1
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Logallo A, Maddock LCH, Mu M, Gravogl L, Jin N, Peñas-Defrutos MN, Meyer K, García-Melchor M, Hevia E. Unlocking the Metalation Applications of TMP-powered Fe and Co(II) bis(amides): Synthesis, Structure and Mechanistic Insights. Angew Chem Int Ed Engl 2024; 63:e202402907. [PMID: 38563772 DOI: 10.1002/anie.202402907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/19/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024]
Abstract
Typified by LiTMP and TMPMgCl.LiCl, (TMP=2,2,6,6-tetramethylpiperidide), s-block metal amides have found widespread applications in arene deprotonative metalation. On the contrary, transition metal amides lack sufficient basicity to activate these substrates. Breaking new ground in this field, here we present the synthesis and full characterisation of earth-abundant transition metals M(TMP)2 (M=Fe, Co). Uncovering a new reactivity profile towards fluoroarenes, these amide complexes can promote direct M-H exchange processes regioselectively using one or two of their basic amide arms. Remarkably, even when using a perfluorinated substrate, selective C-H metalation occurs leaving C-F bonds intact. Their kinetic basicity can be boosted by LiCl or NBu4Cl additives which enables formation of kinetically activated ate species. Combining spectroscopic and structural studies with DFT calculations, mechanistic insights have been gained on how these low polarity metalation processes take place. M(TMP)2 can also be used to access ferrocene and cobaltocene by direct deprotonation of cyclopentadiene and undergo efficient CO2 insertion of both amide groups under mild reaction conditions.
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Affiliation(s)
- Alessandra Logallo
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Lewis C H Maddock
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Manting Mu
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
| | - Lisa Gravogl
- Department of Chemistry and Pharmacy, Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Na Jin
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Marconi N Peñas-Defrutos
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
- IU CINQUIMA, Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, 47071, Valladolid, Spain
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Max García-Melchor
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
| | - Eva Hevia
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
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2
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Sekiguchi Y, Pang JH, Ng JS, Chen J, Watanabe K, Takita R, Chiba S. Base-Induced Dehydrogenative and Dearomative Transformation of 1-Naphthylmethylamines to 1,4-Dihydronaphthalene-1-carbonitriles. JACS AU 2022; 2:2758-2764. [PMID: 36590271 PMCID: PMC9795570 DOI: 10.1021/jacsau.2c00487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
Solvothermal treatment of 1-naphthylmethylamine with potassium hydride (KH) or n-butyllithium (n-BuLi)-potassium t-butoxide (t-BuOK) in THF induces unusual two consecutive β-hydride eliminations to form 1-naphthonitrile and KH. The freshly generated KH is hydridic enough to undergo dearomative hydride addition to the resultant 1-naphthonitrile regioselectively at the C4 position to afford α-cyano benzylic carbanion, which could be functionalized by a series of electrophiles, liberating the corresponding 1,4-dihydronaphthalene-1-carbonitriles having a quaternary carbon center.
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Affiliation(s)
- Yoshiya Sekiguchi
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Jia Hao Pang
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Jia Sheng Ng
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Jiahua Chen
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Kohei Watanabe
- Graduate
School of Pharmaceutical Sciences, The University
of Tokyo, 7-3-1 Hongo,
Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryo Takita
- Graduate
School of Pharmaceutical Sciences, The University
of Tokyo, 7-3-1 Hongo,
Bunkyo-ku, Tokyo 113-0033, Japan
- School
of Pharmaceutical Sciences, University of
Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Shunsuke Chiba
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
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3
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Pollard VA, Fuentes MA, Robertson SD, Weetman C, Kennedy AR, Brownlie J, Angus FJ, Smylie C, Mulvey RE. Reactivity studies and structural outcomes of a bulky dialkylaluminium amide in the presence of the N-heterocyclic carbene, ItBu. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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4
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Evans R. The interpretation of small molecule diffusion coefficients: Quantitative use of diffusion-ordered NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 117:33-69. [PMID: 32471534 DOI: 10.1016/j.pnmrs.2019.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 06/11/2023]
Abstract
Measuring accurate molecular self-diffusion coefficients, D, by nuclear magnetic resonance (NMR) techniques has become routine as hardware, software and experimental methodologies have all improved. However, the quantitative interpretation of such data remains difficult, particularly for small molecules. This review article first provides a description of, and explanation for, the failure of the Stokes-Einstein equation to accurately predict small molecule diffusion coefficients, before moving on to three broadly complementary methods for their quantitative interpretation. Two are based on power laws, but differ in the nature of the reference molecules used. The third addresses the uncertainties in the Stokes-Einstein equation directly. For all three methods, a wide range of examples are used to show the range of chemistry to which diffusion NMR can be applied, and how best to implement the different methods to obtain quantitative information from the chemical systems studied.
