1
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Webb EW, Cheng K, Winton WP, Klein BJC, Bowden GD, Horikawa M, Liu SW, Wright JS, Verhoog S, Kalyani D, Wismer M, Krska SW, Sanford MS, Scott PJH. Development of High-Throughput Experimentation Approaches for Rapid Radiochemical Exploration. J Am Chem Soc 2024; 146:10581-10590. [PMID: 38580459 DOI: 10.1021/jacs.3c14822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Positron emission tomography is a widely used imaging platform for studying physiological processes. Despite the proliferation of modern synthetic methodologies for radiolabeling, the optimization of these reactions still primarily relies on inefficient one-factor-at-a-time approaches. High-throughput experimentation (HTE) has proven to be a powerful approach for optimizing reactions in many areas of chemical synthesis. However, to date, HTE has rarely been applied to radiochemistry. This is largely because of the short lifetime of common radioisotopes, which presents major challenges for efficient parallel reaction setup and analysis using standard equipment and workflows. Herein, we demonstrate an effective HTE workflow and apply it to the optimization of copper-mediated radiofluorination of pharmaceutically relevant boronate ester substrates. The workflow utilizes commercial equipment and allows for rapid analysis of reactions for optimizing reactions, exploring chemical space using pharmaceutically relevant aryl boronates for radiofluorinations, and constructing large radiochemistry data sets.
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Affiliation(s)
- E William Webb
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Kevin Cheng
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Wade P Winton
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Brandon J C Klein
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Gregory D Bowden
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen 72074, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, Tuebingen 72074, Germany
| | - Mami Horikawa
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - S Wendy Liu
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Jay S Wright
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Stefan Verhoog
- Translational Imaging, Merck and Co., Inc., West Point, Pennsylvania 19486, United States
| | - Dipannita Kalyani
- Discovery Chemistry, Merck Research Laboratories, Merck and Co., Inc., Rahway, New Jersey 07065, United States
| | - Michael Wismer
- Discovery Chemistry, Merck Research Laboratories, Merck and Co., Inc., Rahway, New Jersey 07065, United States
| | - Shane W Krska
- Discovery Chemistry, Merck Research Laboratories, Merck and Co., Inc., Rahway, New Jersey 07065, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 North University Avenue, Ann Arbor, Michigan 48109, United States
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2
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Cheng K, Webb EW, Bowden GD, Wright JS, Shao X, Sanford MS, Scott PJH. Photo- and Cu-Mediated 11C Cyanation of (Hetero)Aryl Thianthrenium Salts. Org Lett 2024. [PMID: 38630573 DOI: 10.1021/acs.orglett.4c00929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
We present a photo- and Cu-mediated 11C cyanation of bench-stable (hetero)aryl thianthrenium salts via an aryl radical addition pathway. The thianthrenium substrates can be readily accessed via C-H functionalization, and the radiocyanation protocol proceeds under mild conditions (<50 °C, 5 min) and can be automated using open-source, readily accessible augmentations to existing radiochemistry equipment.
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Affiliation(s)
- Kevin Cheng
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - E William Webb
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Gregory D Bowden
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72074 Tuebingen, Germany
- Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University, 72074 Tuebingen, Germany
| | - Jay S Wright
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Xia Shao
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
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3
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Carneiro SN, Laffoon JD, Luo L, Sanford MS. Benchmarking Trisaminocyclopropeniums as Mediators for Anodic Oxidation Reactions. J Org Chem 2024. [PMID: 38607957 DOI: 10.1021/acs.joc.4c00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
This report benchmarks a tris(amino)cyclopropenium (TAC) salt as an electron-transfer mediator for anodic oxidation reactions in comparison to two known mediators: a triarylamine and a triarylimidazole derivative. The three mediators have redox potentials, diffusion coefficients, and heterogeneous electron transfer rates similar to those of glassy carbon electrodes in acetonitrile/KPF6. However, they differ significantly in their performance in two electro-organic reactions: anodic fluorination of a dithiane and anodic oxidation of 4-methoxybenzyl alcohol. These differences are rationalized based on variable stability in the presence of reaction components (e.g., NEt3·3HF, lutidine, and Cs2CO3) as well as very different rates of electron transfer with the organic substrate. Overall, this work highlights the advantages and disadvantages of each mediator and provides a foundation for expanding the applications of TACs in electro-organic synthesis moving forward.
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Affiliation(s)
- Sabrina N Carneiro
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joshua D Laffoon
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Long Luo
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Wright JS, Ma R, Webb EW, Winton WP, Stauff J, Cheng K, Brooks AF, Sanford MS, Scott PJH. Zinc-Mediated Radiosynthesis of Unprotected Fluorine-18 Labelled α-Tertiary Amides. Angew Chem Int Ed Engl 2024; 63:e202316365. [PMID: 38010255 PMCID: PMC10872995 DOI: 10.1002/anie.202316365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 11/29/2023]
Abstract
This report describes the development of a Zn(OTf)2 -mediated method for converting α-tertiary haloamides to the corresponding fluorine-18 labelled α-tertiary fluoroamides with no-carrier-added [18 F]tetramethylammonium fluoride. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene is an essential additive for achieving high radiochemical conversion. Under the optimised conditions, radiofluorination proceeds at sterically hindered tertiary sites in high radiochemical conversions, yields, and purities. This method has been successfully automated and applied to access >200 mCi (>7.4 GBq) of several model radiofluorides. Mechanistic studies led to the development of a new, nucleophilic C-H radiofluorination process using N-sulphonyloxyamide substrates.
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Affiliation(s)
- Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Richard Ma
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - E William Webb
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Wade P Winton
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Jenelle Stauff
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Kevin Cheng
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, MI-48109, USA
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI-48109, USA
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5
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Morales M, Preshlock S, Sharninghausen LS, Wright JS, Brooks AF, Sanford MS, Scott PJH. Tandem Iridium-Catalyzed C-H Borylation/Copper-Mediated Radiofluorination of Aromatic C-H Bonds with [ 18F]TBAF. Methods Mol Biol 2024; 2729:45-53. [PMID: 38006490 PMCID: PMC10867631 DOI: 10.1007/978-1-0716-3499-8_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Direct C-H functionalization of (hetero)aromatic C-H bonds with iridium-catalyzed borylation followed by copper-mediated radiofluorination of the in situ generated organoboronates affords fluorine-18 labeled aromatics in high radiochemical conversions and meta-selectivities. This protocol describes the benchtop reaction assembly of the C-H borylation and radiofluorination steps, which can be utilized for the fluorine-18 labeling of densely functionalized bioactive scaffolds.
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Affiliation(s)
- Maria Morales
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Sean Preshlock
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | | | - Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | | | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
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6
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Lisboa AVRD, Duran-Camacho G, Ehrlacher AK, Lasky MR, Sanford MS. Deoxyfluorination of Carboxylic Acids via an In Situ Generated Trifluoromethoxide Salt. Org Lett 2023; 25:9025-9029. [PMID: 38064366 PMCID: PMC10774922 DOI: 10.1021/acs.orglett.3c03706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
An in situ generated pyridinium trifluoromethoxide salt (PyOCF3) is a highly effective deoxyfluorination reagent for the synthesis of acid fluorides. PyOCF3 is formed at room temperature from the reaction of 2,4-dinitro(trifluoromethoxy)benzene with 4-dimethylaminopyridine. PyOCF3 undergoes slow release of fluorophosgene and fluoride, which serve as the electrophile and nucleophile, respectively, for deoxyfluorination. A wide substrate scope and high functional group tolerance are demonstrated. Furthermore, the acid fluorides can be purified by filtration and telescoped to various known reactions.
