1
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Li H, Li Y, Chen J, Lu L, Wang P, Hu J, Ma R, Gao Y, Yi H, Li W, Lei A. Scalable and Selective Electrochemical Hydrogenation of Polycyclic Arenes. Angew Chem Int Ed Engl 2024:e202407392. [PMID: 39031667 DOI: 10.1002/anie.202407392] [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: 04/18/2024] [Indexed: 07/22/2024]
Abstract
The reduction of aromatic compounds constitutes a fundamental and ongoing area of investigation. The selective reduction of polycyclic aromatic compounds to give either fully or partially reduced products remains a challenge, especially in applications to complex molecules at scale. Herein, we present a selective electrochemical hydrogenation of polycyclic arenes conducted under mild conditions. A noteworthy achievement of this approach is the ability to finely control both the complete and partial reduction of specific aromatic rings within polycyclic arenes by judiciously varying the reaction solvents. Mechanistic investigations elucidate the pivotal role played by in situ proton generation and interface regulation in governing reaction selectivity. The reductive electrochemical conditions show a very high level of functional-group tolerance. Furthermore, this methodology represents an easily scalable reduction (demonstrated by the reduction of 1 kg scale starting material) using electrochemical flow chemistry to give key intermediates for the synthesis of specific drugs.
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Affiliation(s)
- Hao Li
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Yan Li
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Jiaye Chen
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Lijun Lu
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Pengjie Wang
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Jingcheng Hu
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Rui Ma
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Yiming Gao
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Hong Yi
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Wu Li
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
| | - Aiwen Lei
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China
- National Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang, 330022, P. R. China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P.R. China
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2
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Liu HY, Neale SE, Hill MS, Mahon MF, McMullin CL, Richards E. [{SiN Dipp}MgNa] 2: A Potent Molecular Reducing Agent. Organometallics 2024; 43:879-888. [PMID: 38665773 PMCID: PMC11041119 DOI: 10.1021/acs.organomet.4c00076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/17/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024]
Abstract
The bimetallic species, [{SiNDipp}MgNa]2 [{SiNDipp} = {CH2SiMe2N(Dipp)}2; (Dipp = 2,6-i-Pr2C6H3)], is shown to be a potent reducing agent, able to effect one- or two-electron reduction of either dioxygen, TEMPO, anthracene, benzophenone, or diphenylacetylene. In most cases, the bimetallic reaction products imply that the dissimilar alkaline metal centers react with a level of cooperativity. EPR analysis of the benzophenone-derived reaction and the concurrent isolation of [{SiNDipp}Mg(OCPh2)2], however, illustrate that treatment with such reducible, but O-basic, species can also result in reactivity in which the metals provide independent reaction products. The notable E-stereochemistry of the diphenylacetylene reduction product prompted a computational investigation of the PhC≡CPh addition. This analysis invokes a series of elementary steps that necessitate ring-opening via Mg+ → Na+ amido group migration of the SiNDipp ligand, providing insight into the previously observed lability of the bidentate dianion and its consequent proclivity toward macrocyclization.
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Affiliation(s)
- Han-Ying Liu
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Samuel E. Neale
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Michael S. Hill
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Mary F. Mahon
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Claire L. McMullin
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Emma Richards
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.
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3
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Steinborn C, Huber T, Lichtenegger J, Plangger I, Höfler D, Schnell SD, Weisheit L, Mayer P, Wurst K, Magauer T. Synthesis of Waixenicin A: Exploring Strategies for Nine-Membered Ring Formation. Chemistry 2024; 30:e202303489. [PMID: 37942708 PMCID: PMC7615592 DOI: 10.1002/chem.202303489] [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: 10/23/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/10/2023]
Abstract
We present a comprehensive account on our efforts behind the recently published synthesis of waixenicin A. Our approach for constructing the dihydropyran ring relied on an Achmatowicz rearrangement. For the assembly of the nine-membered ring, four distinct strategies were investigated. Our initial attempts using radical-based addition/fragmentation reactions targeting the C7-C11 bond proved unsuitable for accessing the 6/9-bicycle. By employing anionic fragmentation conditions at the furfuryl alcohol stage, we successfully reached a 5/9-bicycle. However, subsequent ring-expansion was unsuccessful. Alternative approaches, such as Nozaki-Hiyama-Kishi or Heck reactions to connect the C6-C7 bond, also encountered difficulties, with no nine-membered ring formation observed. Our first breakthrough came from our attempts to install the C5-C6 bond via an intramolecular alkylation. Surprisingly, subsequent functional group modifications proved unexpectedly challenging, necessitating a redesign of our synthetic route. Drawing from all our investigations, we concluded that construction of the C9-C10 bond would enable efficient nine-membered ring alkylation and would facilitate the installation of the desired substitution pattern along the southern periphery. Exploration of this strategy yielded further surprises but ultimately led to the successful synthesis of waixenicin A and 9-deacetoxy-14,15-deepoxyxeniculin. For the latter compound, a bioinspired one-step rearrangement to xeniafauranol A was achieved.
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Affiliation(s)
- Christian Steinborn
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Tatjana Huber
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Julian Lichtenegger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Immanuel Plangger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Denis Höfler
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Simon D Schnell
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Lara Weisheit
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Peter Mayer
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Klaus Wurst
- Institute of General, Inorganic & Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Thomas Magauer
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
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4
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Kiprova N, Desnoyers M, Narobe R, Klufts-Edel A, Chaud J, König B, Compain P, Kern N. Towards a General Access to 1-Azaspirocyclic Systems via Photoinduced, Reductive Decarboxylative Radical Cyclizations. Chemistry 2023:e202303841. [PMID: 38084823 DOI: 10.1002/chem.202303841] [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: 11/18/2023] [Indexed: 01/13/2024]
Abstract
A convenient and versatile approach to important 1-azaspirocyclic systems relevant to medicinal chemistry and natural products is reported herein. The main strategy relies on a reductive decarboxylative cyclization of redox-active esters which can be rapidly assembled from abundant cyclic azaacids and tailored acceptor sidechains, with a focus on alkyne acceptors enabling the generation of useful exo-alkene moieties. Diastereoconvergent variants were studied and could be achieved either through remote stereocontrol or conformational restriction in bicyclic carbamate substrates. Two sets of metal-free photocatalytic conditions employing inexpensive eosin Y were disclosed and studied experimentally to highlight key mechanistic divergences.