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Affiliation(s)
- Robert Evans
- Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, United Kingdom.
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5
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Martínez-Martínez AJ, Kennedy AR, Paprocki V, Fantuzzi F, Dewhurst RD, O'Hara CT, Braunschweig H, Mulvey RE. Selective mono- and dimetallation of a group 3 sandwich complex. Chem Commun (Camb) 2019; 55:9677-9680. [PMID: 31347619 DOI: 10.1039/c9cc03825f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The scandium Cp/COT hybrid sandwich compound [(η5-C5H5)Sc(η8-C8H8)] is resistant to metallation via conventional alkyllithium and lithium amide bases. In this work, clean, selective, stoichiometric and high-yielding mono- and dimetallation is accomplished using tandem trans-metal-trapping (TMT) involving LiTMP and iBu2AlTMP with deprotonation occurring selectively at the Cp and Cp/COT rings respectively, providing the first examples of selective metallation of a sandwich complex featuring a group 3 element.
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Affiliation(s)
- Antonio J Martínez-Martínez
- Supramolecular Organometallic Chemistry Laboratory CIQSO-Center for Research in Sustainable Chemistry & Department of Chemistry University of Huelva Campus El Camen, 21007 Huelva, Spain
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry University of Strathclyde Glasgow, G1 1XL, UK.
| | - Valerie Paprocki
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Felipe Fantuzzi
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Rian D Dewhurst
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Charles T O'Hara
- WestCHEM, Department of Pure and Applied Chemistry University of Strathclyde Glasgow, G1 1XL, UK.
| | - Holger Braunschweig
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry University of Strathclyde Glasgow, G1 1XL, UK.
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6
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Li L, Hong YJ, Chen DY, Xiao WC, Lin MJ. Anion–π interactions in lithium–organic redox flow batteries. Chem Commun (Camb) 2019; 55:2364-2367. [DOI: 10.1039/c8cc09834d] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The interactions between the electrolyte anions and electron-deficient redox-active organic molecules (anion–π interactions) have strong influences on the battery properties due to the anion–π-induced formation of radical anions or sandwich-like aggregates.
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Affiliation(s)
- Lei Li
- College of Chemistry
- Fuzhou University
- China
| | | | - Dong-Yang Chen
- College of Materials Science and Engineering
- Fuzhou University
- China
| | - Wang-Chuan Xiao
- School of Resources and Chemical Engineering
- Sanming Institute of Fluorochemical Industry
- Sanming University
- China
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7
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Akimoto G, Otsuka M, Takita R, Uchiyama M, Hedidi M, Bentabed-Ababsa G, Lassagne F, Erb W, Mongin F. Deprotonative Metalation of Methoxy-Substituted Arenes Using Lithium 2,2,6,6-Tetramethylpiperidide: Experimental and Computational Study. J Org Chem 2018; 83:13498-13506. [PMID: 30345758 DOI: 10.1021/acs.joc.8b02397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The reaction pathways of lithium 2,2,6,6-tetramethylpiperidide (LiTMP)-mediated deprotonative metalation of methoxy-substituted arenes were investigated. Importantly, it was experimentally observed that, whereas TMEDA has no effect on the course of the reactions, the presence of more than the stoichiometric amount of LiCl is deleterious, in particular without an in situ trap. These effects were corroborated by the DFT calculations. The reaction mechanisms, such as the structure of the active species in the deprotonation event, the reaction pathways by each postulated LiTMP complex, the stabilization effects by in situ trapping using zinc species, and some kinetic interpretation, are discussed herein.
