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Cao Z, Lacoudre A, Rossy C, Bibal B. Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis. Beilstein J Org Chem 2019; 15:2465-2472. [PMID: 31666881 PMCID: PMC6808213 DOI: 10.3762/bjoc.15.239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 09/20/2019] [Indexed: 12/30/2022] Open
Abstract
The bis-ortho-thioether 9,10-bis[(o-methylthio)phenyl]anthracene was synthesized as a syn-atropisomer, as revealed by X-ray diffraction. This alkylaryl thioether ligand (L) formed different macrocyclic complexes by coordination with silver(I) salts depending on the nature of the anion: M2L2 for AgOTf and AgOTFA, M6L4 for AgNO3. A discrete M2L complex was obtained in the presence of bulky PPh3AgOTf. These silver(I) complexes adopted similar structures in solution and in the solid state. As each sulfur atom in the ligand is prochiral, macrocycles L2M2 were obtained as mixtures of diastereoisomers, depending on the configurations of the sulfur atoms coordinated to silver cations. The X-ray structures of the two L2·(AgOTf)2 stereoisomers highlighted their different geometry. The catalytic activity of all silver(I) complexes was effective under homogeneous conditions in two tandem addition/cycloisomerization of alkynes using 0.5–1 mol % of catalytic loading.
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Affiliation(s)
- Zhen Cao
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR CNRS 5255, 351 cours de la libération, 33405 Talence, France
| | - Aline Lacoudre
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR CNRS 5255, 351 cours de la libération, 33405 Talence, France
| | - Cybille Rossy
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR CNRS 5255, 351 cours de la libération, 33405 Talence, France
| | - Brigitte Bibal
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR CNRS 5255, 351 cours de la libération, 33405 Talence, France
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Evaluation of reversible interconversion in comprehensive two-dimensional gas chromatography using enantioselective columns in first and second dimensions. J Chromatogr A 2015; 1404:104-14. [DOI: 10.1016/j.chroma.2015.05.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/04/2015] [Accepted: 05/21/2015] [Indexed: 11/18/2022]
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3
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Interconversion of Stereochemically Labile Enantiomers (Enantiomerization). Top Curr Chem (Cham) 2013; 341:231-69. [DOI: 10.1007/128_2013_453] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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4
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Nikitin K, Fleming C, Müller-Bunz H, Ortin Y, McGlinchey MJ. Severe Energy Costs of Double Steric Interactions: Towards a Molecular Clamp. European J Org Chem 2010. [DOI: 10.1002/ejoc.201000847] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Zehm D, Fudickar W, Hans M, Schilde U, Kelling A, Linker T. 9,10-Diarylanthracenes as Molecular Switches: Syntheses, Properties, Isomerisations and Their Reactions with Singlet Oxygen. Chemistry 2008; 14:11429-41. [DOI: 10.1002/chem.200801355] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Fudickar W, Linker T. Remote substituent effects on the photooxygenation of 9,10-diarylanthracenes: strong evidence for polar intermediates. Chem Commun (Camb) 2008:1771-3. [PMID: 18379688 DOI: 10.1039/b719637g] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two different reaction pathways in the photooxygenation of 9,10-diarylanthracenes are identified, with strong evidence for polar (forward, singlet oxygen addition) and radical (backward, thermolysis) intermediates.
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Affiliation(s)
- Werner Fudickar
- Department of Chemistry, University of Potsdam, Karl-Liebknecht Str. 24-25, D-14476, Potsdam/Golm, Germany
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Affiliation(s)
- Daniel Zehm
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam/Golm, Germany
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Wolf C. Stereolabile chiral compounds: analysis by dynamic chromatography and stopped-flow methods. Chem Soc Rev 2005; 34:595-608. [PMID: 15965541 DOI: 10.1039/b502508g] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Enantiomerization and diastereomerization reactions of chiral compounds play a major role in all aspects of chemistry spanning a wide bridge from drug development to supramolecular chemistry. Traditionally, these reactions are studied by variable-temperature NMR spectroscopy and chiroptical methods such as polarimetry. However, powerful complimentary methods based on chromatography and electrophoresis have been developed and applied to a variety of stereolabile chiral compounds. This tutorial review explains the principles, applications, and limitations of dynamic chromatography and chromatographic and electrophoretic stopped-flow analysis for the investigation of isomerization reactions of chiral compounds.
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Affiliation(s)
- Christian Wolf
- Department of Chemistry, Georgetown University, Washington DC 20057, USA.
