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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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2
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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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3
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Facile synthesis of phthalocyanine at low temperature with diisopropylamide anion as nucleophile. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.05.086] [Citation(s) in RCA: 9] [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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4
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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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Mulvey RE, Robertson SD. Synthetically important alkali-metal utility amides: lithium, sodium, and potassium hexamethyldisilazides, diisopropylamides, and tetramethylpiperidides. Angew Chem Int Ed Engl 2013; 52:11470-87. [PMID: 24133015 DOI: 10.1002/anie.201301837] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Indexed: 11/08/2022]
Abstract
Most synthetic chemists will have at some point utilized a sterically demanding secondary amide (R2 N(-) ). The three most important examples, lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS), lithium diisopropylamide (LiDA), and lithium 2,2,6,6-tetramethylpiperidide (LiTMP)-the "utility amides"-have long been indispensible particularly for lithiation (Li-H exchange) reactions. Like organolithium compounds, they exhibit aggregation phenomena and strong Lewis acidity, and thus appear in distinct forms depending on the solvents employed. The structural chemistry of these compounds as well as their sodium and potassium congeners are described in the absence or in the presence of the most synthetically significant donor solvents tetrahydrofuran (THF) and N,N,N',N'-tetramethylethylenediamine (TMEDA) or closely related solvents. Examples of hetero-alkali-metal amides, an increasingly important composition because of the recent escalation of interest in mixed-metal synergic effects, are also included.
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Affiliation(s)
- 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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Mulvey RE, Robertson SD. Nützliche Alkalimetallamide für die Synthese: Lithium-, Natrium- und Kaliumhexamethyldisilazide, -diisopropylamide und -tetramethylpiperidide. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301837] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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Harrison-Marchand A, Mongin F. Mixed AggregAte (MAA): A Single Concept for All Dipolar Organometallic Aggregates. 1. Structural Data. Chem Rev 2013; 113:7470-562. [DOI: 10.1021/cr300295w] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anne Harrison-Marchand
- Laboratoire COBRA de l′Université de Rouen, INSA de Rouen, CNRS, UMR 6014 & FR 3038, IRCOF, Rue Tesnière, 76821 Mont St Aignan Cédex, France
| | - Florence Mongin
- Équipe Chimie et Photonique Moléculaires, Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Bâtiment 10A, case 1003, Avenue du Général Leclerc, 35042 Rennes Cédex, France
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8
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Reich HJ. Role of Organolithium Aggregates and Mixed Aggregates in Organolithium Mechanisms. Chem Rev 2013; 113:7130-78. [DOI: 10.1021/cr400187u] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Hans J. Reich
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
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9
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Zhao J, Liu Y, He Q, Li Y, Ma S. Experimental and theoretical study of tunable 1,3-lithium shift of propargylic/allenylic species, transmetallation, and Pd-catalyzed cross-coupling reactions. Chemistry 2010; 15:11361-72. [PMID: 19760707 DOI: 10.1002/chem.200900325] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The highly selective tuning of the isomerization from 1-arylalka-1,2-dien-1-yllithium to 1-arylalka-1,2-dien-3-yllithium has been realized in the deprotonation of 1-arylalk-1-yne (conditions A and B) and carbolithiation of 1-arylbut-3-en-1-yne with alkyllithium (conditions C and D). Subsequent transmetallation and Pd-catalyzed Negishi coupling reactions afforded 1,1-diaryl or 1,3-diaryl allenes with high selectivity. Deuterium-labeling cross experiments indicated that an intermolecular lithiation process occurred in both 1,3-lithium shift conditions (conditions B and D). 1-Arylalka-1,2-diene was confirmed experimentally to be the intermediate. A computational study at the B3LYP level for the isomerization indicated that the acidity of H at the 3-position is higher than that of the H at the 1-position of 1-phenyl-1,2-butadiene. Under conditions B, iPr(2)NH acts as a proton carrier to finish the 1,3-lithium shift. The overall activation barrier for the rate-determining step in the solvated models is approximately 21.0 kcal mol(-1), indicating that the isomerization is reasonable at room temperature. For the isomerization under conditions D, DFT calculations indicated that the addition of TMEDA (tetramethylethylenediamine) and HMPA (hexamethylphosphoramide) changes the global minimum of the system; among the possible mechanisms (P1-P5) considered, the mechanism catalyzed by dilithiated species (P5) is the most probable one. The overall activation barriers for isomerization in THF and TMEDA solvated models are 22.6 and 19.7 kcal mol(-1), respectively, proving that the isomerization may proceed at RT in THF or at -78 degrees C with TMEDA, due to the fact that the solvation of the additives may increase the concentration of 1-phenyl-1,2-butadienyllithium monomer by a deaggregation effect.
