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Ablyasova O, Guo M, Zamudio-Bayer V, Kubin M, Gitzinger T, da Silva Santos M, Flach M, Timm M, Lundberg M, Lau JT, Hirsch K. Electronic Structure of the Complete Series of Gas-Phase Manganese Acetylacetonates by X-ray Absorption Spectroscopy. J Phys Chem A 2023; 127:7121-7131. [PMID: 37590497 PMCID: PMC10476195 DOI: 10.1021/acs.jpca.3c02794] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/28/2023] [Indexed: 08/19/2023]
Abstract
Metal centers in transition metal-ligand complexes occur in a variety of oxidation states causing their redox activity and therefore making them relevant for applications in physics and chemistry. The electronic state of these complexes can be studied by X-ray absorption spectroscopy, which is, however, due to the complex spectral signature not always straightforward. Here, we study the electronic structure of gas-phase cationic manganese acetylacetonate complexes Mn(acac)1-3+ using X-ray absorption spectroscopy at the metal center and ligand constituents. The spectra are well reproduced by multiconfigurational wave function theory, time-dependent density functional theory as well as parameterized crystal field and charge transfer multiplet simulations. This enables us to get detailed insights into the electronic structure of ground-state Mn(acac)1-3+ and extract empirical parameters such as crystal field strength and exchange coupling from X-ray excitation at both the metal and ligand sites. By comparison to X-ray absorption spectra of neutral, solvated Mn(acac)2,3 complexes, we also show that the effect of coordination on the L3 excitation energy, routinely used to identify oxidation states, can contribute about 40-50% to the observed shift, which for the current study is 1.9 eV per oxidation state.
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Affiliation(s)
- Olesya
S. Ablyasova
- Physikalisches
Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Meiyuan Guo
- SSRL,
SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Department
of Chemistry-Ångström Laboratory, Uppsala University, SE-75120 Uppsala, Sweden
| | - Vicente Zamudio-Bayer
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Markus Kubin
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Tim Gitzinger
- Physikalisches
Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Mayara da Silva Santos
- Physikalisches
Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Max Flach
- Physikalisches
Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Martin Timm
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Marcus Lundberg
- Department
of Chemistry-Ångström Laboratory, Uppsala University, SE-75120 Uppsala, Sweden
| | - J. Tobias Lau
- Physikalisches
Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - Konstantin Hirsch
- Abteilung
für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum
Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
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Montgomery AP, Joyce JM, Danon JJ, Kassiou M. An update on late-stage functionalization in today's drug discovery. Expert Opin Drug Discov 2023; 18:597-613. [PMID: 37114995 DOI: 10.1080/17460441.2023.2205635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
INTRODUCTION Late-stage functionalization (LSF) allows for the introduction of new chemical groups toward the end of a synthetic sequence, which means new molecules can be rapidly accessed without laborious de novo chemical synthesis. Over the last decade, medicinal chemists have begun to implement LSF strategies into their drug discovery programs, affording benefits such as efficient access to diverse libraries to explore structure-activity relationships and the improvement of physicochemical and pharmacokinetic properties. AREAS COVERED An overview of the key advancements in LSF methodology development from 2019 to 2022 and their applicability to drug discovery is provided. In addition, several examples from both academia and industry where LSF methodologies have been applied by medicinal chemists to their drug discovery programs are presented. EXPERT OPINION Utilization of LSF by medicinal chemists is on the rise, both in academia and in industry. The maturation of the LSF field to produce methodologies bearing increased regioselectivity, scope, and functional group tolerance is envisaged to narrow the gap between methodology development and medicinal chemistry research. The authors predict that the sheer versatility of these techniques in facilitating challenging chemical transformations of bioactive molecules will continue to increase the efficiency of the drug discovery process.
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Affiliation(s)
| | - Jack M Joyce
- School of Chemistry, The University of Sydney, Sydney, Australia
| | - Jonathan J Danon
- School of Chemistry, The University of Sydney, Sydney, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, Australia
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John SE, Bora D, Shankaraiah N. Ru(II)-Catalyzed regioselective carbene insertion into β-carbolines and isoquinolines. Org Biomol Chem 2022; 20:5852-5860. [PMID: 35848450 DOI: 10.1039/d2ob00946c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A protocol for carbene insertion into the inert C(sp2)-H bond has been established wherein β-carbolines and isoquinolines are explored as intrinsic directing groups. The Ru(II)-catalyzed strategy employing sulfoxonium ylides as the carbene precursor offers an effective and atom-economical functionalization of substrates of biological interest with only DMSO as the sole by-product. The strategy is scalable to gram scale, and it also showcases a wide range of functional group tolerance. ESI-MS studies assisted in the identification of intermediates and consolidation of a probable mechanistic pathway. Furthermore, investigations revealed that the functionalized molecules not only displayed selective inhibition against cancer cell lines, but also demonstrated promising photophysical properties.
