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Current development of sigma-2 receptor radioligands as potential tumor imaging agents. Bioorg Chem 2021; 115:105163. [PMID: 34289426 DOI: 10.1016/j.bioorg.2021.105163] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/05/2021] [Accepted: 07/08/2021] [Indexed: 12/24/2022]
Abstract
Sigma receptors are transmembrane proteins with two different subtypes: σ1 and σ2. Because of its overexpression in tumors, the σ2 receptor (σ2R) is a well-known biomarker for cancer cells. A large number of small-molecule ligands for the σ2Rs have been identified and tested for imaging the proliferative status of tumors using single photon emission computed tomography (SPECT) and positron emission tomography (PET). These small molecules include derivatives of bicyclic amines, indoles, cyclohexylpiperazines and tetrahydroisoquinolines. This review discusses various aspects of small molecule ligands, such as chemical composition, labeling strategy, affinity for σ2Rs, and in vitro/in vivo investigations. The recent studies described here could be useful for the development of σ2R radioligands as potential tumor imaging agents.
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Alonso Martinez LM, DaSilva JN. Development of a novel [ 18 F]fluorobenzyl derivative of the AT 1 receptor antagonist Candesartan. J Labelled Comp Radiopharm 2020; 64:120-128. [PMID: 33084079 DOI: 10.1002/jlcr.3892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/24/2020] [Accepted: 10/13/2020] [Indexed: 11/11/2022]
Abstract
Candesartan is a clinically approved angiotensin II type 1 receptor (AT1 R)-blocker that selectively binds AT1 Rs in high affinity. We report here the radiosynthesis and automation of the novel [18 F]fluorobenzyl derivative of Candesartan using the Sonogashira cross-coupling reaction. [18 F]Fluorobenzyl-Candesartan ([18 F]7) was developed from 4-[18 F]fluoroiodobenzene ([18 F]FIB) that was conjugated with alkyne-trityl-candesartan with the assistance of a Pd (PPh3 )4 /CuI catalyst followed by acid deprotection. The three-step two-reactor 2-HPLC purification process was automated resulting in >90% pure [18 F]7 in a RCY of 4.6 ± 1.1% (decay corrected from EOB) and molar activities of 1,406-5,513 GBq/mmol. [18 F]FIB was reproducibly obtained by direct radiofluorination of the mono-iodinated triphenylsulfonium salt in the presence of K222/K2 CO3 in an ~30% yield (decay-corrected). [18 F]7 was stable (>97%) up to 4 h in solution and up to 1 h in rat plasma at 37°C. However, the use of Sonogashira cross-coupling reaction to produce [18 F]7 in high yields and molar activities was found to be challenging for routine use in radiochemistry labs.
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Affiliation(s)
- Luis Michel Alonso Martinez
- Radiochemistry and Cyclotron Laboratory, University of Montreal Hospital Research Centre, Montréal, Québec, Canada.,Department of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.,Research Center of the Montreal Heart Institute, Montréal, Québec, Canada
| | - Jean N DaSilva
- Radiochemistry and Cyclotron Laboratory, University of Montreal Hospital Research Centre, Montréal, Québec, Canada.,Department of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Radiology, Radio-oncology and Nuclear Medicine, Université de Montréal, Montréal, Québec, Canada
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3
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Izmer VV, Lebedev AY, Kononovich DS, Borisov IS, Kulyabin PS, Goryunov GP, Uborsky DV, Canich JAM, Voskoboynikov AZ. ansa-Metallocenes Bearing 4-(N-Azolyl)-2-methylindenyl and Related Ligands: Development of Highly Isoselective Catalysts for Propene Polymerization at Higher Temperatures. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00648] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Vyatcheslav V. Izmer
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Artem Y. Lebedev
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Dmitry S. Kononovich
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Ilya S. Borisov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Pavel S. Kulyabin
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Georgy P. Goryunov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Dmitry V. Uborsky
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Jo Ann M. Canich
- Baytown Technology and Engineering Complex, ExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, Texas 77520, United States
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Pauton M, Gillet R, Aubert C, Bluet G, Gruss-Leleu F, Roy S, Perrio C. The first radiosynthesis of 2-amino-5-[ 18F]fluoropyridines via a "minimalist" radiofluorination/palladium-catalyzed amination sequence from anisyl(2-bromopyridinyl)iodonium triflate. Org Biomol Chem 2019; 17:6359-6363. [PMID: 31218326 DOI: 10.1039/c9ob01187k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The synthesis of 2-amino-5-[18F]fluoropyridines was achieved in 8-85% yields by palladium-catalyzed reaction of 2-bromo-5-[18F]fluoropyridine with piperidine, dimethylamine, butylamine, methylpiperazine, benzylamine, aniline and 3-aminopyridine. 2-Bromo-5-[18F]fluoropyridine was obtained by radiofluorination of anisyl(2-bromopyridinyl-5)iodonium triflate (88% yield). The radiofluorination step was performed under "minimalist" conditions to guarantee a successful subsequent amination reaction.
