1
|
Font P, Valdés H, Ribas X. Consolidation of the Oxidant-Free Au(I)/Au(III) Catalysis Enabled by the Hemilabile Ligand Strategy. Angew Chem Int Ed Engl 2024; 63:e202405824. [PMID: 38687322 DOI: 10.1002/anie.202405824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/02/2024]
Abstract
In this minireview we survey the challenges and strategies in gold redox catalysis. Gold's reluctance to oxidative addition reactions due to its high redox potential limits its applicability. Initial attempts to overcome this problem focused on the use of sacrificial external oxidants in stoichiometric amounts to bring Au(I) compounds to Au(III) reactive species. Recently, innovative approaches focused on employing hemilabile ligands, which are capable of coordinating to Au(I) and stabilizing square-planar Au(III) intermediates, thus facilitating oxidative addition steps and enabling oxidant-free catalysis. Notable examples include the use of the (P^N) bidendate MeDalphos ligand to achieve various cross-coupling reactions via oxidative addition Au(I)/Au(III). Importantly, hemilabile ligand-enabled catalysis allows merging oxidative addition with π-activation, such as oxy- and aminoarylation of alkenols and alkenamines using organohalides, expanding gold's versatility in C-C and C-heteroatom bond formations and unprecedented cyclizations. Moreover, recent advancements in enantioselective catalysis using chiral hemilabile (P^N) ligands are also surveyed. Strikingly, versatile bidentate (C^N) hemilabile ligands as competitors of MeDalphos have appeared recently, by designing scaffolds where phosphine groups are substituted by N-heterocyclic or mesoionic carbenes. Overall, these approaches highlight the evolving landscape of gold redox catalysis and its tremendous potential in a broad scope of transformations.
Collapse
Affiliation(s)
- Pau Font
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, E-17003, Catalonia, Spain
| | - Hugo Valdés
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, E-17003, Catalonia, Spain
- Current address: Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28805, Alcalá de Henares, Madrid, Spain
| | - Xavi Ribas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, E-17003, Catalonia, Spain
| |
Collapse
|
2
|
Vesseur D, Li S, Mallet-Ladeira S, Miqueu K, Bourissou D. Ligand-Enabled Oxidative Fluorination of Gold(I) and Light-Induced Aryl-F Coupling at Gold(III). J Am Chem Soc 2024. [PMID: 38607393 DOI: 10.1021/jacs.4c00913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
MeDalphos Au(I) complexes featuring aryl, alkynyl, and alkyl groups readily react with electrophilic fluorinating reagents such as N-fluorobenzenesulfonimide and Selectfluor. The ensuing [(MeDalphos)Au(R)F]+ complexes have been isolated and characterized by multinuclear NMR spectroscopy as well as X-ray diffraction. They adopt a square-planar contra-thermodynamic structure, with F trans to N. DFT/IBO calculations show that the N lone pair of MeDalphos assists and directs the transfer of F+ to gold. The [(MeDalphos)Au(Ar)F]+ (Ar = Mes, 2,6-F2Ph) complexes smoothly engage in C-C cross-coupling with PhCCSiMe3 and Me3SiCN, providing direct evidence for the oxidative fluorination/transmetalation/reductive elimination sequence proposed for F+-promoted gold-catalyzed transformations. Moreover, direct reductive elimination to forge a C-F bond at Au(III) was explored and substantiated. Thermal means proved unsuccessful, leading mostly to decomposition, but irradiation with UV-visible light enabled efficient promotion of aryl-F coupling (up to 90% yield). The light-induced reductive elimination proceeds under mild conditions; it works even with the electron-deprived 2,6-difluorophenyl group, and it is not limited to the contra-thermodynamic form of the aryl Au(III) fluoride complexes.
