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Post-Functionalization of Organometallic Complexes via Click-Reaction. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196494. [PMID: 36235030 PMCID: PMC9614606 DOI: 10.3390/molecules27196494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 11/09/2022]
Abstract
CuAAC (Cu catalyzed azide-alkyne cycloaddition) click-reaction is a simple and powerful method for the post-synthetic modification of organometallic complexes of transition metals. This approach allows the selective introduction of additional donor sites or functional groups to the periphery of the ligand environment. This is especially important if a metalloligand with free donor sites, which are of the same nature as the primary site for the coordination of the primary metal, has to be created. The concept of post-synthetic modification of organometallic complexes by click-reaction is relatively recent and the currently available experimental material does not yet allow us to identify trends and formulate recommendations to address specific problems. In the present study, we have applied the CuAAC reaction for the post-synthetic modification of diimine mononuclear complexes Re(I), Pt(II) and Ir(III) with C≡C bonds at the periphery of the ligand environment and demonstrated that click-chemistry is a powerful tool for the tunable chemical post-synthetic modification of coordination compounds.
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2
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Microwave-Assisted Synthesis: Can Transition Metal Complexes Take Advantage of This “Green” Method? Molecules 2022; 27:molecules27134249. [PMID: 35807493 PMCID: PMC9267986 DOI: 10.3390/molecules27134249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Microwave-assisted synthesis is considered environmental-friendly and, therefore, in agreement with the principles of green chemistry. This form of energy has been employed extensively and successfully in organic synthesis also in the case of metal-catalyzed synthetic procedures. However, it has been less widely exploited in the synthesis of metal complexes. As microwave irradiation has been proving its utility as both a time-saving procedure and an alternative way to carry on tricky transformations, its use can help inorganic chemists, too. This review focuses on the use of microwave irradiation in the preparation of transition metal complexes and organometallic compounds and also includes new, unpublished results. The syntheses of the compounds are described following the group of the periodic table to which the contained metal belongs. A general overview of the results from over 150 papers points out that microwaves can be a useful synthetic tool for inorganic chemists, reducing dramatically the reaction times with respect to traditional heating. This is often accompanied by a more limited risk of decomposition of reagents or products by an increase in yield, purity, and (sometimes) selectivity. In any case, thermal control is operative, whereas nonthermal or specific microwave effects seem to be absent.
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Starck M, Fradgley JD, De Rosa DF, Batsanov AS, Papa M, Taylor MJ, Lovett JE, Lutter JC, Allen MJ, Parker D. Versatile Para-Substituted Pyridine Lanthanide Coordination Complexes Allow Late Stage Tailoring of Complex Function. Chemistry 2021; 27:17921-17927. [PMID: 34705302 PMCID: PMC8688332 DOI: 10.1002/chem.202103243] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Indexed: 12/28/2022]
Abstract
A series of cationic and neutral p-Br and p-NO2 pyridine substituted Eu(III) and Gd(III) coordination complexes serve as versatile synthetic intermediates. Nucleophilic aromatic substitution occurs readily at the para position under mild conditions, allowing C-N and C-C bond forming reactions to take place, permitting the introduction of azide, amino and alkynyl substituents. For Eu(III) complexes, this approach allows late stage tuning of absorption and emission spectral properties, exemplified by the lowering of the energy of an LMCT transition accompanied by a reduction in the Eu-Npy bond length. Additionally, these complexes provide direct access to the corresponding Eu(II) analogues. With the Gd(III) series, the nature of the p-substituent does not significantly change the EPR properties (linewidth, relaxation times), as required for their development as EPR spin probes that can be readily conjugated to biomolecules under mild conditions.
