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Ma HZ, Canty AJ, O'Hair RAJ. Electrospray Ionization Tandem Mass Spectrometry and DFT Survey of Copper(I) Ate Complexes Containing Coordinated Borohydride Anions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1443-1452. [PMID: 35749300 DOI: 10.1021/jasms.2c00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper(I) borohydride ate complexes of the type Cat+[XCu(BH4)]- have been previously postulated as intermediates in the reactions of copper salts with borohydride. Negative ion electrospray ionization of an acetonitrile solution of copper(I) phenylacetylide with a 10-fold excess of sodium borohydride (NaBH4) revealed the formation of a diverse range of mononuclear, dinuclear and trinuclear cuprates with different numbers of BH4-, H- and CN- ligands, the latter likely being formed by abstraction of CN- from the acetonitrile solvent. Collision-induced dissociation was used to examine the fragmentation reactions of the following borohydride containing cuprates: [Cu(H)(BH4)]-, [Cu(BH4)2]-, [Cu(BH4)(CN)]-, [Cu2(H)(BH4)2]-, [Cu2(H)2(BH4)]-, [Cu2(BH4)2(CN)]-, [Cu2(H)(BH4)(CN)]-, [Cu3(H)(BH4)3]-, [Cu3(H)2(BH4)2]-, [Cu3(H)3(BH4)]-, [Cu3(BH4)2(CN)2]-, and [Cu3(H)(BH4)2(CN)]-. In all cases, BH3 loss is observed. For many of the dinuclear and trinuclear complexes cluster fragmentation by loss of CuH was also observed. In the case of [Cu2(H)2(BH4)]- and [Cu3(H)3(BH4)]-, loss of H2 was also observed. DFT calculations were used to explore potential structures of the various borohydride-containing cuprates and to predict the overall reaction energetics for the various fragmentation channels.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
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2
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Auth T, Grabarics M, Schlangen M, Pagel K, Koszinowski K. Modular Ion Mobility Calibrants for Organometallic Anions Based on Tetraorganylborate Salts. Anal Chem 2021; 93:9797-9807. [PMID: 34227799 DOI: 10.1021/acs.analchem.1c01333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Organometallics are widely used in catalysis and synthesis. Their analysis relies heavily on mass spectrometric methods, among which traveling-wave ion mobility spectrometry (TWIMS) has gained increasing importance. Collision cross sections (CCS) obtainable by TWIMS significantly aid the structural characterization of ions in the gas phase, but for organometallics, their accuracy has been limited by the lack of appropriate calibrants. Here, we propose tetraorganylborates and their alkali-metal bound oligomers [Mn-1(BR4)n]- (M = Li, Na, K, Rb, Cs; R = aryl, Et; n = 1-6) as calibrants for electrospray ionization (ESI) TWIMS. These species chemically resemble typical organometallics and readily form upon negative-ion mode ESI of solutions of alkali-metal tetraorganylborates. By combining different tetraorganylborate salts, we have generated a large number of anions in a modular manner and determined their CCS values by drift-tube ion mobility spectrometry (DTIMS) (DTCCSHe = 81-585, DTCCSN2 = 130-704 Å2). In proof-of-concept experiments, we then applied these DTCCS values to the calibration of a TWIMS instrument and analyzed phenylcuprate and argentate anions, [Lin-1MnPh2n]- and [MnPhn+1]- (M = Cu, Ag), as prototypical reactive organometallics. The TWCCSN2 values derived from TWIMS measurements are in excellent agreement with those determined by DTIMS (<2% relative difference), demonstrating the effectiveness of the proposed calibration scheme. Moreover, we used theoretical methods to predict the structures and CCS values of the anions considered. These predictions are in good agreement with the experimental results and give further insight into the trends governing the assembly of tetraorganylborate, cuprate, and argentate oligomers.
