1
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Della Sala P, Calice U, Iuliano V, Geremia S, Hickey N, Belviso S, Summa FF, Monaco G, Gaeta C, Superchi S. Chirality Sensing of Cryptochiral Guests with Prism[n]arenes. Chemistry 2024; 30:e202401625. [PMID: 38717117 DOI: 10.1002/chem.202401625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Indexed: 06/11/2024]
Abstract
Optical chirality sensing has gained significant attention in recent years. Within this field, the quest for stereodynamic chiroptical probes capable of detecting cryptochiral guests presents a formidable challenge. Macrocycles exhibiting planar chirality have emerged as promising candidates for amplifying the chirality of cryptochiral guests. In this study, we demonstrate that the formation of host-guest complexes between cryptochiral molecules and planar chiral prismarenes triggers electronic circular dichroism (ECD) signals via host-guest complexation-induced chirality amplification. The absolute configuration of the most stable chiral macrocyclic host-guest complex has been established by resorting to both exciton model and DFT computations. Furthermore, we demonstrated that this supramolecular chirality sensing system can be employed to determine the enantiomeric composition of scalemic mixtures by measuring the ECD bands intensity. The information described here opens the way for the use of prismarenes as stereodynamic probes for sensing of cryptochiral guests.
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Affiliation(s)
- Paolo Della Sala
- Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, Salerno, Italy
| | - Umberto Calice
- Dipartimento di Scienze, Università della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Veronica Iuliano
- Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, Salerno, Italy
| | - Silvano Geremia
- Centro di Eccellenza in Biocristallografia, Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy
| | - Neal Hickey
- Centro di Eccellenza in Biocristallografia, Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy
| | - Sandra Belviso
- Dipartimento di Scienze, Università della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Francesco F Summa
- Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, Salerno, Italy
| | - Guglielmo Monaco
- Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, Salerno, Italy
| | - Carmine Gaeta
- Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, Salerno, Italy
| | - Stefano Superchi
- Dipartimento di Scienze, Università della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
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2
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5,5,7,7-Tetrametyl-6,7-dihydro-5H-dibenzo[c,e]azepine. MOLBANK 2023. [DOI: 10.3390/m1554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
5,5,7,7-Tetrametyl-6,7-dihydro-5H-dibenzo[c,e]azepine has been synthesized as a possible pro-chiral (or tropos) unit for the construction of a chiral catalyst and as a molecular chirality sensor for the absolute configuration assignment by chiroptical spectroscopy. A straightforward synthetic strategy for the preparation of the title compound in high overall yield through sequential addition of the four methyl groups on benzylic positions has been described. A VT-NMR study was used to determine the rotational barrier of the aryl–aryl bond in this biphenylazepine, revealing its torsional flexibility at room temperature, which makes the biphenylazepine suitable as both a chirality probe and a tropos moiety in chiral ligands.
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3
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Summa A, Scafato P, Belviso S, Monaco G, Zanasi R, Longhi G, Abbate S, Superchi S. Synthesis and Stereochemical Characterization of a Novel Chiral α-Tetrazole Binaphthylazepine Organocatalyst. Molecules 2022; 27:molecules27165113. [PMID: 36014353 PMCID: PMC9413694 DOI: 10.3390/molecules27165113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/02/2022] [Accepted: 08/08/2022] [Indexed: 12/03/2022] Open
Abstract
A novel α-tetrazole-substituted 1,1′-binaphthylazepine chiral catalyst has been synthesized and its absolute configuration has been determined by DFT computational analysis of the vibrational circular dichroism (VCD) spectrum of its precursor. The VCD analysis, carried out through the model averaging method, allowed to assign the absolute configuration of a benzylic stereocenter in the presence of a chiral binaphthyl moiety. The 1,1′-binaphthylazepine tetrazole and the nitrile its immediate synthetic precursor, have been preliminarily tested as chiral organocatalysts in the asymmetric intramolecular oxa-Michael cyclization of 2-hydroxy chalcones for the synthesis of chiral flavanones obtaining low enantioselectivity.