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Affiliation(s)
- Al Vicente Riano D Lisboa
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Geraldo Duran-Camacho
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Annika K Ehrlacher
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew R Lasky
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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7
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Pancoast AR, McCormack SL, Galinat S, Walser-Kuntz R, Jett BM, Sanford MS, Sigman MS. Data science enabled discovery of a highly soluble 2,2'-bipyrimidine anolyte for application in a flow battery. Chem Sci 2023; 14:13734-13742. [PMID: 38075655 PMCID: PMC10699568 DOI: 10.1039/d3sc04084d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 11/01/2023] [Indexed: 02/12/2024] Open
Abstract
Development of non-aqueous redox flow batteries as a viable energy storage solution relies upon the identification of soluble charge carriers capable of storing large amounts of energy over extended time periods. A combination of metrics including number of electrons stored per molecule, redox potential, stability, and solubility of the charge carrier impact performance. In this context, we recently reported a 2,2'-bipyrimidine charge carrier that stores two electrons per molecule with reduction near -2.0 V vs. Fc/Fc+ and high stability. However, these first-generation derivatives showed a modest solubility of 0.17 M (0.34 M e-). Seeking to improve solubility without sacrificing stability, we harnessed the synthetic modularity of this scaffold to design a library of sixteen candidates. Using computed molecular descriptors and a single node decision tree, we found that minimization of the solvent accessible surface area (SASA) can be used to predict derivatives with enhanced solubility. This parameter was used in combination with a heatmap describing stability to de-risk a virtual screen that ultimately identified a 2,2'-bipyrimidine with significantly increased solubility and good stability metrics in the reduced states. This molecule was paired with a cyclopropenium catholyte in a prototype all-organic redox flow battery, achieving a cell potential up to 3 V.
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Affiliation(s)
- Adam R Pancoast
- Department of Chemistry, University of Utah 315 South 1400 East Salt Lake City Utah 84112 USA
- Joint Center for Energy Storage Research 9700 S. Cass Avenue Argonne Illinois 60439 USA
| | - Sara L McCormack
- Department of Chemistry, University of Utah 315 South 1400 East Salt Lake City Utah 84112 USA
- Joint Center for Energy Storage Research 9700 S. Cass Avenue Argonne Illinois 60439 USA
| | - Shelby Galinat
- Department of Chemistry, University of Utah 315 South 1400 East Salt Lake City Utah 84112 USA
| | - Ryan Walser-Kuntz
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor Michigan 48109 USA
- Joint Center for Energy Storage Research 9700 S. Cass Avenue Argonne Illinois 60439 USA
| | - Brianna M Jett
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor Michigan 48109 USA
- Joint Center for Energy Storage Research 9700 S. Cass Avenue Argonne Illinois 60439 USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor Michigan 48109 USA
- Joint Center for Energy Storage Research 9700 S. Cass Avenue Argonne Illinois 60439 USA
| | - Matthew S Sigman
- Department of Chemistry, University of Utah 315 South 1400 East Salt Lake City Utah 84112 USA
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor Michigan 48109 USA
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8
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Horikawa M, Joy ST, Sharninghausen LS, Shao X, Mapp AK, Scott PJH, Sanford MS. C-H radiocyanation of bioactive molecules via sequential iodination/copper-mediated cross-coupling. Chem Sci 2023; 14:12068-12072. [PMID: 37969612 PMCID: PMC10631240 DOI: 10.1039/d3sc03948j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 10/20/2023] [Indexed: 11/17/2023] Open
Abstract
This report describes a net C-H radiocyanation reaction for the transformation of electron rich (hetero)aromatic substrates into 11CN-labeled products. Electrophilic C(sp2)-H iodination of the (hetero)arene with N-iodosuccinimide is followed by Cu-mediated radiocyanation with K11CN. This sequence is applied to a variety of substrates, including the nucleobases uracil and cytosine, the amino acids tyrosine and tryptophan, and the peptide LYRAGWRAFS, which undergoes selective C-H radiocyanation at the tryptophan (W) residue.
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Affiliation(s)
- Mami Horikawa
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor Michigan 48109 USA
| | - Stephen T Joy
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor Michigan 48109 USA
| | - Liam S Sharninghausen
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor Michigan 48109 USA
| | - Xia Shao
- Department of Radiology, University of Michigan 1301 Catherine Ann Arbor Michigan 48109 USA
| | - Anna K Mapp
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor Michigan 48109 USA
| | - Peter J H Scott
- Department of Radiology, University of Michigan 1301 Catherine Ann Arbor Michigan 48109 USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor Michigan 48109 USA
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9
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Jett B, Flynn A, Sigman MS, Sanford MS. Identifying structure-function relationships to modulate crossover in nonaqueous redox flow batteries. J Mater Chem A Mater 2023; 11:22288-22294. [PMID: 38213509 PMCID: PMC10783818 DOI: 10.1039/d3ta02633g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Nonaqueous redox flow batteries (NARFBs) offer a promising solution for large-scale storage of renewable energy. However, crossover of redox active molecules between the two sides of the cell is a major factor limiting their development, as most selective separators are designed for deployment in water, rather than organic solvents. This report describes a systematic investigation of the crossover rates of redox active organic molecules through an anion exchange separator under RFB-relevant non-aqueous conditions (in acetonitrile/KPF6) using a combination of experimental and computational methods. A structurally diverse set of neutral and cationic molecules was selected, and their rates of crossover were determined experimentally with the organic solvent-compatible anion exchange separator Fumasep FAP-375-PP. The resulting data were then fit to various descriptors of molecular size, charge, and hydrophobicity (overall charge, solution diffusion coefficient, globularity, dynamic volume, dynamic surface area, clogP). This analysis resulted in multiple statistical models of crossover rates for this separator. These models were then used to predict tether groups that dramatically slow the crossover of small organic molecules in this system.
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Affiliation(s)
- Brianna Jett
- Department of Chemistry, University of Michigan, 930N University Ave, Ann Arbor, MI 48109, USA
- Joint Center for Energy Storage Research, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - Autumn Flynn
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
- Joint Center for Energy Storage Research, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - Matthew S Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
- Joint Center for Energy Storage Research, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930N University Ave, Ann Arbor, MI 48109, USA
- Joint Center for Energy Storage Research, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
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10
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Hosseini S, Beeler JA, Sanford MS, White HS. Electroorganic synthesis in aqueous solution via generation of strongly oxidizing and reducing intermediates. Faraday Discuss 2023; 247:195-208. [PMID: 37492982 DOI: 10.1039/d3fd00067b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Water is the ideal green solvent for organic electrosynthesis. However, a majority of electroorganic processes require potentials that lie beyond the electrochemical window for water. In general, water oxidation and reduction lead to poor synthetic yields and selectivity or altogether prohibit carrying out a desired reaction. Herein, we report several electroorganic reactions in water using synthetic strategies referred to as reductive oxidation and oxidative reduction. Reductive oxidation involves the homogeneous reduction of peroxydisulfate (S2O82-) via electrogenerated Ru(NH3)62+ at potential of -0.2 V vs. Ag/AgCl (3.5 M KCl) to form the highly oxidizing sulfate radical anion (E0' (SO4˙-/SO42-) = 2.21 V vs. Ag/AgCl), which is capable of oxidizing species beyond the water oxidation potential. Electrochemically generated SO4˙- then efficiently abstracts a hydrogen atom from a variety of organic compounds such as benzyl alcohol and toluene to yield product in water. The reverse analogue of reductive oxidation is oxidative reduction. In this case, the homogeneous oxidation of oxalate (C2O42-) by electrochemically generated Ru(bpy)33+ produces the strongly reducing carbon dioxide radical anion (E0' (CO2˙-/CO2) = -2.1 V vs. Ag/AgCl), which can reduce species at potential beyond the water or proton reduction potential. In preliminary studies, the CO2˙- has been used to homogeneously reduce the C-Br moiety belonging to benzyl bromide at an oxidizing potential in aqueous solution.
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Affiliation(s)
| | - Joshua A Beeler
- Department of Chemistry, University of Utah, 315 S 1400 E Salt Lake City, Utah 84112, USA.
