1
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Liu X, Dong S, Zhu J, Inoue S. Dialumene as a Dimeric or Monomeric Al Synthon for C-F Activation in Monofluorobenzene. J Am Chem Soc 2024; 146:23591-23597. [PMID: 39165246 PMCID: PMC11345846 DOI: 10.1021/jacs.4c08171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 08/22/2024]
Abstract
The activation of C-F bonds has long been regarded as the subject of research in organometallic chemistry, given their synthetic relevance and the fact that fluorine is the most abundant halogen in the Earth's crust. However, C-F bond activation remains a largely unsolved challenge due to the high bond dissociation energies, which was historically dominated by transition metal complexes. Main group elements that can cleave unactivated monofluorobenzene are still quite rare and restricted to s-block complexes with a biphilic nature. Herein, we demonstrate an Al-mediated activation of monofluorobenzene using a neutral dialumene, allowing for the synthesis of the formal oxidative addition products at either double or single aluminum centers. This neutral dialumene system introduces a novel methodology for C-F bond activation based on formal oxidative addition and reductive elimination processes around the two aluminum centers, as demonstrated by combined experimental and computational studies. A "masked" alumylene was unprecedentedly synthesized to prove the proposed reductive elimination pathway. Furthermore, the synthetic utility is highlighted by the functionalization of the resulting aryl-aluminum compounds.
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Affiliation(s)
- Xufang Liu
- TUM
School of Natural Sciences, Department of Chemistry, Institute of
Silicon Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraße 4, Garching bei München 85748, Germany
| | - Shicheng Dong
- State
Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative
Innovation Center of Chemistry for Energy Materials (iChem), Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jun Zhu
- School
of Science and Engineering, The Chinese
University of Hong Kong, Shenzhen 518172, China
| | - Shigeyoshi Inoue
- TUM
School of Natural Sciences, Department of Chemistry, Institute of
Silicon Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraße 4, Garching bei München 85748, Germany
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2
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R Judge N, Logallo A, Hevia E. Main group metal-mediated strategies for C-H and C-F bond activation and functionalisation of fluoroarenes. Chem Sci 2023; 14:11617-11628. [PMID: 37920337 PMCID: PMC10619642 DOI: 10.1039/d3sc03548d] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/11/2023] [Indexed: 11/04/2023] Open
Abstract
With fluoroaromatic compounds increasingly employed as scaffolds in agrochemicals and active pharmaceutical ingredients, the development of methods which facilitate regioselective functionalisation of their C-H and C-F bonds is a frontier of modern synthesis. Along with classical lithiation and nucleophilic aromatic substitution protocols, the vast majority of research efforts have focused on transition metal-mediated transformations enabled by the redox versatilities of these systems. Breaking new ground in this area, recent advances in main group metal chemistry have delineated unique ways in which s-block, Al, Ga and Zn metal complexes can activate this important type of fluorinated molecule. Underpinned by chemical cooperativity, these advances include either the use of heterobimetallic complexes where the combined effect of two metals within a single ligand set enables regioselective low polarity C-H metalation; or the use of novel low valent main group metal complexes supported by special stabilising ligands to induce C-F bond activations. Merging these two different approaches, this Perspective provides an overview of the emerging concept of main-group metal mediated C-H/C-F functionalisation of fluoroarenes. Showcasing the untapped potential that these systems can offer in these processes; focus is placed on how special chemical cooperation is established and how the trapping of key reaction intermediates can inform mechanistic understanding.
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Affiliation(s)
- Neil R Judge
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern Switzerland
| | - Alessandra Logallo
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern Switzerland
| | - Eva Hevia
- Departement für Chemie, Biochemie und Pharmazie, Universität Bern Switzerland
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3
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Liu HY, Hill MS, Mahon MF, McMullin CL, Schwamm RJ. Seven-Membered Cyclic Diamidoalumanyls of Heavier Alkali Metals: Structures and C-H Activation of Arenes. Organometallics 2023; 42:2881-2892. [PMID: 37829511 PMCID: PMC10565898 DOI: 10.1021/acs.organomet.3c00323] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Indexed: 10/14/2023]
Abstract
Like the previously reported potassium-based system, rubidium and cesium reduction of [{SiNDipp}AlI] ({SiNDipp} = {CH2SiMe2NDipp}2) with the heavier alkali metals [M = Rb and Cs] provides dimeric group 1 alumanyl derivatives, [{SiNDipp}AlM]2. In contrast, similar treatment with sodium results in over-reduction and incorporation of a formal equivalent of [{SiNDipp}Na2] into the resultant sodium alumanyl species. The dimeric K, Rb, and Cs compounds display a variable efficacy toward the C-H oxidative addition of arene C-H bonds at elevated temperatures (Cs > Rb > K, 110 °C) to yield (hydrido)(organo)aluminate species. Consistent with the synthetic experimental observations, computational (DFT) assessment of the benzene C-H activation indicates that rate-determining attack of the Al(I) nucleophile within the dimeric species is facilitated by π-engagement of the arene with the electrophilic M+ cation, which becomes increasingly favorable as group 1 is descended.