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Affiliation(s)
- Jinbo Zhao
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, PR China
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10
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Fernández I, Oña-Burgos P, Armbruster F, Krummenacher I, Breher F. 7Li,15N heteronuclear multiple quantum shift correlation—a fast and reliable 2D NMR method on natural abundant nuclei. Chem Commun (Camb) 2009:2586-8. [PMID: 19532898 DOI: 10.1039/b902053e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Li D, Sun C, Williard PG. Characterization of a Chiral Enolate Aggregate and Observation of 6Li−1H Scalar Coupling. J Am Chem Soc 2008; 130:11726-36. [DOI: 10.1021/ja802114j] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Deyu Li
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
| | - Chengzao Sun
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
| | - Paul G. Williard
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
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12
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Clegg W, García-Álvarez J, García-Álvarez P, Graham DV, Harrington RW, Hevia E, Kennedy AR, Mulvey RE, Russo L. Synthesis, Structural Authentication, and Structurally Defined Metalation Reactions of Lithium and Sodium DA-Zincate Bases (DA = diisopropylamide) with Phenylacetylene. Organometallics 2008. [DOI: 10.1021/om8001813] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- William Clegg
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Joaquín García-Álvarez
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Pablo García-Álvarez
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - David V. Graham
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Ross W. Harrington
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Eva Hevia
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Luca Russo
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland G1 1XL, U.K., and School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
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13
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Popenova S, Mawhinney RC, Schreckenbach G. Density Functional Study of Lithium Hexamethyldisilazide (LiHMDS) Complexes: Effects of Solvation and Aggregation. Inorg Chem 2007; 46:3856-64. [PMID: 17432844 DOI: 10.1021/ic061599s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The title compound, lithium hexamethyldisilazide (LiHMDS), has been studied using modern quantum-chemical methods in the form of the B3LYP approach. Monomers, dimers, trimers, and tetramers, microsolvated with up to four THF molecules have been considered. The choice of model complex is seen to be important-for instance, the simpler water molecule is shown to be an inappropriate substitute for the THF solvent. Calculated lithium NMR shieldings are reported, but by themselves, they seem to be insufficient for unequivocal assignments of the different species. The energetics of aggregation and solvation have been studied. Temperature effects are seen to be important, and the degrees of solvation and aggregation are higher at 0 K than at 298 K. The highest degree of THF solvation for the monomer and dimer is found to be three (0 K) and two (298 K), respectively. The highest possible degree of aggregation for unsolvated LiHMDS is four. However, in nonpolar solvents, formation of the LiHDMS dimer from the trimer is thermodynamically preferred. The pathway is likely to involve an intermediate tetramer. In THF solution, di-solvated monomers and dimers are the most likely species.
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Affiliation(s)
- Svetlana Popenova
- Department of Chemistry and Biochemistry, Concordia University, Montreal QC, Canada H3G 1M8
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14
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Affiliation(s)
- George Wu
- Chemical Process Research and Development, Schering-Plough Research Institute, Union, New Jersey 07083, USA.
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15
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Pratt LM. A Computational Study of Lithium Dialkylamide Mixed Aggregates with Lithium Chloride. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.890] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Lepore SD, He Y, Damisse P. Studies on the Base-Promoted Conversion of Conjugated Alkynyl Esters to α-Substituted α-Allenyl Esters. J Org Chem 2004; 69:9171-5. [PMID: 15609951 DOI: 10.1021/jo0487754] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the development of an efficient method for the conversion of a variety of conjugated alkynyl esters to alpha-substituted conjugated allenyl esters (racemic) through the use of strong amide bases. Substantially improved yields over typical enolate formation conditions were observed with the use of 2 equiv of lithium diisopropylamide. Trapping studies indicate that the second equivalent of base likely leads to the dianion intermediate, which upon addition of methyl iodide, trimethylsilyl chloride, or tributyltin chloride gives mixtures of alpha-substituted conjugated allenyl and beta,gamma-alkynyl deconjugated esters. Further optimization revealed that additive salts such as LiCl lead primarily to the allenyl product while the use of HMPA as a cosolvent gives the beta,gamma-alkynyl deconjugated alkylation product. The role of base, base concentration, and electrophile on product yield and selectivity is also discussed.
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Affiliation(s)
- Salvatore D Lepore
- Department of Chemistry, Florida Atlantic University, Boca Raton, Florida 33431, USA.
