1
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Kingsbury CJ, Senge MO. Molecular Symmetry and Art: Visualizing the Near-Symmetry of Molecules in Piet Mondrian's De Stijl. Angew Chem Int Ed Engl 2024; 63:e202403754. [PMID: 38619527 DOI: 10.1002/anie.202403754] [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: 02/22/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
Symmetry and shape are essential aspects of molecular structure and how we interpret molecules and their properties. We, as chemists, are comfortable with pictorial representations of structure, in which some nuance is lost-investigating molecular shape numerically by looking at how closely it fits a reference, such as a plane, or a set of vectors or coordinates, is informative, though far from engaging. Often relationships between chemical structure and derived values are obscured. Taking our inspiration from Piet Mondrian's Compositions, we have depicted the symmetry information encoded within 3D data as blocks of color, to show clearly how chemical arguments and resultant molecular distortion may contribute to symmetry. Great art gives us a new perspective on the world; as a pastiche, this art may allow us to look at familiar molecules, such as porphyrins, in a new light, understanding how their shape and properties are intertwined.
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Affiliation(s)
- Christopher J Kingsbury
- School of Chemistry, Chair of Organic Chemistry, Trinity College Dublin, The University of Dublin, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin, D02R590, Ireland
| | - Mathias O Senge
- School of Chemistry, Chair of Organic Chemistry, Trinity College Dublin, The University of Dublin, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin, D02R590, Ireland
- Institute for Advanced Study (TUM-IAS), Focus Group-Molecular and Interfacial Engineering of Organic Nanosystems, Technical University of Munich, Lichtenberg-Str. 2a, 85748, Garching, Germany
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2
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Osadchuk I, Luts HE, Norvaiša K, Borovkov V, Senge MO. Supramolecular Chirogenesis in a Sterically Hindered Porphyrin: A Critical Theoretical Analysis. Chemistry 2023; 29:e202301408. [PMID: 37227167 DOI: 10.1002/chem.202301408] [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: 05/03/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 05/26/2023]
Abstract
The determination of molecular stereochemistry and absolute configuration is an important part of modern chemistry, pharmacology, and biology. Electronic circular dichroism (ECD) spectroscopy is a widely used tool for chirality assignment, especially with porphyrin macrocycles employed as reporter chromophores. However, the mechanisms of induced ECD in porphyrin complexes are yet to be comprehensively rationalized. In this work, the ECD spectra of a sterically hindered hexa-cationic porphyrin with two camphorsulfonic acids in dichloromethane and chloroform were experimentally measured and computationally analyzed. The influence of geometric factors such as the position of chiral guest molecules, distortion of the porphyrin macrocycle, and orientation of aromatic and non-aromatic peripheral substituents on the ECD spectra was theoretically studied. Various potential pitfalls, such as a lack of significant conformations and accidental agreement of experimental and simulated spectra, are considered and discussed.
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Affiliation(s)
- Irina Osadchuk
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Hanna-Eliisa Luts
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Karolis Norvaiša
- School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02R590, Dublin, Ireland
| | - Victor Borovkov
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Mathias O Senge
- School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02R590, Dublin, Ireland
- Institute for Advanced Study (TUM-IAS), Technical University of Munich, Lichtenberg Str. 2a, 85748, Garching, Germany
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3
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Karges J, Cohen SM. Preorganized Homochiral Pyrrole-Based Receptors That Display Enantioselective Anion Binding. European J Org Chem 2022; 2022:e202101346. [PMID: 36778753 PMCID: PMC9912926 DOI: 10.1002/ejoc.202101346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Herein, a new scaffold for anion recognition based on a tripodal tris(pyrrolamide) motif is presented. The receptors were able to bind to a variety of anions with high affinity. Using density functional theory methods, the three-dimensional geometry of the receptor-anion complex was calculated. These calculations show that the receptors bind anions via a preorganized cavity of amide and pyrrole hydrogen bond donor groups. Based on these findings, homochiral tris(pyrrolamide) receptors were prepared, which produced as much as a 1.6-fold greater affinity for (S)-(+)-mandelate over (R)-(-)-mandelate, demonstrating the ability to differentiate between these enantiomeric anions. The interaction of (S)-(+)-mandelate and (R)-(-)-mandelate within the homochiral receptor was examined by solution NMR spectroscopy and density functional theory calculations. These findings indicate that the preorganized positioning of the pyrrole groups and subsequent sterics allows to differentiate between the stereoisomeric anions.
