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McEllin A, Goult CA, Mohiuddin G, Curtis LJ, Tanner TFN, Whitwood AC, Lynam JM, Bruce DW. Gold(III), Mercury(II), and Palladium(II) Complexes of a Series of Isomeric Bis(mono- and dialkoxyphenyl)pyridines: Introduction of Gold through Transmetalation and Catalysis. Inorg Chem 2024; 63:7589-7603. [PMID: 38635870 PMCID: PMC11061838 DOI: 10.1021/acs.inorgchem.3c03791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 04/04/2024] [Accepted: 04/04/2024] [Indexed: 04/20/2024]
Abstract
A series of isomeric bis-2,6-(monoalkoxyphenyl)pyridine and bis-2,6-(dialkoxyphenyl)pyridine ligands were synthesized and characterized. In order to prepare their chlorogold(III) complexes, intermediate chloromercury(II) complexes were first prepared, but unlike observations from previous studies where they were obtained impure and at best in moderate yield, here pure complexes were synthesized, many in rather high yields. Depending on the substitution pattern of the alkoxy chains on the ligands, mono- and/or dimercurated complexes were obtained, characterized by 1H, 13C{1H}, and 199Hg NMR spectroscopy as well as, in several cases, by X-ray crystallography. Factors that may explain this unusual reactivity are discussed. In most cases, transmetalation to the related chlorogold(III) complex proceeded smoothly, although lower yields were obtained when starting from doubly mercurated precursors. Prompted by the propensity of these ligands to mercurate, attempts were made to effect direct auration, but none was successful. However, dimeric, orthometalated complexes of palladium(II) could be prepared and were also amenable to transmetalation to the chlorogold(III) complex, providing for a mercury-free synthesis.
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Affiliation(s)
- Alice
Jane McEllin
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
| | | | - Golam Mohiuddin
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
- Department
of Chemistry, University of Science &
Technology Meghalaya, Ri-Bhoi, Meghalaya 793101, India
| | - Liam J. Curtis
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
| | - Theo F. N. Tanner
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
| | - Adrian C. Whitwood
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
| | - Jason M. Lynam
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
| | - Duncan W. Bruce
- Department
of Chemistry, University of York Heslington, YORK YO10 5DD, U.K.
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Holmsen MSM, Nova A, Tilset M. Cyclometalated (N,C) Au(III) Complexes: The Impact of Trans Effects on Their Synthesis, Structure, and Reactivity. Acc Chem Res 2023; 56:3654-3664. [PMID: 38051910 PMCID: PMC10734256 DOI: 10.1021/acs.accounts.3c00595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 12/07/2023]
Abstract
ConspectusThe early years of gold catalysis were dominated by Au(I) complexes and inorganic Au(III) salts. Thanks to the development of chelating ligands, more sophisticated Au(III) complexes can now be easily prepared and handled. The choice of the ancillary ligand has great consequences for the synthesis, properties, and reactivity of the Au(III) complex in question. Among the major factors controlling reactivity are the "trans effect" and the "trans influence" that a ligand imparts at the ligand trans to itself. The kinetic trans effect manifests itself with an increased labilization of the ligand trans to a given ligand and arises from an interplay between ground-state and transition-state effects. The term trans influence, on the other hand, is a ground-state effect only, describing the tendency of a given ligand to weaken the metal-ligand bond trans to itself. Herein, we will use the term "trans effect" to describe both the kinetic and the thermodynamic properties, whereas the term "trans influence" will refer only to thermodynamic properties. We will describe how these trans effects strongly impact the chemistry of the