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Affiliation(s)
- Natalia Kiprova
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Marine Desnoyers
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Rok Narobe
- Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, Germany
| | - Arthur Klufts-Edel
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Juliane Chaud
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Burkhard König
- Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, Germany
| | - Philippe Compain
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Nicolas Kern
- Laboratoire d'Innovation Moléculaire et Applications (LIMA), UMR 7042, Université de Strasbourg/Université de Haute-Alsace/CNRS, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
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5
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De Luca C, Zanetti D, Battisti T, Ferreira RR, Lopez S, McMillan AH, Lesher-Pérez SC, Maggini L, Bonifazi D. Photoreduction of Anthracenes Catalyzed by peri-Xanthenoxanthene: a Scalable and Sustainable Birch-Type Alternative. Chemistry 2023; 29:e202302129. [PMID: 37593905 DOI: 10.1002/chem.202302129] [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: 07/04/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/19/2023]
Abstract
The typical Birch reduction transforms arenes into cyclohexa-1,4-dienes by using alkali metals, an alcohol as a proton source, and an amine as solvent. Capitalizing on the strong photoreductive properties of peri-xanthenoxanthene (PXX), herein we report the photocatalyzed "Birch-type" reduction of acenes by employing visible blue light irradiation at room temperature in the presence of air. Upon excitation at 405 or 460 nm in the presence of a mixture of N,N-diisopropylethylamine (DIPEA) and trifluoromethanesulfonimide (HNTf2 ) in DMSO, PXX photocatalyzes the selective reduction of full-carbon acene derivatives (24-75 %). Immobilization of PXX onto polydimethylsiloxane (PDMS) beads (PXX-PDMS) allowed the use of the catalyst in heterogeneous batch reactions, giving 9-phenyl-9,10-dihydroanthracene in high yield (68 %). The catalyst could easily be recovered and reused, with no notable drop in performance observed after five reaction cycles. Integration of the PXX-PDMS beads into a microreactor enabled the reduction of acenes under continuous-flow conditions, thereby validating the sustainability and scalability of this heterogeneous-phase approach.
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Affiliation(s)
- Cristian De Luca
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Davide Zanetti
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Tommaso Battisti
- School of Chemistry, Cardiff University, Park Place, CF10 3AT, Cardiff, UK
| | - Rúben R Ferreira
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Sofia Lopez
- División Polímeros Nanoestructurados, Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), UNMdP-CONICET y Departamento de Química, UNMdP, Av. Cristóbal Colón 10850, Mar del Plata, B7606BWV, Buenos Aires, Argentina
| | | | - Sasha Cai Lesher-Pérez
- Department of Chemical Engineering, Department of Biomedical Engineering, University of Michigan, North Campus Research Complex Building 28, 2800 Plymouth Rd, 48109-2800, Ann Arbor, MI, USA
| | - Laura Maggini
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Davide Bonifazi
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
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6
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Zhang J, Mück-Lichtenfeld C, Studer A. Photocatalytic phosphine-mediated water activation for radical hydrogenation. Nature 2023; 619:506-513. [PMID: 37380779 PMCID: PMC10356606 DOI: 10.1038/s41586-023-06141-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/27/2023] [Indexed: 06/30/2023]
Abstract
The chemical activation of water would allow this earth-abundant resource to be transferred into value-added compounds, and is a topic of keen interest in energy research1,2. Here, we demonstrate water activation with a photocatalytic phosphine-mediated radical process under mild conditions. This reaction generates a metal-free PR3-H2O radical cation intermediate, in which both hydrogen atoms are used in the subsequent chemical transformation through sequential heterolytic (H+) and homolytic (H•) cleavage of the two O-H bonds. The PR3-OH radical intermediate provides an ideal platform that mimics the reactivity of a 'free' hydrogen atom, and which can be directly transferred to closed-shell π systems, such as activated alkenes, unactivated alkenes, naphthalenes and quinoline derivatives. The resulting H adduct C radicals are eventually reduced by a thiol co-catalyst, leading to overall transfer hydrogenation of the π system, with the two H atoms of water ending up in the product. The thermodynamic driving force is the strong P=O bond formed in the phosphine oxide by-product. Experimental mechanistic studies and density functional theory calculations support the hydrogen atom transfer of the PR3-OH intermediate as a key step in the radical hydrogenation process.
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Affiliation(s)
- Jingjing Zhang
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Münster, Germany
- Center for Multiscale Theory and Computation, Westfälische Wilhelms-Universität, Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Münster, Germany.
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7
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Yamamoto A, Liu X, Arashiba K, Konomi A, Tanaka H, Yoshizawa K, Nishibayashi Y, Yoshida H. Coordination Structure of Samarium Diiodide in a Tetrahydrofuran-Water Mixture. Inorg Chem 2023; 62:5348-5356. [PMID: 36728764 DOI: 10.1021/acs.inorgchem.2c03752] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Chemoselective reductive conversion of organic and inorganic compounds has been developed by the combination of samarium(II) diiodide (SmI2) and water. Despite the extensive previous studies to elucidate the role of water in the reactivity of SmI2, the direct structural data of the reactive Sm2+-water complexes, SmI2(H2O)n, in an organic solvent-water mixture have not been reported experimentally so far. Herein, we performed the structure analysis of the Sm2+-water complex in tetrahydrofuran (THF) in the presence of water by in situ X-ray absorption spectroscopy using high-energy X-rays (Sm K-edge, 46.8 keV). The analysis revealed the dissociation of the Sm2+-I bonds in the presence of ≥ eight equivalents of water in the THF-water mixture. The origin of the peak shift in the UV/visible absorption spectra after the addition of water into SmI2/THF solution was proposed based on electron transitions simulated with time-dependent density-functional-theory calculations using optimized structures in THF or water. The obtained structural information provides the fundamental insights for elucidating the reactivity and chemoselectivity in the Sm2+-water complex system.
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Affiliation(s)
- Akira Yamamoto
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto606-8501, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto615-8520, Japan
| | - Xueshi Liu
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto606-8501, Japan
| | - Kazuya Arashiba
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-8656, Japan
| | - Asuka Konomi
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka819-0395, Japan
| | - Hiromasa Tanaka
- School of Liberal Arts and Sciences, Daido University, Minami-ku, Nagoya457-8530, Japan
| | - Kazunari Yoshizawa
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto615-8520, Japan.,Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka819-0395, Japan
| | - Yoshiaki Nishibayashi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-8656, Japan
| | - Hisao Yoshida
- Department of Interdisciplinary Environment, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto606-8501, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto615-8520, Japan
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8
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Willis BAN, Schnable D, Schley ND, Ung G. Spinolate Lanthanide Complexes for High Circularly Polarized Luminescence Metrics in the Visible and Near-Infrared. J Am Chem Soc 2022; 144:22421-22425. [PMID: 36445253 DOI: 10.1021/jacs.2c10364] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Analogues of Shibasaki's complexes supported by enantiopure Spinol are synthesized and characterized. The tris(Spinol) LnIII complexes are generated either by ligand deprotonation followed by complexation with lanthanide triflate salts or by in situ deprotonation by Ln(N(SiMe3)2)3 salts in the presence of additional base. The resulting complexes are found to be luminescent and chiroptically active for both circular dichroism and circularly polarized luminescence (CPL), notably producing strong CPL with dissymmetry factors (glum) of up to 0.50, 0.53, and 0.53 for Sm, Tb, and Dy, respectively. The Sm complex is found to be CPL-active in the near-infrared (NIR) region at 980 nm, representing the first report of NIR CPL from Sm. Additionally, the Tb complex, due to efficient sensitization (Φ = 0.846 in tetrahydrofuran) coupled with strong dissymmetry factors, achieves a CPL brightness (BCPL) of 3760 M-1 cm-1, the highest reported for any CPL-active compound to date. These are rare examples of compounds that show simultaneous improvement of both CPL metrics (glum and BCPL). Solid-state structural analysis of the Spinolate complexes and comparisons to other CPL-active analogues of Shibasaki's complexes also suggest that nondistorted geometries should generate even stronger metrics.