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Affiliation(s)
- Mathilde Pauton
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT-UMR 6030, LDM-TEP, Cyceron, Boulevard Henri Becquerel, 14000 Caen, France. and Sanofi R&D, IDD, Isotope Chemistry, 13 Quai Jules Guesde, 94403 Vitry sur Seine Cedex, France
| | - Raphaël Gillet
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT-UMR 6030, LDM-TEP, Cyceron, Boulevard Henri Becquerel, 14000 Caen, France.
| | - Catherine Aubert
- Sanofi R&D, IDD, Isotope Chemistry, 13 Quai Jules Guesde, 94403 Vitry sur Seine Cedex, France
| | - Guillaume Bluet
- Sanofi R&D, IDD, Isotope Chemistry, 13 Quai Jules Guesde, 94403 Vitry sur Seine Cedex, France
| | - Florence Gruss-Leleu
- Sanofi R&D, IDD, Isotope Chemistry, 13 Quai Jules Guesde, 94403 Vitry sur Seine Cedex, France
| | - Sébastien Roy
- Sanofi R&D, IDD, Isotope Chemistry, 13 Quai Jules Guesde, 94403 Vitry sur Seine Cedex, France
| | - Cécile Perrio
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT-UMR 6030, LDM-TEP, Cyceron, Boulevard Henri Becquerel, 14000 Caen, France.
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5
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Ojha NK, Zyryanov GV, Majee A, Charushin VN, Chupakhin ON, Santra S. Copper nanoparticles as inexpensive and efficient catalyst: A valuable contribution in organic synthesis. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.10.004] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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6
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Pai G, Chattopadhyay AP. N-Arylation of nitrogen containing heterocycles with aryl halides using copper nanoparticle catalytic system. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Preshlock S, Tredwell M, Gouverneur V. (18)F-Labeling of Arenes and Heteroarenes for Applications in Positron Emission Tomography. Chem Rev 2016; 116:719-66. [PMID: 26751274 DOI: 10.1021/acs.chemrev.5b00493] [Citation(s) in RCA: 477] [Impact Index Per Article: 59.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Diverse radiochemistry is an essential component of nuclear medicine; this includes imaging techniques such as positron emission tomography (PET). As such, PET can track diseases at an early stage of development, help patient care planning through personalized medicine and support drug discovery programs. Fluorine-18 is the most frequently used radioisotope in PET radiopharmaceuticals for both clinical and preclinical research. Its physical and nuclear characteristics (97% β(+) decay, 109.8 min half-life, 635 keV positron energy) and high specific activity make it an attractive nuclide for labeling and molecular imaging. Arenes and heteroarenes are privileged candidates for (18)F-incorporation as they are metabolically robust and therefore widely used by medicinal chemists and radiochemists alike. For many years, the range of (hetero)arenes amenable to (18)F-fluorination was limited by the lack of chemically diverse precursors, and of radiochemical methods allowing (18)F-incorporation in high selectivity and efficiency (radiochemical yield and purity, specific activity, and radio-scalability). The appearance of late-stage fluorination reactions catalyzed by transition metal or small organic molecules (organocatalysis) has encouraged much research on the use of these activation manifolds for (18)F-fluorination. In this piece, we review all of the reactions known to date to install the (18)F substituent and other key (18)F-motifs (e.g., CF3, CHF2, OCF3, SCF3, OCHF2) of medicinal relevance onto (hetero)arenes. The field has changed significantly in the past five years, and the current trend suggests that the radiochemical space available for PET applications will expand rapidly in the near future.