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10
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Trapp O, Schurig V. Novel direct access to enantiomerization barriers from peak profiles in enantioselective dynamic chromatography: enantiomerization of dialkyl-1,3-allenedicarboxylates. Chirality 2002; 14:465-70. [PMID: 12112339 DOI: 10.1002/chir.10089] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The axially chiral allenes dimethyl-1,3-allenedicarboxylate 1 and diethyl-1,3-allenedicarboxylate 2 show characteristic plateau formation during enantioselective GC separation on the chiral stationary liquid phase Chirasil-beta-Dex. The elution profiles, obtained from temperature-dependent dynamic GC (DGC) experiments (1: 100-140 degrees C; 2: 110-150 degrees C) were evaluated with the recently derived approximation function (AF) k1(approx) = f(t(R)(A),t(R)(B),w(h)(A),h(plateau), N) to yield the enantiomerization rate constant directly k(1). These values were compared with those obtained by computer-aided simulation with ChromWin. The Eyring activation parameters of the experimental interconversion profiles were determined to be: DeltaG(#)(298.15 K) = 103.6 +/- 0.9 kJ mol(-1), DeltaH(#) = 44.7 +/- 0.4 kJ mol(-1), DeltaS(#) = -198 +/- 7 J K(1) mol(-1) for dimethyl-1,3-allenedicarboxylate 1, and DeltaG(#)(298.15 K) = 103.5 +/- 1.1 kJ mol(-1), DeltaH(#) = 44.7 +/- 0.5 kJ mol(-1), DeltaS(#) = -197 +/- 9 J K(-1) mol(-1) for diethyl-1,3-allenedicarboxylate 2. The approximation function (AF) presented here allows the fast determination of rate constants k(1) and activation barriers of enantiomerization DeltaG(#) from chromatographic parameters without extensive computer simulation.
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Affiliation(s)
- Oliver Trapp
- University of Tübingen, Institute of Organic Chemistry, Tübingen, Germany
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Schoetz G, Trapp O, Schurig V. Determination of the cis-trans isomerization barrier of several L-peptidyl-L-proline dipeptides by dynamic capillary electrophoresis and computer simulation. Electrophoresis 2001; 22:2409-15. [PMID: 11519944 DOI: 10.1002/1522-2683(200107)22:12<2409::aid-elps2409>3.0.co;2-c] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dynamic capillary electrophoresis (DCE) and computer simulation of the elution profiles with the theoretical plate and the stochastic model has been applied to determine the isomerization barriers of the three dipeptides L-alanyl-L-proline, L-leucyl-L-proline, and L-phenylalanyl-L-proline. The separation of the rotational cis-trans isomers has been performed in an aqueous 70 mM borate buffer at pH 9.5. Interconversion profiles featuring plateau formation and peak broadening were observed. To determine the rate constants k1 and k(-1) of the cis-trans isomerization in dynamic capillary electrophoresis, equations have been derived for the theoretical plate model and stochastic model. The electropherograms were simulated with the ChromWin software which uses the experimental data plateau height h(plateau), peak width at half height Wh, the total migration times of the cis-trans isomers tR and the electroosmotic break-through time t0 as well as the peak ratio [cis]/[trans]. From temperature-dependent measurements, the rate constants k1 and k(-1) and the kinetic activation parameters deltaG#, deltaH# and deltaS# of the cis-trans isomerization of the three dipeptides were obtained.
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Affiliation(s)
- G Schoetz
- Universität Tübingen, Institut für Organische Chemie, Germany
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Trapp O, Schoetz G, Schurig V. Determination of enantiomerization barriers by dynamic and stopped-flow chromatographic methods. Chirality 2001; 13:403-14. [PMID: 11466759 DOI: 10.1002/chir.1052] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In recent years, dynamic chromatography and stopped-flow chromatographic techniques have become versatile tools for the determination of enantiomerization and isomerization barriers. Increasing demands for the stereochemical safety of chiral drugs contributed to the rapid development of new techniques. New computer-aided evaluation systems allow the on-line determination of interconversion barriers from the experimental chromatograms. Both dynamic chromatography and stopped-flow chromatography have been applied to the entire range of chromatographic methods (GC, SFC, HPLC, CE).