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Affiliation(s)
- Bre-Anna N Willis
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - David Schnable
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Nathan D Schley
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Gaël Ung
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
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9
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Mild and metal-free Birch-type hydrogenation of (hetero)arenes with boron carbonitride in water. Nat Catal 2022. [DOI: 10.1038/s41929-022-00886-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Abstract
Coordination-induced bond weakening is a phenomenon wherein ligand X-H bond homolysis occurs in concert with the energetically favorable oxidation of a coordinating metal complex. The coupling of these two processes enables thermodynamically favorable proton-coupled electron transfer reductions to form weak bonds upon formal hydrogen atom transfer to substrates. Moreover, systems utilizing coordination-induced bond weakening have been shown to facilitate the dehydrogenation of feedstock molecules including water, ammonia, and primary alcohols under mild conditions. The formation of exceptionally weak substrate X-H bonds via small molecule homolysis is a powerful strategy in synthesis and has been shown to enable nitrogen fixation under mild conditions. Coordination-induced bond weakening has also been identified as an integral process in biophotosynthesis and has promising applications in renewable chemical fuel storage systems. This review presents a discussion of the advances made in the study of coordination-induced bond weakening to date. Because of the broad range of metal and ligand species implicated in coordination-induced bond weakening, each literature report is discussed individually and ordered by the identity of the low-valent metal. We then offer mechanistic insights into the basis of coordination-induced bond weakening and conclude with a discussion of opportunities for further research into the development and applications of coordination-induced bond weakening systems.
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Affiliation(s)
- Nicholas G Boekell
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Robert A Flowers
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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11
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Quevedo-Acosta Y, Jurberg ID, Gamba-Sánchez D. Cyclization Strategies Using Imide Derivatives for the Synthesis of Polycyclic Nitrogen‐Containing Compounds. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Igor D. Jurberg
- Universidade Estadual de Campinas Institute of Chemistry 13083 BRAZIL
| | - Diego Gamba-Sánchez
- Universidad de Los Andes Chemistry Department Cra 1 No. 18A-12 Q:305 111711 Bogota COLOMBIA
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12
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Rao CN, Reissig HU. Samarium(II)‐Promoted Cyclizations of Non‐activated Indolyl Sulfinyl Imines to Polycyclic Tertiary Carbinamines. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chintada Nageswara Rao
- Freie Universität Berlin: Freie Universitat Berlin Institut für Chemie und Biochemie 14195 Berlin GERMANY
| | - Hans-Ulrich Reissig
- Freie Universität Berlin Institut für Chemie und Biochemie Takustr. 3 14195 Berlin GERMANY
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13
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Pawar G, Ghouse SM, Kar S, Chelli SM, Dannarm SR, Gour J, Sonti R, Nanduri S. SmI2-mediated C-alkylation of Ketones with Alcohols in Microwave conditions: A Novel Route to Alkylated Ketones. Chem Asian J 2022; 17:e202200041. [PMID: 35191612 DOI: 10.1002/asia.202200041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/15/2022] [Indexed: 11/08/2022]
Abstract
A novel protocol is developed towards the preparation of alkylated ketones from alcohols in presence of catalytic amount of SmI 2 and base with the elimination of water as a single by-product under microwave irradiation conditions. Furthermore, applicability of this methodology to the synthesis of Donepezil and late-stage functionalization in Pregnenolone is also reported. Successful application of this methodology in Friedländer quinolone synthesis using 2-aminobenzyl alcohol and various acetophenones expand the synthetic utility of this protocol.
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Affiliation(s)
- Gaurav Pawar
- NIPER Hyderabad: National Institute of Pharmaceutical Education and Research Hyderabad, Chemical Sciences, INDIA
| | - Shaik Mahammad Ghouse
- NIPER Hyderabad: National Institute of Pharmaceutical Education and Research Hyderabad, Chemical Sciences, INDIA
| | - Swayamsiddha Kar
- Sri Satya Sai Institute of Higher Learning: Sri Sathya Sai University, Department of chemistry, INDIA
| | - Sai Manohar Chelli
- Sri Satya Sai Institute of Higher Learning: Sri Sathya Sai University, Department of chemistry, INDIA
| | - Srinivas Reddy Dannarm
- NIPER Hyderabad: National Institute of Pharmaceutical Education and Research Hyderabad, Pharmaceutical analysis, INDIA
| | - Jitendra Gour
- NIPER Hyderabad: National Institute of Pharmaceutical Education and Research Hyderabad, Chemical Sciences, INDIA
| | - Rajesh Sonti
- NIPER Hyderabad: National Institute of Pharmaceutical Education and Research Hyderabad, Pharmaceutical analysis, INDIA
| | - Srinivas Nanduri
- National Institute of Pharmaceutical Education & Research, Process Chemistry, Balanagar, 500037, Hyderabad, INDIA
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14
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Asako S, Takahashi I, Kurogi T, Murakami Y, Ilies L, Takai K. Birch Reduction of Arenes Using Sodium Dispersion and DMI under Mild Conditions. CHEM LETT 2022. [DOI: 10.1246/cl.210546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Sobi Asako
- Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
- RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Ikko Takahashi
- RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takashi Kurogi
- Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
| | - Yoshiaki Murakami
- KOBELCO ECO-Solutions Co., Ltd., 4-78-1 Wakinohama-cho, Chuo-ku, Kobe 651-0072, Japan
| | - Laurean Ilies
- RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kazuhiko Takai
- Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
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15
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Liu Z, Wei Y, Shi M. Visible-light-mediated regioselective ring-opening hydrogenolysis of donor–acceptor cyclopropanes with DIPEA and H 2O. Org Chem Front 2022. [DOI: 10.1039/d2qo00047d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A visible-light-mediated regioselective ring-opening hydrogenolysis of donor–acceptor cyclopropanes has been developed for the rapid construction of alkylated aryl ketones in good yields with excellent functional group compatibility.
