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Löw H, Mena-Osteritz E, Mullen KM, Jäger CM, von Delius M. Self-Assembly, Adaptive Response, and in,out-Stereoisomerism of Large Orthoformate Cryptands. Chempluschem 2020; 85:1008-1012. [PMID: 32347636 DOI: 10.1002/cplu.202000254] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/16/2020] [Indexed: 12/19/2022]
Abstract
We report on triethylene glycol-based orthoformate cryptands, which adapt their bridgehead configurations in response to metal templates and intramolecular hydrogen bonding in a complex manner. In contrast to smaller 1.1.1-orthoformate cryptands, the inversion from out,out-2.2.2 to in,in-2.2.2 occurs spontaneously by thermal homeomorphic isomerization, i. e., without bond breakage. The global thermodynamic minimum of the entire network, which includes an unprecedented third isomer (in,out-2.2.2), could only be reached under conditions that facilitate dynamic covalent exchange. Both inversion processes were studied in detail, including DFT calculations and MD simulations, which were particularly helpful for explaining differences between equilibrium compositions in solvents chloroform and acetonitrile. Unexpectedly, the system could be driven to the in,out-2.2.2 state by using a metal template with a size mismatch with respect to the out,out-2.2.2 cage.
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Affiliation(s)
- Henrik Löw
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Elena Mena-Osteritz
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Kathleen M Mullen
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Max von Delius
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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Walker TL, Taschner IS, Chandra M S, Taschner MJ, Engle JT, Schrage BR, Ziegler CJ, Gao X, Wheeler SE. Lone-Pair-Induced Topicity Observed in Macrobicyclic Tetra-thia Lactams and Cryptands: Synthesis, Spectral Identification, and Computational Assessment. J Org Chem 2018; 83:10025-10036. [PMID: 30067366 DOI: 10.1021/acs.joc.8b01382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The synthesis of a rigid macrobicyclic N,S lactam L1 and a topologically favored in/in N,S cryptand L2 are reported with X-ray structure analysis, dynamic correlation NMR spectroscopy, and computational analysis. Lactam L1 exhibits two distinct rotameric conformations (plus their enantiomeric counterparts) at 25 °C, as confirmed via NMR spectroscopy and computational analysis. Coalescence of the resonances of L1 was observed at 115 °C, allowing for complete nuclei to frequency correlation. Combining computational investigations with experimental data, topological equilibria and relative energies/strain relating to the perturbation of the pore were determined. Due to the increased conformational strain of the N2S2 template, the nitrogen lone pairs in L2 elicit a unique transannular interaction, resulting in a thermodynamically favored in/in nephroidal racemate. The combination of preferred topology, steric relief, and electronic localization of L2 induces a chiral environment imparted through the amine with a computed inversion barrier of 10.3 kcal mol-1.
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Affiliation(s)
- Tia L Walker
- Department of Chemistry , Indiana University Northwest , Gary , Indiana 46408 , United States
| | - Ian S Taschner
- Department of Chemistry , Indiana University Northwest , Gary , Indiana 46408 , United States
| | - Sharath Chandra M
- Department of Chemistry , Texas A&M University , College Station , Texas 77842 , United States
| | - Michael J Taschner
- Department of Chemistry , The University of Akron , Akron , Ohio 44325 , United States
| | - James T Engle
- Department of Chemistry , The University of Akron , Akron , Ohio 44325 , United States
| | - Briana R Schrage
- Department of Chemistry , The University of Akron , Akron , Ohio 44325 , United States
| | - Christopher J Ziegler
- Department of Chemistry , The University of Akron , Akron , Ohio 44325 , United States
| | - Xinfeng Gao
- Department of Chemistry , Indiana University Bloomington , Bloomington , Indiana 47405 , United States
| | - Steven E Wheeler
- Department of Chemistry , Texas A&M University , College Station , Texas 77842 , United States.,Center for Computational Quantum Chemistry, Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
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Gerus A, Ślepokura K, Panek J, Turek A, Lisowski J. Chiral Cryptates Derived from a Hexaazamacrocycle. J Org Chem 2018; 83:6748-6753. [PMID: 29774743 DOI: 10.1021/acs.joc.8b00670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The reactions of hexaazamacrocycle 1 with 2,6-bis(bromomethyl)pyridine or 2,6-bis[(tosyloxy)methyl)]pyridine in the presence of appropriate carbonates result in the formation of derivatives of cryptand 6: enantiopure azacryptates of sodium and potassium. Crystal structures of these compounds indicate interaction of a metal ion with four pyridine nitrogen atoms and four tertiary amine atoms. The competition reactions monitored by NMR spectroscopy indicate preferential binding of Na+ over K+ as well as higher affinity of 6 for Na+ in comparison with the [2.2.1] cryptand.