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Affiliation(s)
- O Trapp
- University of Tübingen, Institute of Organic Chemistry, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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Mariott P, Trapp O, Shellie R, Schurig VG. Time-resolved cryogenic modulation reveals isomer interconversion profiles in dynamic chromatography. J Chromatogr A 2001; 919:115-26. [PMID: 11459297 DOI: 10.1016/s0021-9673(01)00778-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dynamic chromatographic study of interconversion of E and Z forms of oximes has been investigated by using a novel cryogenic modulation method in a two-dimensional gas chromatographic array. The primary column is a conventional capillary GC column on which the molecular interconversion proceeds. In this case, the molecular dynamical process leads to a peak profile describing the kinetics and thermodynamics of the interconverting molecules during its chromatographic elution. Thus an interconversion region intercedes the elution of the individual stereoisomers of the reaction. Since the molecules are isomers, classical molecular identification methods such as gas chromatography-mass spectrometry are unable to study the individual instantaneous amounts of each of the compounds. Hence the infinitesimal profiles of interconversion along the entire column have never been experimentally observed; rather the total profile is normally subjected to mathematical modelling studies in order to match experiment with theory, and to gain the kinetic parameters of the process. In the present study, an instantaneous ratio of the individual isomers can be found during the chromatographic elution by direct measurement. This is achieved by using a cryogenic zone focussing process, with rapid longitudinal modulation of a cold trap and continual pulsing of collected zones into a fast-analysis high-resolution capillary column on which isomer interconversion is minimized. The data can be displayed as a two-dimensional contour plot to demonstrate the individual isomer profiles. The two-dimensional analysis also allows easy measurement of the peak ratios of the two isomers which is an indicator of the extent of interconversion that has taken place. Two model systems, acetaldoxime and butyraldoxime, were chosen to illustrate the use of the cryogenic modulation procedure. It is anticipated that the procedure could be applied to other molecules which exhibit gas-phase isomerizations or reactions.
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Affiliation(s)
- P Mariott
- Chromatography and Molecular Separations Group, Royal Melbourne Institute of Technology, Victoria, Australia.
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Abstract
The four stereoisomers of chalcogran 1 ((2RS,SRS)-2-ethyl-1,6-di-oxaspiro[4.4]nonane), the principal component of the aggregation pheromone of the bark beetle pityogenes chalcographus, are prone to interconversion at the spiro center (C5). During diastereo- and enantioselective dynamic gas chromatography (DGC), epimerization of 1 gives rise to two independent interconversion peak profiles, each featuring a plateau between the peaks of the interconverting epimers. To determine the rate constants of epimerization by dynamic gas chromatography (DGC), equations to simulate the complex elution profiles were derived, using the theoretical plate model and the stochastic model of the chromatographic process. The Eyring activation parameters of the experimental interconversion profiles, between 70 and 120 C in the presence of the chiral stationary phase (CSP) Chirasil-beta-Dex, were then determined by computer-aided simulation with the aid of the new program Chrom-Win: (2R,5R)-1: deltaG(++) (298.15 K) = 108.0 +/-0.5 kJ mol(-1), deltaH(++) = 47.1+/-0.2 kJ mol(-1), deltaS(++) = -204+/-6 JK(-1) mol(-1): (2R,5S)-1: deltaG(++) (298.15 K) = 108.5+/-0.5 kJ mol(-1), deltaH(++) = 45.8+/-0.2 kJ mol(-1), deltaS(++) = -210 +/-6 J K mol(-1); (2S,5S)-1: deltaG(++) (298.15 K)= 108.1+/-0.5 kJ mol(-1), deltaH(++) = 49.3+/-0.3 kJ mol(-1), deltaS(++) = -197+/-8 J K(-1) mol(-1); (2S,5R)-1: deltaG(++) (298.15 K)=108.6+/-0.5 kJ mol(-1), deltaH(++) = 48.0+/-0.3 kJ mol(-1), deltaS(++) = -203+/-8 J K(-1) mol(-1). The thermodynamic Gibbs free energy of the E/Z equilibrium of the epimers was determined by the stopped-flow multidimensional gas chromatographic technique: deltaG(E/Z) (298.15 K)= -0.5 kJ mol(-1), deltaH(E/Z) = 1.4 kJ mol(-1) and deltaS(E/Z) = 6.3 J K(-1) mol(-1). An interconversion pathway proceeding through ring-opening and formation of a zwitterion and an enol ether/alcohol intermediate of 1 is proposed.
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Affiliation(s)
- O Trapp
- Institut für Organische Chemie, Universität Tübingen, Germany
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Hîrtopeanu A, Suteu C, Uncuta C, Mihai G, Roussel C. Bis[oxo/thioxothiazolinyl] Aromatic Compounds - Synthesis and Conformational Assignment. European J Org Chem 2000. [DOI: 10.1002/(sici)1099-0690(200003)2000:6<1081::aid-ejoc1081>3.0.co;2-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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