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Affiliation(s)
- Zhen Liu
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, People's Republic of China
| | - Yin Wei
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Min Shi
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, People's Republic of China
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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16
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Affiliation(s)
- Sandeepan Maity
- Department of Applied Sciences and Humanities Invertis University Bareilly Uttar Pradesh 243123 India
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17
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Visible light enables catalytic formation of weak chemical bonds with molecular hydrogen. Nat Chem 2021; 13:969-976. [PMID: 34253889 DOI: 10.1038/s41557-021-00732-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 05/13/2021] [Indexed: 02/08/2023]
Abstract
The synthesis of weak chemical bonds at or near thermodynamic potential is a fundamental challenge in chemistry, with applications ranging from catalysis to biology to energy science. Proton-coupled electron transfer using molecular hydrogen is an attractive strategy for synthesizing weak element-hydrogen bonds, but the intrinsic thermodynamics presents a challenge for reactivity. Here we describe the direct photocatalytic synthesis of extremely weak element-hydrogen bonds of metal amido and metal imido complexes, as well as organic compounds with bond dissociation free energies as low as 31 kcal mol-1. Key to this approach is the bifunctional behaviour of the chromophoric iridium hydride photocatalyst. Activation of molecular hydrogen occurs in the ground state and the resulting iridium hydride harvests visible light to enable spontaneous formation of weak chemical bonds near thermodynamic potential with no by-products. Photophysical and mechanistic studies corroborate radical-based reaction pathways and highlight the uniqueness of this photodriven approach in promoting new catalytic chemistry.
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18
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Gaston JJ, Tague AJ, Smyth JE, Butler NM, Willis AC, van Eikema Hommes N, Yu H, Clark T, Keller PA. The Detosylation of Chiral 1,2-Bis(tosylamides). J Org Chem 2021; 86:9163-9180. [PMID: 34153182 DOI: 10.1021/acs.joc.1c00359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The deprotection of chiral 1,2-bis(tosylamides) to their corresponding 1,2-diamines is mostly unsuccessful under standard conditions. In a new methodology, the use of Mg/MeOH with sufficient steric additions allows the facile synthesis of 1,2-diamines in 78-98% yields. These results are rationalized using density functional theory and the examination of inner and outer-sphere reduction mechanisms.
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Affiliation(s)
- Jayden J Gaston
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Andrew J Tague
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Jamie E Smyth
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Nicholas M Butler
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Anthony C Willis
- School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Nico van Eikema Hommes
- Computer Chemistry Center, Department of Chemistry and Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, Nägelsbachstraße 25, 91052 Erlangen, Germany
| | - Haibo Yu
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Timothy Clark
- Computer Chemistry Center, Department of Chemistry and Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, Nägelsbachstraße 25, 91052 Erlangen, Germany
| | - Paul A Keller
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
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19
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Kanda Y, Ishihara Y, Wilde NC, Baran PS. Two-Phase Total Synthesis of Taxanes: Tactics and Strategies. J Org Chem 2020; 85:10293-10320. [DOI: 10.1021/acs.joc.0c01287] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yuzuru Kanda
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Yoshihiro Ishihara
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nathan C. Wilde
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Phil S. Baran
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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20
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Arene dearomatization through a catalytic N-centered radical cascade reaction. Nat Commun 2020; 11:2528. [PMID: 32433521 PMCID: PMC7239915 DOI: 10.1038/s41467-020-16369-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/29/2020] [Indexed: 11/09/2022] Open
Abstract
Arene dearomatization reactions are an important class of synthetic technologies for the rapid assembly of unique chemical architectures. Herein, we report a catalytic protocol to initiate a carboamination/dearomatization cascade that proceeds through transient sulfonamidyl radical intermediates formed from native sulfonamide N-H bonds leading to 1,4-cyclohexadiene-fused sultams. Importantly, this work demonstrates a facile approach to employ two-dimensional aromatic compounds as modular building blocks to generate richly substituted, three-dimensional compounds. These reactions occur at room temperature under visible light irradiation and are catalyzed by the combination of an iridium(III) photocatalyst and a dialkyl phosphate base. Reaction optimization, substrate scope, mechanistic features, and synthetic applications of this transformation are presented.
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21
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Gusarova NK, Trofimov BA. Organophosphorus chemistry based on elemental phosphorus: advances and horizons. RUSSIAN CHEMICAL REVIEWS 2020. [DOI: 10.1070/rcr4903] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The results of studies on the application of elemental phosphorus for the synthesis of important organophosphorus compounds are surveyed and summarized. Currently, this trend represents a synthetically, environmentally and technologically attractive alternative to classical organophosphorus chemistry based on toxic and corrosive phosphorus chlorides. Direct phosphination and phosphinylation of organic compounds with elemental phosphorus (discussed in the first part of the review) basically extend the range of available phosphines, phosphine chalcogenides and phosphinic acids and provides further development of their synthetic potential (discussed in the second part of the review). It is shown that the breakthrough in this area is largely due to the discovery of reactions of elemental phosphorus (white and red) with various electrophiles in superbasic suspensions and emulsions derived from alkali metal hydroxides and to the development of electrochemical, electrocatalytic and catalytic activation of white phosphorus.
The bibliography includes 299 references.
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22
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Ramírez-Solís A, Bartulovich CO, León-Pimentel CI, Saint-Martin H, Boekell NG, Flowers RA. Proton donor effects on the reactivity of SmI2. Experimental and theoretical studies on methanol solvation vs. aqueous solvation. Dalton Trans 2020; 49:7897-7902. [DOI: 10.1039/d0dt01221a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Using both computational and experimental data the SmI2–MeOH system is directly compared to the SmI2–H2O system to uncover the basis for their drastic differences in reactivity.