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Affiliation(s)
- Matthieu Starck
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
| | - Jack D. Fradgley
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
| | | | | | - Maria Papa
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Michael J. Taylor
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Janet E. Lovett
- SUPASchool of Physics and Astronomy and BSRCUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Jacob C. Lutter
- Department of ChemistryWayne State University5101 Cass AvenueDetroitMI 48202USA
| | - Matthew J. Allen
- Department of ChemistryWayne State University5101 Cass AvenueDetroitMI 48202USA
| | - David Parker
- Department of ChemistryDurham UniversitySouth RoadDurhamDH1 3LEUK
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4
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Sørensen TJ, Faulkner S. Multimetallic Lanthanide Complexes: Using Kinetic Control To Define Complex Multimetallic Arrays. Acc Chem Res 2018; 51:2493-2501. [PMID: 30222311 DOI: 10.1021/acs.accounts.8b00205] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Kinetically inert lanthanide complexes are proving to be highly effective building blocks for the preparation of complex heterometallic architectures, allowing complete control of metal ion domains, which cannot be achieved under thermodynamic control. Kinetic stability may render perceivable labile coordination bonds more durable than several types of covalent interactions. For complexes in clinical use, the significance of kinetic stability cannot be overstated, and this Account treats the topic accordingly. Kinetically inert complexes can be used as building blocks for elaborate synthesis. For instance, it is now possible to prepare heterometallic lanthanide complexes containing two or more different lanthanide ions by linking kinetically robust complexes together. This approach can yield bimetallic (f-f' or d-f) and trimetallic (f-f'-f″) lanthanide complexes. In this Account, we describe our studies exploiting the slow dissociation of lanthanide complexes derived from 1,4,7,10-tetraazadodecane-1,4,7,10-tetraacetic acid (DOTA) related ligands to link complexes together through synthetic manipulation of pendent groups on the ligand skeleton or through coordination of bridging donor groups to a d-block metal center. In the course of this work, we have developed a variety of such methods, ranging from peptide coupling and diazotization to Ugi and click chemistry and have also explored the use of alternative strategies that combine orthogonal protecting group chemistry with sequential complexation of different lanthanide ions or that use self-assembly to deliver well-defined multimetallic systems. These well-defined bimetallic systems also have considerable scope for exploitation. Since the earliest studies, it has been clear that there is potential for application in the burgeoning field of molecular imaging. Heterometallic lanthanide complexes can be used as single-molecule bimodal imaging agents through incorporation of MRI active and luminescent components. Alternatively, conventional luminescence methods can be exploited in conjunction with lanthanide luminescence. In the simplest cases, a single lanthanide can be used to achieve a switchable response in combination with a transition metal complex. Bimetallic f-f' complexes allow the full potential of the approach to be realized in systems in which one lanthanide responds to changes in the concentration of an analyte, while a second lanthanide center can be used to define the concentration of the probe itself. This offers a new solution to the old dichotomy of ratiometric imaging that can potentially be applied widely.
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Affiliation(s)
- Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Stephen Faulkner
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
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5
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Junker AKR, Hill LR, Thompson AL, Faulkner S, Sørensen TJ. Shining light on the antenna chromophore in lanthanide based dyes. Dalton Trans 2018; 47:4794-4803. [PMID: 29560975 DOI: 10.1039/c7dt04788f] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Lanthanide based dyes and assays exploit the antenna effect, where a sensitiser-chromophore is used as a light harvesting antenna and subsequent excited state energy transfer populates the emitting lanthanide centred excited state. A rudimentary understanding of the design criteria for designing efficient dyes and assays based on the antenna effect is in place. By preparing kinetically inert lanthanide complexes based on the DO3A scaffold, we are able to study the excited state energy transfer from a 7-methoxy-coumarin antenna chromophore to europium(iii) and terbium(iii) centred excited states. By contrasting the photophysical properties of complexes of metal centres with and without accessible excited states, we are able to separate the contributions from the heavy atom effect, photoinduced electron transfer quenching, excited state energy transfer and molecular conformations. Furthermore, by studying the photophysical properties of the antenna chromophore, we can directly monitor the solution structure and are able to conclude that excited state energy transfer from the chromophore singlet state to the lanthanide centre does occur.