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Affiliation(s)
- Assunta Summa
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
| | - Patrizia Scafato
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
| | - Sandra Belviso
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
| | - Guglielmo Monaco
- Department of Chemistry and Biology “A. Zambelli”, University of Salerno, Via Giovanni Paolo II, 84084 Salerno, Italy
| | - Riccardo Zanasi
- Department of Chemistry and Biology “A. Zambelli”, University of Salerno, Via Giovanni Paolo II, 84084 Salerno, Italy
| | - Giovanna Longhi
- Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
- Unit of Brescia, Consiglio Nazionale delle Ricerche-I.N.O. c/o CSMT, 25123 Brescia, Italy
| | - Sergio Abbate
- Department Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
- Unit of Brescia, Consiglio Nazionale delle Ricerche-I.N.O. c/o CSMT, 25123 Brescia, Italy
| | - Stefano Superchi
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
- Correspondence:
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4
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Marsico G, Calice U, Scafato P, Belviso S, Evidente A, Superchi S. Computational Approaches and Use of Chiroptical Probes in the Absolute Configuration Assignment to Natural Products by ECD Spectroscopy: A 1,2,3-Trihydroxy-p-menthane as a Case Study. Biomolecules 2022; 12:biom12030421. [PMID: 35327613 PMCID: PMC8945943 DOI: 10.3390/biom12030421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/02/2022] [Accepted: 03/06/2022] [Indexed: 12/13/2022] Open
Abstract
In this study, the computational analysis of electronic circular dichroism (ECD) spectra and the employment of biphenyl chiroptical probes were compared in the absolute configuration assignment of (-)-1α,2α,3β-trihydroxy-p-menthane (1), taken as a representative example of a UV-transparent chiral natural product. The usefulness of chiroptical probes in the configurational assignments of natural products and their complementarity to the computational protocols is herein highlighted. The biphenyl probe approach proves to be straightforward, reliable, and suitable for conformationally mobile and ECD silent compounds, not treatable by computational analysis of chiroptical data.
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Affiliation(s)
- Giulia Marsico
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; (G.M.); (U.C.); (P.S.); (S.B.)
| | - Umberto Calice
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; (G.M.); (U.C.); (P.S.); (S.B.)
| | - Patrizia Scafato
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; (G.M.); (U.C.); (P.S.); (S.B.)
| | - Sandra Belviso
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; (G.M.); (U.C.); (P.S.); (S.B.)
| | - Antonio Evidente
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte Sant’Angelo, Via Cintia 4, 80126 Napoli, Italy;
| | - Stefano Superchi
- Department of Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; (G.M.); (U.C.); (P.S.); (S.B.)
- Correspondence: ; Tel.: +39-0971206098
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5
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Omasa K, Ito M, Kubo Y. Zn( ii)-coordination-driven chiroptical and emissive sensing for chiral amines using a quaterphenyl-5′-carbaldehyde. NEW J CHEM 2022. [DOI: 10.1039/d2nj04781k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The formation of an imine between 1 and chiral amine analyte enabled Zn(ii)-assisted CD response, fluorescence and CPL signals.
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Affiliation(s)
- Koichiro Omasa
- Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Masato Ito
- Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Yuji Kubo
- Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
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6
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Górecki M, Frelek J. A Holistic Approach to Determining Stereochemistry of Potential Pharmaceuticals by Circular Dichroism with β-Lactams as Test Cases. Int J Mol Sci 2021; 23:273. [PMID: 35008698 PMCID: PMC8745598 DOI: 10.3390/ijms23010273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 11/17/2022] Open
Abstract
This paper's main objective is to show that many different factors must be considered when solving stereochemical problems to avoid misleading conclusions and obtain conclusive results from the analysis of spectroscopic properties. Particularly in determining the absolute configuration, the use of chiroptical methods is crucial, especially when other techniques, including X-ray crystallography, fail, are not applicable, or give inconclusive results. Based on various β-lactam derivatives as models, we show how to reliably determine their absolute configuration (AC) and preferred conformation from circular dichroism (CD) spectra. Comprehensive CD analysis, employing both approaches, i.e., traditional with their sector and helicity rules, and state-of-the-art supported by quantum chemistry (QC) calculations along with solvation models for both electronic (ECD) and vibrational (VCD) circular dichroism ranges, allows confident defining stereochemistry of the β-lactams studied. Based on an in-depth analysis of the results, we have shown that choosing a proper chiroptical method/s strictly depends on the specific case and certain structural features.