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Affiliation(s)
- Johannes Karges
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Seth M. Cohen
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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4
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Norvaiša K, Maguire S, Donohoe C, O'Brien JE, Twamley B, Gomes-da-Silva LC, Senge MO. Steric Repulsion Induced Conformational Switch in Supramolecular Structures. Chemistry 2021; 28:e202103879. [PMID: 34792217 PMCID: PMC9299809 DOI: 10.1002/chem.202103879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Indexed: 11/24/2022]
Abstract
Inspired by the rigidified architecture of ‘picket‐fence’ systems, we propose a strategy utilizing strain to impose intramolecular tension in already peripherally overcrowded structures leading to selective atropisomeric conversion. Employing this approach, tuneable shape‐persistent porphyrin conformations were acquired exhibiting distinctive supramolecular nanostructures based on the orientation of the peripheral groups. The intrinsic assemblies driven by non‐covalent bonding interactions form supramolecular polymers while encapsulating small molecules in parallel channels or solvent‐accessible voids. The developed molecular strain engineering methodologies combined with synthetic approaches have allowed the introduction of the pivalate units creating a highly strained molecular skeleton. Changes in the absorption spectrum indicated the presence of severe steric repulsions between the peripheral groups which were confirmed by single crystal X‐ray analysis. To release the steric strain introduced by the peripheral units, thermal equilibration strategies were used to selectively convert the most abundant atropisomer to the desirable minor one.
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Affiliation(s)
- Karolis Norvaiša
- School of Chemistry, Chair of Organic Chemistry Trinity Biomedical Sciences Institute Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02 R590, Dublin 2, Ireland
| | - Sophie Maguire
- School of Chemistry, Chair of Organic Chemistry Trinity Biomedical Sciences Institute Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02 R590, Dublin 2, Ireland
| | - Claire Donohoe
- School of Chemistry, Chair of Organic Chemistry Trinity Biomedical Sciences Institute Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02 R590, Dublin 2, Ireland.,CQC, Coimbra Chemistry Center Department of Chemistry, University of Coimbra, 3000-435, Coimbra, Portugal
| | - John E O'Brien
- School of Chemistry Trinity College Dublin, The University of Dublin, D02 PN40, Dublin 2, Ireland
| | - Brendan Twamley
- School of Chemistry Trinity College Dublin, The University of Dublin, D02 PN40, Dublin 2, Ireland
| | - Ligia C Gomes-da-Silva
- CQC, Coimbra Chemistry Center Department of Chemistry, University of Coimbra, 3000-435, Coimbra, Portugal
| | - Mathias O Senge
- School of Chemistry, Chair of Organic Chemistry Trinity Biomedical Sciences Institute Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, D02 R590, Dublin 2, Ireland.,Institute for Advanced Study (TUM-IAS) Focus Group - Molecular and Interfacial Engineering of Organic Nanosystems, Technical University of Munich, Lichtenbergstrasse 2a, D-85748, Garching, Germany
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5
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Norvaiša K, Yeow K, Twamley B, Roucan M, Senge MO. Strategic Synthesis of 'Picket Fence' Porphyrins Based on Nonplanar Macrocycles. European J Org Chem 2021; 2021:1871-1882. [PMID: 33889056 PMCID: PMC8048935 DOI: 10.1002/ejoc.202100154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/04/2021] [Indexed: 12/31/2022]
Abstract
Traditional 'picket fence' porphyrin systems have been a topic of interest for their capacity to direct steric shielding effects selectively to one side of the macrocycle. Sterically overcrowded porphyrin systems that adopt macrocycle deformations have recently drawn attention for their applications in organocatalysis and sensing. Here we explore the combined benefits of nonplanar porphyrins and the old molecular design to bring new concepts to the playing field. The challenging ortho-positions of meso-phenyl residues in dodecasubstituted porphyrin systems led us to transition to less hindered para- and meta-sites and develop selective demethylation based on the steric interplay. Isolation of the symmetrical target compound [2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(3,5-dipivaloyloxyphenyl)porphyrin] was investigated under two synthetic pathways. The obtained insight was used to isolate unsymmetrical [2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(2-nitro-5-pivaloyloxyphenyl)porphyrin]. Upon separation of the atropisomers, a detailed single-crystal X-ray crystallographic analysis highlighted intrinsic intermolecular interactions. The nonplanarity of these systems in combination with 'picket fence' motifs provides an important feature in the design of supramolecular ensembles.