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Affiliation(s)
- Gaku Akimoto
- Graduate School of Pharmaceutical Sciences , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 , Japan.,Advanced Elements Chemistry Research Team, RIKEN Center for Sustainable Resource Science, and Elements Chemistry Laboratory , RIKEN , 2-1 Hirosawa , Wako-shi, Saitama 351-0198 , Japan
| | - Mai Otsuka
- Graduate School of Pharmaceutical Sciences , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 , Japan.,Advanced Elements Chemistry Research Team, RIKEN Center for Sustainable Resource Science, and Elements Chemistry Laboratory , RIKEN , 2-1 Hirosawa , Wako-shi, Saitama 351-0198 , Japan
| | - Ryo Takita
- Graduate School of Pharmaceutical Sciences , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 , Japan.,Advanced Elements Chemistry Research Team, RIKEN Center for Sustainable Resource Science, and Elements Chemistry Laboratory , RIKEN , 2-1 Hirosawa , Wako-shi, Saitama 351-0198 , Japan
| | - Masanobu Uchiyama
- Graduate School of Pharmaceutical Sciences , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 , Japan.,Advanced Elements Chemistry Research Team, RIKEN Center for Sustainable Resource Science, and Elements Chemistry Laboratory , RIKEN , 2-1 Hirosawa , Wako-shi, Saitama 351-0198 , Japan
| | - Madani Hedidi
- Univ Rennes, CNRS , ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes , France.,Laboratoire de Synthèse Organique Appliquée, Faculté des Sciences Exactes et Appliquées , Université Oran 1 Ahmed Ben Bella , BP 1524 El M'Naouer, 31000 Oran , Algeria
| | - Ghenia Bentabed-Ababsa
- Laboratoire de Synthèse Organique Appliquée, Faculté des Sciences Exactes et Appliquées , Université Oran 1 Ahmed Ben Bella , BP 1524 El M'Naouer, 31000 Oran , Algeria
| | - Frédéric Lassagne
- Univ Rennes, CNRS , ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes , France
| | - William Erb
- Univ Rennes, CNRS , ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes , France
| | - Florence Mongin
- Univ Rennes, CNRS , ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes , France
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8
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Uzelac M, Mulvey RE. Trans-Metal-Trapping: Concealed Crossover Complexes En Route to Transmetallation? Chemistry 2018; 24:7786-7793. [PMID: 29603459 DOI: 10.1002/chem.201800489] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/28/2018] [Indexed: 12/14/2022]
Abstract
Defined as the transfer of ligands from one metal to another, transmetallation is a common reaction in organometallic chemistry. Its chemical celebrity stems from its role in important catalytic cycles of cross-coupling reactions such as those of Negishi, Sonogashira, Stille, or Suzuki. This article focuses on trans-metal-trapping (TMT), which could be construed as partially complete transmetallations. On mixing two distinct organometallic compounds, of for example lithium with aluminium or gallium, the two metals meet in a crossover co-complex, but the reaction ceases at that point and full transmetallation is not reached. Though in its infancy, trans-metal-trapping shows promise in transforming failed lithiations into successful lithiations and in stabilising sensitive carbanions through cooperative bimetallic effects making them more amenable to onward reactivity.
