carborane clusters and coming to light (Figure 2).30 56 The volume of papers their metal-containing compounds, and Russell Grimes, who published in this area has grown exponentially, with bis- found that a remarkable boron hydride, namely, B10H16, (pinacolato)diboron appearing as a reactant or reagent in as contains a direct and unsupported B−B bond, where neither many as 8193 publications (SciFinder, 01.02.2016). The utility of the central boron atoms has a terminal hydride (Figure of these remarkable compounds continues to grow rapidly, 9092 DOI: 10.1021/acs.chemrev.6b00193 Chem. Rev. 2016, 116, 9091−9161 Chemical Reviews Review 63−70 Scheme 1. (a) Generic Suzuki−Miyaura Cross-Coupling preparation of B2Cl4 have been examined, including an Reaction; (b) Cross-Coupling of a Diborated Alkene with early reaction using microwave excitation of gaseous boron Iodobenzene; (c) Miyaura Borylation of an Aryl Halide with trichloride,71 these attempts suffered from low yields and harsh B2pin2 reaction conditions. Interestingly, diboron tetrachloride has been prepared by reaction of boron trichloride with boron ° 72 monoxide, x(BO)x, at 200 C. The starting boron monoxide was generated by dehydration of tetrahydroxydiboron(4), B2(OH)4, previously prepared by the hydrolysis of tetrakis- (dimethylamino)diboron(4), B2(NMe2)4, in aqueous hydro- chloric acid solution. Furthermore, Schlesinger et al. inves- fi tigated the reaction of B2Cl4 with BBr3 to obtain the rst proof 63 for the formation of B2Br4. However, later, the diboron tetrabromide species was prepared using a similar methodology to the B2Cl4 system with tetramethoxydiboron(4) and boron tribromide.68,73 The importance of these tetrahydroxy-, tetramethoxy-, and tetraaminodiboron(4) compounds will be addressed later (sections 2.3 and 2.5). Investigations into the synthesis of related diboron tetrahalides, B2I4 and B2F4, were also conducted. The preparation of diboron tetraiodide was first reported by Schumb in 1949 using electrodeless radiofrequency discharge 74,75 to reduce BI3, while B2F4 was initially prepared, almost a 76 decade later, in 1958 from the reaction of B2Cl4 and SbF3. In 1967, Timms reported the formation of B2F4, as well as triboron pentafluoride, during the co-condensation of BF with − ° 77 BF3 at 196 C.
Load more

Recommended publications
  • Triazene (H2NNNH) Or Triimide (HNHNNH) Markofçrstel,[A, D] Yetsedaw A
    DOI:10.1002/cphc.201600414 Articles On the Formation of N3H3 Isomers in Irradiated Ammonia Bearing Ices:Triazene (H2NNNH) or Triimide (HNHNNH) MarkoFçrstel,[a, d] Yetsedaw A. Tsegaw,[b] Pavlo Maksyutenko,[a, d] Alexander M. Mebel,[c] Wolfram Sander,[b] and Ralf I. Kaiser*[a, d] The remarkable versatility of triazenesinsynthesis, polymer theoretical studies with our novel detection scheme of photo- chemistry and pharmacology has led to numerousexperimen- ionization-driven reflectron time-of-flight mass spectroscopy tal and theoretical studies.Surprisingly,only very little is we can obtain information on the isomersoftriazene formed known aboutthe most fundamental triazene:the parentmole- in the films. Using isotopically labeled starting material, we can cule with the chemical formula N3H3.Here we observe molecu- additionally gain insightinthe formation pathways of the iso- lar,isolated N3H3 in the gas phase after it sublimes from ener- mers of N3H3 under investigation and identify the isomers getically processed ammonia and nitrogen films. Combining formedastriazene (H2NNNH) andpossibly triimide(HNHNNH). 1. Introduction During the last decades, triazenes—a class of organic mole- life time of at least 1mswas also inferred as an intermediate cules carrying the =N N=N moiety—have received substan- in the radiolysis of an aqueous solution of hydrazine based on À À tial attention both from the theoretical and organic chemistry asingle absorption feature at 230 nm.[6] The cyclic isomer of [1] communities. Derived from cis-and trans-triazene (HN=NNH2 ; triazene, cyclotriazane, was first reported crystallographically in Scheme1), the substituted counterparts have significant appli- zeolite A, where it was stabilized by asilver cation as [1a,c] [1d] + [7] + cations in synthetic chemistry, polymer science, and phar- Ag(N3H3) .
