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Aliev AE, Motherwell WB. Some Recent Advances in the Design and Use of Molecular Balances for the Experimental Quantification of Intramolecular Noncovalent Interactions of π Systems. Chemistry 2019; 25:10516-10530. [DOI: 10.1002/chem.201900854] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/09/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Abil E. Aliev
- Department of ChemistryUniversity College London 20 Gordon Street London WC1H 0AJ UK
| | - William B. Motherwell
- Department of ChemistryUniversity College London 20 Gordon Street London WC1H 0AJ UK
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2
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Li JY, Chang HI, Feng CN, Wu YT. Rotation of Aryl Groups in 9,10-Diarylphenanthrenes: Does the Rotational Barrier Become Lower as the Backbone Becomes More Crowded? Org Lett 2016; 18:6444-6447. [DOI: 10.1021/acs.orglett.6b03343] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jen-Yi Li
- Department of Chemistry, National Cheng Kung University, No. 1 Ta-Hsueh Road, 70101 Tainan, Taiwan
| | - Hung-Ing Chang
- Department of Chemistry, National Cheng Kung University, No. 1 Ta-Hsueh Road, 70101 Tainan, Taiwan
| | - Chieh-Ning Feng
- Department of Chemistry, National Cheng Kung University, No. 1 Ta-Hsueh Road, 70101 Tainan, Taiwan
| | - Yao-Ting Wu
- Department of Chemistry, National Cheng Kung University, No. 1 Ta-Hsueh Road, 70101 Tainan, Taiwan
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3
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Li Z, Huang X, Chen F, Zhang C, Wang X, Jiao N. Cu-Catalyzed Concise Synthesis of Pyridines and 2-(1H)-Pyridones from Acetaldehydes and Simple Nitrogen Donors. Org Lett 2015; 17:584-7. [DOI: 10.1021/ol5035996] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ziyuan Li
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Xiaoqiang Huang
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Feng Chen
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Chun Zhang
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Xiaoyang Wang
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Ning Jiao
- State
Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical
Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
- State
Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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4
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Gunasekaran P, Perumal S, Menéndez JC, Mancinelli M, Ranieri S, Mazzanti A. Axial Chirality of 4-Arylpyrazolo[3,4-b]pyridines. Conformational Analysis and Absolute Configuration. J Org Chem 2014; 79:11039-50. [DOI: 10.1021/jo502047n] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Pethaiah Gunasekaran
- Department
of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu, India
| | - Subbu Perumal
- Department
of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu, India
| | - J. Carlos Menéndez
- Departamento
de Química Orgánica y Farmacéutica, Facultad
de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Michele Mancinelli
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Silvia Ranieri
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Andrea Mazzanti
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
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5
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Yang Y, Zhao JF, Liu RR, Li JW, Yi MD, Xie GH, Xie LH, Chang YZ, Yin CR, Zhou XH, Zhao Y, Qian Y, Huang W. Diarylfluorenes-based π-stacked molecules: synthesis, X-ray crystallography, and supramolecular light-emitting devices. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.02.090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Ambrogi M, Ciogli A, Mancinelli M, Ranieri S, Mazzanti A. Atropisomers of Arylmaleimides: Stereodynamics and Absolute Configuration. J Org Chem 2013; 78:3709-19. [DOI: 10.1021/jo400200v] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Martina Ambrogi
- Department of Industrial Chemistry
“Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 - Bologna, Italy
| | - Alessia Ciogli
- Dipartimento di Chimica e Tecnologie
del farmaco, Università di Roma “La Sapienza”, P.le A.Moro 5, 00185 - Roma, Italy
| | - Michele Mancinelli
- Department of Industrial Chemistry
“Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 - Bologna, Italy
| | - Silvia Ranieri
- Department of Industrial Chemistry
“Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 - Bologna, Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry
“Toso Montanari”, University of Bologna, Viale Risorgimento 4, 40136 - Bologna, Italy
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7
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Dresselhaus T, Yang J, Kumbhar S, Waller MP. Hybrid Metaheuristic Approach for Nonlocal Optimization of Molecular Systems. J Chem Theory Comput 2013; 9:2137-49. [DOI: 10.1021/ct301079m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Thomas Dresselhaus