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Affiliation(s)
- Alejandro Ramírez-Solís
- Depto. de Física
- Centro de Investigación en Ciencias-IICBA Universidad Autónoma del Estado de Morelos
- Cuernavaca
- Mexico
| | | | - César Iván León-Pimentel
- Depto. de Física
- Centro de Investigación en Ciencias-IICBA Universidad Autónoma del Estado de Morelos
- Cuernavaca
- Mexico
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23
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Photocatalytic activation of alkyl chlorides by assembly-promoted single electron transfer in microheterogeneous solutions. Nat Catal 2019. [DOI: 10.1038/s41929-019-0369-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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24
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Ramírez-Solís A, Bartulovich CO, León-Pimentel CI, Saint-Martin H, Anderson WR, Flowers RA. Experimental and Theoretical Studies on the Aqueous Solvation and Reactivity of SmCl2 and Comparison with SmBr2 and SmI2. Inorg Chem 2019; 58:13927-13932. [DOI: 10.1021/acs.inorgchem.9b01818] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Alejandro Ramírez-Solís
- Departamento de Física, Centro de Investigación en Ciencias-IICBA Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos 62209, Mexico
| | | | | | | | - William R. Anderson
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Robert A. Flowers
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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25
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Chatterjee A, König B. Birch-Type Photoreduction of Arenes and Heteroarenes by Sensitized Electron Transfer. Angew Chem Int Ed Engl 2019; 58:14289-14294. [PMID: 31379035 PMCID: PMC6790943 DOI: 10.1002/anie.201905485] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/30/2019] [Indexed: 01/09/2023]
Abstract
The direct reduction of arenes and heteroarenes by visible-light irradiation remains challenging, as the energy of a single photon is not sufficient for breaking aromatic stabilization. Shown herein is that the energy accumulation of two visible-light photons allows the dearomatization of arenes and heteroarenes. Mechanistic investigations confirm that the combination of energy-transfer and electron-transfer processes generates an arene radical anion, which is subsequently trapped by hydrogen-atom transfer and finally protonated to form the dearomatized product. The photoreduction converts planar aromatic feedstock compounds into molecular skeletons that are of use in organic synthesis.
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Affiliation(s)
- Anamitra Chatterjee
- Universität RegensburgFakultät für Chemie und Pharmazie93040RegensburgGermany
| | - Burkhard König
- Universität RegensburgFakultät für Chemie und Pharmazie93040RegensburgGermany
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26
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Chatterjee A, König B. Birch‐Type Photoreduction of Arenes and Heteroarenes by Sensitized Electron Transfer. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201905485] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Anamitra Chatterjee
- Universität Regensburg Fakultät für Chemie und Pharmazie 93040 Regensburg Germany
| | - Burkhard König
- Universität Regensburg Fakultät für Chemie und Pharmazie 93040 Regensburg Germany
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27
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Craig RA, Smith RC, Roizen JL, Jones AC, Virgil SC, Stoltz BM. Unified Enantioselective, Convergent Synthetic Approach toward the Furanobutenolide-Derived Polycyclic Norcembranoid Diterpenes: Synthesis of a Series of Ineleganoloids by Oxidation-State Manipulation of the Carbocyclic Core. J Org Chem 2019; 84:7722-7746. [PMID: 31066273 DOI: 10.1021/acs.joc.9b00635] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Late-stage synthetic efforts to advance the enatio- and diastereoselectively constructed [6,7,5,5]-fused tetracyclic scaffold toward the polycyclic norditerpenoid ineleganolide are disclosed. The described investigations focus on oxidation-state manipulation around the central cycloheptane ring. Computational evaluation of ground-state energies of dihydroineleganolide is used to rationalize empirical observations and provide insight for further synthetic development, enhancing the understanding of the conformational constraints of these compact polycyclic structures. Advanced synthetic manipulations generated a series of natural product-like compounds termed the ineleganoloids.
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Affiliation(s)
- Robert A Craig
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Russell C Smith
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Jennifer L Roizen
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Amanda C Jones
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Scott C Virgil
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Brian M Stoltz
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
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28
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Chen C, Feng S, Chan KS. Rhodium Porphyrin Catalyzed Regioselective Transfer Hydrogenolysis of C–C σ-Bonds in Cyclopropanes with iPrOH. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00290] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Chen Chen
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China
| | - Shiyu Feng
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China
| | - Kin Shing Chan
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China
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29
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Bartulovich CO, Flowers RA. Coordination-induced O–H bond weakening in Sm(ii)-water complexes. Dalton Trans 2019; 48:16142-16147. [DOI: 10.1039/c9dt03352a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coordination of water to low-valent Sm leads to O–H bond-weakening that enables PCET to substrates.
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Affiliation(s)
| | - R. A. Flowers
- Department of Chemistry Lehigh University
- Bethlehem
- USA
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30
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Transition metal-free regioselective access to 9,10-dihydroanthracenes via the reaction of anthracenes with elemental phosphorus in the KOH/DMSO system. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.10.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Abstract
The use of earth-abundant, cheap, potent, and readily available lanthanide photocatalysts provides an opportunity to complement or even replace rare and precious metal photosensitizers. Moreover, lanthanide photosensitizers have been demonstrated for the generation of a variety of reactive species, including aryl radicals, alkyl radicals, and others, by single-electron-transfer (SET) and hydrogen atom transfer (HAT) pathways under mild reaction conditions. Some lanthanide photocatalysts have unprecedented reducing power from their photoexcited states, achieving the activation of challenging organic substrates that have not otherwise been activated by reported organic or transition-metal photosensitizers. In this Account, we describe our recent advances in the rational design and strategic application of lanthanide photo(redox)catalysis. Our research goals include understanding the photophysics of lanthanide luminophores and incorporating them into new photocatalysis. Among the lanthanides, we have focused on cerium because of the doublet to doublet 4f → 5d excitation and emission, which affords good conservation of energy without losses through spin-state changes, as well as a large natural abundance of that element. We have performed structural, spectroscopic, computational, and reactivity studies to demonstrate that luminescent Ce(III) guanidinate-amide complexes can mediate photocatalytic C(sp3)-C(sp3) bond forming reactions. Taking advantage of the strong reducing power of the cerium excited states and the cerium-halogen bond forming enthalpies, we determined that the reactive, excited-state cerium metalloradical abstracts chloride anion from benzyl chloride to generate the benzyl radical. To control and predict the photocatalytic reactivities, we have also performed photophysical and photochemical studies on a series of mixed-ligand Ce(III) guanidinate-amide and guanidinate-aryloxide complexes to establish structure-property relationship for Ce(III) photocatalysts. We discovered that the emission color is directly related to ligand type and rigidity of the coordination sphere and that the photoluminescent quantum yield is correlated to variation in steric encumbrance around the cerium centers. The low excited-state reduction potentials ( E1/2* ≈ -2.1 to -2.9 V versus Cp2Fe0/+) and relatively fast quenching rates ( kq ≈ 107 M-1 s-1) toward aryl halides enabled the Ce(III) guanidinate-amide complexes to participate in photocatalytic C(sp2)-C(sp2) bond forming reactions through either inner-sphere or outer-sphere SET processes. We have also reported a simple, potent, and air-stable ultraviolet A photoreductant, the hexachlorocerate(III) anion ([CeIIICl6]3-). This complex is a potent photoreductant ( E1/2* ≈ -3.45 V versus Cp2Fe0/+) and exhibits a fast quenching kinetics ( kq ≈ 109-1010 M-1 s-1) toward organohalogens. The [CeIVCl6]2- redox partner can also act as a potent photo-oxidant though a (presumably) long-lived chloride-to-cerium(IV) charge transfer excited state (ε = ∼6000 M-1 cm-1), that was used to turnover photocatalytic dechlorination and Miyuara borylation reactions. With [CeIIICl6]3-, we achieved efficient photoinduced dehalogenation and borylation of unactivated aryl chlorides with broad substrate scope, through formally two-photon cycles where both Ce(III) and Ce(IV) act as photocatalysts. Lanthanide photoredox catalysis is now being applied in several contexts for reactions including photocatalytic dehydrogenation of amines, alkoxy-radical-mediated C-C bond cleavage and amination of alkanols, and C-H activation of alkanes. Overall, simple and potent lanthanide photocatalysis is expected to find practical applications in organic synthesis, pharmaceutical development, and small molecule activation.