commonly encountered cyclometalated (N,C) Au(III) complexes, a class of complexes we have studied for more than a decade. We found that the outcome of reactions like alkylation, arylation, and alkynylation as well as halide metathesis are dictated by the different trans influence of the two termini of the chelating tpy ligand in (tpy)Au(OAcF)2 (tpy = 2-(p-tolyl)pyridine, OAcF = OCOCF3, tpy-C > tpy-N). There is a strong preference for high trans influence ligands to end up trans to tpy-N, whereas the lower trans influence ligands end up trans to tpy-C. Taking advantage of these preferences, tailor-made (N,C)Au(III) complexes could be prepared. For the functionalization of alkenes at (tpy)Au(OAcF)2, the higher trans effect of tpy-C would suggest that the coordination site trans to tpy-C would be kinetically more available than the one trans to tpy-N. However, due to the thermodynamic preference of having the σ-bonded ligand, resulting from the nucleophilic addition to alkenes, trans to tpy-N, functionalization of alkenes was only observed trans to tpy-N. However, for a catalytic process, the reaction should happen trans to tpy-C, as was observed for the trifluoroacetoxylation of acetylene. When functionalizing acetylene in the coordination site trans to tpy-N, protolytic cleavage of the Au-C(vinyl) bond to release the product did not occur at all, whereas trans to tpy-C protolytic cleavage of the Au-C(vinyl) bond occurred readily, in agreement with the higher trans influence of tpy-C over tpy-N. The large impact of the trans effects in Au(III) complexes is finally exemplified with the synthesis of [(tpy)Au(π-allyl)]+[NTf2]-, which resulted in a highly asymmetric π + σ bonding of the allyl moiety. Here, the bonding is such that the most thermodynamically favorable situation is achieved, with the carbon trans to tpy-N bonded in a σ-fashion and the π-allyl double bond being coordinated trans to tpy-C.
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Affiliation(s)
- Marte Sofie Martinsen Holmsen
- Department
of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway
- Centre
for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126, Blindern, N-0316 Oslo, Norway
| | - Ainara Nova
- Department
of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway
- Centre
for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126, Blindern, N-0316 Oslo, Norway
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway
- UiT-The
Arctic University of Norway, N-9037 Tromsø, Norway
| | - Mats Tilset
- Department
of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway
- Centre
for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126, Blindern, N-0316 Oslo, Norway
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway
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Au(III) Cyclometallated Compounds with 2-Arylpyridines and Their Derivatives or Analogues: 34 Years (1989–2022) of NMR and Single Crystal X-ray Studies. INORGANICS 2023. [DOI: 10.3390/inorganics11030100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
A review paper on Au(III) cyclometallated compounds with 2-arylpyridines (2-phenylpyridine, 2-benzylpyridine, 2-benzoylpyridine, 2-phenoxypyridine, 2-phenylsulfanylpyridine, 2-anilinopyridine, 2-(naphth-2-yl)pyridine, 2-(9,9-dialkylfluoren-2-yl)pyridines, 2-(dibenzofuran-4-yl)pyridine, and their derivatives) and their analogues (2-arylquinolines, 1- and 3-arylisoquinolines, 7,8-benzoquinoline), with 113 references. A total of 554 species, containing κ2-N(1),C(6′)*-Au(III), or analogous moiety (i.e., chelated by nitrogen of the pyridine-like ring and the deprotonated ortho- carbon of the phenyl-like ring) and, thus, possessing a character intermediate between metal complexes and organometallics, studied in the years 1989–2022 by NMR spectroscopy and/or single crystal X-ray diffraction (207 X-ray structures), are described. The compounds for which biological or catalytic activity and the luminescence properties were studied are also quoted.