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.
| | - Henry S White
- Department of Chemistry, University of Utah, 315 S 1400 E Salt Lake City, Utah 84112, USA.
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11
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Bunnell A, Lalloo N, Brigham C, Sanford MS. Palladium-Catalyzed Decarbonylative Coupling of (Hetero)Aryl Boronate Esters with Difluorobenzyl Glutarimides. Org Lett 2023; 25:7584-7588. [PMID: 37811852 PMCID: PMC10629228 DOI: 10.1021/acs.orglett.3c03071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
This report describes the Pd-catalyzed decarbonylative coupling of difluorobenzyl glutarimides with (hetero)aryl boronate esters to yield difluorobenzyl-substituted (hetero)arene products. The use of PAd2Bu as the phosphine ligand in combination with neopentylboronate ester nucleophiles proved critical for the selective formation of the decarbonylative coupling product versus analogous difluorobenzyl ketone. This transformation is effective for electronically diverse (hetero)aryl boronate esters and substituted difluorobenzyl glutarimides.
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Affiliation(s)
- Alexander Bunnell
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Naish Lalloo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Conor Brigham
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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12
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Zhang W, Walser-Kuntz R, Tracy JS, Schramm TK, Shee J, Head-Gordon M, Chen G, Helms BA, Sanford MS, Toste FD. Indolo[2,3- b]quinoxaline as a Low Reduction Potential and High Stability Anolyte Scaffold for Nonaqueous Redox Flow Batteries. J Am Chem Soc 2023; 145:18877-18887. [PMID: 37585274 PMCID: PMC10472437 DOI: 10.1021/jacs.3c05210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Indexed: 08/18/2023]
Abstract
Redox flow batteries (RFBs) are a promising stationary energy storage technology for leveling power supply from intermittent renewable energy sources with demand. A central objective for the development of practical, scalable RFBs is to identify affordable and high-performance redox-active molecules as storage materials. Herein, we report the design, synthesis, and evaluation of a new organic scaffold, indolo[2,3-b]quinoxaline, for highly stable, low-reduction potential, and high-solubility anolytes for nonaqueous redox flow batteries (NARFBs). The mixture of 2- and 3-(tert-butyl)-6-(2-methoxyethyl)-6H-indolo[2,3-b]quinoxaline exhibits a low reduction potential (-2.01 V vs Fc/Fc+), high solubility (>2.7 M in acetonitrile), and remarkable stability (99.86% capacity retention over 49.5 h (202 cycles) of H-cell cycling). This anolyte was paired with N-(2-(2-methoxyethoxy)-ethyl)phenothiazine (MEEPT) to achieve a 2.3 V all-organic NARFB exhibiting 95.8% capacity retention over 75.1 h (120 cycles) of cycling.
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Affiliation(s)
- Wenhao Zhang
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Joint
Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Ryan Walser-Kuntz
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Joint
Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Jacob S. Tracy
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Joint
Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Tim K. Schramm
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Chemistry, RWTH Aachen University, Landoltweg 1, Aachen 52074, Germany
| | - James Shee
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Gan Chen
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Brett A. Helms
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Melanie S. Sanford
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Joint
Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - F. Dean Toste
- Chemical
Science Division, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Joint
Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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13
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Blythe IM, Xu J, Fernandez Odell JS, Kampf JW, Bowring MA, Sanford MS. Characterization and Reactivity of Copper(II) and Copper(III) σ-Aryl Intermediates in Aminoquinoline-Directed C-H Functionalization. J Am Chem Soc 2023; 145:18253-18259. [PMID: 37552536 DOI: 10.1021/jacs.3c00914] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Over the past decade, numerous reports have focused on the development and applications of Cu-mediated C-H functionalization reactions; however, to date, little is known about the Cu intermediates involved in these transformations. This paper details the observation and characterization of CuII and CuIII intermediates in aminoquinoline-directed C(sp2)-H functionalization of a fluoroarene substrate. An initial C(sp2)-H activation at CuII occurs at room temperature to afford an isolable anionic cyclometalated CuII complex. This complex undergoes single-electron oxidation with ferrocenium or AgI salts under mild conditions (5 min at room temperature) to afford C(sp2)-C(sp2) or C(sp2)-NO2 coupling products. Spectroscopic studies implicate the formation of a transient diamagnetic CuIII-σ-aryl intermediate that undergoes either (i) a second C(sp2)-H activation at CuIII followed by C-C bond-forming reductive elimination or (ii) reaction with a NO2- nucleophile and C(sp2)-NO2 coupling.
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Affiliation(s)
- Isaac M Blythe
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Jingtong Xu
- Department of Chemistry, Reed College, 3203 Woodstock Boulevard, Portland, Oregon 97202, United States
| | - Joaquin S Fernandez Odell
- Department of Chemistry, Reed College, 3203 Woodstock Boulevard, Portland, Oregon 97202, United States
| | - Jeff W Kampf
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Miriam A Bowring
- Department of Chemistry, Reed College, 3203 Woodstock Boulevard, Portland, Oregon 97202, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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14
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Lalloo N, Brigham CE, Sanford MS. Correction to "Mechanism-Driven Development of Group 10 Metal-Catalyzed Decarbonylative Coupling Reactions". Acc Chem Res 2023. [PMID: 37228006 DOI: 10.1021/acs.accounts.3c00277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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15
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Aguilera EY, Liu EC, Thullen SM, Sanford MS. Transannular Functionalization of Multiple C(sp 3)-H Bonds of Tropane via an Alkene-Bridged Palladium(I) Dimer. Organometallics 2023; 42:627-631. [PMID: 38550877 PMCID: PMC10972606 DOI: 10.1021/acs.organomet.3c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
This communication describes the Pd-catalyzed C(sp3)-H functionalization of a tropane derivative to generate products with functionalization at two (β/γ) or three (β/γ/β) different sites on the alicyclic amine core. These reactions proceed via an initial dehydrogenation to generate an alkene product that can react further to form a Pd(I) alkene-bridged dimer. Functionalization of this dimer affords β/γ/β-functionalized allylic arylation and allylic acetoxylation products.
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Affiliation(s)
- Ellen Y. Aguilera
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - En-Chih Liu
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Scott M. Thullen
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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16
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Walser-Kuntz R, Yan Y, Sigman M, Sanford MS. A Physical Organic Chemistry Approach to Developing Cyclopropenium-Based Energy Storage Materials for Redox Flow Batteries. Acc Chem Res 2023; 56:1239-1250. [PMID: 37094181 DOI: 10.1021/acs.accounts.3c00095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
ConspectusRedox flow batteries (RFBs) represent a promising modality for electrical energy storage. In these systems, energy is stored via paired redox reactions of molecules on opposite sides of an electrochemical cell. Thus, a central objective for the field is to design molecules with the optimal combination of properties to serve as energy storage materials in RFBs. The ideal molecules should undergo reversible redox reactions at relatively high potentials (for the molecule that is oxidized during battery charging, called the catholyte) or low potentials (for the species that is reduced during battery charging, called the anolyte). Furthermore, anolytes and catholytes must be highly soluble in the electrolyte solution and stable to extended electrochemical cycling in all battery-relevant redox states. The ideal candidates would undergo more than one reversible electron transfer event. Finally, the optimal structures should be resistant to crossover through a selective separator in order to maintain isolation of the two sides of the cell. This Account describes our design and optimization of organic molecules for this application. We first provide background for the metrics and experiments used to characterize anolytes/catholytes and to progress them toward deployment in flow batteries. We then use our studies of aminocyclopropenium-based catholytes to illustrate this workflow and approach.We identified tris(dimethylamino) cyclopropenium hexafluorophosphate as a first-generation catholyte for nonaqueous RFBs based on literature reports from the 1970s describing its reversible chemical and electrochemical oxidation. Cyclic voltammetry and electrochemical cycling experiments in acetonitrile/LiPF6 confirmed that this molecule undergoes oxidation at relatively high potential (0.86 V versus ferrocene/ferrocenium) and exhibits moderate stability toward charge-discharge cycling. Replacing the methyl groups with isopropyl substituents led to enhanced cycling stability but poor solubility of the radical dication (<0.1 M in acetonitrile). Solubility was optimized using quantitative structure-property relationship modeling, which predicted derivatives with ≥10-fold enhanced solubility. Cyclopropeniums with 300-500 mV higher redox potentials were identified by replacing one of the dialkylamino substituents with a less electron-donating thioalkyl or aryl group. Multielectron catholytes were developed by creating hybrid structures that contain a di(amino) cyclopropenium conjugated with a phenothiazine moeity. Finally, oligomeric tris(amino) cyclopropeniums were designed as crossover resistant catholytes. Optimization of their solubility enabled the deployment of these oligomers in high concentration asymmetric redox flow batteries with energy densities that are comparable to the state-of-the-art commercial aqueous inorganic systems.
