1
|
Zhou D, Chu W, Chen H, Xu J. Exploration of Directing-Group-Assisted, Copper-Mediated Radiofluorination and Radiosynthesis of [ 18F]Olaparib. ACS Med Chem Lett 2024; 15:116-122. [PMID: 38229754 PMCID: PMC10788942 DOI: 10.1021/acsmedchemlett.3c00465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/08/2023] [Accepted: 12/13/2023] [Indexed: 01/18/2024] Open
Abstract
Copper-mediated radiofluorination (CMRF) of organoboronic precursors is the method of choice for late-stage radiofluorination of aromatic compounds as positron emission tomography (PET) radiotracers. However, CMRF generally requires harsh reaction conditions, a large amount of substrates, and harsh solvents (e.g., DMA) to proceed, affording variable radiochemical yields (RCYs). Using [18F]tosyl fluoride as the source of [18F]fluoride, we have found a highly efficient CMRF of organoboronic precursors, assisted by a directing group (DG) at the ortho position. The reaction can be carried out under mild conditions (even at room temperature) in acetonitrile and results in high RCYs, providing a novel strategy for the radiofluorination of aromatic compounds. The exploration of this strategy also provided more information about side reactions in CMRF. Using this strategy, [18F]olaparib has been radiosynthesized in high RCYs, with high molar activity and high chemical and radiochemical purities, demonstrating the great potential of DG-assisted CMRF in the preparation of 18F-labeled PET radiotracers.
Collapse
Affiliation(s)
- Dong Zhou
- Department of Radiology, School of
Medicine, Washington University in Saint
Louis, Saint Louis, Missouri 63110, United States
| | - Wenhua Chu
- Department of Radiology, School of
Medicine, Washington University in Saint
Louis, Saint Louis, Missouri 63110, United States
| | - Huaping Chen
- Department of Radiology, School of
Medicine, Washington University in Saint
Louis, Saint Louis, Missouri 63110, United States
| | - Jinbin Xu
- Department of Radiology, School of
Medicine, Washington University in Saint
Louis, Saint Louis, Missouri 63110, United States
| |
Collapse
|
2
|
O’Reilly RJ, Karton A. A Systematic Exploration of B-F Bond Dissociation Enthalpies of Fluoroborane-Type Molecules at the CCSD(T)/CBS Level. Molecules 2023; 28:5707. [PMID: 37570677 PMCID: PMC10420309 DOI: 10.3390/molecules28155707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
Fluoroborane-type molecules (R1R2B-F) are of interest in synthetic chemistry, but to date, apart from a handful of small species (such as H2BF, HBF2, and BF3), little is known concerning the effect of substituents in governing the strength of the B-F bonds of such species toward homolytic dissociation in the gas phase. In this study, we have calculated the bond dissociation enthalpies (BDEs) of thirty unique B-F bonds at the CCSD(T)/CBS level using the high-level W1w thermochemical protocol. The B-F bonds in all species considered are very strong, ranging from 545.9 kJ mol-1 in (H2B)2B-F to 729.2 kJ mol-1 HBF2. Nevertheless, these BDEs still vary over a wide range of 183.3 kJ mol-1. The structural properties that affect the BDEs are examined in detail, and the homolytic BDEs are rationalized based on molecule stabilization enthalpies and radical stabilization enthalpies. Since polar B-F bonds may represent a challenging test case for density functional theory (DFT) methods, we proceed to examine the performance of a wide range of DFT methods across the rungs of Jacob's Ladder for their ability to compute B-F BDEs. We find that only a handful of DFT methods can reproduce the CCSD(T)/CBS BDEs with mean absolute deviations (MADs) below the threshold of chemical accuracy (i.e., with average deviations below 4.2 kJ mol-1). The only functionals capable of achieving this feat were (MADs given in parentheses): ωB97M-V (4.0), BMK (3.5), DSD-BLYP (3.8), and DSD-PBEB95 (1.8 kJ mol-1).
