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Liu ZC, Wang ZQ, Zhang X, Yin L. Copper(I)-catalyzed asymmetric alkylation of α-imino-esters. Nat Commun 2023; 14:2187. [PMID: 37069200 PMCID: PMC10110621 DOI: 10.1038/s41467-023-37967-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 04/04/2023] [Indexed: 04/19/2023] Open
Abstract
Asymmetric alkylation of enolates is one of the most direct and important reactions to prepare α-chiral carbonyl compounds. Except for the classical methods that rely on the use of chiral auxiliaries, asymmetric catalysis emerged as a powerful tool, especially asymmetric phase-transfer catalysis. However, in the field of transition metal catalysis, only limited success with asymmetric alkylation of enolates was achieved. Hereby, we disclose a copper(I)-catalyzed asymmetric alkylation of α-imino-esters with various alkyl halides, including allyl bromides, propargyl bromide, benzyl bromides, α-bromo carbonyl compounds, and alkyl iodides. Both linear and cyclic α-imino-esters serve as competent pronucleophiles in the alkylation, which affords α-amino acid derivatives bearing either a trisubstituted or a tetrasubstituted stereogenic carbon center in high to excellent enantioselectivity. Control experiments indicate that the α-imino-ester is activated by a chiral copper(I)-phosphine complex through coordination, thus enabling facile deprotonation to provide a stabilized copper(I)-enolate in the presence of a mild base. Finally, the mildly basic nature allows the asymmetric alkylation of chiral dipeptides with excellent both chemo- and enantioselectivities.
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Affiliation(s)
- Zong-Ci Liu
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032, Shanghai, China
| | - Zi-Qing Wang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032, Shanghai, China
| | - Xuan Zhang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032, Shanghai, China
| | - Liang Yin
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, 200032, Shanghai, China.
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2
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Lui NM, MacMillan SN, Collum DB. Lithiated Oppolzer Enolates: Solution Structures, Mechanism of Alkylation, and Origin of Stereoselectivity. J Am Chem Soc 2022; 144:23379-23395. [PMID: 36534055 PMCID: PMC10071589 DOI: 10.1021/jacs.2c09341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Camphorsultam-based lithium enolates referred to colloquially as Oppolzer enolates are examined spectroscopically, crystallographically, kinetically, and computationally to ascertain the mechanism of alkylation and the origin of the stereoselectivity. Solvent- and substrate-dependent structures include tetramers for alkyl-substituted enolates in toluene, unsymmetric dimers for aryl-substituted enolates in toluene, substrate-independent symmetric dimers in THF and THF/toluene mixtures, HMPA-bridged trisolvated dimers at low HMPA concentrations, and disolvated monomers for the aryl-substituted enolates at elevated HMPA concentrations. Extensive analyses of the stereochemistry of aggregation are included. Rate studies for reaction with allyl bromide implicate an HMPA-solvated ion pair with a +Li(HMPA)4 counterion. Dependencies on toluene and THF are attributed to exclusively secondary-shell (medium) effects. Aided by density functional theory (DFT) computations, a stereochemical model is presented in which neither chelates nor the lithium gegenion serves roles. The stereoselectivity stems from the chirality within the sultam ring and not the camphor skeletal core.
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Affiliation(s)
- Nathan M Lui
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University Ithaca, New York 14853-1301, United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University Ithaca, New York 14853-1301, United States
| | - David B Collum
- Department of Chemistry and Chemical Biology Baker Laboratory, Cornell University Ithaca, New York 14853-1301, United States
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3
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Guo W, Zuo L, Cui M, Yan B, Ni S. Propargylic Amination Enabled the Access to Enantioenriched Acyclic α-Quaternary α-Amino Ketones. J Am Chem Soc 2021; 143:7629-7634. [PMID: 33988363 DOI: 10.1021/jacs.1c03182] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A propargylic amination approach toward chiral acyclic α-quaternary α-amino ketones is described. This Cu-catalyzed procedure could be performed open to air using commercially available amines as nucleophiles. The key to success is the use of rationally designed propargylic cyclic carbonates as substrates, which can generate a Cu-bonded enolate zwitterionic intermediate upon decarboxylation. This protocol features wide functional group tolerance and high asymmetric induction, with typical ee value higher than 93%, and thus advances a great step forward in the challenging synthesis of acyclic chiral α-quaternary α-amino ketones.
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Affiliation(s)
- Wusheng Guo
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, Yanxiang Road 99, Xi'an 710045, China
| | - Linhong Zuo
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, Yanxiang Road 99, Xi'an 710045, China
| | - Manying Cui
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, Yanxiang Road 99, Xi'an 710045, China
| | - Biwei Yan
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, Yanxiang Road 99, Xi'an 710045, China
| | - Shaofei Ni
- Department of Chemistry, Shantou University, Shantou 515063, China
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4
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Kim JH, Paul A, Ghiviriga I, Seidel D. α-C-H Bond Functionalization of Unprotected Alicyclic Amines: Lewis-Acid-Promoted Addition of Enolates to Transient Imines. Org Lett 2021; 23:797-801. [PMID: 33464093 PMCID: PMC7924990 DOI: 10.1021/acs.orglett.0c04024] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Enolizable cyclic imines, obtained in situ from their corresponding lithium amides by oxidation with simple ketone oxidants, are readily alkylated with a range of enolates to provide mono- and polycyclic β-aminoketones in a single operation, including the natural product (±)-myrtine. Nitrile anions also serve as competent nucleophiles in these transformations, which are promoted by BF3 etherate. β-Aminoesters derived from ester enolates can be converted to the corresponding β-lactams.