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Affiliation(s)
- Ryan Walser-Kuntz
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - Yichao Yan
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - MatthewS Sigman
- Joint Center for Energy Storage Research (JCESR), 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
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17
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Hall JR, Blythe IM, Sharninghausen LS, Sanford MS. Copper-Mediated Fluoroalkylation of Aryl Bromides and Chlorides Enabled by Directing Groups. Organometallics 2023; 42:543-546. [PMID: 37841393 PMCID: PMC10575473 DOI: 10.1021/acs.organomet.3c00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
This report describes the reactions between N-heterocyclic carbene copper(I) fluoroalkyl complexes and aryl halides bearing ortho-directing groups. Pyridine, pyrazole, oxazoline, imine, and ester directing groups are shown to dramatically enhance the reactivity of aryl bromides and chlorides with (IPr)CuI-fluoroalkyl complexes (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; fluoroalkyl = difluoromethyl and pentafluoroethyl) to afford aryl-fluoroalkyl coupling products. This approach is leveraged to achieve the Cu-catalyzed directed fluoroalkylation of a series of aryl bromide substrates.
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Affiliation(s)
- Jonathan R. Hall
- University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Isaac M. Blythe
- University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Liam S. Sharninghausen
- University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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18
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Webb EW, Cheng K, Wright JS, Cha J, Shao X, Sanford MS, Scott PJH. Room-Temperature Copper-Mediated Radiocyanation of Aryldiazonium Salts and Aryl Iodides via Aryl Radical Intermediates. J Am Chem Soc 2023; 145:6921-6926. [PMID: 36917154 PMCID: PMC10065967 DOI: 10.1021/jacs.3c00422] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Radiocyanation is an attractive strategy for incorporating carbon-11 into radiotracer targets, particularly given the broad scope of acyl moieties accessible from nitriles. Most existing methods for aromatic radiocyanation require elevated temperatures (Cu-mediated reactions of aryl halides or organometallics) or involve expensive and toxic palladium complexes (Pd-mediated reactions of aryl halides). The current report discloses a complementary approach that leverages the capture of aryl radical intermediates by a Cu-11CN complex to achieve rapid and mild (5 min, room temperature) radiocyanation. In a first example, aryl radicals are generated via the reaction of a CuI mediator with an aryldiazonium salt (a Sandmeyer-type reaction) followed by radiocyanation with Cu-11CN. In a second example, aryl radicals are formed from aryl iodides via visible-light photocatalysis and then captured by a Cu-11CN species to achieve aryl-11CN coupling. This approach provides access to radiocyanated products that are challenging to access using other methods (e.g., ortho-disubstituted aryl nitriles).
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Affiliation(s)
- E. William Webb
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Kevin Cheng
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Jay S. Wright
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Jocelyn Cha
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Xia Shao
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Peter J. H. Scott
- Department of Radiology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, Michigan 48109, United States
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19
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Kaur T, Shao X, Horikawa M, Sharninghausen LS, Preshlock S, Brooks AF, Henderson BD, Koeppe RA, DaSilva AF, Sanford MS, Scott PJH. Strategies for the Production of [ 11C]LY2795050 for Clinical Use. Org Process Res Dev 2023; 27:373-381. [PMID: 36874204 PMCID: PMC9983641 DOI: 10.1021/acs.oprd.2c00388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
This report describes a comparison of four different routes for the clinical-scale radiosynthesis of the κ-opioid receptor antagonist [11C]LY2795050. Palladium-mediated radiocyanation and radiocarbonylation of an aryl iodide precursor as well as copper-mediated radiocyanation of an aryl iodide and an aryl boronate ester have been investigated. Full automation of all four methods is reported, each of which provides [11C]LY2795050 in sufficient radiochemical yield, molar activity, and radiochemical purity for clinical use. The advantages and disadvantages of each radiosynthesis method are compared and contrasted.
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Affiliation(s)
- Tanpreet Kaur
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Xia Shao
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Mami Horikawa
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Liam S. Sharninghausen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Sean Preshlock
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Allen F. Brooks
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Bradford D. Henderson
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Robert A. Koeppe
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Alexandre F. DaSilva
- Headache Orofacial Pain Effort (H.O.P.E.), Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Peter J. H. Scott
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
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20
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Abstract
Transition-metal-catalyzed cross-coupling reactions are widely used in both academia and industry for the construction of carbon-carbon and carbon-heteroatom bonds. The vast majority of cross-coupling reactions utilize aryl (pseudo)halides as the electrophilic coupling partner. Carboxylic acid derivatives (RC(O)X) represent a complementary class of electrophiles that can engage in decarbonylative couplings to produce analogous products. This decarbonylative approach offers the advantage that RC(O)X are abundant and inexpensive. In addition, decarbonylative coupling enables both intramolecular (between R and X of the carboxylic acid derivative) as well as intermolecular bond-forming reactions (in which an exogeneous nucleophile is coupled with the R group derived from RC(O)X). In these intermolecular reactions, the X-substituent on the carboxylic acid can be tuned to facilitate both oxidative addition and transmetalation, thus eliminating the need for an exogeneous base. This Account details our group's development of a diverse variety of base-free decarbonylative coupling reactions catalyzed by group 10 metals. Furthermore, it highlights how catalyst design can be guided by stoichiometric organometallic studies of these systems.Our early studies focused on intramolecular decarbonylative couplings that transform RC(O)X to the corresponding R-X with extrusion of CO. We first identified Pd and Ni monodentate phosphine catalysts that convert aryl thioesters (ArC(O)SR) to the corresponding thioethers (ArSR). We next expanded this reactivity to fluoroalkyl thioesters, using readily available fluoroalkyl carboxylic acids as the fluoroalkyl (RF) source. A Ni-phosphinoferrocene catalyst proved optimal, and the large bite angle bidentate ligand was necessary to promote the challenging RF-S bond-forming reductive elimination step.We next pursued intramolecular decarbonylative couplings of aroyl halides. Palladium-based catalysts bearing dialkylbiaryl ligands (e.g., BrettPhos) were identified as optimal for converting aroyl chlorides (ArC(O)Cl) to aryl chlorides (ArCl). These ligands were selected based on their ability to facilitate the key C-Cl bond-forming reductive elimination step of the catalytic cycle. In contrast, all attempts to convert aroyl fluorides [ArC(O)F)] to aryl fluorides (ArF) were unsuccessful with either Pd- or Ni-based catalysts. Organometallic studies of the Ni-system show that C(O)-F oxidative addition and CO deinsertion proceed smoothly, but the resulting nickel(II) aryl fluoride intermediate fails to undergo C-F bond-forming reductive elimination.In contrast to its inertness to reductive elimination, this nickel(II) aryl fluoride proved highly reactive toward transmetalation. The fluoride ligand serves as an internal base, such that no additional base is required. We leveraged this "transmetalation active" intermediate to achieve base-free Ni-catalyzed intermolecular decarbonylative coupling reactions between aroyl fluorides and boron reagents to access both biaryl and aryl-boronate ester products. By tuning the electrophile, transmetalating reagent, and catalyst, this same approach also proved applicable to base-free intermolecular decarbonylative fluoroalkylation (between difluoromethylacetyl fluoride and arylboronate esters) and aryl amination (between phenol esters and silyl amines).Moving forward, a key goal is to identify catalyst systems that enable more challenging bond constructions via this manifold. In addition, CO inhibition remains a major issue leading to the requirement for high temperatures and high catalyst loadings. Identifying catalysts that are resistant to CO binding and/or approaches to remove CO under mild conditions will be critical for making these reactions more practical and scalable.