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Affiliation(s)
- Anne Kathrine R Junker
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Leila R Hill
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Amber L Thompson
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Stephen Faulkner
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
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6
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Arppe R, Kofod N, Junker AKR, Nielsen LG, Dallerba E, Just Sørensen T. Modulation of the Photophysical Properties of 1-Azathioxanthones by Eu3+, Gd3+, Tb3+, and Yb3+Ions in Methanol. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700720] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Riikka Arppe
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
| | - Nicolaj Kofod
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
| | - Anne Kathrine R. Junker
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
| | - Lea G. Nielsen
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
| | - Elena Dallerba
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 København Ø Denmark
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7
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Junker AKR, Tropiano M, Faulkner S, Sørensen TJ. Kinetically Inert Lanthanide Complexes as Reporter Groups for Binding of Potassium by 18-crown-6. Inorg Chem 2016; 55:12299-12308. [DOI: 10.1021/acs.inorgchem.6b02063] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Anne Kathrine R Junker
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Copenhagen, Denmark
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U. K
| | - Manuel Tropiano
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U. K
| | - Stephen Faulkner
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U. K
| | - Thomas Just Sørensen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Copenhagen, Denmark
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U. K
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8
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O'Malley WI, Abdelkader EH, Aulsebrook ML, Rubbiani R, Loh CT, Grace MR, Spiccia L, Gasser G, Otting G, Tuck KL, Graham B. Luminescent Alkyne-Bearing Terbium(III) Complexes and Their Application to Bioorthogonal Protein Labeling. Inorg Chem 2016; 55:1674-82. [PMID: 26821062 DOI: 10.1021/acs.inorgchem.5b02605] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Two new bifunctional macrocyclic chelate ligands that form luminescent terbium(III) complexes featuring an alkyne group for conjugation to (bio)molecules via the Cu(I)-catalyzed "click" reaction were synthesized. Upon ligation, the complexes exhibit a significant luminescent enhancement when excited at the λ(max) of the "clicked" products. To demonstrate the utility of the complexes for luminescent labeling, they were conjugated in vitro to E. coli aspartate/glutamate-binding protein incorporating a genetically encoded p-azido-L-phenylalanine or p-(azidomethyl)-L-phenylalanine residue. The complexes may prove useful for time-gated assay applications.
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Affiliation(s)
- William I O'Malley
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville VIC 3052, Australia
| | - Elwy H Abdelkader
- Research School of Chemistry, Australian National University , Canberra ACT 2601, Australia
| | | | - Riccardo Rubbiani
- Department of Chemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Choy-Theng Loh
- Research School of Chemistry, Australian National University , Canberra ACT 2601, Australia
| | - Michael R Grace
- School of Chemistry, Monash University , Clayton VIC 3800, Australia
| | - Leone Spiccia
- School of Chemistry, Monash University , Clayton VIC 3800, Australia
| | - Gilles Gasser
- Department of Chemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Gottfried Otting
- Research School of Chemistry, Australian National University , Canberra ACT 2601, Australia
| | - Kellie L Tuck
- School of Chemistry, Monash University , Clayton VIC 3800, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University , Parkville VIC 3052, Australia
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9
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Desbois N, Pacquelet S, Dubois A, Michelin C, Gros CP. Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition. Beilstein J Org Chem 2015; 11:2202-8. [PMID: 26664643 PMCID: PMC4660971 DOI: 10.3762/bjoc.11.239] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/25/2015] [Indexed: 12/12/2022] Open
Abstract
The Cu(I)-catalysed Huisgen cycloaddition, known as “click” reaction, has been applied to the synthesis of a range of triazole-linked porphyrin/corrole to DOTA/NOTA derivatives. Microwave irradiation significantly accelerates the reaction. The synthesis of heterobimetallic complexes was easily achieved in up to 60% isolated yield. Heterobimetallic complexes were easily prepared as potential MRI/PET (SPECT) bimodal contrast agents incorporating one metal (Mn, Gd) for the enhancement of contrast for MRI applications and one “cold” metal (Cu, Ga, In) for future radionuclear imaging applications. Preliminary relaxivity measurements showed that the reported complexes are promising contrast agents (CA) in MRI.
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Affiliation(s)
- Nicolas Desbois
- Université de Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | - Sandrine Pacquelet
- Université de Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | - Adrien Dubois
- Université de Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | - Clément Michelin
- Université de Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | - Claude P Gros
- Université de Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
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10
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Andres J, Borbas KE. Expanding the Versatility of Dipicolinate-Based Luminescent Lanthanide Complexes: A Fast Method for Antenna Testing. Inorg Chem 2015; 54:8174-6. [PMID: 26288077 DOI: 10.1021/acs.inorgchem.5b01579] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A dipicolinate (dpa)-based platform for the rapid testing of potential lanthanide-sensitizing antennae was developed; 4-methyl-7-O-alkylcoumarin-appended dpa could sensitize four lanthanides. The platform could be used to estimate the photophysical properties of a more difficult-to-prepare 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid based structure carrying the same antenna.