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Affiliation(s)
- Thomas Auth
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, Göttingen 37077, Germany
| | - Márkó Grabarics
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Molekülphysik, Faradayweg 4-6, Berlin 14195, Germany
| | - Maria Schlangen
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, Berlin 10623, Germany
| | - Kevin Pagel
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Molekülphysik, Faradayweg 4-6, Berlin 14195, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Universität Göttingen, Tammannstraße 2, Göttingen 37077, Germany
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Daly S, Weske S, Mravak A, Krstić M, Kulesza A, Antoine R, Bonačić-Koutecký V, Dugourd P, Koszinowski K, O’Hair RAJ. Phenyl argentate aggregates [AgnPhn+1]− (n = 2–8): Models for the self-assembly of atom-precise polynuclear organometallics. J Chem Phys 2021; 154:224301. [DOI: 10.1063/5.0052697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Steven Daly
- Institut Lumière Matière, Université Claude Bernard Lyon 1, CNRS UMR, 5306 Lyon, France
| | - Sebastian Weske
- Institute of Organic and Biomolecular Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Antonija Mravak
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM), Faculty of Science, University of Split, Ruđera Boškovića 33, Split 21000, Croatia
| | - Marjan Krstić
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM), Faculty of Science, University of Split, Ruđera Boškovića 33, Split 21000, Croatia
| | - Alexander Kulesza
- Institut Lumière Matière, Université Claude Bernard Lyon 1, CNRS UMR, 5306 Lyon, France
| | - Rodolphe Antoine
- Institut Lumière Matière, Université Claude Bernard Lyon 1, CNRS UMR, 5306 Lyon, France
| | - Vlasta Bonačić-Koutecký
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM), Faculty of Science, University of Split, Ruđera Boškovića 33, Split 21000, Croatia
- Interdisciplinary Center for Advanced Science and Technology (ICAST) at University of Split, Meštrovićevo šetalište 45, Split 21000, Croatia
- Chemistry Department Humboldt, University of Berlin, Brook-Taylor-Straße 2, Berlin 12489, Germany
| | - Philippe Dugourd
- Institut Lumière Matière, Université Claude Bernard Lyon 1, CNRS UMR, 5306 Lyon, France
| | - Konrad Koszinowski
- Institute of Organic and Biomolecular Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Richard A. J. O’Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd., Parkville, Victoria 3010, Australia
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Unravelling the hidden link of lithium halides and application in the synthesis of organocuprates. Nat Commun 2017; 8:14794. [PMID: 28300072 PMCID: PMC5357309 DOI: 10.1038/ncomms14794] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 02/01/2017] [Indexed: 11/18/2022] Open
Abstract
As a versatile metal, copper has demonstrated a wide application in acting as both organometallic reagent and catalyst. Organocuprates are among the most used organometallic reagents in the formation of new carbon–carbon bonds in organic synthesis. Therefore, revealing the real structures of organocuprates in solution is crucial to provide insights into the reactivity of organocuprates. Here we provide several important insights into organocuprate chemistry. The main finding contains the following aspects. The Cu(0) particles were detected via the reduction of CuX by nBuLi or PhLi. The Cu(II) precursors CuX2 (X=Cl, Br) could be used for the preparation of Gilman reagents. In addition, we provide direct evidence for the role and effect of LiX in organocuprate synthesis. Moreover, the EXAFS spectrum provides direct evidence for the exact structure of Li+ CuX2− ate complex in solution. This work not only sheds important light on the role of LiX in the formation of organocuprates but also reports two new routes for organocuprate synthesis. Organocopper species are widely used in synthetic chemistry. Here the authors study the structure of the anionic complex formed from copper salts and lithium halides, showing it to be a key intermediate in the formation of organocuprates, and also show that Cu(II) precursors can form Gilman reagents.
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Putau A, Brand H, Koszinowski K. Intermediates Formed in the Reactions of Organocuprates with α,β-Unsaturated Nitriles. Chemistry 2016; 22:12868-76. [PMID: 27461093 DOI: 10.1002/chem.201602451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 11/10/2022]
Abstract
Conjugate additions of organocuprates are of outstanding importance for organic synthesis. To improve our mechanistic understanding of these reactions, we have used electrospray ionization mass spectrometry for the identification of the ionic intermediates formed upon the treatment of LiCuR2 ⋅LiCN (R=Me, Bu, Ph) with a series of α,β-unsaturated nitriles. Acrylonitrile, the weakest Michael acceptor included, did not afford any detectable intermediates. Fumaronitrile (FN) yielded adducts of the type Lin-1 Cun R2n (FN)n (-) , n=1-3. When subjected to fragmentation in the gas phase, these adducts were not converted into the conjugate addition products, but re-dissociated into the reactants. In contrast, the reaction with 1,1-dicyanoethylene furnished the products of the conjugate addition without any observable intermediates. Tri- and tetracyanoethylene proved to be quite reactive as well. The presence of several cyano groups in these substrates opened up reaction pathways different from simple conjugate additions, however, and led to dimerization and substitution reactions. Moreover, the gas-phase fragmentation behavior of the species formed from these substrates indicated the occurrence of single-electron transfer processes. Additional quantum-chemical calculations provided insight into the structures and stabilities of the observed intermediates and their consecutive reactions.