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Affiliation(s)
- Yusen Qiao
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Eric J. Schelter
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
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32
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Ramírez-Solís A, Bartulovich CO, Chciuk TV, Hernández-Cobos J, Saint-Martin H, Maron L, Anderson WR, Li AM, Flowers RA. Experimental and Theoretical Studies on the Implications of Halide-Dependent Aqueous Solvation of Sm(II). J Am Chem Soc 2018; 140:16731-16739. [DOI: 10.1021/jacs.8b09857] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Alejandro Ramírez-Solís
- Departamento de Física, Centro de Investigación en Ciencias-IICBA, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos 62209 México
| | | | - Tesia V. Chciuk
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Jorge Hernández-Cobos
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Humberto Saint-Martin
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Laurent Maron
- Laboratoire de Physique et Chimie de Nano-objets, Université de Toulouse, INSA-CNRS-UPS, 135, Avenue de Rangueil, 31077 Toulouse, France
| | - William R. Anderson
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Anna M. Li
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Robert A. Flowers
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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33
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Yoo BI, Kim YJ, You Y, Yang JW, Kim SW. Birch Reduction of Aromatic Compounds by Inorganic Electride [Ca 2N] +•e - in an Alcoholic Solvent: An Analogue of Solvated Electrons. J Org Chem 2018; 83:13847-13853. [PMID: 30351945 DOI: 10.1021/acs.joc.8b02094] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Birch reduction of aromatic systems by solvated electrons in alkali metal-ammonia solutions is widely recognized as a key reaction that functionalizes highly stable π-conjugated organic systems. In spite of recent advances in Birch reduction with regard to reducing agent and reaction conditions, there remains an ongoing challenge to develop a simple and efficient Birch reaction under mild conditions. Here, we demonstrate that the inorganic electride [Ca2N]+•e- promotes the Birch reduction of polycyclic aromatic hydrocarbons (PAHs) and naphthalene under alcoholic solvent in the vicinity of room temperature as a solid-type analogy to solvated electrons in alkali metal ammonia solutions. The anionic electrons from electride [Ca2N]+•e- are transferred to PAHs and naphthalene via alcoholysis in a polar cosolvent medium. It is noteworthy that a high conversion yield to the hydrogenated products is ascribed to the extremely high electron transfer efficiency of 98%. This simple protocol utilizing an inorganic electride offers a direct and practical strategy for the reduction of aromatic compounds and provides an outstanding reducing agent for synthetic chemistry.
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Affiliation(s)
- Byung Il Yoo
- Department of Energy Science , Sungkyunkwan University , Suwon 440-746 , Republic of Korea
| | - Ye Ji Kim
- Department of Energy Science , Sungkyunkwan University , Suwon 440-746 , Republic of Korea.,Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Sungkyunkwan University , Suwon 440-746 , Republic of Korea
| | - YoungMin You
- Division of Chemical Engineering and Materials Science , Ewha Womans University , Seoul 120-750 , Republic of Korea
| | - Jung Woon Yang
- Department of Energy Science , Sungkyunkwan University , Suwon 440-746 , Republic of Korea
| | - Sung Wng Kim
- Department of Energy Science , Sungkyunkwan University , Suwon 440-746 , Republic of Korea
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34
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Yang W, Chen C, Chan KS. Hydrodebromination of allylic and benzylic bromides with water catalyzed by a rhodium porphyrin complex. Dalton Trans 2018; 47:12879-12883. [PMID: 30168570 DOI: 10.1039/c8dt02168f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrodebromination of allylic and benzylic bromides was successfully achieved by a rhodium porphyrin complex catalyst using water as the hydrogen source without a sacrificial reductant. Mechanistic investigations suggest that bromine atom abstraction via a rhodium porphyrin metalloradical operates to give the rhodium porphyrin alkyl species and the subsequent hydrolysis of the rhodium porphyrin alkyl species to a hydrocarbon product is a key step to harness the hydrogen from water.
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Affiliation(s)
- Wu Yang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, People's Republic of China.
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35
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Strontium-mediated selective protonation of unsaturated linkage of aromatic hydrocarbons and these derivatives. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.04.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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Lei P, Ding Y, Zhang X, Adijiang A, Li H, Ling Y, An J. A Practical and Chemoselective Ammonia-Free Birch Reduction. Org Lett 2018; 20:3439-3442. [PMID: 29846078 DOI: 10.1021/acs.orglett.8b00891] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel protocol for a significantly improved, practical, and chemoselective ammonia-free Birch reduction mediated by bench-stable sodium dispersions and recoverable 15-crown-5 ether is reported. A broad range of aromatic and heteroaromatic compounds is reduced with excellent yields.
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Affiliation(s)
- Peng Lei
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Yuxuan Ding
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Xiaohe Zhang
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Adila Adijiang
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Hengzhao Li
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Yun Ling
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
| | - Jie An
- College of Science , China Agricultural University , No. 2 Yuanmingyuan West Road , Beijing 100193 , China
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37
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Craig RA, Smith RC, Roizen JL, Jones AC, Virgil SC, Stoltz BM. Development of a Unified Enantioselective, Convergent Synthetic Approach Toward the Furanobutenolide-Derived Polycyclic Norcembranoid Diterpenes: Asymmetric Formation of the Polycyclic Norditerpenoid Carbocyclic Core by Tandem Annulation Cascade. J Org Chem 2018; 83:3467-3485. [PMID: 29464957 PMCID: PMC5889334 DOI: 10.1021/acs.joc.7b02825] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
An enantioselective and diastereoselective approach toward the synthesis of the tetracyclic scaffold of the furanobutenolide-derived polycyclic norditerpenoids is described. Focusing on synthetic efforts toward ineleganolide, the synthetic approach utilizes a palladium-catalyzed enantioselective allylic alkylation for the construction of the requisite chiral tertiary ether. A diastereoselective cyclopropanation-Cope rearrangement cascade enabled the convergent assembly of the ineleganolide [6,7,5,5]-tetracyclic scaffold. Investigation of substrates for this critical tandem annulation process is discussed along with synthetic manipulations of the [6,7,5,5]-tetracyclic scaffold and the attempted interconversion of the [6,7,5,5]-tetracyclic scaffold of ineleganolide to the isomeric [7,6,5,5]-core of scabrolide A and its naturally occurring isomers. Computational evaluation of ground-state energies of late-stage synthetic intermediates was used to guide synthetic development and aid in the investigation of the conformational rigidity of these highly constrained and compact polycyclic structures.