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße
40, 48149 Münster, Germany
| | - Jack Yang
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße
40, 48149 Münster, Germany
| | - Sadhana Kumbhar
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße
40, 48149 Münster, Germany
| | - Mark P. Waller
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße
40, 48149 Münster, Germany
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8
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Alkorta I, Elguero J, Roussel C, Vanthuyne N, Piras P. Atropisomerism and Axial Chirality in Heteroaromatic Compounds. ADVANCES IN HETEROCYCLIC CHEMISTRY 2012. [DOI: 10.1016/b978-0-12-396530-1.00001-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Ghosn MW, Wolf C. Synthesis, Conformational Stability, and Asymmetric Transformation of Atropisomeric 1,8-Bisphenolnaphthalenes. J Org Chem 2011; 76:3888-97. [DOI: 10.1021/jo200309g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marwan W. Ghosn
- Department of Chemistry, Georgetown University, Washington, D.C. 20057, United States
| | - Christian Wolf
- Department of Chemistry, Georgetown University, Washington, D.C. 20057, United States
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10
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Alkorta I, Elguero J. A computational study of the conformation of heterocyclic systems related to biphenyl. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2010.11.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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11
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Mati IK, Cockroft SL. Molecular balances for quantifying non-covalent interactions. Chem Soc Rev 2010; 39:4195-205. [PMID: 20844782 DOI: 10.1039/b822665m] [Citation(s) in RCA: 175] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular interactions underlie the whole of chemistry and biology. This tutorial review illustrates the use of rotameric folding molecules, topoisomers, atropoisomers, and tautomers as molecular balances for quantifying non-covalent interactions. This intramolecular approach enables a wide variety of interactions to be examined with a degree of geometric control that is difficult to achieve in supramolecular complexes. Synthetic variation of molecular balances allows the fundamental physicochemical origins of molecular recognition to be systematically examined by providing insights into the interplay of geometry and solvation on non-covalent interactions.
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Affiliation(s)
- Ioulia K Mati
- School of Chemistry, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, UK EH9 3JJ
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12
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Roussel C, Kaid-Slimane R, Andreoli F, Renaudin M, Vanthuyne N. Synthesis, chiral separation, and absolute configuration of bis-(N-aryl) atropisomeric triads: 1,2-Bis-[4-methyl-2-(thi)oxo-2,3-dihydrothiazol-3-yl]-benzene. Chirality 2009; 21:160-6. [DOI: 10.1002/chir.20599] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Lunazzi L, Mancinelli M, Mazzanti A. Structure, Stereodynamics and Absolute Configuration of the Atropisomers of Hindered Arylanthraquinones. J Org Chem 2008; 74:1345-8. [DOI: 10.1021/jo802383s] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lodovico Lunazzi
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Michele Mancinelli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Andrea Mazzanti
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
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14
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Kawai H, Takeda T, Fujiwara K, Wakeshima M, Hinatsu Y, Suzuki T. Ultralong carbon-carbon bonds in dispirobis(10-methylacridan) derivatives with an acenaphthene, pyracene, or dihydropyracylene skeleton. Chemistry 2008; 14:5780-93. [PMID: 18478615 DOI: 10.1002/chem.200702028] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Acenapthalene, pyracene, and dihydropyracylene attached to two units of spiroacridan are a novel class of hexaphenylethane (HPE) derivatives that have an ultralong Csp3-Csp3 bond (1.77-1.70 A). These sterically challenged molecules were cleanly prepared by C-C bond formation through two-electron reduction from the less-hindered dications. These ultralong bonds were realized based on several molecular-design concepts including enhanced "front strain" through "multiclamping" by means of fusing or bridging aryl groups in the HPE molecule. The lengths of these ultralong bonds and their relation to the conformation (torsional angle) were also validated by means of theoretical calculations. Bond-fission experiments revealed that the bonds are more easily cleaved than standard covalent bonds to produce the corresponding dication upon oxidation with an increase in the length of the C-C bond.