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Affiliation(s)
- Sean Preshlock
- Chemistry Research Laboratory, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Matthew Tredwell
- Chemistry Research Laboratory, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory, University of Oxford , Oxford OX1 3TA, United Kingdom
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Kügler F, Ermert J, Kaufholz P, Coenen HH. 4-[18F]Fluorophenylpiperazines by improved Hartwig-Buchwald N-arylation of 4-[18F]fluoroiodobenzene, formed via hypervalent λ3-iodane precursors: application to build-up of the dopamine D4 ligand [18F]FAUC 316. Molecules 2014; 20:470-86. [PMID: 25558857 PMCID: PMC6272738 DOI: 10.3390/molecules20010470] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/18/2014] [Indexed: 12/24/2022] Open
Abstract
Substituted phenylpiperazines are often neuropharmacologically active compounds and in many cases are essential pharmacophores of neuroligands for different receptors such as D2-like dopaminergic, serotoninergic and other receptors. Nucleophilic, no-carrier-added (n.c.a.) 18F-labelling of these ligands in an aromatic position is desirable for studying receptors with in vivo molecular imaging. 1-(4-[18F]Fluorophenyl)piperazine was synthesized in two reaction steps starting by 18F-labelling of a iodobenzene-iodonium precursor, followed by Pd-catalyzed N-arylation of the intermediate 4-[18F]fluoro-iodobenzene. Different palladium catalysts and solvents were tested with particular attention to the polar solvents dimethylformamide (DMF) and dimethylsulfoxide (DMSO). Weak inorganic bases like potassium phosphate or cesium carbonate seem to be essential for the arylation step and lead to conversation rates above 70% in DMF which is comparable to those in typically used toluene. In DMSO even quantitative conversation was observed. Overall radiochemical yields of up to 40% and 60% in DMF and DMSO, respectively, were reached depending on the labelling yield of the first step. The fluorophenylpiperazine obtained was coupled in a third reaction step with 2-formyl-1H-indole-5-carbonitrile to yield the highly selective dopamine D4 ligand [18F]FAUC 316.
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Affiliation(s)
- Fabian Kügler
- Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich, 52425 Jülich, Germany.
| | - Johannes Ermert
- Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich, 52425 Jülich, Germany.
| | - Peter Kaufholz
- Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich, 52425 Jülich, Germany.
| | - Heinz H Coenen
- Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich, 52425 Jülich, Germany.
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Pai G, Chattopadhyay AP. Ligand-free copper nanoparticle promoted N-arylation of azoles with aryl and heteroaryl iodides. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2013.12.065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Mach RH, Zeng C, Hawkins WG. The σ2 receptor: a novel protein for the imaging and treatment of cancer. J Med Chem 2013; 56:7137-60. [PMID: 23734634 DOI: 10.1021/jm301545c] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The σ2 receptor is an important target for the development of molecular probes in oncology because of its 10-fold higher density in proliferating tumor cells compared with that in quiescent tumor cells and because of the observation that σ2 receptor agonists are able to kill tumor cells via apoptotic and nonapoptotic mechanisms. Although recent evidence indicates that the σ2 receptor binding site is localized within the progesterone receptor membrane component 1 (PGRMC1), most information regarding this protein has been obtained using either radiolabeled or fluorescent receptor-based probes and from biochemical analysis of the effect of σ2 selective ligands on cells grown in culture. This article reviews the development of σ2 receptor ligands and presents an overview of how they have been used in vitro and in vivo to increase our understanding of the role of the σ2 receptor in cancer and proliferation.