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Affiliation(s)
- Aleksandra Gerus
- Department of Chemistry , University of Wrocław , 14 F. Joliot-Curie , 50-383 Wrocław , Poland
| | - Katarzyna Ślepokura
- Department of Chemistry , University of Wrocław , 14 F. Joliot-Curie , 50-383 Wrocław , Poland
| | - Jarosław Panek
- Department of Chemistry , University of Wrocław , 14 F. Joliot-Curie , 50-383 Wrocław , Poland
| | - Aleksandra Turek
- Department of Chemistry , University of Wrocław , 14 F. Joliot-Curie , 50-383 Wrocław , Poland
| | - Jerzy Lisowski
- Department of Chemistry , University of Wrocław , 14 F. Joliot-Curie , 50-383 Wrocław , Poland
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Rizzo C, D'Anna F, Noto R. Functionalised diimidazolium salts: the anion effect on the catalytic ability. RSC Adv 2016. [DOI: 10.1039/c6ra12037g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
How is it possible to catalyze and simultaneously control the outcome of a reaction? Employing task specific ionic liquids and changing their anions.
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Affiliation(s)
- Carla Rizzo
- Università degli Studi di Palermo
- Dipartimento STEBICEF
- Sezione di Chimica
- 90128 Palermo
- Italy
| | - Francesca D'Anna
- Università degli Studi di Palermo
- Dipartimento STEBICEF
- Sezione di Chimica
- 90128 Palermo
- Italy
| | - Renato Noto
- Università degli Studi di Palermo
- Dipartimento STEBICEF
- Sezione di Chimica
- 90128 Palermo
- Italy
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Kole GK, Tan GK, Vittal JJ. Role of anions in the synthesis of cyclobutane derivatives via [2 + 2] cycloaddition reaction in the solid state and their isomerization in solution. J Org Chem 2011; 76:7860-5. [PMID: 21776965 DOI: 10.1021/jo201268p] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
trans-3-(4'-Pyridyl)acrylic acid (4-PA) is inert to photodimerization reaction both in solution and solid state. It is made photoreactive by forming salts with various acids. The anions of these salts play a key role in directing the packing of 4-PAH(+) in the solid state. The anions CF(3)CO(2)(-), Cl(-), ClO(4)(-), and BF(4)(-) direct the parallel alignments of 4-PAH(+) in head-to-tail (HT) fashion and lead to the formation of HT-photodimer. On the other hand, bivalent anion SO(4)(2-) directs parallel alignment of 4-PAH(+) in head-to-head (HH) fashion and lead to the formation of HH-photodimer. The details of the anion-controlled stereoselective syntheses of these two cyclobutane derivatives are presented. Interestingly, both cyclobutane compounds undergo isomerization from rctt-form to rctc-form in solution catalyzed by acid.
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Affiliation(s)
- Goutam Kumar Kole
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
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Bonnot C, Aubert E, Banerji N, Lacour J, Espinosa E, Chambron JC. Kinetic Control in the Chiral Recognition of Three-Bladed Propellers. Chemistry 2010; 16:5706-11. [DOI: 10.1002/chem.200903058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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