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Affiliation(s)
- Marina Uzelac
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
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9
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NMR spectroscopic study of the adduct formation and reactivity of homoleptic rare earth amides with alkali metal benzyl compounds, and the crystal structures of [Li(TMEDA)2][Nd{N(SiMe3)2}3(CH2Ph)] and [{Li(TMP)}2{Li(Ph)}]2. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2017.10.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Arrabal-Campos FM, Álvarez JD, García-Sancho A, Fernández I. Molecular weight prediction in polystyrene blends. Unprecedented use of a genetic algorithm in pulse field gradient spin echo (PGSE) NMR. SOFT MATTER 2017; 13:6620-6626. [PMID: 28920614 DOI: 10.1039/c7sm01569k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A genetic algorithm that uses boxcar functions (diffGA) has been applied for the first time in PGSE NMR. It reconstructs accurate diffusion coefficients for all the components of the mixture, and therefore predicts correct weight-average molecular weights for all of them. The results reported herein complement those obtained with established methods such as ITAMeD, CONTIN and TRAIn algorithms, and provide a detailed solution picture. Its robustness and limits have been stretched in order to ascertain the minimum separation within diffusion coefficients or relative proportion between components. In addition, the new genetic algorithm has been also applied to a mixture of small molecules, providing excellent results at very low computational times.
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Affiliation(s)
- Francisco M Arrabal-Campos
- Department of Chemistry and Physics, Research Centre for Agricultural and Food Biotechnology (BITAL), University of Almería, Ctra. Sacramento, s/n, 04120, Almería, Spain.
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11
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Uzelac M, Kennedy AR, Hevia E. Trans-Metal-Trapping Meets Frustrated-Lewis-Pair Chemistry: Ga(CH 2SiMe 3) 3-Induced C-H Functionalizations. Inorg Chem 2017; 56:8615-8626. [PMID: 28485929 PMCID: PMC5549243 DOI: 10.1021/acs.inorgchem.7b00549] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Merging two topical themes in main-group chemistry, namely, cooperative bimetallics and frustrated-Lewis-pair (FLP) activity, this Forum Article focuses on the cooperativity-induced outcomes observed when the tris(alkyl)gallium compound GaR3 (R = CH2SiMe3) is paired with the lithium amide LiTMP (TMP = 2,2,6,6-tetramethylpiperidide) or the sterically hindered N-heterocyclic carbene (NHC) 1,3-bis(tert-butyl)imidazol-2-ylidene (ItBu). When some previously published work are drawn together with new results, unique tandem reactivities are presented that are driven by the steric mismatch between the individual reagents of these multicomponent reagents. Thus, the LiTMP/GaR3 combination, which on its own fails to form a cocomplex, functions as a highly regioselective base (LiTMP)/trap (GaR3) partnership for the metalation of N-heterocycles such as diazines, 1,3-benzoazoles, and 2-picolines in a trans-metal-trapping (TMT) process that stabilizes the emerging sensitive carbanions. Taking advantage of related steric incompatibility, a novel monometallic FLP system pairing GaR3 with ItBu has been developed for the activation of carbonyl compounds (via C═O insertion) and other molecules with acidic hydrogen atoms such as phenol and phenylacetylene. Shedding new light on how these non-cocomplexing partnerships operate and showcasing the potential of gallium reagents to engage in metalation reactions or FLP activations, areas where the use of this group 13 metal is scant, this Forum Article aims to stimulate more interest and activity toward the advancement of organogallium chemistry.
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Affiliation(s)
- Marina Uzelac
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
| | - Eva Hevia
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
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12
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Peel AJ, Ackroyd R, Wheatley AEH. Metal exchange in lithiocuprates: implications for our understanding of structure and reactivity. Chem Sci 2017; 8:4904-4916. [PMID: 28959414 PMCID: PMC5603898 DOI: 10.1039/c7sc01423f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 04/28/2017] [Indexed: 11/21/2022] Open
Abstract