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Affiliation(s)
- Han-Ying Liu
- 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.
| | - Ryan J. Schwamm
- Department of Chemistry, University
of Bath, Claverton
Down, Bath BA2 7AY, U.K.
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4
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Iwasaki T, Kambe N. Cross- and Multi-Coupling Reactions Using Monofluoroalkanes. CHEM REC 2023; 23:e202300033. [PMID: 37070641 DOI: 10.1002/tcr.202300033] [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: 01/30/2023] [Revised: 04/03/2023] [Indexed: 04/19/2023]
Abstract
Carbon-fluorine bonds are stable and have demonstrated sluggishness against various chemical manipulations. However, selective transformations of C-F bonds can be achieved by developing appropriate conditions as useful synthetic methods in organic chemistry. This review focuses on C-C bond formation at monofluorinated sp3 -hybridized carbons via C-F bond cleavage, including cross-coupling and multi-component coupling reactions. The C-F bond cleavage mechanisms on the sp3 -hybridized carbon centers can be primarily categorized into three types: Lewis acids promoted F atom elimination to generate carbocation intermediates; nucleophilic substitution with metal or carbon nucleophiles supported by the activation of C-F bonds by coordination of Lewis acids; and the cleavage of C-F bonds via a single electron transfer. The characteristic features of alkyl fluorides, in comparison with other (pseudo)halides as promising electrophilic coupling counterparts, are also discussed.
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Affiliation(s)
- Takanori Iwasaki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Nobuaki Kambe
- Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka, 565-0871, Japan
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5
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Mato M, Bruzzese PC, Takahashi F, Leutzsch M, Reijerse EJ, Schnegg A, Cornella J. Oxidative Addition of Aryl Electrophiles into a Red-Light-Active Bismuthinidene. J Am Chem Soc 2023; 145:18742-18747. [PMID: 37603853 PMCID: PMC10472430 DOI: 10.1021/jacs.3c06651] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Indexed: 08/23/2023]
Abstract
The oxidative addition of aryl electrophiles is a fundamental organometallic reaction widely applied in the field of transition metal chemistry and catalysis. However, the analogous version based on main group elements still remains largely underexplored. Here, we report the ability of a well-defined organobismuth(I) complex to undergo formal oxidative addition with a wide range of aryl electrophiles. The process is facilitated by the reactivity of both the ground and excited states of N,C,N-bismuthinidenes upon absorption of low-energy red light.
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Affiliation(s)
- Mauro Mato
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Paolo Cleto Bruzzese
- Max
Planck Institute for Chemical Energy Conversion, Stiftstrasse 34−36, Mülheim an der Ruhr 45470, Germany
| | - Fumiya Takahashi
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Markus Leutzsch
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Edward J. Reijerse
- Max
Planck Institute for Chemical Energy Conversion, Stiftstrasse 34−36, Mülheim an der Ruhr 45470, Germany
| | - Alexander Schnegg
- Max
Planck Institute for Chemical Energy Conversion, Stiftstrasse 34−36, Mülheim an der Ruhr 45470, Germany
| | - Josep Cornella
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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6
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Abstract
ConspectusHypervalent iodine reagents find application as selective chemical oxidants in a diverse array of oxidative transformations. The utility of these reagents is often ascribed to (1) the proclivity to engage being selective two-electron redox transformations; (2) facile ligand exchange at the three-centered, four-electron (3c-4e) hypervalent iodine-ligand (I-X) bonds; and (3) the hypernucleofugacity of aryl iodides. One-electron redox and iodine radical chemistry is well-precedented in the context of inorganic hypervalent iodine chemistry─for example, in the iodide-triiodide couple that drives dye-sensitized solar cells. In contrast, organic hypervalent iodine chemistry has historically been dominated by the two-electron I(I)/I(III) and I(III)/I(V) redox couples, which results from intrinsic instability of the intervening odd-electron species. Transient iodanyl radicals (i.e., formally I(II) species), generated by reductive activation of hypervalent I-X bonds, have recently gained attention as potential intermediates in hypervalent iodine chemistry. Importantly, these open-shell intermediates are typically generated by activation of stoichiometric hypervalent iodine reagents, and the role of the iodanyl radical in substrate functionalization and catalysis is largely unknown.Our group has been interested in advancing the chemistry of iodanyl radicals as intermediates in the sustainable synthesis of hypervalent I(III) and I(V) compounds and as novel platforms for substrate activation at open-shell main-group intermediates. In 2018, we disclosed the first example of aerobic hypervalent iodine catalysis by intercepting reactive intermediates in aldehyde autoxidation chemistry. While we initially hypothesized that the observed oxidation was accomplished by aerobically generated peracids via a two-electron I(I)-to-I(III) oxidation reaction, detailed mechanistic studies revealed the critical role of acetate-stabilized iodanyl radical intermediates. We subsequently leveraged these mechanistic insights to develop hypervalent iodine electrocatalysis. Our studies resulted in the identification of new catalyst design principles that give rise to highly efficient organoiodide electrocatalysts that operate at modest applied potentials. These advances addressed classical challenges in hypervalent iodine electrocatalysis related to the need for high applied potentials and high catalyst loadings. In some cases, we were able to isolate the anodically generated iodanyl radical intermediates, which allowed direct interrogation of the elementary chemical reactions characteristic of iodanyl radicals. Both substrate activation via bidirectional proton-coupled electron transfer (PCET) reactions at I(II) intermediates and disproportionation reactions of I(II) species to generate I(III) compounds have been experimentally validated.This Account discusses the emerging synthetic and catalytic chemistry of iodanyl radicals. Results from our group have demonstrated that these open-shell species can play a critical role in sustainable synthesis of hypervalent iodine reagents and play a heretofore unappreciated role in catalysis. Realization of I(I)/I(II) catalytic cycles as a mechanistic alternative to canonical two-electron iodine redox chemistry promises to open new avenues to application of organoiodides in catalysis.