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Affiliation(s)
- Marcin Górecki
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 St., 01-224 Warsaw, Poland;
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7
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Masi M, Di Lecce R, Maddau L, Marsico G, Superchi S, Evidente A. Argyrotoxins A-C, a trisubstituted dihydroisobenzofuranone, a tetrasubstituted 2-hydroxyethylbenzamide and a tetrasubstitutedphenyl trisubstitutedbutyl ether produced by Alternaria argyroxiphii, the causal agent of leaf spot on African mahogany trees (Khaya senegalensis). PHYTOCHEMISTRY 2021; 191:112921. [PMID: 34425462 DOI: 10.1016/j.phytochem.2021.112921] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
Three previously undescribed metabolites named argyrotoxins A-C, were isolated, together with the well known porritoxinol, its closely related phthalide, a phthalide derivative, zinniol, alternariol and its 4-methyl ether from Alternaria argyroxiphii E.G. Simmons & Aragaki, the causal agent of leaf spot on African mahogany trees, Khaya senegalensis A. Juss. (Meliaceae). The known compounds were identified comparing their physical and spectroscopic properties to those previously reported in literature. Argyrotoxins A-C were characterized essentially by NMR (1H, 13C, COSY, HSQC, HMBC and NOESY NMR spectra) and HRESIMS spectra as 4-(7-methoxy-6-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yloxy)-2-methyl-butyric acid, 5-but-2-enyloxy-N-(2-hydroxyethyl)-2-hydroxymethyl-3-methoxy-4-methyl-benzamide and 1-(5-(hydroxymethyl)-3-methoxy-4-(methoxymethyl)-2-methylphenoxy)-3-methylbutane-2,3-diol, respectively. The absolute configuration of argyrotoxin A was determined through electronic circular dichroism, by applying the biphenyl chiroptical probe approach. The phytoxicity of all metabolites isolated was evaluated by leaf puncture assay at concentration of 1 mg/mL. Zinniol proved to be the most active compound causing necrotic lesions on young leaves of Hedera elix L., Phaseolus vulgaris L. and Quercus ilex L. Argirotoxins A and B were found active, to a minor extent, on Phaseolus vulgaris L. leaves, while porritoxinol exhibited activity on holm oak leaves. The other secondary metabolites herein reported for A. argyroxiphii were inactive.
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Affiliation(s)
- Marco Masi
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Roberta Di Lecce
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Lucia Maddau
- Dipartimento di Agraria, Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari, Viale Italia 39, 07100, Sassari, Italy
| | - Giulia Marsico
- Dipartimento di Scienze, Università della Basilicata, Viale dell'Ateneo Lucano 10, 85100, Potenza, Italy
| | - Stefano Superchi
- Dipartimento di Scienze, Università della Basilicata, Viale dell'Ateneo Lucano 10, 85100, Potenza, Italy
| | - Antonio Evidente
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126, Napoli, Italy.