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Affiliation(s)
- Aliaksei Putau
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Harald Brand
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
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Weske S, Schoop R, Koszinowski K. The Role of Ate Complexes in the Copper-Mediated Trifluoromethylation of Alkynes. Chemistry 2016; 22:11310-6. [PMID: 27385188 DOI: 10.1002/chem.201601261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 01/30/2023]
Abstract
Trifluoromethylation reactions have recently received increased attention because of the beneficial effect of the trifluoromethyl group on the pharmacological properties of numerous substances. A common method to introduce the trifluoromethyl group employs the Ruppert-Prakash reagent, that is, Si(CH3 )3 CF3 , together with a copper(I) halide. We have applied this method to the trifluoromethylation of aromatic alkynes and used electrospray-ionization mass spectrometry to investigate the mechanism of these reactions in tetrahydrofuran, dichloromethane, and acetonitrile as well as with and without added 1,10-phenanthroline. In the absence of the alkyne component, the homoleptic ate complexes [Cu(CF3 )2 ](-) and [Cu(CF3 )4 ](-) were observed. In the presence of the alkynes RH, the heteroleptic complexes [Cu(CF3 )3 R](-) were detected as well. Upon gas-phase fragmentation, these key intermediates released the cross-coupling products R-CF3 with perfect selectivity. Apparently, the [Cu(CF3 )3 R](-) complexes did not originate from homoleptic cuprate anions, but from unobservable neutral precursors. The present results moreover point to the involvement of oxygen as the oxidizing agent.
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Affiliation(s)
- Sebastian Weske
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammanstraße 2, 37077, Göttingen, Germany
| | - Ramona Schoop
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammanstraße 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammanstraße 2, 37077, Göttingen, Germany.
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Molteni R, Bertermann R, Edkins K, Steffen A. An unexpected transmetalation intermediate: isolation and structural characterization of a solely CH3 bridged di-copper(i) complex. Chem Commun (Camb) 2016; 52:5019-22. [PMID: 26983362 DOI: 10.1039/c6cc01510g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Structural characterization of unsupported, two metal centres bridging methyl groups is rare. They have been proposed as transmetalation intermediates in cuprate chemistry, but as yet no structural evidence has been presented. We have isolated a di-copper(i) complex with solely a methyl ligand bridging two Cu(i) atoms, representing a new bonding mode of CH3.
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Affiliation(s)
- Roberto Molteni
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Tsedilin AM, Fakhrutdinov AN, Eremin DB, Zalesskiy SS, Chizhov AO, Kolotyrkina NG, Ananikov VP. How sensitive and accurate are routine NMR and MS measurements? MENDELEEV COMMUNICATIONS 2015. [DOI: 10.1016/j.mencom.2015.11.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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BASF Catalysis Award: A. E. Ashley / Hellmuth Fischer Medal: M. Arenz / Mattauch-Herzog Prize: K. Koszinowski / OMCOS Prize: M. S. Sanford. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201506023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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10
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Katalysepreis der BASF: A. E. Ashley / Hellmuth-Fischer-Medaille: M. Arenz / Mattauch-Herzog-Preis: K. Koszinowski / OMCOS-Preis: M. S. Sanford. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Sung S, Braddock DC, Armstrong A, Brennan C, Sale D, White AJP, Davies RP. Synthesis, characterisation and reactivity of copper(I) amide complexes and studies on their role in the modified Ullmann amination reaction. Chemistry 2015; 21:7179-92. [PMID: 25788223 PMCID: PMC4471577 DOI: 10.1002/chem.201405699] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/29/2022]
Abstract
A series of copper(I) alkylamide complexes have been synthesised; copper(I) dicyclohexylamide (1), copper(I) 2,2,6,6-tetramethylpiperidide (2), copper(I) pyrrolidide (3), copper(I) piperidide (4), and copper(I) benzylamide (5). Their solid-state structures and structures in [D6 ]benzene solution are characterised, with the aggregation state in solution determined by a combination of DOSY NMR spectroscopy and DFT calculations. Complexes 1, 2 and 4 are shown to exist as tetramers in the solid state by X-ray crystallography. In [D6 ]benzene solution, complexes 1, 2 and 5 were found by using (1) H DOSY NMR to exist in rapid equilibrium between aggregates with average aggregation numbers of 2.5, 2.4 and 3.3, respectively, at 0.05 M concentration. Conversely, distinct trimeric, tetrameric and pentameric forms of 3 and 4 were distinguishable by one-dimensional (1) H and (1) H DOSY NMR spectroscopy. Complexes 3-5 are found to react stoichiometrically with iodobenzene, in the presence or absence of 1,10-phenanthroline as an ancillary ligand, to give arylamine products indicative of their role as potential intermediates in the modified Ullmann reaction. The role of phenanthroline has also been explored both in the stoichiometric reaction and in the catalytic Ullmann protocol.