Collapse
Affiliation(s)
- David Vesseur
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069) , CNRS/Université Paul Sabatier , 118 Route de Narbonne, 31062 Toulouse, Cedex 09, France
| | - Shuo Li
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069) , CNRS/Université Paul Sabatier , 118 Route de Narbonne, 31062 Toulouse, Cedex 09, France
| | - Sonia Mallet-Ladeira
- Institut de Chimie de Toulouse (UAR 2599) , 118 Route de Narbonne, 31062 Toulouse, Cedex 09, France
| | - Karinne Miqueu
- E2S-UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM, UMR 5254), CNRS/Université de Pau et des Pays de l'Adour, Hélioparc, 2 Avenue du Président Angot, 64053 Pau, Cedex 09, France
| | - Didier Bourissou
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069) , CNRS/Université Paul Sabatier , 118 Route de Narbonne, 31062 Toulouse, Cedex 09, France
| |
Collapse
|
3
|
Francis F, Wuest M, Woodfield JD, Wuest F. Palladium-Mediated S-Arylation of Cysteine Residues with 4-[ 18F]Fluoroiodobenzene ([ 18F]FIB). Bioconjug Chem 2024; 35:232-244. [PMID: 38215469 DOI: 10.1021/acs.bioconjchem.3c00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024]
Abstract
Transition-metal-mediated bioconjugation chemistry has been used extensively to design and synthesize molecular probes to visualize, characterize, and quantify biological processes within intact living organisms at the cellular and subcellular levels. We demonstrate the development and validation of chemoselective [18F]fluoro-arylation chemistry of cysteine residues using Pd-mediated S-arylation chemistry with 4-[18F]fluoroiodobenzene ([18F]FIB) as an aryl electrophile. The novel bioconjugation technique proceeded in excellent radiochemical yields of 73-96% within 15 min under ambient and aqueous reaction mixture conditions, representing a versatile novel tool for decorating peptides and peptidomimetics with short-lived positron emitter 18F. The chemoselective S-arylation of several peptides and peptidomimetics containing multiple reactive functional groups confirmed the versatility and functional group compatibility. The synthesis and radiolabeling of a novel prostate-specific membrane antigen (PSMA) binding radioligand [18F]6 was accomplished using the novel labeling protocol. The validation of radioligand [18F]6 in a preclinical prostate cancer model with PET resulted in favorable accumulation and retention in PSMA-expressing LNCaP tumors. At the same time, a significantly lower salivary gland uptake was observed compared to clinical PSMA radioligand [18F]PSMA-1007. This finding coincides with ongoing discussions about the molecular basis of the off-target accumulation of PSMA radioligands currently used for clinical imaging and therapy of prostate cancer.
Collapse
Affiliation(s)
- Felix Francis
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Melinda Wuest
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 2 × 4, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, 2-132 Li Ka Shing, Edmonton AB, T6G 2E1 Canada
| | - Jenilee D Woodfield
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 2 × 4, Canada
| | - Frank Wuest
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 2 × 4, Canada
- Cancer Research Institute of Northern Alberta, University of Alberta, 2-132 Li Ka Shing, Edmonton AB, T6G 2E1 Canada
| |
Collapse
|
4
|
Muratov K, Zaripov E, Berezovski MV, Gagosz F. DFT-Enabled Development of Hemilabile (P ∧N) Ligands for Gold(I/III) RedOx Catalysis: Application to the Thiotosylation of Aryl Iodides. J Am Chem Soc 2024; 146:3660-3674. [PMID: 38315643 DOI: 10.1021/jacs.3c08943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Ligand-enabled oxidative addition of Csp2-X bonds to Au(I) centers has recently appeared as a valuable strategy for the development of catalytic RedOx processes. Several cross-coupling reactions that were previously considered difficult to achieve were reported lately, thus expanding the synthetic potential of gold(I) complexes beyond the traditional nucleophilic functionalization of π-systems. MeDalPhos has played an important role in this development and, despite several studies on alternative structures, remains, so far, the only general ligand for such process. We report herein the discovery and DFT-enabled structural optimization of a new family of hemilabile (P∧N) ligands that can promote the oxidative addition of aryl iodides to gold(I). These flexible ligands, which possess a common 2-methylamino heteroaromatic N-donor motif, are structurally and electronically tunable, beyond being easily accessible and affordable. The corresponding Au(I) complexes were shown to outperform the reactivity of (MeDalPhos)Au(I) in a series of alkoxy- and amidoarylations of alkenes. Their synthetic potential and comparatively higher reactivity were further highlighted in the thiotosylation of aryl iodides, a challenging unreported C-S cross-coupling reaction that could not be achieved under classical Pd(0/II) catalysis and that allows for general and divergent access to aryl sulfur derivatives.