New reagents have been sought for directed ortho cupration in which the use of cyanide reagents is eliminated. CuOCN reacts with excess TMPLi (TMP = 2,2,6,6-tetramethylpiperidide) in the presence of limited donor solvent to give crystals that are best represented as (TMP)2Cu0.1Li0.9(OCN)Li2(THF) 8, whereby both Lipshutz-type lithiocuprate (TMP)2Cu(OCN)Li2(THF) 8a and trinuclear (TMP)2(OCN)Li3(THF) 8b are expressed. Treatment of a hydrocarbon solution of TMP2CuLi 9a with LiOCN and THF gives pure 8a. Meanwhile, formation of 8b is systematized by reacting (TMPH2)OCN 10 with TMPH and nBuLi to give (TMP)2(OCN)Li3(THF)211. Important to the attribution of lower/higher order bonding in lithiocuprate chemistry is the observation that in crystalline 8, amide-bridging Cu and Li demonstrate clear preferences for di- and tricoordination, respectively. A large excess of Lewis base gives an 8-membered metallacycle that retains metal disorder and analyses as (TMP)2Cu1.35Li0.659 in the solid state. NMR spectroscopy identifies 9 as a mixture of (TMP)2CuLi 9a and other copper-rich species. Crystals from which the structure of 8 was obtained dissolve to yield evidence for 8b coexisting in solution with in situ-generated 9a, 11 and a kinetic variant on 9a ( i-9a), that is best viewed as an agglomerate of TMPLi and TMPCu. Moving to the use of DALi (DA = diisopropylamide), (DA)2Cu0.09Li0.91(Br)Li2(TMEDA)212 (TMEDA = N,N,N',N'-tetremethylethylenediamine) is isolated, wherein (DA)2Cu(Br)Li2(TMEDA)212a exhibits lower-order Cu coordination. The preparation of (DA)2Li(Br)Li2(TMEDA)212b was systematized using (DAH2)Br, DAH and nBuLi. Lastly, metal disorder is avoided in the 2 : 1 lithium amide : Lipshutz-type monomer adduct (DA)4Cu(OCN)Li4(TMEDA)213.
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Affiliation(s)
- Andrew J Peel
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW UK .
| | - Ryan Ackroyd
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW UK .
| | - Andrew E H Wheatley
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW UK .
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13
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[Bis(Trimethylsilyl)Methyl]Lithium and -Sodium: Solubility in Alkanes and Complexes with O- and N- Donor Ligands. INORGANICS 2017. [DOI: 10.3390/inorganics5020039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In contrast to alkyl compounds of lithium, which play an important role in organometallic chemistry, the corresponding heavier alkali metal compounds are less investigated. These compounds are mostly insoluble in inert solvents or undergo solvolysis in coordinating solvents due to their high reactivity. An exception from this typical behavior is demonstrated by bis(trimethylsilyl)methylsodium. This study examines alkane solutions of bis(trimethylsilyl)methyllithium and -sodium by NMR spectroscopic and cryoscopic methods. In addition, structural studies by X-ray crystallography of the corresponding compounds coordinated by O- and N- ligands (tetrahydrofuran and tetramethylethylenediamine) present possible structural motifs of the uncoordinated compounds in solution.
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14
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Wang Y, Liu J, Huang L, Zhu R, Huang X, Moir R, Huang J. KOtBu-Catalyzed lithiation of PMDTA and the direct functionalization of bridged alkenes under mild conditions. Chem Commun (Camb) 2017; 53:4589-4592. [DOI: 10.1039/c7cc02006f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A practical preparation of the reagent PMDTALi using a super base system under mild conditions has been developed.
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Affiliation(s)
- Yuntao Wang
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
| | - Jialin Liu
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
| | - Lin Huang
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
| | - Ranran Zhu
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
| | - Xueyan Huang
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
| | - Ross Moir
- School of Chemistry
- University of Edinburgh
- UK
| | - Jianhui Huang
- School of Pharmaceutical Science and Technology
- Tianjin University
- Tianjin 300072
- China
- Collaborative Innovation Center of Chemical Science and Engineering
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15
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Guang J, Liu Q, Hopson R, Kagan G, Li W, Monroe TB, Williard PG. Conformational Polymorphism of Lithium Pinacolone Enolate. J Am Chem Soc 2016; 138:15177-15188. [PMID: 27762552 DOI: 10.1021/jacs.6b08177] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A metastable, polymorphic hexameric crystal structure of lithium pinacolone enolate (LiOPin) is reported along with three preparation methods. NMR-based structural characterization implies that the lithium pinacolate hexamer deaggregates to a tetramer in toluene but retains mainly the hexameric structure in nonaromatic hydrocarbon solvents such as cyclohexane. Moreover, the presence of a small amount of lithium aldolate (LiOA) dramatically influences the aggregation state of LiOPin by forming a mixed aggregate with a 3:1 ratio (LiOPin3·LiOA).