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Affiliation(s)
- Karolis Norvaiša
- Chair of Organic ChemistrySchool of ChemistryTrinity Biomedical Sciences InstituteTrinity College DublinThe University of Dublin152–160 Pearse StreetDublin2Ireland
| | - Kathryn Yeow
- Chair of Organic ChemistrySchool of ChemistryTrinity Biomedical Sciences InstituteTrinity College DublinThe University of Dublin152–160 Pearse StreetDublin2Ireland
| | - Brendan Twamley
- School of ChemistryTrinity College DublinThe University of DublinDublin2Ireland
| | - Marie Roucan
- Chair of Organic ChemistrySchool of ChemistryTrinity Biomedical Sciences InstituteTrinity College DublinThe University of Dublin152–160 Pearse StreetDublin2Ireland
| | - Mathias O. Senge
- Chair of Organic ChemistrySchool of ChemistryTrinity Biomedical Sciences InstituteTrinity College DublinThe University of Dublin152–160 Pearse StreetDublin2Ireland
- Institute for Advanced Study (TUM-IAS)Technical University of MunichLichtenbergstrasse 2a85748GarchingGermany
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6
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Sample HC, Senge MO. Nucleophilic Aromatic Substitution (S NAr) and Related Reactions of Porphyrinoids: Mechanistic and Regiochemical Aspects. European J Org Chem 2021; 2021:7-42. [PMID: 33519299 PMCID: PMC7821298 DOI: 10.1002/ejoc.202001183] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 12/29/2022]
Abstract
The nucleophilic substitution of aromatic moieties (SNAr) has been known for over 150 years and found wide use for the functionalization of (hetero)aromatic systems. Currently, several "types" of SNAr reactions have been established and notably the area of porphyrinoid macrocycles has seen many uses thereof. Herein, we detail the SNAr reactions of seven types of porphyrinoids with differing number and type of pyrrole units: subporphyrins, norcorroles, corroles, porphyrins, azuliporphyrins, N-confused porphyrins, and phthalocyanines. For each we analyze the substitution dependent upon: a) the type of nucleophile and b) the site of substitution (α, β, or meso). Along with this we evaluate this route as a synthetic strategy for the generation of unsymmetrical porphyrinoids. Distinct trends can be identified for each type of porphyrinoid discussed, regardless of nucleophile. The use of nucleophilic substitution on porphyrinoids is found to often be a cost-effective procedure with the ability to yield complex substituent patterns, which can be conducted in non-anhydrous solvents with easily accessible simple porphyrinoids.