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Affiliation(s)
- Robert H Mach
- Mallinckrodt Institute of Radiology and ‡Department of Surgery, Washington University School of Medicine , St. Louis, Missouri 63110, United States
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11
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12
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Mu L, Fischer CR, Holland JP, Becaud J, Schubiger PA, Schibli R, Ametamey SM, Graham K, Stellfeld T, Dinkelborg LM, Lehmann L. 18F-Radiolabeling of Aromatic Compounds Using Triarylsulfonium Salts. European J Org Chem 2012. [DOI: 10.1002/ejoc.201101730] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Palladium-Catalyzed sp2 C–N Bond Forming Reactions: Recent Developments and Applications. TOP ORGANOMETAL CHEM 2012. [DOI: 10.1007/3418_2012_56] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Cacchi S, Fabrizi G. Update 1 of: Synthesis and Functionalization of Indoles Through Palladium-Catalyzed Reactions. Chem Rev 2011; 111:PR215-83. [PMID: 21557620 DOI: 10.1021/cr100403z] [Citation(s) in RCA: 603] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sandro Cacchi
- Dipartimento di Chimica e Technologie del Farmaco,
Sapienza, Università di Roma, P.le A. Moro 5, 00185 Roma, Italy
- This is a Chemical Reviews Perennial Review. The root paper of this title was
published in Chem. Rev.2005, 105 (7), 2873−2920, DOI: 10.1021/cr040639b; Published
(Web) July 13, 2005. Updates to the text appear in red type
| | - Giancarlo Fabrizi
- Dipartimento di Chimica e Technologie del Farmaco,
Sapienza, Università di Roma, P.le A. Moro 5, 00185 Roma, Italy
- This is a Chemical Reviews Perennial Review. The root paper of this title was
published in Chem. Rev.2005, 105 (7), 2873−2920, DOI: 10.1021/cr040639b; Published
(Web) July 13, 2005. Updates to the text appear in red type
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Pretze M, Große-Gehling P, Mamat C. Cross-coupling reactions as valuable tool for the preparation of PET radiotracers. Molecules 2011; 16:1129-65. [PMID: 21270732 PMCID: PMC6259626 DOI: 10.3390/molecules16021129] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/17/2011] [Accepted: 01/21/2011] [Indexed: 11/16/2022] Open
Abstract
The increasing application of positron emission tomography (PET) in nuclear medicine has stimulated the extensive development of a multitude of new radiotracers and novel radiolabeling procedures with the most prominent short-lived positron emitters carbon-11 and fluorine-18. Radiolabeling with these radionuclides represents a remarkable challenge. Special attention has to be paid to synthesis time and specific labeling techniques due to the short physical half life of the respective radionuclides 11C (t1/2 = 20.4 min) and 18F (t1/2 = 109.8 min). In the past, numerous transition metal-catalyzed reactions were employed in organic chemistry, even though only a handful of these coupling reactions were adopted in radiochemical practice. Thus, the implementation of modern synthesis methods like cross-coupling reactions offers the possibility to develop a wide variety of novel radiotracers. The introduction of catalysts based on transition metal complexes bears a high potential for rapid, efficient, highly selective and functional group-tolerating incorporation of carbon-11 and fluorine-18 into target molecules. This review deals with design, application and improvement of transition metal-mediated carbon-carbon as well as carbon-heteroatom cross-coupling reactions as a labeling feature with the focus on the preparation of radiolabeled compounds for molecular imaging.
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Affiliation(s)
- Marc Pretze
- Institut für Radiopharmazie, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Philipp Große-Gehling
- OncoRay – National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Fetscherstraße 74, P.O. Box 41, D-01307 Dresden, Germany
| | - Constantin Mamat
- Institut für Radiopharmazie, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden, Germany
- Author to whom correspondence should be addressed; ; Tel.: +49-351-260 2805; Fax: +49-351-260 3232
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Verma AK, Singh J, Larock RC. Benzotriazole: an efficient ligand for the copper-catalyzed N-arylation of indoles. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.07.050] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Joucla L, Djakovitch L. Transition Metal-Catalysed, Direct and Site-Selective N1-, C2- or C3-Arylation of the Indole Nucleus: 20 Years of Improvements. Adv Synth Catal 2009. [DOI: 10.1002/adsc.200900059] [Citation(s) in RCA: 433] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Efficient, one-pot transformation of indoles into functionalized oxindole and spirooxindole systems under Swern conditions. Tetrahedron 2009. [DOI: 10.1016/j.tet.2008.12.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Miller P, Long N, Vilar R, Gee A. Synthese von11C-,18F-,15O- und13N-Radiotracern für die Positronenemissionstomographie. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800222] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Miller P, Long N, Vilar R, Gee A. Synthesis of11C,18F,15O, and13N Radiolabels for Positron Emission Tomography. Angew Chem Int Ed Engl 2008; 47:8998-9033. [DOI: 10.1002/anie.200800222] [Citation(s) in RCA: 726] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Surry D, Buchwald S. Biarylphosphanliganden in der palladiumkatalysierten Aminierung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800497] [Citation(s) in RCA: 500] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Palladium-catalyzed amination reactions of aryl halides have undergone rapid development in the last 12 years, largely driven by the implementation of new classes of ligands. Biaryl phosphanes have proven to provide especially active catalysts in this context. This Review discusses the application of these catalysts in C-N cross-coupling reactions in the synthesis of heterocycles and pharmaceuticals, in materials science, and in natural product synthesis.