    [Show full text]
  • Frontiers in Iridium-Catalyzed CH Borylation
    Frontiers in Iridium-Catalyzed C-H Borylation: Attaining Novel Reactivity and Selectivity By Matthew Alan Larsen A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemistry in the Graduate Division of the University of California, Berkeley Committee in charge: Professor John F. Hartwig, Chair Professor Robert G. Bergman Professor Alexis T. Bell Fall 2016 Abstract Frontiers in Iridium-Catalyzed C-H Borylation: Attaining Novel Reactivity and Selectivity By Matthew Alan Larsen Doctor of Philosophy in Chemistry University of California, Berkeley Professor John F. Hartwig, Chair The following dissertation discusses the development of novel methodology for the catalytic borylation of C-H bonds and includes in-depth studies on the mechanism and selectivity of these synthetic transformations. These methods include the borylation of heteroaryl C-H bonds, the selective borylation of benzylic C-H bonds, and the directed and undirected borylation of unactivated alkyl C-H bonds. Chapter 1 contains a comprehensive review of C-H borylation methodology. This review focuses on the initial development of catalytic C-H borylation and on the state-of- the-art of methodology for the undirected and directed borylation of aryl, benzylic, and alkyl C-H bonds. Additionally, this review highlights knowledge gaps and unsolved challenges. Furthermore, this review provides the author’s opinion on future directions for research on the borylation of C-H bonds. Chapter 2 describes the study of the iridium-catalyzed borylation of heteroaryl C- H bonds. Contained is an examination of the scope of the borylation of heterocycles containing more than one heteroatom and rules for predicting the site-selectivity of this reaction.
    [Show full text]
  • Studies on New Vasodilators, Ws-1228 a and B Ii. Structure and Synthesis
    VOL. XXXV NO. 2 THE JOURNAL OF ANTIBIOTICS 157 STUDIES ON NEW VASODILATORS, WS-1228 A AND B II. STRUCTURE AND SYNTHESIS HIROKAZU TANAKA, KEIZO YOSHIDA, YOSHIKUNI ITOH and HIROSHI IMANAKA Fermentation Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., Osaka, Japan (Received for publication October 26, 1981) The structure of new hypotensive vasodilators, WS-1228 A and B, produced by Strepto- myces aureofaciens, were determined as I and 2, respectively, on the basis of their spectral and chemical evidences. WS-1228 A (1), having N-hydroxytriazene moiety, was synthesized from (E,E,E)-2,4,7- undecatrienal (4) by condensation with hydrazine hydrate followed by nitrosation. In the course of screening for new biologically active compounds, we found that Streptomyces aureofaciens produces hypotensive vasodilators designated as WS-1228 A (1) and B (2). Taxonomy, isolation and characterization of these compounds have been reported in the preceding papery. This report describes the structure elucidations of WS-1228 A (1) and B (2) and the synthesis of 1. WS-1228 A (1) WS-1228 B (2) WS-1228 A (1) was isolated as yellow needles [mp 100 - 102°C (dec.)] which showed a positive color reaction to ferric chloride reagent. Elemental analysis and mass spectrum established the molecular formula of 1 as C11H17N3O. Absorption bands at 1612 and 1580 cm-1 in its IR spectrum (Fig. 1) and at 300 nm in its UV spectrum suggested the presence of the triene oxime moiety. The PMR spectrum (Fig. Fig. 1. IR spectrum of WS-1228 A (1) (Nujol). 158 THE JOURNAL OF ANTIBIOTICS FEB.