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Affiliation(s)
- Simon Sung
- Department of Chemistry, Imperial College LondonSouth Kensington, London, SW7 2AZ (UK)
| | | | - Alan Armstrong
- Department of Chemistry, Imperial College LondonSouth Kensington, London, SW7 2AZ (UK)
| | - Colin Brennan
- Process Studies Group, Syngenta, Jealott*s Hill Research CentreBracknell, Berkshire RG42 6EY (UK)
| | - David Sale
- Process Studies Group, Syngenta, Jealott*s Hill Research CentreBracknell, Berkshire RG42 6EY (UK)
| | - Andrew J P White
- Department of Chemistry, Imperial College LondonSouth Kensington, London, SW7 2AZ (UK)
| | - Robert P Davies
- Department of Chemistry, Imperial College LondonSouth Kensington, London, SW7 2AZ (UK)
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Eremin DB, Ananikov VP. Exceptional Behavior of Ni2O2 Species Revealed by ESI-MS and MS/MS Studies in Solution. Application of Superatomic Core To Facilitate New Chemical Transformations. Organometallics 2014. [DOI: 10.1021/om500637k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Dmitry B. Eremin
- Zelinsky
Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Pr. 47, Moscow 119991, Russia
| | - Valentine P. Ananikov
- Zelinsky
Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Pr. 47, Moscow 119991, Russia
- Department
of Chemistry, Saint Petersburg State University, Stary Petergof, 198504, Russia
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Orlov NV, Chistyakov IV, Khemchyan LL, Ananikov VP, Beletskaya IP, Starikova ZA. Exclusive selectivity in the one-pot formation of C-C and C-Se bonds involving Ni-catalyzed alkyne hydroselenation: optimization of the synthetic procedure and a mechanistic study. J Org Chem 2014; 79:12111-21. [PMID: 25288369 DOI: 10.1021/jo501953f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A unique Ni-catalyzed transformation is reported for the one-pot highly selective synthesis of previously unknown monoseleno-substituted 1,3-dienes starting from easily available terminal alkynes and benzeneselenol. The combination of a readily available catalyst precursor, Ni(acac)2, and an appropriately tuned phosphine ligand, PPh2Cy, resulted in the exclusive assembly of the s-gauche diene skeleton via the selective formation of C-C and C-Se bonds. The unusual diene products were stable under regular experimental conditions, and the products maintained the s-gauche geometry both in the solid state and in solution, as confirmed by X-ray analysis and NMR spectroscopy. Thorough mechanistic studies using ESI-MS revealed the key Ni-containing species involved in the reaction.
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Affiliation(s)
- Nikolay V Orlov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky Prospect 47, Moscow 119991, Russia
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Bluemke TD, Clegg W, García-Alvarez P, Kennedy AR, Koszinowski K, McCall MD, Russo L, Hevia E. Structural and reactivity insights in Mg–Zn hybrid chemistry: Zn–I exchange and Pd-catalysed cross-coupling applications of aromatic substrates. Chem Sci 2014. [DOI: 10.1039/c4sc01263a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Rijs NJ, Yoshikai N, Nakamura E, O’Hair RAJ. Unraveling Organocuprate Complexity: Fundamental Insights into Intrinsic Group Transfer Selectivity in Alkylation Reactions. J Org Chem 2014; 79:1320-34. [DOI: 10.1021/jo4027325] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
| | - Naohiko Yoshikai
- Division
of Chemistry and Biological Chemistry, School of Physical and Mathematical
Sciences, Nanyang Technological University, Singapore 637371
| | - Eiichi Nakamura
- Department
of Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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