1
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Sasaki M, Shimabara R, Takegawa T, Kotomori Y, Otani Y, Ohwada T, Takeda K. Steric Course of Deprotonation/Substitution of Chelating/Dipole-Stabilizing-Group-Substituted α-Amino- and α-Oxynitriles. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michiko Sasaki
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Rumiko Shimabara
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Tomo Takegawa
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Yuri Kotomori
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
| | - Yuko Otani
- Graduate School of Pharmaceutical Sciences; The University of Tokyo; 7-3-1 Hongo 113-0033 Bunkyo-Ku, Tokyo Japan
| | - Tomohiko Ohwada
- Graduate School of Pharmaceutical Sciences; The University of Tokyo; 7-3-1 Hongo 113-0033 Bunkyo-Ku, Tokyo Japan
| | - Kei Takeda
- Department of Synthetic Organic Chemistry; Institute of Biomedical & Health Science; Hiroshima University; 1-2-3 Kasumi 734-8553 Minami-Ku, Hiroshima Japan
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2
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Strzalko T, Wartski L, Corset J, Castellà-Ventura M, Froment F. Study of the Lithiated Phenylacetonitrile Monoanions and Dianions Formed According to the Lithiated Base Used (LHMDS, LDA, or n-BuLi). 2. Alkylation and Deuteriation Mechanism Study by Vibrational and NMR Spectroscopy and Quantum Chemistry Calculations. J Org Chem 2012; 77:6431-42. [DOI: 10.1021/jo300758g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tekla Strzalko
- LSOM - CNRS/U-PSUD, Institut de Chimie Moléculaire et des Matériaux d’Orsay,
15 Rue Georges Clémenceau, 91405 Orsay Cedex, France
| | - Lya Wartski
- LSOM - CNRS/U-PSUD, Institut de Chimie Moléculaire et des Matériaux d’Orsay,
15 Rue Georges Clémenceau, 91405 Orsay Cedex, France
| | - Jacques Corset
- LADIR - CNRS/UPMC, 4 Place Jussieu, 75252 Paris Cedex 05, France
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3
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Abstract
In a computational study of a stereoselective C-C bond formation, the SAMP alkylation, a previously proposed S(E)2'-front mechanism is evaluated taking into account all current experimental evidence. Using semiempirical, density functional and perturbation theoretical methods, the structure of the key intermediate is revealed and the metalloretentive nature of the mechanism is explained. The experimental ee values of a range of reactions with different electrophiles and carbonyl sources can be correlated with calculated differences in activation energies. Furthermore, it can be concluded that the selectivity derives from the internal stabilization of the transition state 3_syn (corresponding to an electrophilic attack from above the lithiohydrazone plane) by electrophile-lithium interactions. The fast computational approach can be used best as a screening method which excludes less promising candidates to guide this synthetic method.
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Affiliation(s)
- Rainer Koch
- Institut für Reine und Angewandte Chemie and Center of Interface Science, Carl von Ossietzky Universität Oldenburg, P.O. Box 2503, 26111, Oldenburg, Germany.
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4
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Štefane B. Selective Addition of Organolithium Reagents to BF2-Chelates of β-Ketoesters. Org Lett 2010; 12:2900-3. [DOI: 10.1021/ol100620j] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Bogdan Štefane
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia
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5
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Fleming FF, Gudipati S. Cyclic Metalated Nitriles: Stereoselective Cyclizations to cis- and trans-Hydrindanes, Decalins, and Bicyclo[4.3.0]undecanes. European J Org Chem 2008; 2008:10.1002/ejoc.200800715. [PMID: 24260015 PMCID: PMC3831376 DOI: 10.1002/ejoc.200800715] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Indexed: 11/07/2022]
Abstract
Metalated nitriles are nucleophilic chameleons whose precise identity is determined by the nature of the metal, the solvent, the temperature, and the structure of the nitrile. The review surveys the different structural types and their cyclization trajectories to show how to selectively tune the metalated nitrile geometry for stereoselective cyclizations to a variety of cis or trans hydrindanes, decalins, and bicyclo[4.3.0]undecanes.