Collapse
Affiliation(s)
- Robert J. O’Reilly
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia
| | - Amir Karton
- School of Science and Technology, University of New England, Armidale, NSW 2351, Australia
| |
Collapse
|
3
|
Kirschner S, Peters M, Yuan K, Uzelac M, Ingleson MJ. Developing organoboranes as phase transfer catalysts for nucleophilic fluorination using CsF. Chem Sci 2022; 13:2661-2668. [PMID: 35340859 PMCID: PMC8890113 DOI: 10.1039/d2sc00303a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/09/2022] [Indexed: 12/05/2022] Open
Abstract
Despite the general high fluorophilicity of boron, organoboranes such as BEt3 and 3,5-(CF3)2C6H3–BPin are shown herein for the first time, to our knowledge, to be effective (solid to solution) phase-transfer catalysts for the fluorination of certain organohalides with CsF. Significant (up to 30% e.e.) chiral induction during nucleophilic fluorination to form β-fluoroamines using oxazaborolidine (pre)catalysts and CsF also can be achieved. Screening different boranes revealed a correlation between calculated fluoride affinity of the borane and nucleophilic fluorination reactivity, with sufficient fluoride affinity required for boranes to react with CsF and form Cs[fluoroborate] salts, but too high a fluoride affinity leading to fluoroborates that are poor at transferring fluoride to an electrophile. Fluoride affinity is only one component controlling reactivity in this context; effective fluorination also is dependent on the ligation of Cs+ which effects both the phase transfer of CsF and the magnitude of the [Cs⋯F-BR3] interaction and thus the B–F bond strength. Effective ligation of Cs+ (e.g. by [2.2.2]-cryptand) facilitates phase transfer of CsF by the borane but also weakens the Cs⋯F–B interaction which in turn strengthens the B–F bond – thus disfavouring fluoride transfer to an electrophile. Combined, these findings indicate that optimal borane mediated fluorination occurs using robust (to the fluorination conditions) boranes with fluoride affinity of ca. 105 kJ mol−1 (relative to Me3Si+) under conditions where a signficant Cs⋯F–B interaction persists. Simple boranes with the optimal fluoride ion affinity are effective as catalysts for phase transfer nucleophilic fluorination with CsF.![]()
Collapse
Affiliation(s)
- Sven Kirschner
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Matthew Peters
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Kang Yuan
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Marina Uzelac
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| | - Michael J Ingleson
- EaStCHEM School of Chemistry, The University of Edinburgh David Brewster Road Edinburgh EH9 3FJ UK
| |
Collapse
|
4
|
Zhu W, Zhen X, Wu J, Cheng Y, An J, Ma X, Liu J, Qin Y, Zhu H, Xue J, Jiang X. Catalytic asymmetric nucleophilic fluorination using BF 3·Et 2O as fluorine source and activating reagent. Nat Commun 2021; 12:3957. [PMID: 34172752 PMCID: PMC8233348 DOI: 10.1038/s41467-021-24278-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 06/09/2021] [Indexed: 01/16/2023] Open
Abstract
Fluorination using chiral catalytic methods could result in a direct access to asymmetric fluorine chemistry. However, challenges in catalytic asymmetric fluorinations, especially the longstanding stereochemical challenges existed in BF3·Et2O-based fluorinations, have not yet been addressed. Here we report the catalytic asymmetric nucleophilic fluorination using BF3·Et2O as the fluorine reagent in the presence of chiral iodine catalyst. Various chiral fluorinated oxazine products were obtained with good to excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >20:1 dr). Control experiments (the desired fluoro-oxazines could not be obtained when Py·HF or Et3N·3HF were employed as the fluorine source) indicated that BF3·Et2O acted not only as a fluorine reagent but also as the activating reagent for activation of iodosylbenzene. Catalytic asymmetric fluorination remains elusive, especially the longstanding stereochemical challenges which exist in BF3Et2O-based fluorinations. Here the authors show a catalytic asymmetric nucleophilic fluorination using BF3·Et2O as the fluorine reagent in the presence of chiral iodine catalyst.