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Affiliation(s)
- Asim Maity
- Texas A&M University, College Station, Texas 77843, United States
| | - Brandon L. Frey
- Texas A&M University, College Station, Texas 77843, United States
| | - David C. Powers
- Texas A&M University, College Station, Texas 77843, United States
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7
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Poole EW, Bustos I, Hood TM, Smart JE, Chaplin AB. Iridium complexes of an ortho-trifluoromethylphenyl substituted PONOP pincer ligand. Dalton Trans 2023; 52:1096-1104. [PMID: 36602231 PMCID: PMC9872493 DOI: 10.1039/d2dt03608h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The synthesis and iridium coordination chemistry of a new pyridine-based phosphinito pincer ligand 2,6-(ArF2PO)2C5H3N (PONOP-ArF; ArF = 2-(CF3)C6H4) are described, where the P-donors have ortho-trifluoromethylphenyl substituents. The iridium(III) 2,2'-biphenyl (biph) derivative [Ir(PONOP-ArF)(biph)Cl] was obtained by reaction with [Ir(biph)(COD)Cl]2 (COD = 1,5-cyclooctadiene) and subsequent halide ion abstraction enabled isolation of [Ir(PONOP-ArF)(biph)]+ which features an Ir ← F-C bonding interaction in the solid state. Hydrogenolysis of the biphenyl ligand and formation of [Ir(PONOP-ArF)(H)2]+ was achieved by prolonged reaction of [Ir(PONOP-ArF)(biph)]+ with dihydrogen. This transformation paved the way for isolation and crystallographic characterisation of low valent iridium derivatives through treatment of the dihydride with tert-butylethylene (TBE). The iridium(I) π-complex [Ir(PONOP-ArF)(TBE)]+ is thermally stable but substitution of TBE can be achieved by reaction with carbon monoxide. The solid-state structure of the mono-carbonyl product [Ir(PONOP-ArF)(CO)]+ is notable for an intermolecular anagostic interaction between the metal centre and a pentane molecule which co-crystallises within a cleft defined by two aryl phosphine substituents.
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Affiliation(s)
- Ethan W. Poole
- Department of Chemistry, University of WarwickGibbet Hill RoadCoventry CV4 7ALUK
| | - Itxaso Bustos
- Department of Chemistry, University of WarwickGibbet Hill RoadCoventry CV4 7ALUK,Facultad de Química de San Sebastián, Universidad del País Vasco (UPV/EHU)Apdo. 107220080 San SebastiánSpain
| | - Thomas M. Hood
- Department of Chemistry, University of WarwickGibbet Hill RoadCoventry CV4 7ALUK
| | - Jennifer E. Smart
- Department of Chemistry, University of WarwickGibbet Hill RoadCoventry CV4 7ALUK
| | - Adrian B. Chaplin
- Department of Chemistry, University of WarwickGibbet Hill RoadCoventry CV4 7ALUK
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8
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Krüger J, Wölper C, Schulz S. Role of Group 13 Metals in the Electronic Properties of L(X)M-Substituted Pnictinidenes. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- Julia Krüger
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstraße 5-7, Essen 45141, Germany
| | - Christoph Wölper
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstraße 5-7, Essen 45141, Germany
| | - Stephan Schulz
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstraße 5-7, Essen 45141, Germany
- Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, Duisburg 47057, Germany
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9
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Morris LJ, Rajeshkumar T, Maron L, Okuda J. Reversible Oxidative Addition of Zinc Hydride at a Gallium(I)-Centre: Labile Mono- and Bis(hydridogallyl)zinc Complexes. Chemistry 2022; 28:e202201480. [PMID: 35819049 PMCID: PMC9804236 DOI: 10.1002/chem.202201480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Indexed: 01/05/2023]
Abstract
In the presence of TMEDA (N,N,N',N'-tetramethylethylenediamine), partially deaggregated zinc dihydride as hydrocarbon suspensions react with the gallium(I) compound [(BDI)Ga] (I, BDI={HC(C(CH3 )N(2,6-iPr2 -C6 H3 ))2 }- ) by formal oxidative addition of a Zn-H bond to the gallium(I) centre. Dissociation of the labile TMEDA ligand in the resulting complex [(BDI)Ga(H)-(H)Zn(tmeda)] (1) facilitates insertion of a second equiv. of I into the remaining Zn-H to form a thermally sensitive trinuclear species [{(BDI)Ga(H)}2 Zn] (2). Compound 1 exchanges with polymeric zinc dideuteride [ZnD2 ]n in the presence of TMEDA, and with compounds I and 2 via sequential and reversible ligand dissociation and gallium(I) insertion. Spectroscopic and computational studies demonstrate the reversibility of oxidative addition of each Zn-H bond to the gallium(I) centres.