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Affiliation(s)
- David S Surry
- Department of Chemistry, Room 18-490, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Bellina F, Calandri C, Cauteruccio S, Rossi R. Selective, Efficient and Functional Group-Tolerant CuOAc-MediatedN-Arylation of 1H-Indoles and 9H-Carbazole with Aryl Iodides Under Base-Free and Ligandless Conditions. European J Org Chem 2007. [DOI: 10.1002/ejoc.200601084] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Wuest F. Fluorine-18 labeling of small molecules: the use of 18F-labeled aryl fluorides derived from no-carrier-added [18F]fluoride as labeling precursors. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2007:51-78. [PMID: 17172152 DOI: 10.1007/978-3-540-49527-7_3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The favourable long-half life, the ease of production and the low energy of the emitted positron make 18F an ideal radionuclide for PET imaging. Radiochemistry of 18F basically relies on two distinctive types of reactions: nucleophilic and electrophilic reactions. All syntheses of 18F-labeled radiotracers are based on either [18F]fluoride ion or [18F]fluorine gas as simple primary labeling precursors which are obtained directly from the cyclotron. They can be applied either directly to the radiosynthesis or they can be transformed into more complex labeling precursors enabling the multi-step build-up of organic tracer molecules. The topic of this review is a survey on the application of several 18F-labeled aryl fluorides as building blocks derived from no-carrier-added (n.c.a.) [18F] fluoride to build up small monomeric PET radiotracers at high specific radioactivity by multi-step synthesis procedures.
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Affiliation(s)
- F Wuest
- PET Tracer Department, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Centre Rossendorf, Dresden, Germany.
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Steiniger B, Wuest FR. Synthesis of18F-labelled biphenyls via SUZUKI cross-coupling with 4-[18F]fluoroiodobenzene. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.1099] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kassiou M, Dannals RF, Liu X, Wong DF, Ravert HT, Scheffel UA. Synthesis and in vivo evaluation of a new PET radioligand for studying sigma-2 receptors. Bioorg Med Chem 2005; 13:3623-6. [PMID: 15862990 DOI: 10.1016/j.bmc.2005.03.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 03/14/2005] [Accepted: 03/21/2005] [Indexed: 11/17/2022]
Abstract
The cyclohexyl piperazine 1 (1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydro-naphthalen-1-yl)-propyl]-piperazine) has been shown to be a potent and selective sigma-2 receptor ligand. In the present study, we prepared [(11)C]1 by O-alkylation of the phenolic precursor 2 with [(11)C]CH(3)I. [(11)C]1 was obtained in a 29% non-decay corrected yield and specific activity of 9299 mCi/micromol calculated at end-of-synthesis. The biodistribution of [(11)C]1 in mouse brain demonstrated rapid and homogenous concentration in all brain structures, which included the cortex, thalamus, cerebellum and striatum. Co-administration of unlabelled 1 (1 mg/kg) or the sigma-2 selective ligand SM-21 (1 mg/kg) failed to show any significant inhibition of [(11)C]1 uptake in the mouse brain. The evaluation of this radioligand in vivo in the mouse clearly indicates that it does not possess the required properties for studying sigma-2 receptors in the brain using PET.
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Affiliation(s)
- Michael Kassiou
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Missenden Rd., Camperdown, NSW 2050, Australia.
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