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17
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Abstract
Computational methods were used to determine the structure of dilithiodiamines and the effects of solvation by ethereal solvents. Solvation was examined by the use of microsolvation with explicit dimethyl ether or THF ligands and by the combined use of microsolvation and the IEFPCM continuum solvent model. It was determined that each of the compounds studied exists exclusively as a bridged intramolecular dimer, both in the gas phase and in solution. Thermodynamic properties were calculated at 200 and 298 K to estimate the effect of temperature on the cyclization energies. Infrared spectroscopy was used to confirm the proposed intramolecular dimer structures.
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Affiliation(s)
- Lawrence M Pratt
- Department of Chemistry, Fisk University, Nashville, Tennessee 37209, USA.
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Development of Chiral Catalysts for Stereoselective Synthesis by Deprotonations – Experimentation in Interplay with Computational Chemistry. ADVANCES IN QUANTUM CHEMISTRY 2004. [DOI: 10.1016/s0065-3276(04)47001-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Wiedemann SH, Ramírez A, Collum DB. Lithium 2,2,6,6-Tetramethylpiperidide-Mediated α- and β-Lithiations of Epoxides: Solvent-Dependent Mechanisms. J Am Chem Soc 2003; 125:15893-901. [PMID: 14677981 DOI: 10.1021/ja0304087] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lithium 2,2,6,6-tetramethylpiperidide (LiTMP)-mediated alpha- and beta-lithiations of epoxides are described. LiTMP displays a markedly higher reactivity than does lithium diisopropylamide, consistent with literature reports. Detailed rate studies of LiTMP/THF and LiTMP/Me(2)NEt mixtures reveal similar rates but significant mechanistic differences. LiTMP-mediated alpha-lithiation of cis-cyclooctene oxide with subsequent oxacarbenoid formation and transannular C-H insertion proceeds via monosolvated dimers in both THF and Me(2)NEt. LiTMP-mediated beta-lithiation of 2,3-dimethyl-2-butene oxide affords the corresponding allylic alcohol via a monosolvated monomer in THF and a monosolvated dimer in Me(2)NEt. We discuss how the solvent-dependent aggregation of LiTMP markedly influences the rate profile. The reaction transition structures are examined with density functional computations.
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Affiliation(s)
- Sean H Wiedemann
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA
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Corset J, Castellà-Ventura M, Froment F, Strzalko T, Wartski L. Study of the lithiated phenylacetonitrile monoanions and dianions formed according to the lithiated base used (LHMDS, LDA, or n-BuLi). 1. Evidence of heterodimer ("Quadac") or dianion formation by vibrational spectroscopy. J Org Chem 2003; 68:3902-11. [PMID: 12737570 DOI: 10.1021/jo020492t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is evidenced through vibrational spectroscopy that a heterodimer or "Quadac" is formed when an excess of base (LHMDS, LDA, or n-BuLi) is added to PhCH(2)CN in THF, THF-hexane, or THF-toluene solution. The amount of heterodimer increases with the pK(H)(a) of the lithiated base. A dianionic species may be formed through decomposition of this heterodimer if the pK(H)(a) of the base is sufficiently high, as in the case of n-BuLi. With LDA, only a very small amount of dianion is observed, and with LHMDS, no dianion is detected. The predominant dianionic species observed are the linear and bridged separated ion pairs of the dilithiated dianion. The presence of the amine in the medium is of paramount importance. The PhCHCNLi monomer-dimer equilibrium is entropy driven toward the dimer solvated by the amine.
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Affiliation(s)
- Jacques Corset
- LADIR - CNRS (UMR 7075), 2 Rue Henri Dunant, BP 28, 94320 Thiais, France
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Rutherford JL, Collum DB. Lithium diisopropylamide: oligomer structures at low ligand concentrations. J Am Chem Soc 2001; 123:199-202. [PMID: 11456504 DOI: 10.1021/ja003104i] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One- and two-dimensional (6)Li and (15)N NMR spectroscopic studies of lithium diisopropylamide (LDA) solvated by substoichiometric concentrations of oxetane, THF, Et(2)O, and diisopropylamine are described. Partially solvated dimers and trimers are identified. Possible benefits of carrying out organolithium chemistry at low ligand concentrations are discussed.