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Affiliation(s)
- Jie Guang
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Qiyong Liu
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Russell Hopson
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Gerald Kagan
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Weibin Li
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Thomas B Monroe
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Paul G Williard
- Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
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16
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Morisako S, Shang R, Yamamoto Y. Synthesis of a Sterically Demanding Dispiropiperidine and Its Application in Monoamidodialkyl Zincate Complexes. Inorg Chem 2016; 55:10767-10773. [PMID: 27682309 DOI: 10.1021/acs.inorgchem.6b01965] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The new sterically hindered piperidine analog, dispiro[cyclohexane-2,2'-piperidine-6',2″-cyclohexane] (CPC(H), 2), and its N-methylated derivative CPC(Me) (3) were synthesized from commercially available starting materials in short steps. The N-lithiated amide LiCPC (4) was also isolated from 2 as a cyclictrimer in single crystals and showed slightly larger steric hindrance than that of lithium 2,2,6,6-tetramethylpiperidide (LiTMP) in the competitive methylation reaction with methyl trifluoromethanesulfonate. In addition, the heterobimetallic heteroleptic zincate complexes [Li(μ-NR2)(μ-Et)Zn(Et)] (NR2 = CPC, 5, and NR2 = TMP, 6) were obtained as THF- and TMEDA-coordinated monomer 5·(THF)2, 6·(THF)2, 5·TMEDA, and 6·TMEDA (THF = tetrahydrofuran, TMEDA = N,N,N',N'-tetramethylethylenediamine). These molecular structures bearing different amido ligands in single crystals showed little structural differences from crystallographic studies. Diffusion-ordered spectroscopy (DOSY) revealed that the solution structures of the zincate complexes 5·(THF)2 and 6·(THF)2 only differ in the number of coordination THF molecules. In the deprotonation reactions with tert-butyl 3-bromobenzoate, the zincate complexes containing the CPC ligand [Li(μ-CPC)(μ-R)Zn(R)] (R = Et (5), tBu) showed moderately improved regioselectivity for the 6 position in comparison to those containing the TMP ligand [Li(μ-TMP)(μ-R)Zn(R)] (R = Et (6), tBu).
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Affiliation(s)
- Shogo Morisako
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Rong Shang
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Yohsuke Yamamoto
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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17
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Arrabal-Campos FM, Oña-Burgos P, Fernández I. Molecular weight prediction with no dependence on solvent viscosity. A quantitative pulse field gradient diffusion NMR approach. Polym Chem 2016. [DOI: 10.1039/c6py00691d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To progress on the practical issues of molecular weight prediction via diffusion NMR, the first log(Dη) vs. log(Mw) calibration curve is provided, allowing the easy and fast determination of weight-average molecular weights with no matter of the solvent used.
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Affiliation(s)
| | - Pascual Oña-Burgos
- Department of Chemistry and Physics
- ceiA3
- Universidad de Almería
- Almería
- Spain
| | - Ignacio Fernández
- Department of Chemistry and Physics
- ceiA3
- Universidad de Almería
- Almería
- Spain
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18
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Orr SA, Kennedy AR, Liggat JJ, McLellan R, Mulvey RE, Robertson SD. Accessible heavier s-block dihydropyridines: structural elucidation and reactivity of isolable molecular hydride sources. Dalton Trans 2016; 45:6234-40. [DOI: 10.1039/c5dt04224k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Transmetallation of lithiodihydropyridines with Group 1 alkoxides provides facile access to reactive MH (M = Na, K) sources, which show significant structural diversity due in part to the distinct ways that Na/K engage with the σ (green) and π (red) donor systems of the DHP ligands.