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Affiliation(s)
- Louis J. Morris
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
- Chemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUnited Kingdom
| | | | - Laurent Maron
- CNRSINSAUPSUMR 5215LPCNOUniversité de Toulouse31077ToulouseFrance
| | - Jun Okuda
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
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10
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Ghosh B, Phukan AK. Unravelling the Potential of Ylides in Stabilizing Low-Valent Group 13 Compounds: Theoretical Predictions of Stable, Five-Membered Group 13 (Aluminum and Gallium) Carbenoids Capable of Small-Molecule Activation. Inorg Chem 2022; 61:14606-14615. [PMID: 36059112 DOI: 10.1021/acs.inorgchem.2c01630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Computational investigations provide evidence toward the remarkable ability of strongly electron-donating ylidic functionalities in stabilizing singlet group 13 carbenoids with promising ligand properties. All of the proposed carbenoids are found to be considerably nucleophilic and possess significant singlet-triplet energy separation values. The calculated activation barriers and reaction free energies obtained for the cleavage of different enthalpically strong bonds by these carbenoids are found to be either comparable to or lower than those of the experimentally evaluated aluminum and gallium carbenoids, thereby indicating their potential in small-molecule activation.
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Affiliation(s)
- Bijoy Ghosh
- Department of Chemical Sciences, Tezpur University, Napam 784028, Assam, India
| | - Ashwini K Phukan
- Department of Chemical Sciences, Tezpur University, Napam 784028, Assam, India
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11
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Du X, Zhang C, Liu S. Radical-Friedel-Crafts benzylation of arenes with benzyl ethers over 2H-MoS 2: ether cleavage into carbon- and oxygen-centered radicals. Dalton Trans 2022; 51:15322-15329. [PMID: 36102605 DOI: 10.1039/d2dt02801h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The selective activation of C-O ether bonds is an essential tool in organic synthesis and natural polymer depolymerization. However, the direct cleavage of the ether bond is still challenging work, especially breaking this inert and redox-neutral bond to provide one active carbon radical and another oxygen-centered fragment with oxidation capacity that can participate in the controllable radical reaction. We herein report that commercial 2H-MoS2 with negligible acidity can efficiently catalyze the benzylation of arenes with benzyl ethers, and a new Radical-Friedel-Crafts mechanism is proposed, which is quite different from the strong acid-catalyzed Friedel-Crafts mechanism. With dibenzyl ether as the model benzylation reagent, 2H-MoS2 can achieve the homolytic cleavage of the Bn-OR bond to generate the benzyl carbon radical and RO˙ species, identified by EPR measurement and radical trap experiments. The following radical-involved benzylation is confirmed by the Hammett results and a plausible pathway is proposed to clarify the Radical-Friedel-Crafts process. Heterogeneous 2H-MoS2 can be consecutively used four times without regeneration and it offers 94-95% yields of 2-benzyl-1,4-dimethylbenzene from dibenzyl ether and p-xylene in 30 min at 140 °C. Furthermore, this mechanism can provide some inspiration to activate the ether bond and to utilize ether as an oxidant in C-H bond activation.
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Affiliation(s)
- Xinze Du
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chaofeng Zhang
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.,College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China.
| | - Shenglin Liu
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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12
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Dodonov VA, Sokolov VG, Baranov EV, Skatova AA, Xu W, Zhao Y, Yang XJ, Fedushkin IL. Reactivity of Transition Metal Gallylene Complexes Toward Substrates with Multiple Carbon–Element Bonds. Inorg Chem 2022; 61:14962-14972. [DOI: 10.1021/acs.inorgchem.2c01296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vladimir A. Dodonov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Vladimir G. Sokolov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Evgeny V. Baranov
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Alexandra A. Skatova
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
| | - Wenhua Xu
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Yanxia Zhao
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Xiao-Juan Yang
- College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China
| | - Igor L. Fedushkin
- G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences (IOMC RAS), Tropinina 49, Nizhny Novgorod 603950, Russian Federation
- Kozma Minin Nizhny Novgorod State Pedagogical University, Ulyanova 1, Nizhny Novgorod 603005, Russian Federation
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13
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Bücker A, Wölper C, Haberhauer G, Schulz S. Structurally characterised intermediate of the oxidative addition of a heteroleptic germylene to gallanediyle. Chem Commun (Camb) 2022; 58:9758-9761. [PMID: 35959720 DOI: 10.1039/d2cc03561h] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bond activation reactions using main group metal complexes are gaining increasing interest. We report on reactions of LGa (L = HC[C(Me)N(Ar)]2, Ar = Dipp = 2,6-i-Pr2C6H3,) with heteroleptic tetrylenes L'ECl (E = Ge, Sn; L' = N(SiMe3)Ar), yielding the donor-acceptor complex LGa-Sn(Cl)L' (1) or the oxidative addition product L(Cl)GaGeL' (3). The reaction with DMPGeCl (DMP = 2,6-Mes2C6H3, Mes = 2,4,6-Me3C6H2) yielded LGa(μ-Cl)GeDMP (2), which represents an intermediate of the oxidative addition reaction. 1-3 were characterized by NMR and IR spectroscopy as well as by single crystal X-ray diffraction (sc-XRD), while their electronic nature was analyzed by quantum chemical calculations.