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Affiliation(s)
- Naish Lalloo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Conor E. Brigham
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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21
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Lasky MR, Salvador TK, Mukhopadhyay S, Remy MS, Vaid TP, Sanford MS. Photochemical C(sp 2 )-H Pyridination via Arene-Pyridinium Electron Donor-Acceptor Complexes. Angew Chem Int Ed Engl 2022; 61:e202208741. [PMID: 36100577 PMCID: PMC9828204 DOI: 10.1002/anie.202208741] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Indexed: 01/12/2023]
Abstract
This report describes the development of a photochemical method for C(sp2 )-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. Experimental and DFT studies show that black light (λmax ≈350 nm) irradiation of solutions of protonated pyridines (acceptors) and aromatic C-H substrates (donors) results in single electron transfer to form aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. With some modification of the reaction conditions, this EDA activation mode is also effective for promoting the oxidatively triggered SN Ar pyridination of aryl halides. Overall, this report represents an inexpensive and atom-economical approach to photochemical pyridination reactions that eliminates the requirement of an exogenous photocatalyst.
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Affiliation(s)
- Matthew R. Lasky
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Tolani K. Salvador
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | | | | | - Thomas P. Vaid
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Melanie S. Sanford
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
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22
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Milbauer MW, Kampf JW, Sanford MS. Nickel(IV) Intermediates in Aminoquinoline-Directed C(sp 2)–C(sp 3) Coupling. J Am Chem Soc 2022; 144:21030-21034. [DOI: 10.1021/jacs.2c10778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Michael W. Milbauer
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Jeff W. Kampf
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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23
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Abstract
We describe the nonaqueous redox-matched flow battery (RMFB), where charge is stored on redox-active moieties covalently tethered to non-circulating, insoluble polymer beads and charge is transferred between the electrodes and the beads via soluble mediators with redox potentials matched to the active moieties on the beads. The RMFB reported herein uses ferrocene and viologen derivatives bound to crosslinked polystyrene beads. Charge storage in the beads leads to a high (approximately 1.0-1.7 M) effective concentration of active material in the reservoirs while preventing crossover of that material. The relatively low concentration of soluble mediators (15 mM) eliminates the need for high-solubility molecules to create high energy density batteries. Nernstian redox exchange between the beads and redox-matched mediators was fast relative to the cycle time of the RMFB. This approach is generalizable to many different redox-active moieties via attachment to the versatile Merrifield resin.
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Affiliation(s)
- Dukhan Kim
- Macromolecular Science and Engineering Program, University of Michigan, 2800 Plymouth Rd, Ann Arbor, Michigan 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, USA
| | - Thomas P Vaid
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, USA
| | - Anne J McNeil
- Macromolecular Science and Engineering Program, University of Michigan, 2800 Plymouth Rd, Ann Arbor, Michigan 48109, USA.,Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, USA
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24
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Sharninghausen LS, Preshlock S, Joy ST, Horikawa M, Shao X, Winton WP, Stauff J, Kaur T, Koeppe RA, Mapp AK, Scott PJH, Sanford MS. Copper-Mediated Radiocyanation of Unprotected Amino Acids and Peptides. J Am Chem Soc 2022; 144:7422-7429. [PMID: 35437016 PMCID: PMC9887455 DOI: 10.1021/jacs.2c01959] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This report describes a copper-mediated radiocyanation of aryl halides that is applicable to complex molecules. This transformation tolerates an exceptionally wide range of functional groups, including unprotected amino acids. As such, it enables the site-specific introduction of [11C]CN into peptides at an iodophenylalanine residue. The use of a diamine-ligated copper(I) mediator is crucial for achieving high radiochemical yield under relatively mild conditions, thus limiting racemization and competing side reactions of other amino acid side chains. The reaction has been scaled and automated to deliver radiolabeled peptides, including analogues of adrenocorticotropic hormone 1-27 (ACTH) and nociceptin (NOP). For instance, this Cu-mediated radiocyanation was leveraged to prepare >40 mCi of [11C]cyano-NOP to evaluate biodistribution in a primate using positron emission tomography. This investigation provides preliminary evidence that nociceptin crosses the blood-brain barrier and shows uptake across all brain regions (SUV > 1 at 60 min post injection), consistent with the known distribution of NOP receptors in the rhesus brain.
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Affiliation(s)
- Liam S. Sharninghausen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Sean Preshlock
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Stephen T. Joy
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Mami Horikawa
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Xia Shao
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Wade P. Winton
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Jenelle Stauff
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Tanpreet Kaur
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Robert A. Koeppe
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Anna K. Mapp
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States,Corresponding Author: Peter J. H. Scott. . Melanie S. Sanford. . Anna K. Mapp.
| | - Peter J. H. Scott
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States,Corresponding Author: Peter J. H. Scott. . Melanie S. Sanford. . Anna K. Mapp.
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States,Corresponding Author: Peter J. H. Scott. . Melanie S. Sanford. . Anna K. Mapp.
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25
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Yan Y, Vogt DB, Vaid TP, Sigman MS, Sanford MS. Development of High Energy Density Diaminocyclopropenium‐Phenothiazine Hybrid Catholytes for Non‐Aqueous Redox Flow Batteries. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yichao Yan
- Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48109 USA
- Joint Center for Energy Storage Research (JCESR) 9700 South Cass Avenue Argonne IL 60439 USA
| | - David B. Vogt
- Department of Chemistry University of Utah 315 South 1400 East Salt Lake City UT 84112 USA
- Joint Center for Energy Storage Research (JCESR) 9700 South Cass Avenue Argonne IL 60439 USA
| | - Thomas P. Vaid
- Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48109 USA
- Joint Center for Energy Storage Research (JCESR) 9700 South Cass Avenue Argonne IL 60439 USA
| | - Matthew S. Sigman
- Department of Chemistry University of Utah 315 South 1400 East Salt Lake City UT 84112 USA
- Joint Center for Energy Storage Research (JCESR) 9700 South Cass Avenue Argonne IL 60439 USA
| | - Melanie S. Sanford
- Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48109 USA
- Joint Center for Energy Storage Research (JCESR) 9700 South Cass Avenue Argonne IL 60439 USA
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26
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Lalloo N, Malapit CA, Taimoory SM, Brigham CE, Sanford MS. Decarbonylative Fluoroalkylation at Palladium(II): From Fundamental Organometallic Studies to Catalysis. J Am Chem Soc 2021; 143:18617-18625. [PMID: 34709804 DOI: 10.1021/jacs.1c08551] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This Article describes the development of a decarbonylative Pd-catalyzed aryl-fluoroalkyl bond-forming reaction that couples fluoroalkylcarboxylic acid-derived electrophiles [RFC(O)X] with aryl organometallics (Ar-M'). This reaction was optimized by interrogating the individual steps of the catalytic cycle (oxidative addition, carbonyl de-insertion, transmetalation, and reductive elimination) to identify a compatible pair of coupling partners and an appropriate Pd catalyst. These stoichiometric organometallic studies revealed several critical elements for reaction design. First, uncatalyzed background reactions between RFC(O)X and Ar-M' can be avoided by using M' = boronate ester. Second, carbonyl de-insertion and Ar-RF reductive elimination are the two slowest steps of the catalytic cycle when RF = CF3. Both steps are dramatically accelerated upon changing to RF = CHF2. Computational studies reveal that a favorable F2C-H---X interaction contributes to accelerating carbonyl de-insertion in this system. Finally, transmetalation is slow with X = difluoroacetate but fast with X = F. Ultimately, these studies enabled the development of an (SPhos)Pd-catalyzed decarbonylative difluoromethylation of aryl neopentylglycol boronate esters with difluoroacetyl fluoride.