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Affiliation(s)
- Julien Andres
- Department of Chemistry, Biomedical Center, Uppsala University , 75 123 Uppsala, Sweden
| | - K Eszter Borbas
- Department of Chemistry, Biomedical Center, Uppsala University , 75 123 Uppsala, Sweden
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11
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Tropiano M, Kenwright AM, Faulkner S. Lanthanide complexes of azidophenacyl-DO3A as new synthons for click chemistry and the synthesis of heterometallic lanthanide arrays. Chemistry 2015; 21:5697-9. [PMID: 25754928 DOI: 10.1002/chem.201500188] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Indexed: 12/18/2022]
Abstract
Lanthanide complexes of azidophenacyl DO3A are effective substrates for click reactions with ethyne derivatives, giving rise to aryl triazole appended lanthanide complexes, in which the aryl triazole acts as an effective sensitising chromophore for lanthanide luminescence. They also undergo click chemistry with propargylDO3A derivatives, giving rise to heterometallic complexes.
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Affiliation(s)
- Manuel Tropiano
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA (UK)
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12
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Cakić N, Gündüz S, Rengarasu R, Angelovski G. Synthetic strategies for preparation of cyclen-based MRI contrast agents. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2014.12.087] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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13
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Xiong R, Andres J, Scheffler K, Borbas KE. Synthesis and characterisation of lanthanide-hydroporphyrin dyads. Dalton Trans 2015; 44:2541-53. [DOI: 10.1039/c4dt02448f] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hydroporphyrin-linked lanthanide complexes with variations in tetrapyrrole structure, linker length and mode of attachment are reported.
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Affiliation(s)
- Ruisheng Xiong
- Department of Chemistry – BMC
- Uppsala University
- 75123 Uppsala
- Sweden
| | - Julien Andres
- Department of Chemistry – BMC
- Uppsala University
- 75123 Uppsala
- Sweden
| | - Kira Scheffler
- Department of Chemistry – BMC
- Uppsala University
- 75123 Uppsala
- Sweden
| | - K. Eszter Borbas
- Department of Chemistry – BMC
- Uppsala University
- 75123 Uppsala
- Sweden
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14
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Hopper LE, Allen MJ. Rapid synthesis of 1,7-bis( t-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO2A- t-Bu ester). Tetrahedron Lett 2014; 55:5560-5561. [PMID: 25506095 DOI: 10.1016/j.tetlet.2014.08.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A three-step route was used to synthesize 1,7-bis(t-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO2A-t-Bu ester) from 1,4,7,10-tetraazacyclododecane (cyclen). The overall time of reaction was reduced from a combined ~56 h to 2.3 h with an overall yield comparable to previously reported methods.
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Affiliation(s)
- Lauren E Hopper
- Department of Chemistry, Wayne State University, Detroit, MI 48202, United States
| | - Matthew J Allen
- Department of Chemistry, Wayne State University, Detroit, MI 48202, United States
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15
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Designing reactivity-based responsive lanthanide probes for multicolor detection in biological systems. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.10.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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16
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Butler SJ, Delbianco M, Evans NH, Frawley AT, Pal R, Parker D, Puckrin RS, Yufit DS. Utility of tris(4-bromopyridyl) europium complexes as versatile intermediates in the divergent synthesis of emissive chiral probes. Dalton Trans 2014; 43:5721-30. [DOI: 10.1039/c4dt00253a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The tribromopyridyl complex is a versatile late intermediate in the divergent synthesis of emissive triazole and aryl–alkynyl substituted complexes.