    [Show full text]
  • 1 Structure, Properties, and Preparation of Boronic Acid Derivatives Overview of Their Reactions and Applications Dennis G
    j1 1 Structure, Properties, and Preparation of Boronic Acid Derivatives Overview of Their Reactions and Applications Dennis G. Hall 1.1 Introduction and Historical Background Structurally, boronic acids are trivalent boron-containing organic compounds that possess one carbon-based substituent (i.e., a CÀB bond) and two hydroxyl groups to fill the remaining valences on the boron atom (Figure 1.1). With only six valence electrons and a consequent deficiency of two electrons, the sp2-hybridized boron atom possesses a vacant p-orbital. This low-energy orbital is orthogonal to the three substituents, which are oriented in a trigonal planar geometry. Unlike carbox- ylic acids, their carbon analogues, boronic acids, are not found in nature. These abiotic compounds are derived synthetically from primary sources of boron such as boric acid, which is made by the acidification of borax with carbon dioxide. Borate esters, one of the key precursors of boronic acid derivatives, are made by simple dehydration of boric acid with alcohols. The first preparation and isolation of a boronic acid was reported by Frankland in 1860 [1]. By treating diethylzinc with triethylborate, the highly air-sensitive triethylborane was obtained, and its slow oxidation in ambient air eventually provided ethylboronic acid. Boronic acids are the products of a twofold oxidation of boranes. Their stability to atmospheric oxidation is considerably superior to that of borinic acids, which result from the first oxidation of boranes. The product of a third oxidation of boranes, boric acid, is a very stable and relatively benign compound to humans (Section 1.2.2.3). Their unique properties and reactivity as mild organic Lewis acids, coupled with their stability and ease of handling, are what make boronic acids a particularly attractive class of synthetic intermediates.
    [Show full text]
  • Binuclear Copper(I) Borohydride Complex Containing Bridging Bis
    crystals Article Binuclear Copper(I) Borohydride Complex Containing Bridging Bis(diphenylphosphino) Methane Ligands: Polymorphic Structures of 2 [(µ2-dppm)2Cu2(η -BH4)2] Dichloromethane Solvate Natalia V. Belkova 1 ID , Igor E. Golub 1,2 ID , Evgenii I. Gutsul 1, Konstantin A. Lyssenko 1, Alexander S. Peregudov 1, Viktor D. Makhaev 3, Oleg A. Filippov 1 ID , Lina M. Epstein 1, Andrea Rossin 4 ID , Maurizio Peruzzini 4 and Elena S. Shubina 1,* ID 1 A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), 119991 Moscow, Russia; [email protected] (N.V.B.); [email protected] (I.E.G.); [email protected] (E.I.G.); [email protected] (K.A.L.); [email protected] (A.S.P.); [email protected] (O.A.F.); [email protected] (L.M.E.) 2 Inorganic Chemistry Department, Peoples’ Friendship University of Russia (RUDN University), 117198 Moscow, Russia 3 Institute of Problems of Chemical Physics, Russian Academy of Sciences (IPCP RAS), 142432 Moscow, Russia; [email protected] 4 Istituto di Chimica dei Composti Organometallici Consiglio Nazionale delle Ricerche (ICCOM CNR), 50019 Sesto Fiorentino, Italy; [email protected] (A.R.); [email protected] (M.P.) * Correspondence: [email protected]; Tel.: +7-495-135-5085 Academic Editor: Sławomir J. Grabowski Received: 18 September 2017; Accepted: 17 October 2017; Published: 20 October 2017 Abstract: Bis(diphenylphosphino)methane copper(I) tetrahydroborate was synthesized by ligands exchange in bis(triphenylphosphine) copper(I) tetrahydroborate, and characterized by XRD, FTIR, NMR spectroscopy. According to XRD the title compound has dimeric structure, [(µ2-dppm)2Cu2(η2-BH4)2], and crystallizes as CH2Cl2 solvate in two polymorphic forms (orthorhombic, 1, and monoclinic, 2) The details of molecular geometry and the crystal-packing pattern in polymorphs were studied.