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Affiliation(s)
- J L Rutherford
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA
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22
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Rutherford JL, Collum DB. NMR Spectroscopic Studies of Lithium Diethylamide: Insights into Ring Laddering. J Am Chem Soc 1999. [DOI: 10.1021/ja992169m] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jennifer L. Rutherford
- Contribution from the Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - David B. Collum
- Contribution from the Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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23
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Pratt LM, Robbins S. A computational study of structure, bonding, and aggregation of N–Lithioaziridine. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0166-1280(98)00372-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Wu G, Wong Y, Chen X, Ding Z. A Novel One-Step Diastereo- and Enantioselective Formation of trans-Azetidinones and Its Application to the Total Synthesis of Cholesterol Absorption Inhibitors. J Org Chem 1999; 64:3714-3718. [PMID: 11674502 DOI: 10.1021/jo990428k] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient and practical asymmetric process was developed for the synthesis of azetidinone-based cholesterol absorption inhibitors. Key to this synthesis was the discovery of a novel one-step diastereo- and enantioselective formation of trans beta-lactams starting from commercially available 3(S)-hydroxy-gamma-lactone. Various trans beta-lactams can be prepared in good yields and with better than 95:5 enantio- and diastereoselctivity. A Lewis acid-catalyzed aldol condensation and a highly enantioselective oxazaborolidine-catalyzed chiral reduction completes the side chain.
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Affiliation(s)
- Guangzhong Wu
- Chemical Process Research and Development, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033
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25
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van Vliet GLJ, de Kanter FJJ, Schakel M, Klumpp GW, Spek AL, Lutz M. X‐ray Crystal Structures and Some Solution Structures of Lithium Amides with Intramolecular Complexation of Lithium by Tertiary Amide Groups. Chemistry 1999. [DOI: 10.1002/(sici)1521-3765(19990301)5:3<1091::aid-chem1091>3.0.co;2-#] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- G. L. J. van Vliet
- Scheikundig Laboratorium, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL‐1081 HV Amsterdam (The Netherlands), Fax: (+31) 20‐4447488
| | - F. J. J. de Kanter
- Scheikundig Laboratorium, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL‐1081 HV Amsterdam (The Netherlands), Fax: (+31) 20‐4447488
| | - M. Schakel
- Scheikundig Laboratorium, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL‐1081 HV Amsterdam (The Netherlands), Fax: (+31) 20‐4447488
| | - G. W. Klumpp
- Scheikundig Laboratorium, Vrije Universiteit Amsterdam, De Boelelaan 1083, NL‐1081 HV Amsterdam (The Netherlands), Fax: (+31) 20‐4447488
| | - A. L. Spek
- Bijvoet Center for Biomolecular Research, Universiteit Utrecht, Padualaan 8, NL‐3584 CH Utrecht (The Netherlands)
| | - M. Lutz
- Bijvoet Center for Biomolecular Research, Universiteit Utrecht, Padualaan 8, NL‐3584 CH Utrecht (The Netherlands)
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26
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Remenar JF, Lucht BL, Kruglyak D, Romesberg FE, James H. Gilchirst, and, Collum DB. Lithium 2,2,6,6-Tetramethylpiperidide and Lithium 2,2,4,6,6-Pentamethylpiperidide: Influence of TMEDA and Related Chelating Ligands on the Solution Structures. Characterization of Higher Cyclic Oligomers, Cyclic Dimers, Open Dimers, and Monomers. J Org Chem 1997. [DOI: 10.1021/jo970520l] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julius F. Remenar
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Brett L. Lucht
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Dmitriy Kruglyak
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Floyd E. Romesberg
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | | | - David B. Collum
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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27
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Aubrecht KB, Collum DB. Solution Structure of Lithium Dicyclohexylamide (Cy2NLi) and Related Mixed Aggregates: Comparison with Lithium Diisopropylamide. J Org Chem 1996. [DOI: 10.1021/jo961084q] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine B. Aubrecht
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - David B. Collum
- Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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28
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Lucht BL, Bernstein MP, Remenar JF, Collum DB. Polydentate Amine and Ether Solvates of Lithium Hexamethyldisilazide (LiHMDS): Relationship of Ligand Structure, Relative Solvation Energy, and Aggregation State. J Am Chem Soc 1996. [DOI: 10.1021/ja9618199] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brett L. Lucht
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Max P. Bernstein
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Julius F. Remenar
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - David B. Collum
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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29