Collapse
Affiliation(s)
- Karim Muratov
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Emil Zaripov
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Maxim V Berezovski
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa K1N 6N5, Canada
| | - Fabien Gagosz
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa K1N 6N5, Canada
| |
Collapse
|
5
|
Zielke FM, Rutjes FPJT. Recent Advances in Bioorthogonal Ligation and Bioconjugation. Top Curr Chem (Cham) 2023; 381:35. [PMID: 37991570 PMCID: PMC10665463 DOI: 10.1007/s41061-023-00445-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/23/2023] [Indexed: 11/23/2023]
Abstract
The desire to create biomolecules modified with functionalities that go beyond nature's toolbox has resulted in the development of biocompatible and selective methodologies and reagents, each with different scope and limitations. In this overview, we highlight recent advances in the field of bioconjugation from 2016 to 2023. First, (metal-mediated) protein functionalization by exploiting the specific reactivity of amino acids will be discussed, followed by novel bioorthogonal reagents for bioconjugation of modified biomolecules.
Collapse
Affiliation(s)
- Florian M Zielke
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Floris P J T Rutjes
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
| |
Collapse
|
6
|
Halder R, Ma G, Rickmeier J, McDaniel JW, Petzold R, Neumann CN, Murphy JM, Ritter T. Deoxyfluorination of phenols for chemoselective 18F-labeling of peptides. Nat Protoc 2023; 18:3614-3651. [PMID: 37853158 DOI: 10.1038/s41596-023-00890-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/14/2023] [Indexed: 10/20/2023]
Abstract
The challenge of forming C-18F bonds is often a bottleneck in the development of new 18F-labeled tracer molecules for noninvasive functional imaging studies using positron emission tomography (PET). Nucleophilic aromatic substitution is the most widely employed reaction to functionalize aromatic substrates with the radioactive fluorine-18 but its scope is restricted to arenes containing electron-withdrawing substituents. Furthermore, many protic functional groups are incompatible with basic fluoride anions. Peptide substrates, which are highly desirable targets for PET molecular imaging, are particularly challenging to label with fluorine-18 because they are densely functionalized and sensitive to high temperatures and basic conditions. To expand the utility of nucleophilic aromatic substitution with fluorine-18, we describe two complementary procedures for the radiodeoxyfluorination of bench-stable and easy-to-access phenols that ensure rapid access to densely functionalized electron-rich and electron-poor 18F-aryl fluorides. The first procedure details the synthesis of an 18F-synthon and its subsequent ligation to the cysteine residue of Arg-Gly-Asp-Cys in 10.5 h from commercially available starting materials (189-min radiosynthesis). The second procedure describes the incorporation of commercially available CpRu(Fmoc-tyrosine)OTf into a fully protected peptide Lys-Met-Glu-(CpRu-Tyr)-Leu via solid-phase peptide synthesis and subsequent ruthenium-mediated uronium deoxyfluorination with fluorine-18 followed by deprotection, accomplished within 7 d (116-min radiosynthesis). Both radiolabeling methods are highly chemoselective and have conveniently been automated using commercially available radiosynthesis equipment so that the procedures described can be employed for the synthesis of peptide-based PET probes for in vivo imaging studies according to as low as reasonably achievable (ALARA) principles.
Collapse
Affiliation(s)
- Riya Halder
- Department of Organic Synthesis, Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
- Institute of Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Gaoyuan Ma
- Department of Molecular and Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Strateos Inc., San Diego, CA, USA
| | - Jens Rickmeier
- Department of Organic Synthesis, Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
| | - James W McDaniel
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Roland Petzold
- Department of Organic Synthesis, Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
| | - Constanze N Neumann
- Department of Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
| | - Jennifer M Murphy
- Department of Molecular and Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Tobias Ritter
- Department of Organic Synthesis, Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
| |
Collapse
|
7
|
Chassé M, Pees A, Lindberg A, Liang SH, Vasdev N. Spirocyclic Iodonium Ylides for Fluorine-18 Radiolabeling of Non-Activated Arenes: From Concept to Clinical Research. CHEM REC 2023; 23:e202300072. [PMID: 37183954 DOI: 10.1002/tcr.202300072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/27/2023] [Indexed: 05/16/2023]
Abstract
Positron emission tomography (PET) is a powerful imaging tool for drug discovery, clinical diagnosis, and monitoring of disease progression. Fluorine-18 is the most common radionuclide used for PET, but advances in radiotracer development have been limited by the historical lack of methodologies and precursors amenable to radiolabeling with fluorine-18. Radiolabeling of electron-rich (hetero)aromatic rings remains a long-standing challenge in the production of PET radiopharmaceuticals. In this personal account, we discuss the history of spirocyclic iodonium ylide precursors, from inception to applications in clinical research, for the incorporation of fluorine-18 into complex non-activated (hetero)aromatic rings.