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8
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Auras S, Trapp O. Scorpio‐Ligand: Synthesis of Biphenyl‐Dihydroazepine Phosphoramidite Ligands for Asymmetric Hydrogenation. Helv Chim Acta 2021. [DOI: 10.1002/hlca.202100147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stefanie Auras
- Department of Chemistry Ludwig Maximilian University Munich Butenandtstr. 5–13 DE-81377 Munich Germany
| | - Oliver Trapp
- Department of Chemistry Ludwig Maximilian University Munich Butenandtstr. 5–13 DE-81377 Munich Germany
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9
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Absolute Configuration Sensing of Chiral Aryl- and Aryloxy-Propionic Acids by Biphenyl Chiroptical Probes. CHEMOSENSORS 2021. [DOI: 10.3390/chemosensors9070154] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The absolute configuration of chiral 2-aryl and 2-aryloxy propionic acids, which are among the most common chiral environmental pollutants, has been readily and reliably established by either electronic circular dichroism spectroscopy or optical rotation measurements employing suitably designed 4,4′-disubstituted biphenyl probes. In fact, the 4,4′-biphenyl substitution gives rise to a red shift of the diagnostic electronic circular dichroism signal of the biphenyl A band employed for the configuration assignment, removing its overlap with other interfering dichroic bands and allowing its clear sign identification. The largest A band red shift, and thus the most reliable results, are obtained by employing as a probe the 4,4′-dinitro substituted biphenylazepine 3c. The method was applied to the absolute configuration assignment of 2-arylpropionic acids ibuprofen (1a), naproxen (1b), ketoprofen (1c) and flurbiprofen (1d), as well as to the 2-aryloxypropionic acids 2-phenoxypropionic acid (2a) and 2-naphthoxypropionic acid (2b). This approach, allowing us to reveal the sample’s absolute configuration by simple optical rotation measurements, is potentially applicable to online analyses of both the enantiomeric composition and absolute configuration of these chiral pollutants.
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10
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“Double-Twist”-Based Dynamic Induction of Optical Activity in Multichromophoric System. Symmetry (Basel) 2021. [DOI: 10.3390/sym13020325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The electronic circular dichroism (CD)-silent 2,5-bis(biphen-2-yl)terephthalaldehyde has been used as a sensor (reporter) of chirality for primary amines. The through-space inductor–reporter interactions force a change in the chromophore conformation toward one of the diastereomeric forms. The structure of the reporter, with the terminal flipping biphenyl groups, led to generating Cotton effects in both lower- and higher-energy regions of the ECD spectrum. The induction of an optical activity in the chromophore was due to the cascade point-to-axial chirality transmission mechanism. The reporter system turned out to be sensitive to the subtle differences in the inductor structure. Despite the size of the chiral substituent, the molecular structure of the inductor–reporter systems in the solid-state showed many similarities. The most important one was the tendency of the core part of the molecules to adapt pseudocentrosymmetric conformation. Supported by a weak dispersion and Van der Waals interactions, the face-to-face and edge-to-face interactions between the π-electron systems present in the molecule were found to be responsible for the molecular arrangement in the crystal.
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11
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Mądry T, Czapik A, Kwit M. Point-to-Axial Chirality Transmission: A Highly Sensitive Triaryl Chirality Probe for Stereochemical Assignments of Amines. J Org Chem 2020; 85:10413-10431. [PMID: 32806087 PMCID: PMC7458434 DOI: 10.1021/acs.joc.0c00734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Indexed: 01/17/2023]
Abstract
A readily available stereodynamic and the electronic circular dichroism (ECD)-silent 2,5-di(1-naphthyl)-terephthalaldehyde-based probe has been applied for chirality sensing of primary amines. The chiral amine (the inductor) forces a change in the structure of the chromophore system through the point-to-axial chirality transmission mechanism. As a result, efficient induction of optical activity in the chromophoric system is observed. The butterflylike structure of the probe, with the terminal aryl groups acting as changeable "wings", allowed for the generation of exciton Cotton effects in the region of 1Bb electronic transition in the naphthalene chromophores. The sign of the exciton couplets observed for inductor-reporter systems might be correlated with an absolute configuration of the inductor, whereas the linear relationship between amplitudes of the specific Cotton effect and enantiomeric excess of the parent amine gives potentiality for quantitative chirality sensing. Despite the structural simplicity, the probe turned out to be unprecedentedly highly sensitive to even subtle differences in the inductor structure (i.e., O vs CH2).