Collapse
Affiliation(s)
- Weiwei Zhu
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Xiang Zhen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, China
| | - Jingyuan Wu
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yaping Cheng
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Junkai An
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, China
| | - Xingyu Ma
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jikun Liu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, China
| | - Yuji Qin
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Hao Zhu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, China
| | - Jijun Xue
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, China
| | - Xianxing Jiang
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China.
| |
Collapse
|
5
|
Ton NNH, Mai BK, Nguyen TV. Tropylium-Promoted Hydroboration Reactions: Mechanistic Insights Via Experimental and Computational Studies. J Org Chem 2021; 86:9117-9133. [PMID: 34134487 DOI: 10.1021/acs.joc.1c01208] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydroboration reaction of alkynes is one of the most synthetically powerful tools to access organoboron compounds, versatile precursors for cross-coupling chemistry. This type of reaction has traditionally been mediated by transition-metal or main group catalysts. Herein, we report a novel method using tropylium salts, typically known as organic oxidants and Lewis acids, to promote the hydroboration reaction of alkynes. A broad range of vinylboranes can be easily accessed via this metal-free protocol. Similar hydroboration reactions of alkenes and epoxides can also be efficiently catalyzed by the same tropylium catalysts. Experimental studies and DFT calculations suggested that the reaction follows an uncommon mechanistic pathway, which is triggered by the hydride abstraction of pinacolborane with tropylium ion. This is followed by a series of in situ counterion-activated substituent exchanges to generate boron intermediates that promote the hydroboration reaction.
Collapse
Affiliation(s)
- Nhan N H Ton
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Thanh Vinh Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| |
Collapse
|
6
|
Remete AM, Kiss L. Synthesis of Fluorine-Containing Molecular Entities Through Fluoride Ring Opening of Oxiranes and Aziridines. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Attila Márió Remete
- Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
- Interdisciplinary Excellence Centre; Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
| | - Loránd Kiss
- Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
- Interdisciplinary Excellence Centre; Institute of Pharmaceutical Chemistry; University of Szeged; Eötvös u. 6 6720 Szeged Hungary
| |
Collapse
|
7
|
Agahi R, Challinor AJ, Carter NB, Thomas SP. Earth-Abundant Metal Catalysis Enabled by Counterion Activation. Org Lett 2019; 21:993-997. [PMID: 30714742 DOI: 10.1021/acs.orglett.8b03986] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A precatalyst activation strategy has been developed for earth-abundant metal catalysis enabled by counterion dissociation and demonstrated through alkene hydroboration. Commercially available iron and cobalt tetrafluoroborate salts were found to catalyze the hydroboration of aryl and alkyl alkenes with good functional group tolerance (Fe, 12 substrates; Co, 13 substrates) with three structurally distinct ligands. Key to this endogenous activation was counterion dissociation to generate fluoride which indirectly activates the precatalyst by reaction with pinacol borane.
Collapse
Affiliation(s)
- Riaz Agahi
- EaStCHEM School of Chemistry , University of Edinburgh , David Brewster Road , Edinburgh , EH9 3FJ , U.K
| | - Amy J Challinor
- EaStCHEM School of Chemistry , University of Edinburgh , David Brewster Road , Edinburgh , EH9 3FJ , U.K
| | - Neil B Carter
- Syngenta , Jealott's Hill International Research Centre , Bracknell , Berkshire RG42 6EX , U.K
| | - Stephen P Thomas
- EaStCHEM School of Chemistry , University of Edinburgh , David Brewster Road , Edinburgh , EH9 3FJ , U.K
| |
Collapse
|
8
|
Kuehn L, Stang M, Würtemberger-Pietsch S, Friedrich A, Schneider H, Radius U, Marder TB. FBpin and its adducts and their role in catalytic borylations. Faraday Discuss 2019; 220:350-363. [DOI: 10.1039/c9fd00053d] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluoride ion plays a dual role in both metal-catalysed and metal-free borylation reactions by activating B2pin2 and trapping Lewis acidic FBpin.