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Affiliation(s)
- Harry C. Sample
- School of ChemistryTrinity Biomedical Sciences InstituteThe University of Dublin152‐160 Pearse StreetDublin 2Ireland
| | - Mathias O. Senge
- Institute for Advanced Study (TUM‐IAS)Technical University of MunichLichtenbergstrasse 2a85748GarchingGermany
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7
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Norvaiša K, O'Brien JE, Gibbons DJ, Senge MO. Elucidating Atropisomerism in Nonplanar Porphyrins with Tunable Supramolecular Complexes. Chemistry 2020; 27:331-339. [PMID: 33405259 PMCID: PMC7839692 DOI: 10.1002/chem.202003414] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Indexed: 12/19/2022]
Abstract
Atropisomerism is a fundamental feature of substituted biaryls resulting from rotation around the biaryl axis. Different stereoisomers are formed due to restricted rotation about the single bond, a situation often found in substituted porphyrins. Previously NMR determination of porphyrin atropisomers proved difficult, if not almost impossible to accomplish, due to low resolution or unresolvable resonance signals that predominantly overlapped. Here, we shed some light on this fundamental issue found in porphyrinoid stereochemistry. Using benzenesulfonic acid (BSA) for host‐guest interactions and performing 1D, 2D NMR spectroscopic analyses, we were able to characterize all four rotamers of the nonplanar 5,10,15,20‐tetrakis(2‐aminophenyl)‐2,3,7,8,12,13,17,18‐octaethylporphyirin as restricted H‐bonding complexes. Additionally, X‐ray structural analysis was used to investigate aspects of the weak host–guest interactions. A detailed assignment of the chemical signals suggests charge‐assisted complexation as a key to unravel the atropisomeric enigma. From a method development perspective, symmetry operations unique to porphyrin atropisomers offer an essential handle to accurately identify the rotamers using NMR techniques only.
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Affiliation(s)
- Karolis Norvaiša
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
| | - John E O'Brien
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
| | - Dáire J Gibbons
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
| | - Mathias O Senge
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland.,Institute for Advanced Study (TUM-IAS), Technical University of Munich, Lichtenbergstrasse 2 a, 85748, Garching, Germany
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8
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Suzuki W, Kotani H, Ishizuka T, Kojima T. A Mechanistic Dichotomy in Two-Electron Reduction of Dioxygen Catalyzed by N,N'-Dimethylated Porphyrin Isomers. Chemistry 2020; 26:10480-10486. [PMID: 32329533 DOI: 10.1002/chem.202000942] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/23/2020] [Indexed: 12/13/2022]
Abstract
Selective two-electron reduction of dioxygen (O2 ) to hydrogen peroxide (H2 O2 ) has been achieved by two saddle-distorted N,N'-dimethylated porphyrin isomers, an N21,N'22-dimethylated porphyrin (anti-Me2 P) and an N21,N'23-dimethylated porphyrin (syn-Me2 P) as catalysts and ferrocene derivatives as electron donors in the presence of protic acids in acetonitrile. The higher catalytic performance in an oxygen reduction reaction (ORR) was achieved by anti-Me2 P with higher turnover number (TON=250 for 30 min) than that by syn-Me2 P (TON=218 for 60 min). The reactive intermediates in the catalytic ORR were confirmed to be the corresponding isophlorins (anti-Me2 Iph or syn-Me2 Iph) by spectroscopic measurements. The rate-determining step in the catalytic ORRs was concluded to be proton-coupled electron-transfer reduction of O2 with isophlorins based on kinetic analysis. The ORR rate by anti-Me2 Iph was accelerated by external protons, judging from the dependence of the observed initial rates on acid concentrations. In contrast, no acceleration of the ORR rate with syn-Me2 Iph by external protons was observed. The different mechanisms in the O2 reduction by the two isomers should be derived from that of the arrangement of hydrogen bonding of a O2 with inner NH protons of the isophlorins.
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Affiliation(s)
- Wataru Suzuki
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan
| | - Hiroaki Kotani
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan
| | - Tomoya Ishizuka
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan
| | - Takahiko Kojima
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8571, Japan
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Norvaiša K, Kielmann M, Senge MO. Porphyrins as Colorimetric and Photometric Biosensors in Modern Bioanalytical Systems. Chembiochem 2020; 21:1793-1807. [PMID: 32187831 PMCID: PMC7383976 DOI: 10.1002/cbic.202000067] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/04/2020] [Indexed: 12/18/2022]
Abstract
Advances in porphyrin chemistry have provided novel materials and exciting technologies for bioanalysis such as colorimetric sensor array (CSA), photo-electrochemical (PEC) biosensing, and nanocomposites as peroxidase mimetics for glucose detection. This review highlights selected recent advances in the construction of supramolecular assemblies based on the porphyrin macrocycle that provide recognition of various biologically important entities through the unique porphyrin properties associated with colorimetry, spectrophotometry, and photo-electrochemistry.