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Affiliation(s)
- Hidetoshi Kawai
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810 (Japan).
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15
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Lunazzi L, Mancinelli M, Mazzanti A. Stereodynamics and Conformational Chirality of the Atropisomers of Ditolyl Anthrones and Anthraquinone. J Org Chem 2008; 73:5354-9. [DOI: 10.1021/jo800677n] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Lodovico Lunazzi
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Michele Mancinelli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Andrea Mazzanti
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
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16
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Lunazzi L, Mancinelli M, Mazzanti A. Arylbiphenylene Atropisomers: Structure, Conformation, Stereodynamics, and Absolute Configuration. J Org Chem 2008; 73:2198-205. [DOI: 10.1021/jo702502n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lodovico Lunazzi
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Michele Mancinelli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
| | - Andrea Mazzanti
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale Risorgimento 4, Bologna 40136, Italy
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17
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Lunazzi L, Mancinelli M, Mazzanti A. Unprecedented Detection of Enantiomerization π-Barriers Due to Restricted Aryl Torsion: Case of 1,8-Di-arylbiphenylenes. J Org Chem 2007; 72:10045-50. [DOI: 10.1021/jo701917v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lodovico Lunazzi
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale, Risorgimento 4, Bologna 40136, Italy
| | - Michele Mancinelli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale, Risorgimento 4, Bologna 40136, Italy
| | - Andrea Mazzanti
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Viale, Risorgimento 4, Bologna 40136, Italy
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18
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Mei X, Wolf C. Highly congested nondistorted diheteroarylnaphthalenes: model compounds for the investigation of intramolecular pi-stacking interactions. J Org Chem 2005; 70:2299-305. [PMID: 15760218 DOI: 10.1021/jo0479361] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[structure: see text] The rigid, highly congested structure of 1,8-diacridylnaphthalenes has been studied in solution and in the solid state. The unique geometry of these compounds forces the acridyl rings to undergo face-to-face interactions while rendering T-shaped orientations and face-to-edge interactions impossible. Crystallographic analysis shows that splaying between the heteroaryl rings decreases while twisting between the cofacial rings increases as the acridyl nitrogens of the 1,8-diacridylnaphthalene framework are subsequently oxidized. The peri-acridyl rings are slightly splayed but remain perfectly planar in all cases. The significant decrease in splaying indicates enhanced pi-pi-attraction between the electron-rich acridyl N-oxide moieties, which is in agreement with recently reported symmetry-adapted perturbation theory calculations. The pi-stacking and the molecular geometry between the acridyl rings observed in the solid state have been confirmed through in-solution studies showing characteristic proton NMR upfield shifts and optical properties indicative of static intramolecular arene-arene interactions. Acridyl protons located directly above the adjacent aryl moiety as a consequence of twisting between the heteroaryl rings were identified by COSY NMR measurements and found to intrude into the pi-cloud and diamagnetic ring current of the neighboring acridine. Different shapes and strong red shifts of the fluorescence emission maxima of the diacridylnaphthalenes in comparison to parental acridyl monomers have been attributed to static excimer emission.