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Affiliation(s)
- Naish Lalloo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Christian A Malapit
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - S Maryamdokht Taimoory
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Conor E Brigham
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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27
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Yan Y, Vogt DB, Vaid TP, Sigman MS, Sanford MS. Development of High Energy Density Diaminocyclopropenium-Phenothiazine Hybrid Catholytes for Non-Aqueous Redox Flow Batteries. Angew Chem Int Ed Engl 2021; 60:27039-27045. [PMID: 34672070 DOI: 10.1002/anie.202111939] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Indexed: 11/08/2022]
Abstract
This report describes the design of diaminocyclopropenium-phenothiazine hybrid catholytes for non-aqueous redox flow batteries. The molecules are synthesized in a rapid and modular fashion by appending a diaminocyclopropenium (DAC) substituent to the nitrogen of the phenothiazine. Combining a versatile C-N coupling protocol (which provides access to diverse derivatives) with computation and structure-property analysis enabled the identification of a catholyte that displays stable two-electron cycling at potentials of 0.64 and 1.00 V vs. Fc/Fc+ as well as high solubility in all oxidation states (≥0.45 M in TBAPF6 /MeCN). This catholyte was deployed in a high energy density two-electron RFB, exhibiting >90 % capacity retention over 266 hours of flow cell cycling at >0.5 M electron concentration.
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Affiliation(s)
- Yichao Yan
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - David B Vogt
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT, 84112, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Thomas P Vaid
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Matthew S Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT, 84112, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, IL, 60439, USA
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28
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Lee SJ, Morales-Colón MT, Brooks AF, Wright JS, Makaravage KJ, Scott PJH, Sanford MS. S NAr Radiofluorination with In Situ Generated [ 18F]Tetramethylammonium Fluoride. J Org Chem 2021; 86:14121-14130. [PMID: 34505779 DOI: 10.1021/acs.joc.1c01491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This report describes a method for the nucleophilic radiofluorination of (hetero)aryl chlorides, (hetero)aryl triflates, and nitroarenes using a combination of [18F]KF·K2.2.2 and Me4NHCO3 for the in situ formation of a strongly nucleophilic fluorinating reagent (proposed to be [18F]Me4NF). This method is applied to 24 substrates bearing diverse functional groups, and it generates [18F](hetero)aryl fluoride products in good to excellent radiochemical yields in the presence of ambient air/moisture. The reaction is applied to the preparation of 18F-labeled HQ-415 for potential (pre)clinical use.
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Affiliation(s)
- So Jeong Lee
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States.,Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114,United States
| | - María T Morales-Colón
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Katarina J Makaravage
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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29
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Roy P, Bour JR, Kampf JW, Sanford MS. Correction to "Catalytically Relevant Intermediates in the Ni-Catalyzed C(sp 2)-H and C(sp 3)-H Functionalization of Aminoquinoline Substrates". J Am Chem Soc 2021; 143:14021. [PMID: 34406753 DOI: 10.1021/jacs.1c07700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Yan Y, Robinson SG, Vaid TP, Sigman MS, Sanford MS. Simultaneously Enhancing the Redox Potential and Stability of Multi-Redox Organic Catholytes by Incorporating Cyclopropenium Substituents. J Am Chem Soc 2021; 143:13450-13459. [PMID: 34387084 DOI: 10.1021/jacs.1c07237] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High redox potential, two-electron organic catholytes for nonaqueous redox flow batteries were developed by appending diaminocyclopropenium (DAC) substituents to phenazine and phenothiazine cores. The parent heterocycles exhibit two partially reversible oxidations at moderate potentials [both at lower than 0.7 V vs ferrocene/ferrocenium (Fc/Fc+)]. The incorporation of DAC substituents has a dual effect on these systems. The DAC groups increase the redox potential of both couples by ∼300 mV while simultaneously rendering the second oxidation (which occurs at 1.20 V vs Fc/Fc+ in the phenothiazine derivative) reversible. The electron-withdrawing nature of the DAC unit is responsible for the increase in redox potential, while the DAC substituents stabilize oxidized forms of the molecules through resonance delocalization of charge and unpaired spin density. These new catholytes were deployed in two-electron redox flow batteries that exhibit voltages of up to 2.0 V and no detectable crossover over 250 cycles.
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Affiliation(s)
- Yichao Yan
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Sophia G Robinson
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Thomas P Vaid
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Matthew S Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.,Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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31
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Duran-Camacho G, Ferguson DM, Kampf JW, Bland DC, Sanford MS. Isolable Pyridinium Trifluoromethoxide Salt for Nucleophilic Trifluoromethoxylation. Org Lett 2021; 23:5138-5142. [PMID: 34139121 DOI: 10.1021/acs.orglett.1c01664] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An isolable pyridinium trifluoromethoxide salt is prepared from the reaction of 4-dimethylaminopyridine with the commercially available liquid 2,4-dinitro(trifluoromethoxy)benzene. The salt is an effective trifluoromethoxide source for SN2 reactions to form trifluoromethyl ethers.
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Affiliation(s)
- Geraldo Duran-Camacho
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Devin M Ferguson
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Jeff W Kampf
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Douglas C Bland
- Product & Process Technology R&D, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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32
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Mantell MA, Lasky MR, Lee M, Remy M, Sanford MS. S NAr and C-H Amination of Electron Rich Arenes with Pyridine as a Nucleophile Using Photoredox Catalysis. Org Lett 2021; 23:5213-5217. [PMID: 34161730 DOI: 10.1021/acs.orglett.1c01749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This report describes the development of two photocatalytic methods for the pyridination of electron rich arenes. First, an SNAr-type reaction between aryl halides and pyridine is developed and optimized. This transformation affords selective substitution of C(sp2)-halogen over C(sp2)-OR bonds to afford arylpyridinium products under anaerobic conditions. Under complementary aerobic conditions, analogous substrates are shown to undergo oxidative C(sp2)-H pyridination.
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Affiliation(s)
- Mark A Mantell
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew R Lasky
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melissa Lee
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew Remy
- Corporate R&D, Dow, 1710 Building, Midland, Michigan 48667, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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33
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Abstract
Nucleophilic aromatic fluorination (SNAr) is among the most common methods for the formation of C(sp2)-F bonds. Despite many recent advances, a long-standing limitation of these transformations is the requirement for rigorously dry, aprotic conditions to maintain the nucleophilicity of fluoride and suppress the generation of side products. This report addresses this challenge by leveraging tetramethylammonium fluoride alcohol adducts (Me4NF·ROH) as fluoride sources for SNAr fluorination. Through systematic tuning of the alcohol substituent (R), tetramethylammonium fluoride tert-amyl alcohol (Me4NF·t-AmylOH) was identified as an inexpensive, practical, and bench-stable reagent for SNAr fluorination under mild and convenient conditions (80 °C in DMSO, without the requirement for drying of reagents or solvent). A substrate scope of more than 50 (hetero) aryl halides and nitroarene electrophiles is demonstrated.