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Affiliation(s)
- Samantha A. Orr
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - Alan R. Kennedy
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - John J. Liggat
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - Ross McLellan
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - Robert E. Mulvey
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - Stuart D. Robertson
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
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19
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Ojeda-Amador AI, Martínez-Martínez AJ, Kennedy AR, O'Hara CT. Synthetic and Structural Studies of Mixed Sodium Bis(trimethylsilyl)amide/Sodium Halide Aggregates in the Presence of η(2)-N,N-, η(3)-N,N,N/N,O,N-, and η(4)-N,N,N,N-Donor Ligands. Inorg Chem 2015; 54:9833-44. [PMID: 26417943 DOI: 10.1021/acs.inorgchem.5b01584] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When n-hexane solutions of an excess of sodium bis(trimethylsilyl)amide (NaHMDS) are combined with cesium halide (halide = Cl, Br, or I) in the presence of the tetradentate donor molecule [tris[2-(dimethylamino)ethyl]amine] (Me6TREN), the isolation and characterization of a series of sodium amide/sodium halide mixed aggregates was forthcoming. Cesium halide was employed because it efficiently reacted with NaHMDS to produce a molecular, soluble source of sodium halide salt (which was subsequently captured by an excess of NaHMDS) via a methathetical reaction. These mixed sodium amide/sodium halide complexes are formally sodium sodiates, are deficient in halide with respect to the amide, and have the general formula [{Na5(μ-HMDS)5(μ5-X)}{Na(Me6TREN)}] [where X = Cl (1), Br (2), or I (3)]. The influence of the donor ligand was studied for the NaI/NaHMDS system, and when n-hexane solutions of this composition were treated with tridentate donors such as N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDETA) or N,N,N',N'-tetramethyldiaminoethyl ether (TMDAE), solvent-separated ion-pair cocomplexes [Na5(μ-HMDS)5(μ5-I)](-)[Na3(μ-HMDS)2(PMDETA)2](+) (4) and [Na5(μ-HMDS)5(μ5-I)](-)[Na(TMDAE)2](+) (5) were isolated. However, upon reaction with bidentate proligands such as the chiral diamine (R,R)-N,N,N',N'-tetramethylcyclohexane-1,2-diamine [(R,R)-TMCDA] or N,N,N',N'-tetramethylethylenediamine (TMEDA), neutral complexes [Na4(μ-HMDS)3(μ4-I)(donor)2] [donor = (R,R)-TMCDA (6) and TMEDA (7)] were produced. To illustrate the generality of the latter reaction with other halides, [Na4(μ-HMDS)3(μ4-Br)(TMEDA)2] (8) was also prepared by employing NaBr in the synthesis instead of NaI.
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Affiliation(s)
- Ana I Ojeda-Amador
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, United Kingdom
| | - Antonio J Martínez-Martínez
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, United Kingdom
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, United Kingdom
| | - Charles T O'Hara
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, United Kingdom
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20
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Fuentes MÁ, Kennedy AR, Mulvey RE, Parkinson JA, Rantanen T, Robertson SD, Snieckus V. Adding a Structural Context to the Deprotometalation and Trans-Metal Trapping Chemistry of Phenyl-Substituted Benzotriazole. Chemistry 2015; 21:14812-22. [DOI: 10.1002/chem.201502534] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Indexed: 11/06/2022]
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21
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Guang J, Hopson R, Williard PG. Diffusion Coefficient-Formula Weight (D-FW) Analysis of 2H Diffusion-Ordered NMR Spectroscopy (DOSY). J Org Chem 2015; 80:9102-7. [DOI: 10.1021/acs.joc.5b01457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jie Guang
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Russell Hopson
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Paul G. Williard
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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22
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Armstrong DR, Harris CMM, Kennedy AR, Liggat JJ, McLellan R, Mulvey RE, Urquhart MDT, Robertson SD. Developing Lithium Chemistry of 1,2-Dihydropyridines: From Kinetic Intermediates to Isolable Characterized Compounds. Chemistry 2015; 21:14410-20. [DOI: 10.1002/chem.201501880] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Indexed: 11/06/2022]
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23
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Neufeld R, John M, Stalke D. The Donor-Base-Free Aggregation of Lithium Diisopropyl Amide in Hydrocarbons Revealed by a DOSY Method. Angew Chem Int Ed Engl 2015; 54:6994-8. [PMID: 26014367 DOI: 10.1002/anie.201502576] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Indexed: 11/08/2022]
Abstract
Lithium diisopropyl amide (LDA) is a very prominent reagent that plays a key role in organic synthesis, serving as a base par excellence for a broad range of deprotonation reactions. However, the state of aggregation in solution in the absence of donor bases was unclear. In this paper we solved this problem by employing DOSY NMR experiments based on a newly elaborated external calibration curve (ECC) approach with normalized diffusion coefficients.