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Affiliation(s)
- Xuefeng Mei
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
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19
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Dipyridyl/pyridinium thieno[2,3-b]thiophenes as new atropisomeric systems. Synthesis, conformational analysis and energy minimization. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.01.123] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Tumambac GE, Wolf C. Synthesis and Stereodynamics of Highly Constrained 1,8-Bis(2,2‘-dialkyl-4,4‘-diquinolyl)naphthalenes (2). J Org Chem 2005; 70:2930-8. [PMID: 15822951 DOI: 10.1021/jo048399n] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Axially chiral 1,8-bis(2,2'-diphenyl-4,4'-diquinolyl)naphthalene, 8, and 1,8-bis(2,2'-diisopropyl-4,4'diquinolyl)naphthalene N,N'-dioxide, 9, have been prepared to study the stereodynamics of these and other 1,8-diheteroarylnaphthalenes based on reversible first-order isomerization kinetics and crystallographic data. The ratio of the two enantiomeric anti-conformers to the meso syn-isomer of 8 and 9 was determined as 1.2:1 and 9.6:1. Investigation of the conformational stability of the atropisomers at enhanced temperatures using HPLC and NMR spectroscopy revealed a Gibbs activation energy of 122.4 (121.8) kJ/mol and 115.2 (109.0) kJ/mol for the anti/syn- (syn/anti)-isomerization of 8 and 9, respectively. Comparison of the conformational stability of a series of 1,8-dipyridylnaphthalenes and 1,8-diquinolylnaphthalenes shows that the latter exhibit a significantly higher rotational energy barrier. While the syn- and anti-isomers of 1,8-dipyridylnaphthalenes interconvert rapidly at room temperature the stereoisomers of 1,8-diquinolylnaphthalenes can be isolated by chromatography or crystallization and stored at 25 degrees C for several months without any sign of racemization. The conformational stability of 1,8-diquinolylnaphthalenes is a consequence of significantly increased steric hindrance to isomerization in a highly congested T-shaped transition state. Conversion of 1,8-diheteroarylnaphthalenes to their corresponding N,N'-dioxides was found to result in an increased anti/syn-ratio and decreased rotational energy barrier, which was attributed to synergistic repulsive dipole/dipole interactions destabilizing the diastereomeric ground states and facilitated out-of-plane bending reducing the steric hindrance in the T-shaped transition state.
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Affiliation(s)
- Gilbert E Tumambac
- Department of Chemistry, Georgetown University, Washington, D.C. 20057, USA
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21
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Synthesis of 4,5-diarylquinazolines: a system with cofacial aromatic rings. Diazines. Part 39. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.04.065] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Grilli S, Lunazzi L, Mazzanti A, Pinamonti M. Conformational studies by dynamic NMR spectroscopy. Part 96: Stereomutations of highly hindered naphthylphenyl atropisomers in solution and in the solids. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.01.094] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Tumambac GE, Wolf C. Synthesis and Stereodynamics of Highly Constrained 1,8-Bis(2,2‘-dialkyl-4,4‘-diquinolyl)naphthalenes. J Org Chem 2004; 69:2048-55. [PMID: 15058953 DOI: 10.1021/jo035547l] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The syn and anti isomers of axially chiral 1,8-diquinolylnaphthalenes have been synthesized via Pd-catalyzed Stille coupling of 1,8-dibromonaphthalene and 2-alkyl-4-trimethylstannylquinolines. Optimization of the cross-coupling reaction allowed the preparation of highly constrained 1,8-bis(2,2'-dimethyl-4,4'-diquinolyl)naphthalene, 2, and 1,8-bis(2,2'-diisopropyl-4,4'-diquinolyl)naphthalene, 3, in 42% and 41% yield, respectively. Employing Pd(PPh(3))(4) and CuO as the cocatalysts in the coupling reaction of 1,8-dibromonaphthalene and 2-alkyl-4-trimethylstannylquinolines proved to be superior over other catalysts such as PdCl(2)(dppf), Pd(2)(dba)(3)/P(t-Bu)(3), and POPd. The C(2)-symmetric anti isomers of 2 and 3 were found to be more stable than the corresponding meso syn isomer. The ratio of the two enantiomeric anti conformers to the syn conformer was determined as 7.9:1 for 2 and 8.6:1 for 3 by NMR and HPLC analysis. The atropisomers of 2 and 3 were found to be stable to rotation about the chiral axis at room temperature and all three stereoisomers of 2 were isolated by semipreparative HPLC on a Chiralpak AD column. The diastereoisomers of 3 were separated via preferential crystallization of the anti isomers from diethyl ether. Slow syn/anti interconversion was observed for both atropisomers at enhanced temperature, and the diastereomerization and enantiomerization processes were monitored by NMR and HPLC. The Gibbs activation energy, DeltaG++, for the isomerization of 2 was determined as 116.0 (112.1) kJ/mol for the conversion of the anti (syn) to the syn (anti) isomer at 71.0 degrees C. The rotational energy barrier of 3 was determined as 115.2 (111.1) kJ/mol for the conversion of the anti (syn) to the syn (anti) isomer at 66.2 degrees C.