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Affiliation(s)
- María T Morales-Colón
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Yi Yang See
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - So Jeong Lee
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Douglas C Bland
- Process Sciences & Technology, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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34
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Wright JS, Sharninghausen LS, Preshlock S, Brooks AF, Sanford MS, Scott PJH. Sequential Ir/Cu-Mediated Method for the Meta-Selective C-H Radiofluorination of (Hetero)Arenes. J Am Chem Soc 2021; 143:6915-6921. [PMID: 33914521 DOI: 10.1021/jacs.1c00523] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This article describes a sequential Ir/Cu-mediated process for the meta-selective C-H radiofluorination of (hetero)arene substrates. In the first step, Ir-catalyzed C(sp2)-H borylation affords (hetero)aryl pinacolboronate (BPin) esters. The intermediate organoboronates are then directly subjected to copper-mediated radiofluorination with [18F]tetrabutylammonium fluoride to afford fluorine-18 labeled (hetero)arenes in high radiochemical yield and radiochemical purity. This entire process is performed on a benchtop without Schlenk or glovebox techniques and circumvents the need to isolate (hetero)aryl boronate esters. The reaction was automated on a TracerLab FXFN module with 1,3-dimethoxybenzene and a meta-tyrosine derivative. The products, [18F]1-fluoro-3,5-dimethoxybenzene and an 18F-labeled meta-tyrosine derivative, were obtained in 37 ± 5% isolated radiochemical yield and >99% radiochemical purity and 25% isolated radiochemical yield and 99% radiochemical purity, and 0.52 Ci/μmol (19.24 GBq/μmol) molar activity (Am), respectively.
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Affiliation(s)
- Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Liam S Sharninghausen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Sean Preshlock
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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35
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Aguilera EY, Sanford MS. Palladium‐Mediated C
γ
−H Functionalization of Alicyclic Amines. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ellen Y. Aguilera
- Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48109 USA
| | - Melanie S. Sanford
- Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48109 USA
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36
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Aguilera EY, Sanford MS. Palladium-Mediated C γ -H Functionalization of Alicyclic Amines. Angew Chem Int Ed Engl 2021; 60:11227-11230. [PMID: 33720500 DOI: 10.1002/anie.202101782] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/11/2021] [Indexed: 01/01/2023]
Abstract
This paper describes a new method for the transannular functionalization of the γ-C-H bonds in alicyclic amines to install C(sp3 )-halogen, oxygen, nitrogen, boron, and sulfur bonds. The key challenge for this transformation is controlling the relative rate of Cγ -H versus Cα -H functionalization. We demonstrate that this selectivity can be achieved by pre-complexation of the substrate with Pd prior to the addition of oxidant. This approach enables the use of diverse oxidants that ultimately install various heteroatom functional groups at the γ-position with high site- and diastereoselectivity.
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Affiliation(s)
- Ellen Y Aguilera
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
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37
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Tanzey SS, Mossine AV, Sowa AR, Torres J, Brooks AF, Sanford MS, Scott PJH. A spot test for determination of residual TBA levels in 18F-radiotracers for human use using Dragendorff reagent. Anal Methods 2020; 12:5004-5009. [PMID: 33000785 DOI: 10.1039/d0ay01565b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
When utilizing [18F]tetrabutylammonium fluoride ([18F]TBAF) in the synthesis of 18F-labeled radiotracers for clinical positron emission tomography (PET) imaging, it is necessary to confirm that residual TBA levels in formulated doses do not exceed established specifications (≤2.6 mg per patient dose). Historically this has been accomplished using HPLC, but this is time consuming for short-lived PET radiotracers and limited by the need for expensive equipment. This motivated us to introduce a TLC spot test for determining residual TBA, and we have developed a new method which employs the Dragendorff reagent. Herein we report details of the TLC method and use it to quantify residual TBA in different formulations of 6-[18F]fluoro-DOPA.
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Affiliation(s)
- Sean S Tanzey
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA.
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38
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Abstract
The identification of reliable, general, and high yielding methods for the formation of C(sp2)-fluorine bonds remains a major challenge for synthetic organic chemists. A very common approach involves nucleophilic aromatic fluorination (SNAr fluorination) reactions of aryl chlorides or nitroarenes. Despite being known for more than a century, traditional SNAr fluorination reactions suffer from significant limitations, particularly on a process scale. These include the high cost of common reagents [e.g., cesium fluoride (CsF)], a requirement for elevated temperatures and long reaction times, poor functional group tolerance, and the need for rigorous exclusion of water. This Account summarizes our collaboration with Corteva Agriscience (previously Dow Agrosciences) to address many of these challenges. This collaboration has provided a platform for fundamental scientific advances involving the development of new methods, reagents, and substrates for mild and high yielding nucleophilic fluorination reactions.Our early studies established that the combination of potassium fluoride (KF) and superstoichiometric tetrabutylammonium chloride (Bu4NCl) serves as a cost-effective alternative to CsF for the SNAr fluorination of chloropicolinate substrates. However, these reactions still require elevated temperatures (>130 °C) and afford moderate yields due to competing decomposition of the substrate and product. The need for high temperature is largely due to slow reaction rates resulting from the low concentration of the active fluorinating reagent [anhydrous tetrabutylammonium fluoride (Bu4NF)] under these conditions. To address this issue, we developed several strategies for generating high concentration solutions of anhydrous tetraalkylammonium fluoride in situ by combining fluorine-containing electrophiles (e.g., hexafluorobenzene, acyl fluorides, sulfonyl fluorides) with tetraalkylammonium nucleophiles (R4NCN or R4NOR). These systems enable SNAr fluorination under unusually mild conditions, affording nearly quantitative yield with chloropicolinate substrates at room temperature. However, the high cost of the electrophiles and the generation of large quantities of byproducts in the R4NF-forming step render this approach unsuitable for process scale applications. As an alternative, we next explored anhydrous tetramethylammonium fluoride (Me4NF) for these transformations. This highly reactive fluoride source can be synthesized directly from inexpensive KF and Me4NCl and then dried by heating under vacuum. Unlike Bu4NF, it is not susceptible to Hofmann elimination. As such, anhydrous Me4NF is stable and isolable, as well as highly effective for the room temperature SNAr fluorination of chloropicolinates and other electron deficient substrates.The studies with anhydrous R4NF drew our attention to another challenge associated with traditional SNAr fluorination reactions: their limitation to substrates bearing resonance electron-withdrawing groups. We hypothesized that this challenge could be addressed by circumventing the Meisenheimer intermediate, a canonical mechanistic feature of SNAr fluorination. By designing reactions that involve an alternative concerted delivery of the fluoride to the ipso C(sp2) center, we developed a deoxyfluorination of arylfluorosulfonates using anhydrous Me4NF. This reaction exhibits a broad scope with respect to the aryl electrophile, with substrates bearing both electron-withdrawing (CN, ester, CF3, Cl) and moderately electron donating (phenyl, alkyl) substituents participating in deoxyfluorination. These deoxyfluorination conditions were also expanded to nonaromatic substrates, including aldehydes and benzylic/aliphatic alcohols.This Account concludes by delineating several ongoing challenges and opportunities in this fast-moving field. For instance, one important future direction will be to address the high moisture sensitivity of these transformations. In addition, the application of these new reagents and methods in the synthesis of pharmaceuticals, agrochemicals, and PET imaging agents will continue to test the versatility and functional group compatibility of these methods.
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Affiliation(s)
- Yi Yang See
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - María T. Morales-Colón
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Douglas C. Bland
- Product and Process Technology R&D, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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39
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Yan Y, Vaid TP, Sanford MS. Bis(diisopropylamino)cyclopropenium-arene Cations as High Oxidation Potential and High Stability Catholytes for Non-aqueous Redox Flow Batteries. J Am Chem Soc 2020; 142:17564-17571. [DOI: 10.1021/jacs.0c07464] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Yichao Yan
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Thomas P. Vaid
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Joint Center for Energy Storage Research (JCESR), 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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40
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Abstract
This report describes the development of a nickel-catalyzed decarbonylative reaction for the synthesis of fluoroalkyl thioethers (RFSR) from the corresponding thioesters. Readily available, inexpensive, and stable fluoroalkyl carboxylic acids (RFCO2H) serve as the fluoroalkyl (RF) source in this transformation. Stoichiometric organometallic studies reveal that RF-S bond-forming reductive elimination is a challenging step in the catalytic cycle. This led to the identification of diphenylphosphinoferrocene as the optimal ligand for this transformation. Ultimately, this method was applied to the construction of diverse fluoroalkyl thioethers (RFSR), with R = both aryl and alkyl.