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Affiliation(s)
- Tomasz Mądry
- Department
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznan, Poland
| | - Agnieszka Czapik
- Department
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznan, Poland
| | - Marcin Kwit
- Department
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznan, Poland
- Center
for Advanced Technologies, Adam Mickiewicz
University, Uniwersytetu
Poznanskiego 10, 61 614 Poznan, Poland
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12
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Santoro E, Vergura S, Scafato P, Belviso S, Masi M, Evidente A, Superchi S. Absolute Configuration Assignment to Chiral Natural Products by Biphenyl Chiroptical Probes: The Case of the Phytotoxins Colletochlorin A and Agropyrenol. JOURNAL OF NATURAL PRODUCTS 2020; 83:1061-1068. [PMID: 32091903 PMCID: PMC7997626 DOI: 10.1021/acs.jnatprod.9b01068] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The application of flexible biphenyls as chiroptical probes for the absolute configuration assignment to chiral natural products is described. The method is straightforward and reliable and can be applied to conformationally mobile and ECD silent compounds, not treatable by computational analysis of chiroptical data. By this approach, the (6'R) absolute configuration of the phytotoxin colletochlorin A (1) was confirmed, while the absolute configuration of the phytotoxin agropyrenol (2), previously assigned by the NMR Mosher method, was revised and assigned as (3'S,4'S). Moreover, with the biphenyl method the configurational assignment can be obtained simply by the sign of a diagnostic Cotton effect at 250 nm in the ECD spectrum, thus allowing application without the need of advanced knowledge of chiroptical spectroscopy and computational protocols.
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Affiliation(s)
- Ernesto Santoro
- Department
of Sciences, University of Basilicata, Viale dell’Ateneo Lucano
10, 85100 Potenza, Italy
| | - Stefania Vergura
- Department
of Sciences, University of Basilicata, Viale dell’Ateneo Lucano
10, 85100 Potenza, Italy
| | - Patrizia Scafato
- Department
of Sciences, University of Basilicata, Viale dell’Ateneo Lucano
10, 85100 Potenza, Italy
| | - Sandra Belviso
- Department
of Sciences, University of Basilicata, Viale dell’Ateneo Lucano
10, 85100 Potenza, Italy
| | - Marco Masi
- Department
of Chemical Sciences, University of Naples
Federico II, Complesso Universitario Monte San’Angelo, Via Cintia 4, 80126 Napoli, Italy
| | - Antonio Evidente
- Department
of Chemical Sciences, University of Naples
Federico II, Complesso Universitario Monte San’Angelo, Via Cintia 4, 80126 Napoli, Italy
| | - Stefano Superchi
- Department
of Sciences, University of Basilicata, Viale dell’Ateneo Lucano
10, 85100 Potenza, Italy
- Tel: +39-0971-20-6098. Fax: +39-0971-20-5678.
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13
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Padula D, Mazzeo G, Santoro E, Scafato P, Belviso S, Superchi S. Amplification of the chiroptical response of UV-transparent amines and alcohols by N-phthalimide derivatization enabling absolute configuration determination through ECD computational analysis. Org Biomol Chem 2020; 18:2094-2102. [PMID: 32107518 DOI: 10.1039/d0ob00052c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The stereoselective transformation of chiral UV-transparent amines and alcohols to phthalimides has proved to be a simple and efficient method to enhance the chiroptical response of these substrates allowing their reliable absolute configuration determination by computational analysis of ECD spectra. Such a transformation also leads to a significant reduction in the molecular conformational flexibility thus simplifying the conformational analysis required by the computational treatment. The method described herein thus allows the absolute configuration assignment to these challenging substrates to be much easier and reliable.
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Affiliation(s)
- Daniele Padula
- Dipartimento di Scienze, Università della Basilicata, via dell'Ateneo Lucano, 85100, Potenza, Italy.