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Affiliation(s)
- Fraser F. Fleming
- Department of Chemistry and Biochemistry, Mellon Hall, Duquesne University, Pittsburgh PA 15282-1530, USA
| | - Subramanyham Gudipati
- Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, N.J. 07033-0530, USA Fax: +1-908-740-7441
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6
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Aharonovich S, Kapon M, Botoshanski M, Eisen MS. N,N′-Bis-Silylated Lithium Aryl Amidinates: Synthesis, Characterization, and the Gradual Transition of Coordination Mode from σ Toward π Originated by Crystal Packing Interactions. Organometallics 2008. [DOI: 10.1021/om701216p] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sinai Aharonovich
- Schulich Faculty of Chemistry and Institute of Catalysis Science and Technology, Kyriat Hatechnion, Haifa, 32000, Israel
| | - Moshe Kapon
- Schulich Faculty of Chemistry and Institute of Catalysis Science and Technology, Kyriat Hatechnion, Haifa, 32000, Israel
| | - Mark Botoshanski
- Schulich Faculty of Chemistry and Institute of Catalysis Science and Technology, Kyriat Hatechnion, Haifa, 32000, Israel
| | - Moris S. Eisen
- Schulich Faculty of Chemistry and Institute of Catalysis Science and Technology, Kyriat Hatechnion, Haifa, 32000, Israel
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7
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Fleming FF, Liu W, Ghosh S, Steward OW. Metalated Nitriles: Internal 1,2-Asymmetric Induction. J Org Chem 2008; 73:2803-10. [DOI: 10.1021/jo702681e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fraser F. Fleming
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530
| | - Wang Liu
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530
| | - Somraj Ghosh
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530
| | - Omar W. Steward
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530
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8
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Braun L, Kehr G, Blömker T, Fröhlich R, Erker G. Preferred Phosphorus Ylide Formation Upon Alkylation of Lithiobis(diphenylphosphanyl)acetonitrile. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700082] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Leonie Braun
- Universität Münster, Organisch‐Chemisches Institut, Corrensstrasse 40, 48149 Münster, Germany, Fax: +49‐251‐83‐36503
| | - Gerald Kehr
- Universität Münster, Organisch‐Chemisches Institut, Corrensstrasse 40, 48149 Münster, Germany, Fax: +49‐251‐83‐36503
| | - Tobias Blömker
- Universität Münster, Organisch‐Chemisches Institut, Corrensstrasse 40, 48149 Münster, Germany, Fax: +49‐251‐83‐36503
| | - Roland Fröhlich
- Universität Münster, Organisch‐Chemisches Institut, Corrensstrasse 40, 48149 Münster, Germany, Fax: +49‐251‐83‐36503
| | - Gerhard Erker
- Universität Münster, Organisch‐Chemisches Institut, Corrensstrasse 40, 48149 Münster, Germany, Fax: +49‐251‐83‐36503
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9
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Fleming FF, Vu VA, Shook BC, Rahman M, Steward OW. Metalated Nitriles: Chelation-Controlled Cyclizations to cis and trans Hydrindanes and Decalins. J Org Chem 2007; 72:1431-6. [PMID: 17249734 DOI: 10.1021/jo062270r] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chelation provides a powerful means of stereocontrol in alkylations of metalated nitriles. Doubly deprotonating a series of cyclic beta-hydroxynitriles triggers cyclizations that implicate metalated nitrile intermediates having configurations imposed by chelation with an adjacent, chiral lithium alkoxide. Identifying chelation as a general stereocontrol element explains several previously anomalous alkylations of metalated nitriles and provides a potential solution to the long-standing difficulty of synthesizing trans-hydrindanes. Employing chelation to control the metalated nitrile geometry permits selective cyclizations to cis and trans hydrindanes and decalins and provides key insight into the geometrical requirements of these demanding cyclizations.
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Affiliation(s)
- Fraser F Fleming
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282-1530, USA.