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Affiliation(s)
- Anna Bücker
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45117 Essen, Germany.
| | - Christoph Wölper
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45117 Essen, Germany.
| | - Gebhard Haberhauer
- Institute of Organic Chemistry, University of Duisburg-Essen, 45117 Essen, Germany
| | - Stephan Schulz
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45117 Essen, Germany. .,Center for Nanointegration Duisburg-Essen (Cenide), University of Duisburg-Essen, 47057 Duisburg, Germany
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14
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Bakewell C, Hobson K, Carmalt CJ. Exploring Equilibria between Aluminium(I) and Aluminium(III): The Formation of Dihydroalanes, Masked Dialumenes and Aluminium(I) Species. Angew Chem Int Ed Engl 2022; 61:e202205901. [PMID: 35474268 PMCID: PMC9401008 DOI: 10.1002/anie.202205901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Indexed: 11/08/2022]
Abstract
The design of new reductive routes to low oxidation state aluminium (Al) compounds offers the opportunity to better understand redox processes at the metal centre and develop reactivity accordingly. Here, a monomeric AlI compound acts as a stoichiometric reducing agent towards a series of AlIII dihydrides, leading to the formation of new low oxidation state species including symmetric and asymmetric dihydrodialanes, and a masked dialumene. These compounds are formed by a series of equilibrium processes involving AlI , AlII and AlIII species and product formation can be manipulated by fine-tuning the reaction conditions. The transient formation of monomeric AlI compounds is proposed: this is shown to be energetically viable by computational (DFT) investigations and reactivity studies show support for the formation of AlI species. Importantly, despite the potential for the equilibrium mixtures to lead to ill-defined reactivity, controlled reactivity of these low oxidation state species is observed.
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Affiliation(s)
- Clare Bakewell
- Department of ChemistryKing's College London7 Trinity StreetLondonSE1 1DBUK
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Katie Hobson
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
| | - Claire J. Carmalt
- Department of ChemistryUniversity College London20 Gordon StreetLondonWC1H 0AJUK
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15
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Boreen MA, Ye CZ, Kerridge A, McCabe KN, Skeel BA, Maron L, Arnold J. Does Reduction-Induced Isomerization of a Uranium(III) Aryl Complex Proceed via C-H Oxidative Addition and Reductive Elimination across the Uranium(II/IV) Redox Couple? Inorg Chem 2022; 61:8955-8965. [PMID: 35654478 DOI: 10.1021/acs.inorgchem.2c01563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reaction of the uranium(III) bis(amidinate) aryl complex {TerphC(NiPr)2}2U(Terph) (2, where Terph = 4,4″-di-tert-butyl-m-terphenyl-2'-yl) with a strong reductant enabled isolation of isomeric uranium(III) bis(amidinate) aryl product {TerphC(NiPr)2}2U(Terph*) (3, where Terph* = 4,4″-di-tert-butyl-m-terphenyl-4'-yl). In terms of connectivity, 3 differs from 2 only in the positions of the U-C and C-H bonds on the central aryl ring of the m-terphenyl-based ligand. A deuterium labeling study ruled out mechanisms for this isomerization involving intermolecular abstraction or deprotonation of the ligand C-H bonds activated during the reaction. Due to the complexity of this rapid, heterogeneous reaction, experimental studies could not further distinguish between two different intramolecular C-H activation mechanisms. However, high-level computational studies were consistent with a mechanism that included two sets of unimolecular, mononuclear C-H oxidative addition and reductive elimination steps involving uranium(II/IV).