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Affiliation(s)
- Gilbert E Tumambac
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
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24
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Lomas JS, Vaissermann J. Solvent and structure effects on rotamerization in 3,4-alkylenedioxy- and 3,4-dialkoxy-2,5-bis[di(tert-butyl) hydroxymethyl]thiophenes: an NMR, IR, molecular mechanics and single-crystal x-ray study. J PHYS ORG CHEM 2004. [DOI: 10.1002/poc.696] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Wolf C, Mei X. Synthesis of conformationally stable 1,8-diarylnaphthalenes: development of new photoluminescent sensors for ion-selective recognition. J Am Chem Soc 2003; 125:10651-8. [PMID: 12940749 DOI: 10.1021/ja0358145] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Highly constrained 1,8-diarylnaphthalenes exhibiting stability to isomerization have been prepared utilizing two consecutive CuO-promoted Stille cross-couplings of 1,8-dibromonaphthalene and 4-alkyl-9-trimethylstannylacridines. Screening of Pd catalysts Pd(PPh(3))(4), PdCl(2)dppf, or Pd(2)(dba)(3)/t-Bu(3)P and bases such as Cy(2)NMe, t-BuOK, K(3)PO(4), and Cs(2)CO(3) in DME or DMF revealed superior results of Stille over Suzuki coupling with acridylboronic acids or pinacolate derivatives. The meso syn- and C(2)-symmetric anti-isomers of 1,8-bis(4,4'-dimethyl-9,9'-diacridyl)naphthalene, 2, and 1,8-bis(4,4'-diisopropyl-9,9'-diacridyl)naphthalene, 3, did not show any sign of syn/anti-interconversion after heating to 180 degrees C for 24 h. Using the Eyring equation, we calculated the Gibbs standard activation energy for isomerization, DeltaG degrees (), to be higher than 180 kJ/mol. PM3 calculations of 2 and 3 suggest a highly congested structure exhibiting two parallel acridyl moieties perpendicular to the naphthalene ring. UV and fluorescence spectroscopy studies of 2 and 3 revealed remarkable quantum yields of these blue and green light emitters. Fluorescence titration experiments with the syn-isomer of 2 showed highly efficient quenching by Cu(II) ions, whereas almost no quenching effects were observed with Cu(I) and Zn(II) salts. The striking difference in fluorescence quenching was attributed to significant photoinduced electron transfer, resulting in nonradiative relaxation of excited Cu(II)-syn-2. Stern-Völmer plots of syn-2 in the presence of CuCl(2) showed a sigmoidal quenching curve indicating cooperative recognition, whereas a linear response was observed with CuCl and ZnCl(2). Fluorescence experiments in the presence of various amounts of CuCl, CuBr, and Cu(ACN)(4)BF(4) proved that the quenching is cation selective and independent of the nature of counteranions.
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Affiliation(s)
- Christian Wolf
- Department of Chemistry, Georgetown University, Washington, D.C. 20057, USA.
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26
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Lomas JS, Cordier C. Rotational isomerism in 3,4-alkylenedioxy-2,5-bis[di(tert-butyl)hydroxymethyl]thiophenes>. J PHYS ORG CHEM 2003. [DOI: 10.1002/poc.640] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Wolf C, Tumambac GE. Investigation of the Stereodynamics of Axially Chiral 1,8-Bis(2,2‘-diphenyl-4,4‘-dipyridyl)naphthalene and Cryogenic Separation of Its syn/anti-Isomers. J Phys Chem A 2003. [DOI: 10.1021/jp0272926] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christian Wolf
- Department of Chemistry, Georgetown University, Washington, D.C. 20057
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28
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Gibson KR, Hitzel L, Mortishire-Smith RJ, Gerhard U, Jelley RA, Reeve AJ, Rowley M, Nadin A, Owens AP. Synthesis and conformational dynamics of tricyclic pyridones containing a fused seven-membered ring. J Org Chem 2002; 67:9354-60. [PMID: 12492338 DOI: 10.1021/jo026411a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new synthetic approach to tricyclic pyridones bearing a fused seven-membered ring is described. These compounds exhibit atropisomerism and exist in enantiomeric forms. Chiral HPLC separation of the enantiomers has allowed the rates of racemization to be measured and hence the free energy barrier for flipping the seven-membered ring to be deduced. Introduction of a further element of planar chirality leads to diastereomeric atropisomerism. The rate of interconversion of the diastereomers has been quantified by 2D EXSY NMR spectroscopy allowing a full description of the conformational dynamics of the system.