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10
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Braun L, Liptau P, Kehr G, Ugolotti J, Fröhlich R, Erker G. Bis(diphenylphosphino)acetonitrile: Synthesis, ligand properties and application in catalytic carbon–carbon coupling. Dalton Trans 2007:1409-15. [PMID: 17387401 DOI: 10.1039/b616847g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Treatment of acetonitrile (1 equiv.) with n-butyllithium (0.95 equiv.) followed by chlorodiphenylphosphine (0.95 equiv.) under optimised reaction conditions gave a ca. 60% yield of bis(diphenylphosphino)acetonitrile (dppmCN, 1). The bidentate ligand was employed in the synthesis of the four-membered chelate metal complexes (dppmCN)MCl(2) [M = Pd (6a), Pt (6b)] and (dppmCN)RuCp*(Cl) (7). A very active catalyst for bromobenzene/phenylboronic acid Suzuki-Miyaura coupling was in situ generated by treatment of Pd(OAc)(2) with bis(diphenylphosphino)acetonitrile [TOF (1 h) >600000].
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Affiliation(s)
- Leonie Braun
- Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
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11
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Ramirez A, Sun X, Collum DB. Lithium Diisopropylamide-Mediated Enolization: Catalysis by Hemilabile Ligands. J Am Chem Soc 2006; 128:10326-36. [PMID: 16881665 DOI: 10.1021/ja062147h] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structural, kinetic, and computational studies reveal the mechanistic complexities of a lithium diisopropylamide (LDA)-mediated ester enolization. Hemilabile amino ether MeOCH2CH2NMe2, binding as an eta1 (ether-bound) ligand in the reactant and as an eta2 (chelating) ligand in the transition structure, accelerates the enolization 10,000-fold compared with n-BuOMe. At the onset of the reaction, a dimer-based enolization prevails. As the reaction proceeds, significantly less reactive LDA-enolate mixed dimers appear and divert the reaction through monomer- and mixed dimer-based pathways. The mechanistic and computational investigations lead to a proof-of-principle ligand-catalyzed enolization in which an ancillary ligand allows the catalytic ligand to re-enter the catalytic cycle.
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Affiliation(s)
- Antonio Ramirez
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA
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12
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Yang X, Maeda S, Ohno K. Global Investigation on the Potential Energy Surface of CH3CN: Application of the Scaled Hypersphere Search Method. J Phys Chem A 2005; 109:7319-28. [PMID: 16834097 DOI: 10.1021/jp052067k] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An extensive quantum chemical study of the potential energy surface (PES) for all possible isomerization and dissociation reactions of CH3CN is reported at the DFT (B3LYP/6-311++G(d,p)) and CCSD(T)/ cc-pVTZ//B3LYP/6-311++G(d,p) levels of theory. The pathways around the equilibrium structures can be discovered by the scaled hypersphere search (SHS) method, which enables us to make a global analysis of the potential energy surface for a given chemical composition in combination with a downhill-walk algorithm. Seventeen equilibrium structures and 59 interconversion transition states have been found on the singlet PES. The four lowest lying isomers with thermodynamic stability are also kinetically stable with the lowest conversion barriers of 49.69-101.53 kcal/mol at the CCSD(T)/cc-pVTZ//B3LYP/6-311++G(d,p) level, whereas three-membered-ring isomers c-CH2NCH, c-CH2CNH, and c-CHNHCH can be considered as metastable intermediates which can further convert into the low-lying chain-like isomers and higher lying acyclic isomers with the lowest conversion energies of 21.70-59.99 kcal/mol. Thirteen available dissociation channels depending on the different initial isomers have been identified. A prediction can be made for the possible mechanism explaining the migration of a hydrogen atom in competition with the CC bond dissociation. Several new energetically accessible pathways are found to be responsible for the migration of the hydrogen atom. The present results demonstrate that the SHS method is an efficient and powerful technique for global mapping of reaction pathways on PESs.