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Hylland KT, Schmidtke IL, Wragg DS, Nova A, Tilset M. Synthesis of substituted (N,C) and (N,C,C) Au(III) complexes: the influence of sterics and electronics on cyclometalation reactions. Dalton Trans 2022; 51:5082-5097. [PMID: 35262546 DOI: 10.1039/d2dt00371f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cyclometalated Au(III) complexes are of interest due to their catalytic, medicinal, and photophysical properties. Herein, we describe the synthesis of derivatives of the type (N,C)Au(OAcF)2 (OAcF = trifluoroacetate) and (N,C,C)AuOAcF by a cyclometalation route, where (N,C) and (N,C,C) are chelating 2-arylpyridine ligands. The scope of the synthesis is explored by substituting the 2-arylpyridine core with electron donor or acceptor substituents at one or both rings. Notably, a variety of functionalized Au(III) complexes can be obtained in one step from the corresponding ligand and Au(OAc)3, eliminating the need for organomercury intermediates, which is commonly reported for similar syntheses. The influence of substituents in the ligand backbone on the resulting complexes was assessed using DFT calculations, 15N NMR spectroscopy and single-crystal X-ray diffraction analysis. A correlation between the electronic properties of the (N,C) ligands and their ability to undergo cyclometalation was found from experimental studies combined with natural charge analysis, suggesting the cyclometalation at Au(III) to take place via an electrophilic aromatic substitution-type mechanism. The formation of Au(III) pincer complexes from tridentate (N,C,C) ligands was investigated by synthesis and DFT calculations, in order to assess the feasibility of C(sp3)-H bond activation as a synthetic pathway to (N,C,C) cyclometalated Au(III) complexes. It was found that C(sp3)-H bond activation is feasible for ligands containing different alkyl groups (isopropyl and ethyl), although the C-H activation is less energetically favored compared to a ligand containing tert-butyl groups.
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Affiliation(s)
- Knut T Hylland
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - Inga L Schmidtke
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - David S Wragg
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway
| | - Ainara Nova
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway.,Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, N-0315 Oslo, Norway.,UiT-The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Mats Tilset
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway. .,Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0316 Oslo, Norway.,Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, N-0315 Oslo, Norway
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Tang MC, Chan MY, Yam VWW. Molecular Design of Luminescent Gold(III) Emitters as Thermally Evaporable and Solution-Processable Organic Light-Emitting Device (OLED) Materials. Chem Rev 2021; 121:7249-7279. [DOI: 10.1021/acs.chemrev.0c00936] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Man-Chung Tang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Mei-Yee Chan
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Vivian Wing-Wah Yam
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
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Eppel D, Eryiğit A, Rudolph M, Brückner M, Rominger F, Asiri AM, Hashmi ASK. Mechanochemical Gold(III)-Carbon Bond Formation. Angew Chem Int Ed Engl 2021; 60:13636-13640. [PMID: 33825267 PMCID: PMC8251521 DOI: 10.1002/anie.202017065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 12/03/2022]
Abstract
Starting from a [(MeO C^N^C)AuCl] complex as precursor, a direct substitution by C,H-activation from sp-, sp2 - or sp3 -C,H-bonds under basic conditions in a planetary ball mill was achieved. Because of the extraordinary photophysical properties of the target compounds, this protocol provides an easy access to a highly valued complex class. In contrast to existing protocols, no pre-functionalization of the starting materials is necessary and the use of expensive transition metal catalysts can be avoided, which makes this application appealing also for industrial purposes. In addition the methodology was not restricted to pincer complexes, which was demonstrated by the substitution of chelate type [(tpy)AuCl2 ] complexes.
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Affiliation(s)
- Daniel Eppel
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Alpay Eryiğit
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Matthias Rudolph
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Margit Brückner
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Frank Rominger
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Abdullah M. Asiri
- Chemistry DepartmentFaculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi-Arabia
| | - A. Stephen K. Hashmi
- Organisch-Chemisches InstitutUniversität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
- Chemistry DepartmentFaculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi-Arabia
- Heidelberg Center for the Environment (HCE)Im Neuenheimer Feld 229Germany
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Eppel D, Eryiğit A, Rudolph M, Brückner M, Rominger F, Asiri AM, Hashmi ASK. Mechanochemische Bildung von Gold(III)‐Kohlenstoffbindungen. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202017065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Daniel Eppel
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Alpay Eryiğit
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Matthias Rudolph
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Margit Brückner
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Frank Rominger
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Abdullah M. Asiri
- Chemistry Department Faculty of Science King Abdulaziz University Jeddah 21589 Saudi-Arabien
| | - A. Stephen K. Hashmi
- Organisch-Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
- Chemistry Department Faculty of Science King Abdulaziz University Jeddah 21589 Saudi-Arabien
- Heidelberg Center for the Environment (HCE) Im Neuenheimer Feld 229 Deutschland
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