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Affiliation(s)
- Conor E. Brigham
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Christian A. Malapit
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Naish Lalloo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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41
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42
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Affiliation(s)
- Melanie S. Sanford
- University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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43
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Wright JS, Kaur T, Preshlock S, Tanzey SS, Winton WP, Sharninghausen LS, Wiesner N, Brooks AF, Sanford MS, Scott PJH. Copper-Mediated Late-stage Radiofluorination: Five Years of Impact on Pre-clinical and Clinical PET Imaging. Clin Transl Imaging 2020; 8:167-206. [PMID: 33748018 DOI: 10.1007/s40336-020-00368-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Purpose Copper-mediated radiofluorination (CMRF) is emerging as the method of choice for the formation of aromatic C-18F bonds. This minireview examines proof-of-concept, pre-clinical, and in-human imaging studies of new and established imaging agents containing aromatic C-18F bonds synthesized with CMRF. An exhaustive discussion of CMRF methods is not provided, although key developments that have enabled or improved upon the syntheses of fluorine-18 imaging agents are discussed. Methods A comprehensive literature search from April 2014 onwards of the Web of Science and PubMed library databases was performed to find reports that utilize CMRF for the synthesis of fluorine-18 radiopharmaceuticals, and these represent the primary body of research discussed in this minireview. Select conference proceedings, previous reports describing alternative methods for the synthesis of imaging agents, and preceding fluorine-19 methodologies have also been included for discussion. Conclusions CMRF has significantly expanded the chemical space that is accessible to fluorine-18 radiolabeling with production methods that can meet the regulatory requirements for use in Nuclear Medicine. Furthermore, it has enabled novel and improved syntheses of radiopharmaceuticals and facilitated subsequent PET imaging studies. The rapid adoption of CMRF will undoubtedly continue to simplify the production of imaging agents and inspire the development of new radiofluorination methodologies.
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Affiliation(s)
- Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tanpreet Kaur
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sean Preshlock
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sean S Tanzey
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wade P Winton
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Nicholas Wiesner
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
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Mossine AV, Tanzey SS, Brooks AF, Makaravage KJ, Ichiishi N, Miller JM, Henderson BD, Erhard T, Bruetting C, Skaddan MB, Sanford MS, Scott PJH. Synthesis of high-molar-activity [ 18F]6-fluoro-L-DOPA suitable for human use via Cu-mediated fluorination of a BPin precursor. Nat Protoc 2020; 15:1742-1759. [PMID: 32269382 PMCID: PMC7333241 DOI: 10.1038/s41596-020-0305-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/27/2020] [Indexed: 11/09/2022]
Abstract
[18F]6-fluoro-L-DOPA ([18F]FDOPA) is a diagnostic radiopharmaceutical for positron emission tomography (PET) imaging that is used to image Parkinson's disease, brain tumors, and focal hyperinsulinism of infancy. Despite these important applications, [18F]FDOPA PET remains underutilized because of synthetic challenges associated with accessing the radiotracer for clinical use; these stem from the need to radiofluorinate a highly electron-rich catechol ring in the presence of an amino acid. To address this longstanding challenge in the PET radiochemistry community, we have developed a one-pot, two-step synthesis of high-molar-activity [18F]FDOPA by Cu-mediated fluorination of a pinacol boronate (BPin) precursor. The method is fully automated, has been validated to work well at two separate sites (an academic facility with a cyclotron on site and an industry lab purchasing [18F]fluoride from an outside vendor), and provides [18F]FDOPA in reasonable radiochemical yield (2.44 ± 0.70 GBq, 66 ± 19 mCi, 5 ± 1%), excellent radiochemical purity (>98%) and high molar activity (76 ± 30 TBq/mmol, 2,050 ± 804 Ci/mmol), n = 26. Herein we report a detailed protocol for the synthesis of [18F]FDOPA that has been successfully implemented at two sites and validated for production of the radiotracer for human use.
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Affiliation(s)
- Andrew V Mossine
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
- Curium Pharma, Nuclear Medicine Manufacturing, Noblesville, IN, USA
| | - Sean S Tanzey
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Katarina J Makaravage
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Cambridge, MA, USA
| | - Naoko Ichiishi
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
- Takeda Pharmaceuticals International Co., Process Chemistry, Boston, MA, USA
| | - Jason M Miller
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
- Environmental Analysis Branch, US Army Corps of Engineers, Detroit, MI, USA
| | | | - Thomas Erhard
- AbbVie Deustschland GmbH & Co. KG Ludwigschafen, Ludwigshafen, Germany
| | | | | | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA.
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Shrestha A, Hendriks KH, Sigman MS, Minteer SD, Sanford MS. Realization of an Asymmetric Non‐Aqueous Redox Flow Battery through Molecular Design to Minimize Active Species Crossover and Decomposition. Chemistry 2020; 26:5369-5373. [DOI: 10.1002/chem.202000749] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Anuska Shrestha
- Joint Center for Energy Storage Research Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48104 USA
| | - Koen H. Hendriks
- Joint Center for Energy Storage Research Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48104 USA
| | - Mathew S. Sigman
- Joint Center for Energy Storage Research Department of Chemistry University of Utah 315 South 1400 East Salt Lake City UT 84112 USA
| | - Shelley D. Minteer
- Joint Center for Energy Storage Research Department of Chemistry University of Utah 315 South 1400 East Salt Lake City UT 84112 USA
| | - Melanie S. Sanford
- Joint Center for Energy Storage Research Department of Chemistry University of Michigan 930 North University Avenue Ann Arbor MI 48104 USA
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Sharninghausen LS, Brooks AF, Winton WP, Makaravage KJ, Scott PJH, Sanford MS. NHC-Copper Mediated Ligand-Directed Radiofluorination of Aryl Halides. J Am Chem Soc 2020; 142:7362-7367. [PMID: 32250612 DOI: 10.1021/jacs.0c02637] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
[18F]-labeled aryl fluorides are widely used as radiotracers for positron emission tomography (PET) imaging. Aryl halides (ArX) are particularly attractive precursors to these radiotracers, as they are readily available, inexpensive, and stable. However, to date, the direct preparation of [18F]-aryl fluorides from aryl halides remains limited to SNAr reactions between highly activated ArX substrates and K18F. This report describes an aryl halide radiofluorination reaction in which the C(sp2)-18F bond is formed via a copper-mediated pathway. Copper N-heterocyclic carbene complexes serve as mediators for this transformation, using aryl halide substrates with directing groups at the ortho position. This reaction is applied to the radiofluorination of electronically diverse aryl halide derivatives, including the bioactive molecules vismodegib and PH089.
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Affiliation(s)
- Liam S Sharninghausen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Allen F Brooks
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Wade P Winton
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Katarina J Makaravage
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Affiliation(s)
- Yi Yang See
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Abstract
The reaction of carboxylic acid derivatives with amines to form amide bonds has been the most widely used transformation in organic synthesis over the past century. Its utility is driven by the broad availability of the starting materials as well as the kinetic and thermodynamic driving force for amide bond formation. As such, the invention of new reactions between carboxylic acid derivatives and amines that strategically deviate from amide bond formation remains both a challenge and an opportunity for synthetic chemists. This report describes the development of a nickel-catalyzed decarbonylative reaction that couples (hetero)aromatic esters with a broad scope of amines to form (hetero)aryl amine products. The successful realization of this transformation was predicated on strategic design of the cross-coupling partners (phenol esters and silyl amines) to preclude conventional reactivity that forms inert amide byproducts.
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Affiliation(s)
- Christian A Malapit
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Margarida Borrell
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Michael W Milbauer
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Conor E Brigham
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Sanford MS, Chiu P, Kozlowski MC, Puchlopek-Dermenci ALA. Celebrating Women in Organic Chemistry. J Org Chem 2020; 85:1769-1772. [DOI: 10.1021/acs.joc.0c00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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