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Affiliation(s)
- Michael A Boreen
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Christopher Z Ye
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Andrew Kerridge
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, U.K
| | - Karl N McCabe
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, Toulouse 31077, France
| | - Brighton A Skeel
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, Toulouse 31077, France
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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16
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Bakewell C, Hobson K, Carmalt CJ. Exploring Equilibria between Aluminium(I) and Aluminium(III): The Formation of Dihydroalanes, Masked Dialumenes and Aluminium(I) Species. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205901] [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)
- Clare Bakewell
- Department of Chemistry King's College London 7 Trinity Street London SE1 1DB UK
- Department of Chemistry University College London 20 Gordon Street London WC1H 0AJ UK
| | - Katie Hobson
- Department of Chemistry University College London 20 Gordon Street London WC1H 0AJ UK
| | - Claire J. Carmalt
- Department of Chemistry University College London 20 Gordon Street London WC1H 0AJ UK
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17
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Helling C, Ganesamoorthy C, Wölper C, Schulz S. Geminal C-Cl and Si-Cl bond activation of chloromethanes and chlorosilanes by gallanediyl LGa. Dalton Trans 2022; 51:2050-2058. [PMID: 35040458 DOI: 10.1039/d1dt04192d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The activation of relatively inert E-X σ-bonds by low-valent main group metal complexes is receiving increasing interest. We here confirm the promising potential of gallanediyl LGa (L = HC[C(Me)N(Dip)]2, Dip = 2,6-i-Pr2C6H3) to activate E-Cl (E = C, Si) σ-bonds of group 14 element compounds. Equimolar reactions of LGa with chloromethanes and chlorosilanes EHxCl4-x (E = C, x = 0-2; E = Si, x = 0, 1) occurred with E-Cl bond insertion and formation of gallylmethanes and -silanes L(Cl)GaEHxCl3-x (E = C, x = 2 (1), 1 (2), 0 (3); E = Si, x = 1 (4)). In contrast, consecutive insertion into a geminal E-Cl bond was observed with two equivalents of LGa, yielding digallyl complexes [L(Cl)Ga]2EHxCl2-x (E = C, x = 2 (5); E = Si, x = 1 (6), 0 (7)). Compounds 1-7 were characterized by heteronuclear NMR (1H, 13C, 29Si (4, 6)), IR spectroscopy and elemental analysis, and their solid-state structures were determined by single-crystal X-ray diffraction (sc-XRD).
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Affiliation(s)
- Christoph Helling
- Faculty of Chemistry, University of Duisburg-Essen, Universitätsstr. 5-7, S07 S03 C30, D-45117 Essen, Germany.
| | - Chelladurai Ganesamoorthy
- Faculty of Chemistry, University of Duisburg-Essen, Universitätsstr. 5-7, S07 S03 C30, D-45117 Essen, Germany.
| | - Christoph Wölper
- Faculty of Chemistry, University of Duisburg-Essen, Universitätsstr. 5-7, S07 S03 C30, D-45117 Essen, Germany.
| | - Stephan Schulz
- Faculty of Chemistry, University of Duisburg-Essen, Universitätsstr. 5-7, S07 S03 C30, D-45117 Essen, Germany. .,Center for NanoIntegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany
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18
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Moon HW, Cornella J. Bismuth Redox Catalysis: An Emerging Main-Group Platform for Organic Synthesis. ACS Catal 2022; 12:1382-1393. [PMID: 35096470 PMCID: PMC8787757 DOI: 10.1021/acscatal.1c04897] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/09/2021] [Indexed: 12/11/2022]
Abstract
![]()
Bismuth has recently
been shown to be able to maneuver between
different oxidation states, enabling access to unique redox cycles
that can be harnessed in the context of organic synthesis. Indeed,
various catalytic Bi redox platforms have been discovered and revealed
emerging opportunities in the field of main group redox catalysis.
The goal of this perspective is to provide an overview of the synthetic
methodologies that have been developed to date, which capitalize on
the Bi redox cycling. Recent catalytic methods via low-valent Bi(II)/Bi(III),
Bi(I)/Bi(III), and high-valent Bi(III)/Bi(V) redox couples are covered
as well as their underlying mechanisms and key intermediates. In addition,
we illustrate different design strategies stabilizing low-valent and
high-valent bismuth species, and highlight the characteristic reactivity
of bismuth complexes, compared to the lighter p-block
and d-block elements. Although it is not redox catalysis
in nature, we also discuss a recent example of non-Lewis acid, redox-neutral
Bi(III) catalysis proceeding through catalytic organometallic steps.
We close by discussing opportunities and future directions in this
emerging field of catalysis. We hope that this Perspective will provide
synthetic chemists with guiding principles for the future development
of catalytic transformations employing bismuth.
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Affiliation(s)
- Hye Won Moon
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Josep Cornella
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
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19
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Chen S, Lin C, Xu Y, Liu X, Shen L. Pd(II)‐Catalyzed Selective Amination of Inert γ‐C(sp3)‐O Bonds of Aliphatic Amides with Hydrazines. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100765] [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)
- Sai Chen
- Jiangxi Science and Technology Normal University College of Chemistry and Chemical Engineering CHINA
| | - Cong Lin
- Jiangxi Science & Technology Normal University College of Chemistry and Chemical Engineering Fenglin Road 605, College of Chemistry and Chemical Engineering, Nanchang, China 330013 Nanchang CHINA
| | - Yiqing Xu
- Jiangxi Science and Technology Normal University College of Chemistry and Chemical Engineering CHINA
| | - Xiuhong Liu
- Jiangxi Science and Technology Normal University College of Chemistry and Chemical Engineering CHINA
| | - Liang Shen
- Jiangxi Science and Technology Normal University College of Chemistry and Chemical Engineering CHINA
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20
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Ghosh B, Cabrera-Trujillo JJ, Fernández I, Phukan AK. Stable N-heterocyclic borylenes with promising ligand properties: a contribution from theory. Inorg Chem Front 2022. [DOI: 10.1039/d2qi01511k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DFT calculations reveal the power of ylides in stabilizing neutral singlet cyclic borylenes that are found to be capable of activating a variety of small molecules having enthalpically strong bonds.