    [Show full text]
  • Cuh-Catalyzed Enantioselective Alkylation of Indole Derivatives with Ligand-Controlled Regiodivergence
    CuH-Catalyzed Enantioselective Alkylation of Indole Derivatives with Ligand-Controlled Regiodivergence The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Ye, Yuxuan et al. "CuH-Catalyzed Enantioselective Alkylation of Indole Derivatives with Ligand-Controlled Regiodivergence." Journal of the American Chemical Society 141, 9 (January 2019): 3901–3909 © 2019 American Chemical Society As Published http://dx.doi.org/10.1021/jacs.8b11838 Publisher American Chemical Society (ACS) Version Author's final manuscript Citable link https://hdl.handle.net/1721.1/126070 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. HHS Public Access Author manuscript Author ManuscriptAuthor Manuscript Author J Am Chem Manuscript Author Soc. Author Manuscript Author manuscript; available in PMC 2020 March 06. Published in final edited form as: J Am Chem Soc. 2019 March 06; 141(9): 3901–3909. doi:10.1021/jacs.8b11838. CuH-Catalyzed Enantioselective Alkylation of Indole Derivatives with Ligand-Controlled Regiodivergence Yuxuan Ye1, Seoung-Tae Kim2,3, Jinhoon Jeong2,3, Mu-Hyun Baik2,3,*, and Stephen L. Buchwald1,* 1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, United States 2Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea 3Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea Abstract Enantioenriched molecules bearing indole-substituted stereocenters form a class of privileged compounds in biological, medicinal, and organic chemistry.
    [Show full text]
  • Copper Hydride Catalyzed Hydroamination of Alkenes and Alkynes
    Copper Hydride Catalyzed Hydroamination of Alkenes and Alkynes The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Pirnot, Michael T., Yi-Ming Wang, and Stephen L. Buchwald. “Copper Hydride Catalyzed Hydroamination of Alkenes and Alkynes.” Angewandte Chemie International Edition 55.1 (2016): 48–57. As Published http://dx.doi.org/10.1002/anie.201507594 Publisher Wiley Blackwell Version Author's final manuscript Citable link http://hdl.handle.net/1721.1/110464 Terms of Use Creative Commons Attribution-Noncommercial-Share Alike Detailed Terms http://creativecommons.org/licenses/by-nc-sa/4.0/ HHS Public Access Author manuscript Author Manuscript Author ManuscriptAngew Chem Author Manuscript Int Ed Engl Author Manuscript . Author manuscript; available in PMC 2016 March 08. Published in final edited form as: Angew Chem Int Ed Engl. 2016 January 4; 55(1): 48–57. doi:10.1002/anie.201507594. Copper Hydride-Catalyzed Hydroamination of Alkenes and Alkynes Dr. Michael T. Pirnot†, Dr. Yi-Ming Wang†, and Prof. Dr. Stephen L. Buchwald Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, MA 02139 (USA) Stephen L. Buchwald: [email protected] Abstract Over the past few years, CuH-catalyzed hydroamination has been discovered and developed as a robust and conceptually novel approach for the synthesis of enantioenriched secondary and tertiary amines. The success in this area of research was made possible through the large body of precedent in copper(I) hydride catalysis and the well-explored use of hydroxylamine esters as electrophilic amine sources in related copper-catalyzed processes.
    [Show full text]
  • Condensed-Phase Photochemistry in the Absence of Radiation Chemistry Ella Mullikin
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Wellesley College Wellesley College Wellesley College Digital Scholarship and Archive Faculty Research and Scholarship 6-27-2018 Condensed-Phase Photochemistry in the Absence of Radiation Chemistry Ella Mullikin Pierce van Mulbregt Jeniffer Perea Muhammad Kasule Jean Huang See next page for additional authors Follow this and additional works at: https://repository.wellesley.edu/scholarship Version: Post-print Recommended Citation E. Mullikin, P. van Mulbregt, J. Perea, M. Kasule, J. Huang, C. Buffo, J. Campbell, L. Gates, H. M. Cumberbatch, Z. Peeler, H. Schneider, J. Lukens, S. T. Bao, R. Tano-Menka, S. Baniya, K. Cui, M. Thompson, A. Hay, L. Widdup, A. Caldwell-Overdier, J. Huang, M. C. Boyer, M. Rajappan, G. Echebiri and C. R. Arumainayagam, ACS Earth and Space Chemistry, 2018, DOI: 10.1021/ acsearthspacechem.8b00027. This Article is brought to you for free and open access by Wellesley College Digital Scholarship and Archive. It has been accepted for inclusion in Faculty Research and Scholarship by an authorized administrator of Wellesley College Digital Scholarship and Archive. For more information, please contact [email protected]. Authors Ella Mullikin, Pierce van Mulbregt, Jeniffer Perea, Muhammad Kasule, Jean Huang, Christina Buffo, Jyoti Campbell, Leslie Gates, Helen M. Cumberbatch, Zoe Peeler, Hope Schneider, Julia Lukens, Si Tong Bao, Rhoda Tano-Menka, Subha Baniya, Kendra Cui, Mayla Thompson, Aury Hay, Lily Widdup, Anna Caldwell- Overier, Justine Huang, Michael C. Boyer, Mahesh Rajappan, Geraldine Echebiri, and Christopher R. Arumainayagam This article is available at Wellesley College Digital Scholarship and Archive: https://repository.wellesley.edu/scholarship/183 Condensed-Phase Photochemistry in the Absence of Radiation Chemistry Ella Mullikin,1 Pierce van Mulbregt,2 Jeniffer Perea,1 Muhammad Kasule,3 Jean Huang,1 Christina Buffo,1 Jyoti Campbell,1 Leslie Gates,1 Helen M.