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Affiliation(s)
| | | | - Nicholas H. Evans
- Department of Chemistry
- Durham University
- Durham DH1 3LE, UK
- Department of Chemistry
- Lancaster University
| | | | - Robert Pal
- Department of Chemistry
- Durham University
- Durham DH1 3LE, UK
| | - David Parker
- Department of Chemistry
- Durham University
- Durham DH1 3LE, UK
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17
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Stasiuk GJ, Long NJ. The ubiquitous DOTA and its derivatives: the impact of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid on biomedical imaging. Chem Commun (Camb) 2013; 49:2732-46. [PMID: 23392443 DOI: 10.1039/c3cc38507h] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Over the last twenty-five years 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) has made a significant impact on the field of diagnostic imaging. DOTA is not the only metal chelate in use in medical diagnostics, but it is the only one to significantly impact on all of the major imaging modalities Magnetic Resonance (MR), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Fluorescence imaging. This crossover of modalities has been possible due to the versatility of DOTA firstly, to complex a variety of metal ions and secondly, the ease with which it can be modified for different disease states. This has driven research over the last two decades into the chemistry of DOTA and the modification of the substituent pendant arms of this macrocycle to create functional, targeted and dual-modal imaging agents. The primary use of DOTA has been with the lanthanide series of metals, gadolinium for MRI, europium and terbium for fluorescence and neodymium for near infra-red imaging. There are now many research groups dedicated to the use of lanthanides with DOTA although other chelates such as DTPA and NOTA are being increasingly employed. The ease with which DOTA can be conjugated to peptides has given rise to targeted imaging agents seen in the PET, SPECT and radiotherapy fields. These modalities use a variety of radiometals that complex with DOTA, e.g.(64)Cu and (68)Ga which are used in clinical PET scans, (111)In, and (90)Y for SPECT and radiotherapy. In this article, we will demonstrate the remarkable versatility of DOTA, how it has crossed the imaging modality boundaries and how it has been successfully transferred into the clinic.
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Affiliation(s)
- Graeme J Stasiuk
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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18
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Szíjjártó C, Pershagen E, Ilchenko NO, Borbas KE. A versatile long-wavelength-absorbing scaffold for Eu-based responsive probes. Chemistry 2013; 19:3099-109. [PMID: 23307197 DOI: 10.1002/chem.201203957] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Indexed: 12/27/2022]
Abstract
Coumarin-sensitized, long-wavelength-absorbing luminescent Eu(III)-complexes have been synthesized and characterized. The lanthanide binding site consists of a cyclen-based chelating framework that is attached through a short linker to a 7-hydroxycoumarin, a 7-B(OH)(2)-coumarin, a 7-O-(4-pinacolatoboronbenzyl)-coumarin or a 7-O-(4-methoxybenzyl)-coumarin. The syntheses are straightforward, use readily available building blocks, and proceed through a small number of high-yielding steps. The sensitivity of coumarin photophysics to the 7-substituent enables modulation of the antenna-absorption properties, and thus the lanthanide excitation spectrum. Reactions of the boronate-based functionalities (cages) with H(2)O(2) yielded the corresponding 7-hydroxycoumarin species. The same species was produced with peroxynitrite in a ×10(6)-10(7)-fold faster reaction. Both reactions resulted in the emergence of a strong ≈407 nm excitation band, with concomitant decrease of the 366 nm band of the caged probe. In aqueous solution the methoxybenzyl caged Eu-complex was quenched by ONOO(-). We have shown that preliminary screening of simple coumarin-based antennae through UV/Vis absorption spectroscopy is possible as the changes in absorption profile translate with good fidelity to changes in Eu(III)-excitation profile in the fully elaborated complex. Taken together, our results show that the 7-hydroxycoumarin antenna is a viable scaffold for the construction of turn-on and ratiometric luminescent probes.
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Affiliation(s)
- Csongor Szíjjártó
- Department of Chemistry, BMC, Uppsala University, Box 576, 75123 Uppsala, Sweden
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19
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20
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Suchý M, Bartha R, Hudson RHE. “Click” chemistry toward bis(DOTA-derived) heterometallic complexes: potential bimodal MRI/PET(SPECT) molecular imaging probes. RSC Adv 2013. [DOI: 10.1039/c3ra23260c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Laakso J, Rosser GA, Szíjjártó C, Beeby A, Borbas KE. Synthesis of chlorin-sensitized near infrared-emitting lanthanide complexes. Inorg Chem 2012; 51:10366-74. [PMID: 22978627 DOI: 10.1021/ic3015354] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lanthanide (Yb(3+), Nd(3+)) complexes equipped with red-absorbing hydroporphyrin (chlorin) antennae were synthesized and characterized. The syntheses are scalable, highly modular, and enable the introduction of different chlorins functionalized with a single reactive group (COOH or NH(2)). Absorption maxima were dependent on chlorin substitution pattern (monomeso aryl or dimeso aryl) and metalation state (free base or zinc chelate). The complexes benefit from dual chlorin (610-639 nm) and lanthanide (980 or 1065 nm for Yb- or Nd-complexes, respectively) emission in the biologically relevant red and near IR region of the spectrum.
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Affiliation(s)
- Johanna Laakso
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691, Stockholm, Sweden
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