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Affiliation(s)
- Bijoy Ghosh
- Department of Chemical Sciences, Tezpur University, Napam 784028, Assam, India
| | - Jorge Juan Cabrera-Trujillo
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Ashwini K. Phukan
- Department of Chemical Sciences, Tezpur University, Napam 784028, Assam, India
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21
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Chen Y, Wang F, Liu BX, Rao WD, Wang SY. A Ni( ii)-catalyzed reductive cross-coupling reaction of oxalates and thiosulfonates/selenosulfonates. Org Chem Front 2022. [DOI: 10.1039/d1qo01614h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Ni(ii)-catalyzed reductive cross-coupling reaction of oxalates and thiosulfonates/selenosulfonates to synthesize benzylic sulfides/selenides under mild conditions is developed.
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Affiliation(s)
- Ying Chen
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China
| | - Fei Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China
| | - Bo-Xi Liu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China
| | - Wei-Dong Rao
- Key Laboratory of Biomass-based Green Fuels and Chemicals, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Shun-Yi Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China
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22
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Hoobler PR, Villegas-Escobar N, Turney JM, Toro-Labbé A, Schaefer HF. Substituent Effects on Aluminyl Anions and Derived Systems: A High-Level Theory. J Phys Chem A 2021; 125:10379-10391. [PMID: 34812036 DOI: 10.1021/acs.jpca.1c08918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aluminyl anions are low-valent aluminum species bearing a lone pair of electrons and a negative charge. These systems have drawn recent synthetic interest for their nucleophilic nature, allowing for the activation of σ-bonds, and have been proposed as a pathway to hydrogen energy storage. In this research, we provide high-level ab initio geometries and energies for both the simplest aluminyl anion (AlH2-) and several substituted derivatives. Geometries are reported using the gold-standard CCSD(T)/aug-cc-pV(T+d)Z level of theory. Energies were extrapolated to the complete basis set limit through the focal point approach, utilizing coupled-cluster methods through perturbative quadruples and basis sets up to five-ζ quality. Geometries were rationalized using electrostatic, steric, and orbital donation effects. The donation from substituents to Al is accompanied by back-donation effects, a property traditionally thought of in transition-metal systems. Stereoelectronic effects through the secondary orbital interaction play a fundamental role in stabilizing these low-valent aluminum compounds and would likely also affect the feasibility of their use within several industrial applications. The energetic analysis of the formation of each substituted anion is rationalized as the result of three energetic schemes. The effectiveness of these schemes for determining the relative formation energies is discussed.
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Affiliation(s)
- Preston R Hoobler
- Department of Chemistry, Covenant College, Lookout Mountain, Georgia 30750, United States
| | - Nery Villegas-Escobar
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, Santiago 8370854, Chile
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Alejandro Toro-Labbé
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna, Santiago 4860, Chile
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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23
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Brown RK, Hooper TN, Rekhroukh F, White AJP, Costa PJ, Crimmin MR. Alumination of aryl methyl ethers: switching between sp 2 and sp 3 C-O bond functionalisation with Pd-catalysis. Chem Commun (Camb) 2021; 57:11673-11676. [PMID: 34672313 PMCID: PMC8567294 DOI: 10.1039/d1cc05408b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The reaction of [{(ArNCMe)2CH}Al] (Ar = 2,6-di-iso-propylphenyl) with aryl methyl ethers proceeded with alumination of the sp3 C-O bond. The selectivity of this reaction could be switched by inclusion of a catalyst. In the presence of [Pd(PCy3)2], chemoselective sp2 C-O bond functionalisation was observed. Kinetic isotope experiments and DFT calculations support a catalytic pathway involving the ligand-assisted oxidative addition of the sp2 C-O bond to a Pd-Al intermetallic complex.