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14
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Vergura S, Scafato P, Belviso S, Superchi S. Absolute Configuration Assignment from Optical Rotation Data by Means of Biphenyl Chiroptical Probes. Chemistry 2019; 25:5682-5690. [PMID: 30730078 DOI: 10.1002/chem.201806435] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/06/2019] [Indexed: 11/10/2022]
Abstract
A non-empirical approach for the assignment of the absolute configuration of chiral 2-alkyl-substituted carboxylic acids and primary amines by [α]D measurements has been developed. The method requires the conversion of the chiral acids or amines into the corresponding 4,4'-disubstituted biphenylamides or biphenylazepines, respectively. In these derivatives a central-to-axial chirality transfer induces a preferred torsion in the biphenyl moiety revealed by the sign of the biphenyl A band in the ECD spectrum. By 4,4'-substitution on the biphenyl moiety a redshift of the A band is obtained, leading to an increase of its relative contribution to optical rotation. This allows to reliably establish a direct correlation between the [α]D sign, the biphenyl twist and, then, the substrate absolute configuration. This approach thus constitutes a really practical and reliable method to assign the absolute configuration of chiral carboxylic acids and primary amines by simple and straightforward [α]D measurement, readily obtainable by a routine instrumentation like the polarimeter.
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Affiliation(s)
- Stefania Vergura
- Department of Science, Università degli Studi della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Patrizia Scafato
- Department of Science, Università degli Studi della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Sandra Belviso
- Department of Science, Università degli Studi della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Stefano Superchi
- Department of Science, Università degli Studi della Basilicata, Via dell'Ateneo Lucano, 10, 85100, Potenza, Italy
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15
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Li H, Fan W, Hong X. Understanding the axial chirality control of quinidine-derived ammonium cation-directed O-alkylation: a computational study. Org Biomol Chem 2019; 17:1916-1923. [PMID: 30280168 DOI: 10.1039/c8ob02173b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
As a privileged chiral scaffold, cinchona alkaloid and its derivatives have reached remarkable success in catalytic asymmetric organic synthesis. In addition to the wide applications of point chirality control, Smith and co-workers recently discovered a quinidine-derived ammonium cation-catalyzed O-alkylation of tetralones, providing an effective approach for the synthesis of axially chiral biaryls. Using density functional theory (DFT) calculations, we studied the reaction mechanism and origins of enantioselectivity of this novel transformation. A stepwise strategy is adopted to ensure efficient and thorough exploration of the massive conformational space of transition state. Our computations suggested that enolate oxygen forms two hydrogen bonds with the chiral ammonium catalyst, and the non-covalent interactions between the cationic benzylic fragment and the methoxy group of enolate plays a critical role in determining the enantioselectivity.
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Affiliation(s)
- Han Li
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, China.
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16
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Marsico G, Pignataro BA, Masi M, Evidente A, Casella F, Zonno MC, Tak JH, Bloomquist JR, Superchi S, Scafato P. Asymmetric synthesis and structure-activity studies of the fungal metabolites colletorin A, colletochlorin A and their halogenates analogues. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.05.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Gong C, Guo H, Zeng X, Xu H, Zeng Q, Zhang J, Xie J. Flexible and rigid dicarboxylic acids enable the assembly of achiral and chiral 3D Co(ii) metal–organic frameworks. Dalton Trans 2018; 47:6917-6923. [DOI: 10.1039/c8dt00600h] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The homochirality of the 3D Co(ii) MOFs may arise from the rotation of the two phenyl rings in the biphenyl-4,4′-dicarboxylic acid ligand.
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Affiliation(s)
- Chunhua Gong
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
| | - Haiyang Guo
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
| | - Xianghua Zeng
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
| | - Hao Xu
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
| | - Qingdao Zeng
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology
- CAS Center for Excellence in Nanoscience
- National Center for Nanoscience and Technology (NCNST)
- Beijing 100190
- P. R. China
| | - Junyong Zhang
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
| | - Jingli Xie
- College of Biological
- Chemical Science and Engineering
- Jiaxing University
- Jiaxing 314001
- P. R. China
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