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Affiliation(s)
- Xia Yang
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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13
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Fleming FF, Zhang Z, Liu W, Knochel P. Metalated Nitriles: Organolithium, -magnesium, and -copper Exchange of α-Halonitriles. J Org Chem 2005; 70:2200-5. [PMID: 15760206 DOI: 10.1021/jo047877r] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] alpha-Halonitriles react with alkyllithium, organomagnesium, and lithium dimethylcuprate reagents generating reactive, metalated nitriles. The rapid halogen-metal exchange with alkyllithium and Grignard reagents allows selective exchange in the presence of reactive carbonyl electrophiles, including aldehydes, providing a high-yielding alkylation protocol. Lithiated and magnesiated nitriles react with propargyl bromide by S(N)2 displacement whereas organocopper nitriles react by S(N)2' displacement, correlating with the formation of a C-metalated nitrile.
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Affiliation(s)
- Fraser F Fleming
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, USA.
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14
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Sott R, Granander J, Hilmersson G. Mixed Complexes Formed by Lithioacetonitrile and Chiral Lithium Amides: Observation of 6Li,15N and 6Li,13C Couplings Due to Both C−Li and N−Li Contacts. J Am Chem Soc 2004; 126:6798-805. [PMID: 15161308 DOI: 10.1021/ja0388461] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
NMR spectroscopic studies have been performed on the mixed complexes formed by the lithium salt of acetonitrile (LiCH(2)CN) and the chiral lithium amides Li-(S)-N-(2-methoxybenzyl)-1-amino-1-phenyl-2-ethoxyethane (Li-1) and Li-(S)-N-isopropyl-2-amino-1-phenyl-3-methoxypropane (Li-2) in diethyl ether and tetrahydrofuran solvent. In diethyl ether Li-1 and LiCH(2)CN form a mixed dimeric (1:1) complex, while Li-2 and LiCH(2)CN form a mixed trimeric (2:1) complex. The dimer undergoes fast exchange between ketenimine and bridged structures. Both (1)J((15)N,(6)Li) and (1)J((13)C,(6)Li) couplings were observed for the respectively isotopically labeled compounds. In the trimeric complex the CH(2)CN anion also undergoes fast degenerate exchange between ketenimine and bridged structures, and the complex appears C(2)-symmetric on the NMR spectroscopy time scale. Both the dimer and trimer complexes have the bridged acetonitrile anion in common, as indicated by the highly shielded alpha-carbon (13)C NMR shifts (delta -6.1 and -7.4, respectively). In tetrahydrofuran only N-metalated mixed LiCH(2)CN dimers were observed for both Li-1 and Li-2 with the less shielded (13)C NMR shifts of delta -2.5 and -2.2 for the alpha-carbon of LiCH(2)CN of the complexes.
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Affiliation(s)
- Richard Sott
- Organic Chemistry, Department of Chemistry, Göteborg University, S-412 96 Göteborg, Sweden
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15
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Ramírez A, Lobkovsky E, Collum DB. Hemilabile Ligands in Organolithium Chemistry: Substituent Effects on Lithium Ion Chelation. J Am Chem Soc 2003; 125:15376-87. [PMID: 14664582 DOI: 10.1021/ja030322d] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The lithium diisopropylamide-mediated 1,2-elimination of 1-bromocyclooctene to provide cyclooctyne is investigated using approximately 50 potentially hemilabile polyethers and amino ethers. Rate laws for selected ligands reveal chelated monomer-based pathways. The dependence of the rates on ligand structure shows that anticipated rate accelerations based on the gem-dimethyl effect are nonexistent and that substituents generally retard the reaction. With the aid of semiempirical and DFT computational studies, the factors influencing chelation are discussed. It seems that severe buttressing within chelates of the substitutionally rich ligands precludes a net stabilization of the chelates relative to nonchelated (eta(1)-solvated) forms. One ligand-MeOCH(2)CH(2)NMe(2)-appears to promote elimination uniquely by a higher-coordinate monomer-based pathway.