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Affiliation(s)
- Jae Hyun Kim
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Anirudra Paul
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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5
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Wang F, Yang T, Wu T, Zheng LS, Yin C, Shi Y, Ye XY, Chen GQ, Zhang X. Asymmetric Transfer Hydrogenation of α-Substituted-β-Keto Carbonitriles via Dynamic Kinetic Resolution. J Am Chem Soc 2021; 143:2477-2483. [PMID: 33529522 DOI: 10.1021/jacs.0c13273] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A catalytic protocol for the enantio- and diastereoselective reduction of α-substituted-β-keto carbonitriles is described. The reaction involves a DKR-ATH process with the simultaneous construction of β-hydroxy carbonitrile scaffolds with two contiguous stereogenic centers. A wide range of α-substituted-β-keto carbonitriles were obtained in high yields (94%-98%) and excellent enantio- and diastereoselectivities (up to >99% ee, up to >99:1 dr). The origin of the diastereoselectivity was also rationalized by DFT calculations. Furthermore, this methodology offers rapid access to the pharmaceutical intermediates of Ipenoxazone and Tapentadol.
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Affiliation(s)
- Fangyuan Wang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, People's Republic of China.,Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Tilong Yang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Ting Wu
- College of Innovation and Entrepreneurship, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Long-Sheng Zheng
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Congcong Yin
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Yongjie Shi
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
| | - Xiang-Yu Ye
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, People's Republic of China
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6
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Yan B, Zuo L, Chang X, Liu T, Cui M, Liu Y, Sun H, Chen W, Guo W. Kinetically Controllable Pd-Catalyzed Decarboxylation Enabled [5 + 2] and [3 + 2] Cycloaddition toward Carbocycles Featuring Quaternary Carbons. Org Lett 2021; 23:351-357. [DOI: 10.1021/acs.orglett.0c03856] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Biwei Yan
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Linhong Zuo
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Xiaowei Chang
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Teng Liu
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Manying Cui
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Yang Liu
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Haiyu Sun
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Weipeng Chen
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
| | - Wusheng Guo
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an710045, China
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7
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Münch A, Knauer L, Ott H, Sindlinger C, Herbst-Irmer R, Strohmann C, Stalke D. Insight into the Bonding and Aggregation of Alkyllithiums by Experimental Charge Density Studies and Energy Decomposition Analyses. J Am Chem Soc 2020; 142:15897-15906. [PMID: 32811141 DOI: 10.1021/jacs.0c06035] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this Article, the organolithiums [((-)-sparteine)LitBu] (1), [(ABCO)LitBu]2 (2), and [(ABCO)2(LiiPr)4] (3) are investigated by means of experimental and theoretical charge density determination to elucidate the nature of the Li-C and Li-N bonds. Furthermore, the valence shell charge concentrations (VSCCs) in the nonbonding region of the deprotonated Cα-atom will provide some insight on the localization of the carbanionic lone pair. Analysis of the electron density (ρ(rBCP)), Laplacian (∇2ρ(rBCP)), and the energy decomposition (EDA) confirmed that the Li-C/N bond exhibits astonishingly similar characteristics, to reveal an increasingly polar contact with decreasing aggregate size. This explains former observations on the incorporation of halide salts in organolithium reagents. Furthermore, it could be shown that the bonding properties of the iPr group are similar to those of the tBu substituent. The accuracy of fit to all previously determined properties in organolithiums is remarkable.
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Affiliation(s)
- Annika Münch
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Lena Knauer
- Institut für Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Straβe 6, Dortmund 44227, Germany
| | - Holger Ott
- Bruker AXS GmbH, Östliche Rheinbrückenstraβe 49, Karlsruhe 76187, Germany
| | - Christian Sindlinger
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
| | - Carsten Strohmann
- Institut für Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Straβe 6, Dortmund 44227, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraβe 4, Göttingen 37077, Germany
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8
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Fairley M, Bole LJ, Mulks FF, Main L, Kennedy AR, O'Hara CT, García-Alvarez J, Hevia E. Ultrafast amidation of esters using lithium amides under aerobic ambient temperature conditions in sustainable solvents. Chem Sci 2020; 11:6500-6509. [PMID: 32874519 PMCID: PMC7441706 DOI: 10.1039/d0sc01349h] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/29/2020] [Indexed: 12/16/2022] Open
Abstract
Using 2-methyl THF as solvent enables efficient and ultrafast amidation of esters by lithium amides at room temperature in air, edging closer towards reaching air- and moisture-compatible polar organometallic chemistry.