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Affiliation(s)
- Roman Neufeld
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen (Germany)
| | - Michael John
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen (Germany)
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen (Germany).
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24
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Neufeld R, John M, Stalke D. Aufklärung der donorbasenfreien Aggregation von Lithiumdiisopropylamid in Kohlenwasserstoffen mithilfe einer DOSY-Methode. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502576] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Rathman T‘L, Schwindeman JA. Preparation, Properties, and Safe Handling of Commercial Organolithiums: Alkyllithiums, Lithium sec-Organoamides, and Lithium Alkoxides. Org Process Res Dev 2014. [DOI: 10.1021/op500161b] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Terry ‘Li’ Rathman
- t-Links Consulting, 3843 Gardner Park Drive, Gastonia, North Carolina 28054, United States
| | - James A. Schwindeman
- Rohner Inc., 4066 Belle
Meade Circle, Belmont, North
Carolina 28012, United States
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26
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Kennedy AR, Leenhouts SM, Liggat JJ, Martínez-Martínez AJ, Miller K, Mulvey RE, O'Hara CT, O'Keefe P, Steven A. Dehydromethylation of alkali metal salts of the utility amide 2,2,6,6-tetramethylpiperidide (TMP). Chem Commun (Camb) 2014; 50:10588-91. [DOI: 10.1039/c4cc04959d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Su C, Guang J, Williard PG. Structures of Lithium N-Monosubstituted Anilides: Trisolvated Monomer to Tetrasolvated Dimer. J Org Chem 2014; 79:1032-9. [DOI: 10.1021/jo402498z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Jie Guang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Paul G. Williard
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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28
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Armstrong DR, Crosbie E, Hevia E, Mulvey RE, Ramsay DL, Robertson SD. TMP (2,2,6,6-tetramethylpiperidide)-aluminate bases: lithium-mediated alumination or lithiation–alkylaluminium-trapping reagents? Chem Sci 2014. [DOI: 10.1039/c4sc01108b] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Surprisingly lithium TMP-aluminate reagents are not capable of directly aluminating anisole as previously thought but operateviasequential lithiation–alkylaluminium trapping.
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Affiliation(s)
- David R. Armstrong
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - Elaine Crosbie
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - Eva Hevia
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - Robert E. Mulvey
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - Donna L. Ramsay
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - Stuart D. Robertson
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
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29
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Martínez-Martínez AJ, Armstrong DR, Conway B, Fleming BJ, Klett J, Kennedy AR, Mulvey RE, Robertson SD, O'Hara CT. Pre-inverse-crowns: synthetic, structural and reactivity studies of alkali metal magnesiates primed for inverse crown formation. Chem Sci 2014. [DOI: 10.1039/c3sc52816b] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The synthesis, structure and reactivity of donor-free sodium and potassium magnesiates are assessed culminating in the unique 1,4-dimetallation of naphthalene.
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Affiliation(s)
| | - D. R. Armstrong
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - B. Conway
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - B. J. Fleming
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - J. Klett
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - A. R. Kennedy
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - R. E. Mulvey
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - S. D. Robertson
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
| | - C. T. O'Hara
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow, UK
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30
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Bomparola R, Davies RP, Hornaeur S, White AJP. Lithium heterocuprates: the influence of the amido group on organoamidocuprate structures. Dalton Trans 2014; 43:14359-67. [PMID: 24930778 DOI: 10.1039/c4dt00965g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural isomers of a number of lithium heteroamidocuprates LiCuR(NR′2) have been studied in the solid state and in solution, with the steric and electronic properties of the amido group (NR′2) shown to significantly influence the solid-state structures and the position of the solution equilibrium.
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