    [Show full text]
  • Sop Pyrophoric 2 12/16/2019
    Owner DOC. NO. REV. DATE C.H.O SOP PYROPHORIC 2 12/16/2019 DOC. TITLE SOP FOR PYROPHORIC CHEMICALS Environmental Health & Safety STANDARD OPERATING PROCEDURES (SOP) FOR WORKING WITH PYROPHORIC CHEMICALS AT AMHERST COLLEGE ___________________________________________________________________ General Information Pyrophoric Chemicals are solid, liquid, or gas compounds that, when exposed to air or moisture at or below 54°C (130°F), can spontaneously ignite. Examples of Pyrophoric chemicals used at Amherst College Laboratories include: sodium hydride, zinc powder, and Grignard reagents. See the “Appendix” page below for a full list of Pyrophoric Chemicals. Pyrophoric chemicals are often used as catalysts in chemical reactions or as reducing and deprotonating agents in organic chemistry. Note that Pyrophoric chemicals may also be characterized by other hazards, hence, users of these chemicals may also need to refer to other SOPs that cover other hazards. In addition, each individual chemical’s Safety Data Sheet (SDS) should be consulted before they are used. _____________________________________________________________________________________ Personal Protective Equipment When working with Pyrophoric Chemicals, the following personal protective equipment (PPE) must be worn, at a minimum. Depending on the specific chemical, other forms of protection might be required. Consult the SDS for each chemical before use: Splash goggles Lab coat (Fire resistant lab coat highly recommended) Long pants Close toed shoes Gloves – Nitrile gloves adequate for accidental contact with small quantities. However, the use of fire resistant Nomex/ Leather Pilot’s gloves is highly recommended _____________________________________________________________________________________ Safety Devices All work with Pyrophoric chemicals must be done in a glove box, vacuum manifold, or any enclosed inert environment. If work must be done in a fume hood, ensure that the hood sash is in the lowest feasible position.
    [Show full text]
  • Reductive Α-Borylation of Α,Β-Unsaturated Esters Using NHC
    Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Reductive a-borylation of a,b-unsaturated esters using NHC–BH3 activated by I2 as a metal-free Cite this: Chem. Sci.,2019,10,1434 a † All publication charges for this article route to -boryl esters have been paid for by the Royal Society of Chemistry James E. Radcliffe, Valerio Fasano, Ralph W. Adams, Peiran You and Michael J. Ingleson * Useful a-boryl esters can be synthesized in one step from a,b-unsaturated esters using just a simple to access NHC–BH3 (NHC ¼ N-heterocyclic carbene) and catalytic I2. The scope of this reductive a-borylation methodology is excellent and includes a range of alkyl, aryl substituted and cyclic and acyclic a,b-unsaturated esters. Mechanistic studies involving reductive borylation of a cyclic a,b-unsaturated ester with NHC–BD3/I2 indicated that concerted hydroboration of the alkene moiety in the a,b-unsaturated ester proceeds instead of a stepwise process involving initial 1,4-hydroboration; this is in contrast to the recently reported reductive a-silylation. The BH2(NHC) unit can be transformed into Creative Commons Attribution 3.0 Unported Licence. electrophilic BX2(NHC) moieties (X ¼ halide) and the ester moiety can be reduced to the alcohol with the borane unit remaining intact to form b-boryl alcohols. The use of a chiral auxiliary, 8-phenylmenthyl Received 27th September 2018 ester, also enables effective stereo-control of the newly formed C–B bond. Combined two Accepted 17th November 2018 step ester reduction/borane oxidation forms diols, including excellent e.e.