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Affiliation(s)
- Karl R Gibson
- Medicinal Chemistry Department, Merck Sharp & Dohme Research Laboratories, The Neuroscience Research Centre, Terlings Park, Harlow, Essex CM20 2QR, UK
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29
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Gawroński J, Kacprzak K. Architecture and function of atropisomeric molecular triads. Chirality 2002; 14:689-702. [PMID: 12237827 DOI: 10.1002/chir.10127] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Molecular triads, B-A-B, in which the central unit A is aromatic or heteroaromatic, can exist as syn or anti conformers or atropisomers of correspondingly C or S shape. These stereoisomers are either discrete conformer species, often distinguished by NMR spectroscopy, or can be separated at ambient temperature as stable atropisomers. In the latter case syn and anti stereoisomers exhibit different (e.g., complex-forming) properties. Practical applications of atropisomeric triads as ligands in asymmetric dihydroxylation are also discussed.
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Affiliation(s)
- J Gawroński
- Department of Chemistry, A. Mickiewicz University, Poznań, Poland.
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30
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Wolf C, Ghebremariam BT. Dynamic stereochemistry of 1,8-bis(2,2′-disubstituted-4,4′-dipyridyl)naphthalenes and their N,N′-dioxide derivatives. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00266-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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DellErba C, Gasparrini F, Grilli S, Lunazzi L, Mazzanti A, Novi M, Pierini M, Tavani C, Villani C. Conformational studies by dynamic NMR. 86. Structure, stereodynamics, and cryogenic enantioseparation of the stereolabile isomers of o-dinaphthylphenyl derivatives. J Org Chem 2002; 67:1663-8. [PMID: 11871900 DOI: 10.1021/jo016397m] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Static and dynamic stereochemistry of the hydrocarbon comprising a phenyl ring bearing two alpha-naphthyl substituents in the ortho positions, i.e., 1,2-di-(4-methyl-naphth-1-yl)-benzene 1, has been studied by a combination of variable temperature NMR, cryogenic HPLC, and MM calculations. Whereas in solution both syn (meso) and anti (chiral) forms were observed and the corresponding interconversion barrier was determined (Delta G(++) = 19.5 kcal mol(-1)), only the diastereoisomer anti was found to be present in the crystalline state (X-ray diffraction). When the molecule is rendered asymmetric by introduction of a nitro group in the phenyl ring as in 1,2-di-(4-methyl-naphth-1-yl)-4-nitrobenzene 2, the chiral syn and anti diastereoisomers are simultaneously present both in solution and in the solid state, albeit in different proportions. Cryogenic chromatography on a HPLC chiral stationary phase at 20 degrees C allowed the stereolabile diastereoisomers and the corresponding enantiomers to be separated.