Collapse
Affiliation(s)
- Laura Kuehn
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Martin Stang
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Sabrina Würtemberger-Pietsch
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Heidi Schneider
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Udo Radius
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Todd B. Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| |
Collapse
|
9
|
Wang L, Lear JM, Rafferty SM, Fosu SC, Nagib DA. Ketyl radical reactivity via atom transfer catalysis. Science 2018; 362:225-229. [PMID: 30309953 PMCID: PMC6504239 DOI: 10.1126/science.aau1777] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/13/2018] [Indexed: 11/02/2022]
Abstract
Single-electron reduction of a carbonyl to a ketyl enables access to a polarity-reversed platform of reactivity for this cornerstone functional group. However, the synthetic utility of the ketyl radical is hindered by the strong reductants necessary for its generation, which also limit its reactivity to net reductive mechanisms. We report a strategy for net redox-neutral generation and reaction of ketyl radicals. The in situ conversion of aldehydes to α-acetoxy iodides lowers their reduction potential by more than 1 volt, allowing for milder access to the corresponding ketyl radicals and an oxidative termination event. Upon subjecting these iodides to a dimanganese decacarbonyl precatalyst and visible light irradiation, an atom transfer radical addition (ATRA) mechanism affords a broad scope of vinyl iodide products with high Z-selectivity.
Collapse
Affiliation(s)
- Lu Wang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Jeremy M Lear
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Sean M Rafferty
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Stacy C Fosu
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - David A Nagib
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
10
|
Subramaniyan V, Mani G. Synthesis, Reactions, and Structures of Heterocycle-Tethered Boranes and Their Precursors. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vasudevan Subramaniyan
- Department of Chemistry, Indian Institute of Technology - Kharagpur, Kharagpur, West Bengal, India 721 302
| | - Ganesan Mani
- Department of Chemistry, Indian Institute of Technology - Kharagpur, Kharagpur, West Bengal, India 721 302
| |
Collapse
|
11
|
Yoshida H, Kimura M, Osaka I, Takaki K. Copper-Catalyzed Borylstannylation of Alkynes with Tin Fluorides. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00058] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroto Yoshida
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Miki Kimura
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Itaru Osaka
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Ken Takaki
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| |
Collapse
|
12
|
Légaré MA, Rochette É, Légaré Lavergne J, Bouchard N, Fontaine FG. Bench-stable frustrated Lewis pair chemistry: fluoroborate salts as precatalysts for the C–H borylation of heteroarenes. Chem Commun (Camb) 2016; 52:5387-90. [DOI: 10.1039/c6cc01267a] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Air and moisture-stable fluoroborate derivatives of (tetramethylpiperidino)benzene are stable and convenient precatalysts for the dehydrogenative borylation of heteroarenes.
Collapse
Affiliation(s)
- Marc-André Légaré
- Département de Chimie
- Centre de Catalyse et de Chimie Verte (C3V)
- Université Laval
- Quebec City (Qc)
- Canada
| | - Étienne Rochette
- Département de Chimie
- Centre de Catalyse et de Chimie Verte (C3V)
- Université Laval
- Quebec City (Qc)
- Canada
| | - Julien Légaré Lavergne
- Département de Chimie
- Centre de Catalyse et de Chimie Verte (C3V)
- Université Laval
- Quebec City (Qc)
- Canada
| | - Nicolas Bouchard
- Département de Chimie
- Centre de Catalyse et de Chimie Verte (C3V)
- Université Laval
- Quebec City (Qc)
- Canada
| | - Frédéric-Georges Fontaine
- Département de Chimie
- Centre de Catalyse et de Chimie Verte (C3V)
- Université Laval
- Quebec City (Qc)
- Canada
| |
Collapse
|