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Affiliation(s)
- Antonio Ramírez
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853-1301, USA
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16
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Carlier PR. Configurational stability of chiral lithiated cyclopropylnitriles: a density functional study. Chirality 2003; 15:340-7. [PMID: 12666242 DOI: 10.1002/chir.10222] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chiral, configurationally stable lithiated nitriles would be valuable intermediates for asymmetric carbon-carbon bond-forming reactions. To gain insight into the design of such species, Walborsky's attempted enantioselective deprotonation/trapping reactions of a chiral cyclopropylnitrile were studied computationally up to the MP2(fc)/6-31+G* and B3LYP/6-31+G* levels. Investigation of cyclopropylnitrile/LiNH(2) deprotonation transition structures demonstrated a significant (20-23 kcal/mol) kinetic preference for N-lithiation, and a facile (4-6 kcal/mol barrier) "conducted tour" racemization pathway for the N-lithiated nitrile product. Addition of a model directing group (formyl) to the beta-carbon of the cyclopropyl ring is predicted to significantly favor C-lithiation over N-lithiation, both kinetically and thermodynamically. Thus, chiral beta-Lewis base substituted cyclopropylnitriles may serve as precursors to chiral, configurationally stable organolithium reagents.
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Affiliation(s)
- Paul R Carlier
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.
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17
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Henderson KW, Kennedy AR, MacDougall DJ. Aggregation patterns in alpha,alpha'-stabilized carbanions: assembly of a sodium cage polymer by slip-stacking of dimers. Inorg Chem 2003; 42:2736-41. [PMID: 12691583 DOI: 10.1021/ic026194w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The alpha,alpha'-stabilized carbanion complexes [PhSO(2)CHCNNa.THF], 3, [t-BuSO(2)CHCNNa], 4, [PhSO(2)CHCNK], 5, [t-BuSO(2)CHCNK], 6, and [MeSO(2)CHCNLi.TMEDA], 7, have been synthesized via the metalation of the parent (organo)sulfonylacetonitriles by BuLi, BuNa, or BnK in THF solution (or THF/TMEDA in the case of 7). In addition, complexes 3 and 7 have been characterized by single-crystal X-ray analyses and have been found to adopt related structures in the solid state. Complex 7 is a molecular dimer containing a central 12-membered (OSCCNLi)(2) ring core, with each metal rendered tetracoordinate by binding to a chelating TMEDA molecule. As found in related complexes, no direct carbanion to lithium contacts are present in the structure of 7. Complex 3 forms a polymeric cage structure composed of associated "dimeric" (OSCCNNa)(2) rings, similar to those found in 7. The larger sodium cations, and the presence of only one THF molecule/metal, allow additional contacts with the anions, leading to hexacoordination at the metal centers. These contacts include long-range transannular Na-N interactions (2.8042(14) A) across the central dimeric ring and "interdimer" Na-C connections (2.8718(15) A). Dissolution of complexes 3-6 and their lithiated derivatives [PhSO(2)CHCNLi.TMEDA], 1, and [t-BuSO(2)CHCNLi.THF], 2, in DMSO-d(6) results in almost identical chemical shifts for each type of ligand. This suggests that charge-separated complexes of the form [RSO(2)CHCN](-)[M(DMSO-d(6))(n)()](+) are formed in highly polar solution.
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Affiliation(s)
- Kenneth W Henderson
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556-5670, USA
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18
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Köhn U, Anders E. Synthesis of chiral lithium carbamates from (S)-2-(N,N-dialkyl-aminomethyl)pyrrolidines and (S)-methoxymethylpyrrolidine. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)02388-2] [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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19
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Henderson KW, Kennedy AR, MacDougall DJ, Shanks D. Solid-State and Theoretical Model Structures of Monolithiated (Organosulfonyl)acetonitriles and the Characterization and Reactivity of Their Geminated Dilithio Derivatives. Organometallics 2002. [DOI: 10.1021/om0107845] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kenneth W. Henderson
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, U.K
| | - Alan R. Kennedy
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, U.K
| | - Dugald J. MacDougall
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, U.K
| | - David Shanks
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, U.K
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20
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21
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Ojea V, Ruiz M, Shapiro G, Pombo-Villar E. Conjugate additions of 1-propenylphosphonates to metalated Schöllkopf's bis-lactim ether: stereocontrolled access to 2-amino-3-methyl-4-phosphonobutanoic acids. J Org Chem 2000; 65:1984-95. [PMID: 10774017 DOI: 10.1021/jo991402w] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diastereoselectivity in the conjugate addition of metalated Schöllkopf's bis-lactim ethers 5a-e to (E)- and (Z)-1-propenylphosphonates 4a,b was studied experimentally and theoretically and utilized to achieve a direct and stereocontrolled synthesis of all four diastereoisomers of 2-amino-3-methyl-4-phosphonobutanoic acid, 6a,b and their enantiomers. The relative stereochemistry was assigned from an NMR study of cyclic derivatives 13a,b. According to semiempirical calculations, both in vacuo (PM3) or a dielectric continuum (PM3/COSMO), initial lithium-phosphoryl coordination, without an energy barrier, to form a solvated chelate complex is followed by the rate-determining reorganization to the 1,4-addition product through an eight-membered transition state. The translation of the Z,E geometry into a syn, anti configuration at the adducts originates from an orientational preference in the transition state for a compact disposition of the reaction partners.