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Affiliation(s)
- Karolis Norvaiša
- School of Chemistry, SFI Tetrapyrrole LaboratoryTrinity Biomedical Sciences Institute152–160 Pearse Street, Trinity College Dublin The University of DublinDublin2Ireland
| | - Marc Kielmann
- School of Chemistry, SFI Tetrapyrrole LaboratoryTrinity Biomedical Sciences Institute152–160 Pearse Street, Trinity College Dublin The University of DublinDublin2Ireland
| | - Mathias O. Senge
- School of Chemistry, SFI Tetrapyrrole LaboratoryTrinity Biomedical Sciences Institute152–160 Pearse Street, Trinity College Dublin The University of DublinDublin2Ireland
- Institute for Advanced Study (TUM-IAS)Lichtenberg-Strasse 2a85748GarchingGermany
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Kielmann M, Flanagan KJ, Senge MO. Targeted Synthesis of Regioisomerically Pure Dodecasubstituted Type I Porphyrins through the Exploitation of Peri-interactions. J Org Chem 2020; 85:7603-7610. [PMID: 32393039 DOI: 10.1021/acs.joc.0c00798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A targeted synthesis of dodecasubstituted type I porphyrins that utilizes the reaction of unsymmetrical 3,4-difunctionalized pyrroles and sterically demanding aldehydes was developed. This way, type I porphyrins could be obtained as the only type isomers, likely due to a minimization of the steric strain arising from peri-interactions. Uniquely, this method does not depend on lengthy precursor syntheses, the separation of isomers, or impractical limitations of the scale. In addition, single-crystal X-ray analysis was used to elucidate the structural features of the macrocycles.
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Affiliation(s)
- Marc Kielmann
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Keith J Flanagan
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Mathias O Senge
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
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Callaghan S, Flanagan KJ, O'Brien JE, Senge MO. Short-Chained Anthracene Strapped Porphyrins and their Endoperoxides. European J Org Chem 2020; 2020:2735-2744. [PMID: 32612450 PMCID: PMC7319435 DOI: 10.1002/ejoc.202000283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Indexed: 01/04/2023]
Abstract
The syntheses of short-chained anthracene-strapped porphyrins and their Zn(II)complexes are reported. The key synthetic step is a [2+2] condensation between a dipyrromethane and an anthracene bisaldehyde, 2,2'-((anthracene-9,10-diylbis(methylene))bis(oxy))dibenzaldehyde. Following exposure to white light, self-sensitized singlet oxygen and the anthracene moieties underwent [4+2] cycloaddition reactions to yield the corresponding endoperoxides. 1H NMR studies demonstrate that the endoperoxide readily formed in [D]chloroform and decayed at 85 °C. X-ray crystallography and absorption spectroscopy were used to confirm macrocyclic distortion in the parent strapped porphyrins and endoperoxides. Additionally, X-ray crystallography indicated that endoperoxide formation occurred exclusively on the outside face of the anthracene moiety.
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Affiliation(s)
- Susan Callaghan
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse StreetDublin 2Ireland
| | - Keith J. Flanagan
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse StreetDublin 2Ireland
| | - John E. O'Brien
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse StreetDublin 2Ireland
| | - Mathias O. Senge
- School of ChemistryTrinity College DublinThe University of DublinTrinity Biomedical Sciences Institute152‐160 Pearse StreetDublin 2Ireland
- Institute for Advanced Study (TUM‐IAS)Technische Universität MünchenLichtenberg‐Str. 2a85748GarchingGermany
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