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Affiliation(s)
- Carlo DellErba
- Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, Genova 16146, Italy
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32
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Lavieri S, Zoltewicz JA. Polar-pi and cation-pi stabilizing interactions between constrained cofacial aromatic rings favoring the more sterically hindered diastereomer. J Org Chem 2001; 66:7227-30. [PMID: 11597259 DOI: 10.1021/jo010537a] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S Lavieri
- Faculty of Pharmacy, Universidad Central de Venezuela, Caracas
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33
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Iovine PM, Kellett MA, Redmore NP, Therien MJ. Syntheses and 1H NMR Spectroscopy of Rigid, Cofacially Aligned, Porphyrin−Bridge−Quinone Systems in Which the Interplanar Separations between the Porphyrin, Aromatic Bridge, and Quinone Are Less than the Sum of Their Respective van der Waals Radii. J Am Chem Soc 2000. [DOI: 10.1021/ja000759a] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peter M. Iovine
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323
| | - Matthew A. Kellett
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323
| | - Naomi P. Redmore
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323
| | - Michael J. Therien
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323
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34
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Conformational studies by dynamic NMR. 74.(1) stereomutations of the conformational enantiomers in peri-substituted 1-acylnaphthalenes. J Org Chem 2000; 65:3200-6. [PMID: 10814215 DOI: 10.1021/jo991853g] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Naphthalenes bearing an acyl and a phenyl group in a peri relationship give rise to a pair of enantiomers in the temperature range where the rotations of the acyl group are slow. Such enantiomers were observed by means of low temperature NMR spectra in chiral environments. The barrier to rotation for the acyl substituents, that causes the interconversion of the enantiomers, was demonstrated to be lower than that for the phenyl group. In an appropriately synthesized derivative it was possible to measure the two barriers that were found equal to 10.4 and 15.9 kcal mol(-)(1), respectively. The barriers for the acyl group rotation increase regularly (from 9.5 to 13.2 kcal mol(-)(1)) with the increasing dimension of the RCO groups (R = Me, Et, Pr(i), Bu(t)). When a bromine atom replaces the phenyl group, the enantiomerization barrier for the corresponding acyl derivatives increases significantly.
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35
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Zoltewicz JA, Maier NM, Fabian WMF. π-Cation and π-Dipole-Stabilizing Interactions in a Simple Model System with Cofacial Aromatic Rings. J Org Chem 1998. [DOI: 10.1021/jo9801465] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- John A. Zoltewicz
- Department of Chemistry, University of Florida, Gainesville, Forida 32611-7200
| | - Norbert M. Maier
- Department of Chemistry, University of Florida, Gainesville, Forida 32611-7200
| | - Walter M. F. Fabian
- Institut für Organische Chemie, Karl-Franzens Universität, A-8010 Graz, Austria
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36
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37
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Walden SE, Glatzhofer DT. Distinctive Normal Harmonic Vibrations of [2.2]Paracyclophane. J Phys Chem A 1997. [DOI: 10.1021/jp9720395] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Susan E. Walden
- Department of Chemistry and Biochemistry and the Center for Photonic and Electronic Materials and Devices, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, Oklahoma 73019
| | - Daniel T. Glatzhofer
- Department of Chemistry and Biochemistry and the Center for Photonic and Electronic Materials and Devices, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, Oklahoma 73019
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38
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Zoltewicz JA, Maier NM, Fabian WMF. Electrostatic Effects on the Population of Atropisomers of Charged and Dipolar Derivatives of 1,8-Di(2'-pyridyl)naphthalene. J Org Chem 1997; 62:2763-2766. [PMID: 11671637 DOI: 10.1021/jo962232f] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dicationic 1',1'-dimethyl (6a), dipolar 1',1'-dioxide (6b), and 6',6'-dipyridone (7) derivatives of 1,8-di(2'-pyridyl)naphthalene were prepared. Proton NMR failed to reveal the presence of individual anti-syn atropisomers over a wide range of temperatures. By contrast, the 1',1"-dimethyl derivative of 1-(2'-pyridyl)-8-(3"-pyridyl)naphthalene (8), a positional isomer of 6a, existed in DMSO-d(6) as a 2:1 mixture of anti to syn atropisomers at ambient temperatures. Electrostatic repulsion is believed to cause the anti atropisomer to be favored, especially in 6a where the charged regions are closer together than in 8, owing to the splayed-out arrangement of the rings. AM1 and PM3 computations confirm that the anti is highly favored over the synisomer for 6a, 6b, and 7.
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Affiliation(s)
- John A. Zoltewicz
- Institut für Organische Chemie, Karl-Franzens Universität, A-8010 Graz, Austria
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