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Affiliation(s)
- V Ojea
- Novartis Pharma Ltd., Basel, Switzerland.
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22
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Functionalization by metalation of the benzene moiety of benzodiazines. Determination of structures by long-range 1H-15N correlation at natural abundance. Diazines XXV. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00202-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Katritzky AR, Piffl M, Lang H, Anders E. Regioselectivity of the Reactions of Heteroatom-Stabilized Allyl Anions with Electrophiles. Chem Rev 1999; 99:665-722. [PMID: 11749429 DOI: 10.1021/cr9404297] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alan R. Katritzky
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, and Institut für Organische Chemie und Makromolekulare Chemie der Friedrich-Schiller-Universität Jena, Humboldtstrasse 10, D-07743 Jena, Germany
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Nilsson Lill SO, Arvidsson PI, Ahlberg P. Computational study of solvation and stereoselectivity in deprotonation of cyclohexene oxide by a chiral lithium amide. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0957-4166(98)00501-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Oliva M, Domingo LR, Safont VS, Andrés J, Castillo R, Moliner V. Theoretical study of the molecular mechanism of the domino pathways for squarate ester sequential reactions. J PHYS ORG CHEM 1999. [DOI: 10.1002/(sici)1099-1395(199901)12:1<61::aid-poc93>3.0.co;2-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Aurell MJ, Domingo LR, Mestres R, Muñoz E, Zaragozá RJ. Conjugate addition of organolithium reagents to α,β-unsaturated carboxylic acids. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(98)01073-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Hilmersson G, Arvidsson PI, Davidsson Ö, Håkansson M. Toward Solution-State Structure. A 6Li,1H HOESY NMR, X-ray Diffraction, Semiempirical (PM3, MNDO), and ab Initio Computational Study of a Chiral Lithium Amide. J Am Chem Soc 1998. [DOI: 10.1021/ja9724708] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Göran Hilmersson
- Contribution from the Department of Organic Chemistry, Göteborg University, S-412 96 Göteborg, Sweden, and Department of Inorganic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Per I. Arvidsson
- Contribution from the Department of Organic Chemistry, Göteborg University, S-412 96 Göteborg, Sweden, and Department of Inorganic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Öjvind Davidsson
- Contribution from the Department of Organic Chemistry, Göteborg University, S-412 96 Göteborg, Sweden, and Department of Inorganic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Mikael Håkansson
- Contribution from the Department of Organic Chemistry, Göteborg University, S-412 96 Göteborg, Sweden, and Department of Inorganic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden
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Plé N, Turck A, Heynderickx A, Quéguiner G. First metallation of iodo diazines. Iodo and nitrogen directed metallations. Diazines XXII. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00526-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Strzalko T, Seyden-Penne J, Wartski L, Corset J, Castella-Ventura M, Froment F. 1,2- vs 1,4-Regioselectivity of Lithiated Phenylacetonitrile toward α,β-Unsaturated Carbonyl Compounds. 1. Monomer−Dimer Equilibrium of Lithiated Phenylacetonitrile Ion Pairs in Solution and Structure Determination of the Species by Spectroscopic Methods and ab Initio Calculations. Evidence of a Lithium Bridged Monomeric Ion Pair. J Org Chem 1998. [DOI: 10.1021/jo9614497] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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