Lithium amides constitute one of the most commonly used classes of reagents in synthetic chemistry. However, despite having many applications, their use is handicapped by the requirement of low temperatures, in order to control their reactivity, as well as the need for dry organic solvents and protective inert atmosphere protocols to prevent their fast decomposition. Advancing the development of air- and moisture-compatible polar organometallic chemistry, the chemoselective and ultrafast amidation of esters mediated by lithium amides is reported. Establishing a novel sustainable access to carboxamides, this has been accomplished via direct C–O bond cleavage of a range of esters using glycerol or 2-MeTHF as a solvent, in air. High yields and good selectivity are observed while operating at ambient temperature, without the need for transition-metal mediation, and the protocol extends to transamidation processes. Pre-coordination of the organic substrate to the reactive lithium amide as a key step in the amidation processes has been assessed, enabling the structural elucidation of the coordination adduct [{Li(NPh2)(O
Created by potrace 1.16, written by Peter Selinger 2001-2019
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CPh(NMe2))}2] (8) when toluene is employed as a solvent. No evidence for formation of a complex of this type has been found when using donor THF as a solvent. Structural and spectroscopic insights into the constitution of selected lithium amides in 2-MeTHF are provided that support the involvement of small kinetically activated aggregates that can react rapidly with the organic substrates, favouring the C–O bond cleavage/C–N bond formation processes over competing hydrolysis/degradation of the lithium amides by moisture or air.
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Affiliation(s)
- Michael Fairley
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK
| | - Leonie J Bole
- Department für Chemie und Biochemie , Universität Bern , CH3012 , Bern , Switzerland .
| | - Florian F Mulks
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK.,Department für Chemie und Biochemie , Universität Bern , CH3012 , Bern , Switzerland .
| | - Laura Main
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK
| | - Alan R Kennedy
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK
| | - Charles T O'Hara
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK
| | - Joaquín García-Alvarez
- Laboratorio de Compuestos Organometálicos y Catálisis (Unidad Asociada al CSIC) , Centro de Innovación en Química Avanzada (ORFEO-CINQA) , Departamento de Química Orgánica e Inorgánica (IUQOEM) , Facultad de Química , Universidad de Oviedo , E-33071 , Oviedo , Spain
| | - Eva Hevia
- Department of Pure and Applied Chemistry , University of Strathclyde Glasgow , G1 1XL , UK.,Department für Chemie und Biochemie , Universität Bern , CH3012 , Bern , Switzerland .
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9
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Hedouin M, Harrison-Marchand A, Maddaluno J, Oulyadi H. Accurate measurement of effective Li–Li scalar coupling constants: the NMR missing link for alkyllithium aggregates. Chem Commun (Camb) 2020; 56:15565-15568. [DOI: 10.1039/d0cc06871c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alkyllitium mixed aggregates: dynamics-free value of the 2JLi–Li as a simple access to various structural factors, including the dynamics, solvation and the steric hindrance of alkyl chains.
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Affiliation(s)
- Matthieu Hedouin
- Normandie Université
- UNIROUEN
- INSA de Rouen
- CNRS
- Laboratoire COBRA (UMR 6014 & FR 3038)
| | | | - Jacques Maddaluno
- Normandie Université
- UNIROUEN
- INSA de Rouen
- CNRS
- Laboratoire COBRA (UMR 6014 & FR 3038)
| | - Hassan Oulyadi
- Normandie Université
- UNIROUEN
- INSA de Rouen
- CNRS
- Laboratoire COBRA (UMR 6014 & FR 3038)
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10
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Zhou Y, Keresztes I, MacMillan SN, Collum DB. Disodium Salts of Pseudoephedrine-Derived Myers Enolates: Stereoselectivity and Mechanism of Alkylation. J Am Chem Soc 2019; 141:16865-16876. [PMID: 31613094 DOI: 10.1021/jacs.9b08176] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pseudoephedrine-derived dianionic Myers enolates were generated using sodium diisopropylamide (NaDA) in THF solution. The reactivities and selectivities of the disodium salts largely mirror those of the dilithium salts but without the requisite large excesses of inorganic salts (LiCl) or mandated dilute solutions. The disodium salts require careful control of temperature to preclude deleterious aggregate aging effects traced to changes in the aggregate structure and intervening O-alkylations. Structural studies and density functional theory (DFT) computations show a dominant highly symmetric polyhedron quite different from the lithium analogue. No enolate-NaDA mixed aggregates are observed with excess NaDA. Rate studies show an alkylation mechanism involving an intervening tetramer-monomer pre-equilibrium followed by rate-limiting alkylation of tetrasolvated monomers. DFT computations were conducted to explore the possible influences on stereochemistry. A crystal deriving from samples aged at ambient temperature contains six dianionic subunits and two monoanionic (alkoxide-only) subunits. A new preparation of concentrated solutions of NaDA in THF solution is described.
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Affiliation(s)
- Yuhui Zhou
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Ivan Keresztes
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
| | - David B Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853-1301 , United States
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