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Affiliation(s)
- Stephy Elza John
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India.
| | - Darshana Bora
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India.
| | - Nagula Shankaraiah
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500037, India.
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Jei BB, Yang L, Ackermann L. Selective Labeling of Peptides with o-Carboranes via Manganese(I)-Catalyzed C-H Activation. Chemistry 2022; 28:e202200811. [PMID: 35420234 PMCID: PMC9320968 DOI: 10.1002/chem.202200811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Indexed: 12/15/2022]
Abstract
A robust method for the selective labeling of peptides via manganese(I) catalysis was devised to achieve the C-2 alkenylation of tryptophan containing peptides with 1-ethynyl-o-carboranes. The manganese-catalyzed C-H activation was accomplished with high catalytic efficiency, and featured low toxicity, high functional group tolerance and excellent E-stereoselectivity. This approach unravels a promising tool for the assembly of o-carborane with structurally complex peptides of relevance to applications in boron neutron capture therapy.
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Affiliation(s)
- Becky Bongsuiru Jei
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTamannstraße 237077GöttingenGermany
- Woehler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Long Yang
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTamannstraße 237077GöttingenGermany
- Woehler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTamannstraße 237077GöttingenGermany
- Woehler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
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Das KK, Ghosh AK, Hajra A. Late-stage ortho-C-H alkenylation of 2-arylindazoles in aqueous medium by Manganese(i)-catalysis. RSC Adv 2022; 12:19412-19416. [PMID: 35865587 PMCID: PMC9251645 DOI: 10.1039/d2ra03547b] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/27/2022] [Indexed: 12/22/2022] Open
Abstract
Earth-abundant and water-tolerant manganese(i) catalyzed alkenylation of 2-arylindazole with alkyl and aryl alkynes through C–H bond activation is described with a unique level of E-selectivity. The reaction proceeds through the control of C3 nucleophilicity of 2-aryl indazoles. This method is applied to the late-stage functionalization of complex molecules including ethinylestradiol, norethisterone, and N-protected amino acid derivatives. The kinetic isotope studies suggest that the C–H bond activation step may not be the rate-determining step. Earth-abundant and water-tolerant manganese(i) catalyzed alkenylation of 2-arylindazole with alkyl and aryl alkynes through C–H bond activation is described with a unique level of E-selectivity.![]()
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Affiliation(s)
- Krishna Kanta Das
- Department of Chemistry, Visva-Bharati (A Central University) Santiniketan, 731235 West Bengal India
| | - Asim Kumar Ghosh
- Department of Chemistry, Visva-Bharati (A Central University) Santiniketan, 731235 West Bengal India
| | - Alakananda Hajra
- Department of Chemistry, Visva-Bharati (A Central University) Santiniketan, 731235 West Bengal India
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He X, Zhao Y, Zhang Z, Shen X. Tuning the Reactivity of Alkoxyl Radicals from Cyclization to 1,2-Silyl Transfer: Stereoselective Synthesis of β-Substituted Cycloalcohols. Org Lett 2022; 24:1991-1995. [DOI: 10.1021/acs.orglett.2c00428] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Xingyi He
- Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Yunlong Zhao
- Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Zeguo Zhang
- Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Xiao Shen
- Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
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Kaplaneris N, Ackermann L. Earth-abundant 3d transition metals on the rise in catalysis. Beilstein J Org Chem 2022; 18:86-88. [PMID: 35047085 PMCID: PMC8744453 DOI: 10.3762/bjoc.18.8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 12/29/2021] [Indexed: 01/02/2023] Open
Affiliation(s)
- Nikolaos Kaplaneris
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
- Wöhler Research Institute for Sustainable Chemistry (WISCh), Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
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C-H activation by immobilized heterogeneous photocatalysts. Photochem Photobiol Sci 2021; 20:1563-1572. [PMID: 34784051 DOI: 10.1007/s43630-021-00132-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/01/2021] [Indexed: 10/19/2022]
Abstract
During the last decades, the merger of photocatalysis with transition metal chemistry has been surfaced as a sustainable tool in modern molecular syntheses. This Account highlights major advances in synergistic photo-enabled C‒H activations. Inspired by our homogenous ruthenium- and copper-catalyzed C‒H activations in the absence of an exogenous photosensitizer, this Account describes the recent progress on heterogeneous photo-induced C‒H activation enabled by immobilized hybrid catalysts until September 2021, with a topical focus on recyclability as well as robustness of the heterogeneous photocatalyst.
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