Collapse
Affiliation(s)
- Melissa Chassé
- Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), 250 College Street, Toronto, ON M5T 1R8, Canada
| | - Anna Pees
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), 250 College Street, Toronto, ON M5T 1R8, Canada
| | - Anton Lindberg
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), 250 College Street, Toronto, ON M5T 1R8, Canada
| | - Steven H Liang
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, 30322, USA
| | - Neil Vasdev
- Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH), 250 College Street, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, 250 College Street, Toronto, ON M5T 1R8, Canada
| |
Collapse
|
8
|
Gao P, Xu J, Zhou T, Liu Y, Bisz E, Dziuk B, Lalancette R, Szostak R, Zhang D, Szostak M. L-Shaped Heterobidentate Imidazo[1,5-a]pyridin-3-ylidene (N,C)-Ligands for Oxidant-Free Au I /Au III Catalysis. Angew Chem Int Ed Engl 2023; 62:e202218427. [PMID: 36696514 PMCID: PMC9992098 DOI: 10.1002/anie.202218427] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/18/2023] [Accepted: 01/25/2023] [Indexed: 01/26/2023]
Abstract
In the last decade, major advances have been made in homogeneous gold catalysis. However, AuI /AuIII catalytic cycle remains much less explored due to the reluctance of AuI to undergo oxidative addition and the stability of the AuIII intermediate. Herein, we report activation of aryl halides at gold(I) enabled by NHC (NHC=N-heterocyclic carbene) ligands through the development of a new class of L-shaped heterobidentate ImPy (ImPy=imidazo[1,5-a]pyridin-3-ylidene) N,C ligands that feature hemilabile character of the amino group in combination with strong σ-donation of the carbene center in a rigid conformation, imposed by the ligand architecture. Detailed characterization and control studies reveal key ligand features for AuI /AuIII redox cycle, wherein the hemilabile nitrogen is placed at the coordinating position of a rigid framework. Given the tremendous significance of homogeneous gold catalysis, we anticipate that this ligand platform will find widespread application.
Collapse
Affiliation(s)
- Pengcheng Gao
- Department of Chemistry, Rutgers University, 73 Warren Street, 07102, Newark, NJ, USA
| | - Jihong Xu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Tongliang Zhou
- Department of Chemistry, Rutgers University, 73 Warren Street, 07102, Newark, NJ, USA
| | - Yanhong Liu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Elwira Bisz
- Department of Chemistry, Opole University, 48 Oleska Street, 45-052, Opole, Poland
| | - Błażej Dziuk
- Department of Chemistry, University of Science and Technology, Norwida 4/6, 50-373, Wroclaw, Poland
| | - Roger Lalancette
- Department of Chemistry, Rutgers University, 73 Warren Street, 07102, Newark, NJ, USA
| | - Roman Szostak
- Department of Chemistry, Wroclaw University, F. Joliot-Curie 14, 50-383, Wroclaw, Poland
| | - Dongju Zhang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Michal Szostak
- Department of Chemistry, Rutgers University, 73 Warren Street, 07102, Newark, NJ, USA
| |
Collapse
|
9
|
McCallum T. Heart of gold: enabling ligands for oxidative addition of haloorganics in Au(I)/Au(III) catalysed cross-coupling reactions. Org Biomol Chem 2023; 21:1629-1646. [PMID: 36727215 DOI: 10.1039/d3ob00002h] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The field of Au-catalysis has been an area rich with new discoveries due to the unique properties of the lustrous element. In the past decade, developments in Au(I)/Au(III) cross-coupling methodology have been made possible with the use of external oxidants that facilitate the challenging oxidation of Au(I) to Au(III) in a stable and catalytically competent fashion. Until recently, Au-chemistry was not known to undergo catalytic transformations that feature oxidative addition of haloarenes like those that were made famous by transition metals such as Pd and Ni. The discovery that ligand modification could facilitate the oxidative addition of Au(I) with haloorganics to provide Au(III) intermediates that are competent in other areas of catalysis (i.e. Lewis acid catalysis) has revolutionized this field and has led to the invention of new cross-coupling methodology. The recent advances at the leading edge in the emerging field of Au(I)/Au(III) catalysis under redox-neutral conditions are highlighted.
Collapse
Affiliation(s)
- Terry McCallum
- The Canadian Bank Note Company, Ottawa, Ontario, Canada.
| |
Collapse
|