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Affiliation(s)
- Robert A. Craig
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Russell C. Smith
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Jennifer L. Roizen
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Amanda C. Jones
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Scott C. Virgil
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Brian M. Stoltz
- Warren and Katherine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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38
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Mullane KC, Cheisson T, Nakamaru-Ogiso E, Manor BC, Carroll PJ, Schelter EJ. Reduction of Carbonyl Groups by Uranium(III) and Formation of a Stable Amide Radical Anion. Chemistry 2018; 24:826-837. [PMID: 28873254 DOI: 10.1002/chem.201703396] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Indexed: 12/25/2022]
Abstract
Methyl benzoate, N,N-dimethylbenzamide, and benzophenone were reduced by UIII [N(SiMe3 )2 ]3 resulting in uranium(IV) products. Reduction of benzophenone lead to UIV [OC⋅Ph2 )][N(SiMe3 )2 ]3 , (1.1) which forms the dinuclear complex, [N(SiMe3 )2 ]3 UIV (OCPhPh-CPh2 O)UIV [N(SiMe3 )2 ]3 (1.2), through coupling of the ketyl radical species upon crystallization. Reaction of N,N-dimethylbenzamide with UIII [N(SiMe3 )2 ]3 resulted in UIV [OC⋅(Ph)(NMe2 )][N(SiMe3 )2 ]3 (2), a uranium(IV) compound and the first example of a charge-separated amide radical. In the case of methyl benzoate, the reduction resulted in UIV (OMe)[N(SiMe3 )2 ]3 (3) and benzaldehyde as the reduced organic fragment. Compound 2 showed the ability to act as a uranium(III) synthon in its reactivity with trimethylsilyl azide, a reaction that yielded UV (=NSiMe3 )[N(SiMe3 )2 ]3 . Additionally, 2 was reduced with potassium graphite resulting in [U(μ-O)[O=C(NMe2 )(Ph)][N(SiMe3 )2 ]2 ]2 (4), a dinuclear uranium compound bridged by oxo ligands. Reduction of 2 in the presence of 15-crown-5 afforded isolation of the mono-oxo compound, [(15-crown-5)2 K][UO[N(SiMe3 )2 ]3 ] (5). The results expand the reduction capabilities of UIII complexes and demonstrate a strategy for isolating novel metal-stabilized radicals.
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Affiliation(s)
- Kimberly C Mullane
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Pennsylvania, 19104, USA
| | - Thibault Cheisson
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Pennsylvania, 19104, USA
| | - Eiko Nakamaru-Ogiso
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, 19104, USA.,Mitochondrial Medicine Center, Children's Hospital of Philadelphia, Pennsylvania, 19104, USA
| | - Brian C Manor
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Pennsylvania, 19104, USA
| | - Patrick J Carroll
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Pennsylvania, 19104, USA
| | - Eric J Schelter
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Pennsylvania, 19104, USA
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39
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Konarev DV, Kuzmin AV, Nakano Y, Khasanov SS, Otsuka A, Yamochi H, Kitagawa H, Lyubovskaya RN. Synthesis and properties of N-methylimidazole solvates of vanadium(ii), chromium(ii) and iron(ii) phthalocyanines. Strong NIR absorption in VII(MeIm)2(Pc2−). Dalton Trans 2018. [DOI: 10.1039/c8dt00459e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crystal structures and optical and magnetic properties of N-methylimidazole (MeIm) solvates of vanadium(ii), chromium(ii) and iron(ii) phthalocyanines have been studied.
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Affiliation(s)
- Dmitri V. Konarev
- Institute of Problems of Chemical Physics RAS
- Chernogolovka
- 142432 Russia
| | | | - Yoshiaki Nakano
- Division of Chemistry
- Graduate School of Science
- Kyoto University
- Kyoto 606-8502
- Japan
| | | | - Akihiro Otsuka
- Division of Chemistry
- Graduate School of Science
- Kyoto University
- Kyoto 606-8502
- Japan
| | - Hideki Yamochi
- Division of Chemistry
- Graduate School of Science
- Kyoto University
- Kyoto 606-8502
- Japan
| | - Hiroshi Kitagawa
- Division of Chemistry
- Graduate School of Science
- Kyoto University
- Kyoto 606-8502
- Japan
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40
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Ghosh SK, Cummins CC, Gladysz JA. A direct route from white phosphorus and fluorous alkyl and aryl iodides to the corresponding trialkyl- and triarylphosphines. Org Chem Front 2018. [DOI: 10.1039/c8qo00943k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The title reaction is effected with samarium(ii) reductants that generate fluorous radicals that add to P4 with phosphorus–phosphorus bond cleavage.
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Affiliation(s)
| | | | - John A. Gladysz
- Department of Chemistry
- Texas A&M University
- Texas 77843-3012
- USA
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41
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Piontek A, Szostak M. Iron-Catalyzed C(sp2)-C(sp3) Cross-Coupling of Alkyl Grignard Reagents with Polyaromatic Tosylates. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701654] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Aleksandra Piontek
- Department of Chemistry; Opole University; 48 Oleska Street 45-052 Opole Poland
| | - Michal Szostak
- Department of Chemistry; Opole University; 48 Oleska Street 45-052 Opole Poland
- Department of Chemistry; Rutgers University; 73 Warren Street 07102 Newark NJ USA
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42
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Synthesis of Nitrogen Heterocycles Using Samarium(II) Iodide. Molecules 2017; 22:molecules22112018. [PMID: 29160806 PMCID: PMC6150357 DOI: 10.3390/molecules22112018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 11/11/2017] [Accepted: 11/13/2017] [Indexed: 11/19/2022] Open
Abstract
Nitrogen heterocycles represent vital structural motifs in biologically-active natural products and pharmaceuticals. As a result, the development of new, convenient and more efficient processes to N-heterocycles is of great interest to synthetic chemists. Samarium(II) iodide (SmI2, Kagan’s reagent) has been widely used to forge challenging C–C bonds through reductive coupling reactions. Historically, the use of SmI2 in organic synthesis has been focused on the construction of carbocycles and oxygen-containing motifs. Recently, significant advances have taken place in the use of SmI2 for the synthesis of nitrogen heterocycles, enabled in large part by the unique combination of high reducing power of this reagent (E1/2 of up to −2.8 V) with excellent chemoselectivity of the reductive umpolung cyclizations mediated by SmI2. In particular, radical cross-coupling reactions exploiting SmI2-induced selective generation of aminoketyl radicals have emerged as concise and efficient methods for constructing 2-azabicycles, pyrrolidines and complex polycyclic barbiturates. Moreover, a broad range of novel processes involving SmI2-promoted formation of aminyl radicals have been leveraged for the synthesis of complex nitrogen-containing molecular architectures by direct and tethered pathways. Applications to the synthesis of natural products have highlighted the generality of processes and the intermediates accessible with SmI2. In this review, recent advances involving the synthesis of nitrogen heterocycles using SmI2 are summarized, with a major focus on reductive coupling reactions that enable one-step construction of nitrogen-containing motifs in a highly efficient manner, while taking advantage of the spectacular selectivity of the venerable Kagan’s reagent.