    [Show full text]
  • Activation of Diboron Reagents: the Development of Mild Conditions for the Synthesis of Unique Organoboron Compounds
    Activation of diboron reagents: The development of mild conditions for the synthesis of unique organoboron compounds Steven Brandon Thorpe Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Chemistry Webster L. Santos, Chairman Paul R. Carlier David G. I. Kingston James M. Tanko March 23, 2012 Blacksburg, Virginia Keywords: borylation, diboron reagent, boronic ester, conjugate addition, copper catalysis © 2012 by Steven B. Thorpe Activation of diboron reagents: The development of mild conditions for the synthesis of unique organoboron compounds Steven Brandon Thorpe ABSTRACT The first successful synthesis and isolation of a boronic acid was reported in 1860 by Frankland in the pursuit of novel organometallic compounds. For more than a century, further studies of boronic acids were sparsely published. Suzuki and Miyaura jumpstarted the field in 1979 with an innovative carbon-carbon bond forming reaction employing an organoboronic acid and a carbon halide under palladium catalysis. Indeed, the Nobel Prize in Chemistry was awarded to Professor Akira Suzuki, along with Professors Richard Heck and Ei-ichi Negishi, in 2010 for their important contributions in palladium-catalyzed cross-coupling chemistry. Over the last 30 years, reports on organoboron compounds have increased exponentially. This dissertation describes the author’s contributions to the development of preparative methods for organoboronic acid derivatives
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8.598,022 B2 Kaim Et Al
    US008598O22B2 (12) United States Patent (10) Patent No.: US 8.598,022 B2 Kaim et al. (45) Date of Patent: Dec. 3, 2013 (54) ISOTOPICALLY-ENRICHED (52) U.S. Cl. BORON-CONTAINING COMPOUNDS, AND USPC ............ 438/515; 257/E21.334; 257/E21.473; METHODS OF MAKING AND USING SAME 427/523 (58) Field of Classification Search (75) Inventors: Robert Kaim, Brookline, MA (US); USPC ................... 438/515; 257/E21.334, E21,473; Joseph D. Sweeney, Winsted, CT (US); 427/523 Oleg Byl, Southbury, CT (US); Sharad See application file for complete search history. N. Yedave, Danbury, CT (US); Edward E. Jones, Woodbury, CT (US); Peng (56) References Cited Zou, Ridgefield, CT (US); Ying Tang, Brookfield, CT (US); Barry Lewis U.S. PATENT DOCUMENTS Chambers, Midlothian, VA (US); 4.331,647 A 5/1982 Goldenberg Richard S. Ray, New Milford, CT (US) 4,348,376 A 9/1982 Goldenberg (73) Assignee: Advanced Technology Materials, Inc., (Continued) Danbury, CT (US) FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this EP OOT9705 A1 5, 1983 patent is extended or adjusted under 35 EP O656668 B1 3, 1999 U.S.C. 154(b) by 107 days. (Continued) (21) Appl. No.: 13/300,575 OTHER PUBLICATIONS Byl, O., et al., “Properties of Diboron Tetrafluoride (B2F4), A New (22) Filed: Nov. 19, 2011 Gas for Boron Ion Implantation”, “AIP Conference Proceedings', Jan. 1, 2011, pp. 408-410, vol. 1321. (65) Prior Publication Data d Continue US 2012/0108044 A1 May 3, 2012 ( ) Related U.S. Application Data Primary Examiner — Michelle Mandala (74) Attorney, Agent, or Firm — Hultquist, PLLC; Steven J.
    [Show full text]