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Giacobbe SA, Rossi T. Alkyl groups on the metal enhance the reactivity of the “classical” zirconium enolate of 1-methoxycyclohexanone. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0957-4166(96)00402-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Andrews PC, Barnett ND, Mulvey RE, Clegg W, O'Neil PA, Barr D, Cowton L, Dawson AJ, Wakefield BJ. X-ray crystallographic studies and comparative reactivity studies of a sodium diisopropylamide (NDA) complex and related hindered amides. J Organomet Chem 1996. [DOI: 10.1016/0022-328x(96)06203-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Bauer W. Organolithium Chemistry: NMR-Based Distinction of Cyclic Dimers from Cyclic Trimers by 6Li{13C}-HMQC-TOCSY. J Am Chem Soc 1996. [DOI: 10.1021/ja954273j] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Walter Bauer
- Contribution from the Institut für Organische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, D-91054 Erlangen, Germany
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32
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Koch R, Wiedel B, Anders E. Theoretical Study of the Deprotonation of Nitriles, RCH2CN: Ab Initio and PM3 Calculations of Intermediate Aggregates and Transition States. J Org Chem 1996. [DOI: 10.1021/jo9519470] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rainer Koch
- Institut für Organische Chemie und Makromolekulare Chemie der Universität Jena, Humboldtstrasse 10, D-07743 Jena, Germany
| | - Bernd Wiedel
- Institut für Organische Chemie und Makromolekulare Chemie der Universität Jena, Humboldtstrasse 10, D-07743 Jena, Germany
| | - Ernst Anders
- Institut für Organische Chemie und Makromolekulare Chemie der Universität Jena, Humboldtstrasse 10, D-07743 Jena, Germany
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33
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Lucht BL, Collum DB. Lithium Ion Solvation: Amine and Unsaturated Hydrocarbon Solvates of Lithium Hexamethyldisilazide (LiHMDS). J Am Chem Soc 1996. [DOI: 10.1021/ja953029p] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brett L. Lucht
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - David B. Collum
- Contribution from the Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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34
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Koizumi T, Morihashi K, Kikuchi O. Ab Initio MO Calculations of NMR15N–6Li Coupling Constants in Lithium Amide Monomers, Oligomers, and Mixed Aggregates with LiCl. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1996. [DOI: 10.1246/bcsj.69.305] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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35
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Kremer T, Harder S, Junge M, Schleyer PVR. Mixed Aggregates of Alkali Metal Compounds: Structure and Stability of “Superbase” Models. Organometallics 1996. [DOI: 10.1021/om950720s] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas Kremer
- Institut für Organische Chemie der Friedrich Alexander Universität Erlangen-Nürnberg, Henkestrasse 42, D-91054 Erlangen, Germany
| | - Sjoerd Harder
- Institut für Organische Chemie der Friedrich Alexander Universität Erlangen-Nürnberg, Henkestrasse 42, D-91054 Erlangen, Germany
| | - Michael Junge
- Institut für Organische Chemie der Friedrich Alexander Universität Erlangen-Nürnberg, Henkestrasse 42, D-91054 Erlangen, Germany
| | - Paul von Ragué Schleyer
- Institut für Organische Chemie der Friedrich Alexander Universität Erlangen-Nürnberg, Henkestrasse 42, D-91054 Erlangen, Germany
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36
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Photoprocesses of eosine and rose bengal ion pairs with cationic surfactant in non-polar solvent: application in photosensitization studies. J Photochem Photobiol A Chem 1994. [DOI: 10.1016/1010-6030(93)02777-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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37
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Wei Y, Bakthavatchalam R. A comparative study of solid state and solution aldol addition reactions of the lithium enolate of methyl 3,3-dimethylbutanoate: stereochemistry and mechanistic implications. Tetrahedron 1993. [DOI: 10.1016/s0040-4020(01)86317-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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38
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A new synthetic approach to enediynes related to the neocarzinostatin chromophore from α-trimethylsilyl α-allenyl carbonyl compounds. Tetrahedron Lett 1993. [DOI: 10.1016/0040-4039(93)89017-k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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39
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Boche G, Langlotz I, Marsch M, Harms K, Nudelman NES. [Lithium Piperidide-Piperidine]4: Crystal Structure of an Oligomeric 1:1 Lithium Amide-Amine Mixed Complex, an Intermediate in theN-Lithiation of Amines. Angew Chem Int Ed Engl 1992. [DOI: 10.1002/anie.199212051] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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40
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Boche G, Langlotz I, Marsch M, Harms K, Nudelman NES. [Lithiumpiperidid-Piperidin]4: Kristallstruktur eines oligomeren Lithiumamid-Amin-Komplexes, einer Zwischenstufe bei der Lithiierung von Aminen. Angew Chem Int Ed Engl 1992. [DOI: 10.1002/ange.19921040922] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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