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43
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Maity S, Flowers RA, Hoz S. Aza versus Oxophilicity of SmI
2
: A Break of a Paradigm. Chemistry 2017; 23:17070-17077. [PMID: 29024166 DOI: 10.1002/chem.201703394] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Sandeepan Maity
- Department of Chemistry Lehigh University 6 E Packer Ave. Bethlehem Pennsylvania- 18015 USA
- Department of Chemistry Bar-Ilan University Geha Road Ramat Gan- 52900 Israel
| | - Robert A. Flowers
- Department of Chemistry Lehigh University 6 E Packer Ave. Bethlehem Pennsylvania- 18015 USA
| | - Shmaryahu Hoz
- Department of Chemistry Bar-Ilan University Geha Road Ramat Gan- 52900 Israel
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44
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Huang HM, Procter DJ. Radical Heterocyclization and Heterocyclization Cascades Triggered by Electron Transfer to Amide-Type Carbonyl Compounds. Angew Chem Int Ed Engl 2017; 56:14262-14266. [DOI: 10.1002/anie.201708354] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Huan-Ming Huang
- School of Chemistry; University of Manchester; Manchester M13 9PL UK
| | - David J. Procter
- School of Chemistry; University of Manchester; Manchester M13 9PL UK
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45
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Huang HM, Procter DJ. Radical Heterocyclization and Heterocyclization Cascades Triggered by Electron Transfer to Amide-Type Carbonyl Compounds. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708354] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Huan-Ming Huang
- School of Chemistry; University of Manchester; Manchester M13 9PL UK
| | - David J. Procter
- School of Chemistry; University of Manchester; Manchester M13 9PL UK
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46
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Smith AJ, Young A, Rohrbach S, O'Connor EF, Allison M, Wang HS, Poole DL, Tuttle T, Murphy JA. Electron-Transfer and Hydride-Transfer Pathways in the Stoltz-Grubbs Reducing System (KOtBu/Et3SiH). Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201707914] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Andrew J. Smith
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Allan Young
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Simon Rohrbach
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Erin F. O'Connor
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Mark Allison
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Hong-Shuang Wang
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - Darren L. Poole
- Flexible Discovery Unit; GlaxoSmithKline Medicines Research Centre; Gunnels Wood Road Stevenage SG1 2NY UK
| | - Tell Tuttle
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
| | - John A. Murphy
- Department of Pure and Applied Chemistry; University of Strathclyde; 295 Cathedral Street Glasgow G1 1XL UK
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47
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Smith AJ, Young A, Rohrbach S, O'Connor EF, Allison M, Wang HS, Poole DL, Tuttle T, Murphy JA. Electron-Transfer and Hydride-Transfer Pathways in the Stoltz-Grubbs Reducing System (KOtBu/Et 3 SiH). Angew Chem Int Ed Engl 2017; 56:13747-13751. [PMID: 28892585 PMCID: PMC5656899 DOI: 10.1002/anie.201707914] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/28/2017] [Indexed: 01/30/2023]
Abstract
Recent studies by Stoltz, Grubbs et al. have shown that triethylsilane and potassium tert-butoxide react to form a highly attractive and versatile system that shows (reversible) silylation of arenes and heteroarenes as well as reductive cleavage of C-O bonds in aryl ethers and C-S bonds in aryl thioethers. Their extensive mechanistic studies indicate a complex network of reactions with a number of possible intermediates and mechanisms, but their reactions likely feature silyl radicals undergoing addition reactions and SH 2 reactions. This paper focuses on the same system, but through computational and experimental studies, reports complementary facets of its chemistry based on a) single-electron transfer (SET), and b) hydride delivery reactions to arenes.
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Affiliation(s)
- Andrew J Smith
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Allan Young
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Simon Rohrbach
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Erin F O'Connor
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Mark Allison
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Hong-Shuang Wang
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - Darren L Poole
- Flexible Discovery Unit, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Tell Tuttle
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
| | - John A Murphy
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK
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48
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Kolmar SS, Mayer JM. SmI 2(H 2O) n Reduction of Electron Rich Enamines by Proton-Coupled Electron Transfer. J Am Chem Soc 2017; 139:10687-10692. [PMID: 28718640 PMCID: PMC5812026 DOI: 10.1021/jacs.7b03667] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Samarium diiodide in the presence of water and THF (SmI2(H2O)n) has in recent years become a versatile and useful reagent, mainly for reducing carbonyl-type substrates. This work reports the reduction of several enamines by SmI2(H2O)n. Mechanistic experiments implicate a concerted proton-coupled electron transfer (PCET) pathway, based on various pieces of evidence against initial outer-sphere electron transfer, proton transfer, or substrate coordination. A thermochemical analysis indicates that the C-H bond formed in the rate-determining step has a bond dissociation free energy (BDFE) of ∼32 kcal mol-1. The O-H BDFE of the samarium aquo ion is estimated to be 26 kcal mol-1, which is among the weakest known X-H bonds of stable reagents. Thus, SmI2(H2O)n should be able to form very weak C-H bonds. The reduction of these highly electron rich substrates by SmI2(H2O)n shows that this reagent is a very strong hydrogen atom donor as well as an outer-sphere reductant.
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Affiliation(s)
- Scott S. Kolmar
- Department of Chemistry, Yale University, New Haven, Connecticut, 06520
| | - James M. Mayer
- Department of Chemistry, Yale University, New Haven, Connecticut, 06520
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49
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Chciuk TV, Anderson WR, Flowers RA. Reversibility of Ketone Reduction by SmI2–Water and Formation of Organosamarium Intermediates. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00392] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Tesia V. Chciuk
- Department of Chemistry, Lehigh University, 6
East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - William R. Anderson
- Department of Chemistry, Lehigh University, 6
East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Robert A. Flowers
- Department of Chemistry, Lehigh University, 6
East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
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50
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Jones C. Dimeric magnesium(I) β-diketiminates: a new class of quasi-universal reducing agent. Nat Rev Chem 2017. [DOI: 10.1038/s41570-017-0059] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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