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Affiliation(s)
- Ryan K Brown
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Thomas N Hooper
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Feriel Rekhroukh
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Andrew J P White
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Paulo J Costa
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
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24
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Villegas-Escobar N, Toro-Labbé A, Schaefer HF. Contrasting the Mechanism of H 2 Activation by Monomeric and Potassium-Stabilized Dimeric Al I Complexes: Do Potassium Atoms Exert any Cooperative Effect? Chemistry 2021; 27:17369-17378. [PMID: 34613646 DOI: 10.1002/chem.202103082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Indexed: 11/06/2022]
Abstract
Aluminyl anions are low-valent, anionic, and carbenoid aluminum species commonly found stabilized with potassium cations from the reaction of Al-halogen precursors and alkali compounds. These systems are very reactive toward the activation of σ-bonds and in reactions with electrophiles. Various research groups have detected that the potassium atoms play a stabilization role via electrostatic and cation ⋯ π interactions with nearby (aromatic)-carbocyclic rings from both the ligand and from the reaction with unsaturated substrates. Since stabilizing K⋯H bonds are witnessed in the activation of this class of molecules, we aim to unveil the role of these metals in the activation of the smaller and less polarizable H2 molecule, together with a comprehensive characterization of the reaction mechanism. In this work, the activation of H2 utilizing a NON-xanthene-Al dimer, [K{Al(NON)}]2 (D) and monomeric, [Al(NON)]- (M) complexes are studied using density functional theory and high-level coupled-cluster theory to reveal the potential role of K+ atoms during the activation of this gas. Furthermore, we aim to reveal whether D is more reactive than M (or vice versa), or if complicity between the two monomer units exits within the D complex toward the activation of H2 . The results suggest that activation energies using the dimeric and monomeric complexes were found to be very close (around 33 kcal mol-1 ). However, a partition of activation energies unveiled that the nature of the energy barriers for the monomeric and dimeric complexes are inherently different. The former is dominated by a more substantial distortion of the reactants (and increased interaction energies between them). Interestingly, during the oxidative addition, the distortion of the Al complex is minimal, while H2 distorts the most, usually over 0.77 Δ E d i s t ≠ . Overall, it is found here that electrostatic and induction energies between the complexes and H2 are the main stabilizing components up to the respective transition states. The results suggest that the K+ atoms act as stabilizers of the dimeric structure, and their cooperative role on the reaction mechanism may be negligible, acting as mere spectators in the activation of H2 . Cooperation between the two monomers in D is lacking, and therefore the subsequent activation of H2 is wholly disengaged.
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Affiliation(s)
- Nery Villegas-Escobar
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, General Gana 1702, Santiago, 8370854, Chile
| | - Alejandro Toro-Labbé
- Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia, 30602, USA
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25
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Morris LJ, Carpentier A, Maron L, Okuda J. Reductive elimination of [AlH 2] + from a cationic Ga-Al dihydride. Chem Commun (Camb) 2021; 57:9454-9457. [PMID: 34528962 DOI: 10.1039/d1cc03706d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Oxidative addition of TMEDA-supported [AlH2]+ to [{BDI}Ga] (BDI = {HC(C(CH3)N(2,6-iPr2-C6H3))2}) provides [{BDI}Ga(H)-Al(H)(tmeda)][B(C6H3-3,5-Me2)4] (TMEDA = N,N,N'N'-tetramethylethylenediamine) with a covalent metal-metal bond. The reaction is readily reversed by substituting TMEDA for an N-heterocyclic carbene or dissolving in THF.
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Affiliation(s)
- Louis J Morris
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany.
| | - Ambre Carpentier
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 avenue de Rangueil, 31077 Toulouse, France.
| | - Laurent Maron
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 avenue de Rangueil, 31077 Toulouse, France.
| | - Jun Okuda
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany.
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26
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Cabrera‐Trujillo JJ, Fernández I. Factors Controlling the Aluminum(I)-meta-Selective C-H Activation in Arenes. Chemistry 2021; 27:12422-12429. [PMID: 34184800 PMCID: PMC8457071 DOI: 10.1002/chem.202101944] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Indexed: 11/17/2022]
Abstract
The so far poorly understood factors controlling the complete meta-selectivity observed in the C-H activation reactions of alkylarenes promoted by aluminyl anions have been explored in detail by means of Density Functional Theory calculations. To this end, a combination of state-of-the-art computational methods, namely the activation strain model of reactivity and energy decomposition analysis, has been applied to quantitatively unveil the origin of the selectivity of the transformation as well as the influence of the associated potassium cation. It is found that the selectivity takes place during the initial nucleophilic addition step where the key LP(Al)→π*(C=C) molecular orbital interaction is more stabilizing for the meta-pathway, which results in a stronger interaction between the reactants along the entire transformation.
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Affiliation(s)
- Jorge Juan Cabrera‐Trujillo
- Departmento de Química Orgánica I and Centro de Innovación enQuímica Avanzada (ORFEO-CINQA)Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040MadridSpain
| | - Israel Fernández
- Departmento de Química Orgánica I and Centro de Innovación enQuímica Avanzada (ORFEO-CINQA)Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040MadridSpain
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27
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Wiesinger M, Rösch B, Knüpfer C, Mai J, Langer J, Harder S. Carbon‐Halogen Bond Activation with Powerful Heavy Alkaline Earth Metal Hydrides. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100529] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael Wiesinger
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Bastian Rösch
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Christian Knüpfer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jonathan Mai
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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28
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Pang Y, Leutzsch M, Nöthling N, Katzenburg F, Cornella J. Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers. J Am Chem Soc 2021; 143:12487-12493. [PMID: 34358426 PMCID: PMC8377712 DOI: 10.1021/jacs.1c06735] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support a Bi(I)/Bi(III) redox cycle that comprises C(sp2)-F oxidative addition, F/H ligand metathesis, and C(sp2)-H reductive elimination. Isolation and characterization of a cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests the feasible oxidative addition of Phebox-Bi(I) into the C(sp2)-F bond. Spectroscopic evidence was provided for the formation of a transient Phebox-Bi(III)(4-tetrafluoropyridyl) hydride during catalysis, which decomposes at low temperature to afford the corresponding C(sp2)-H bond while regenerating the propagating Phebox-Bi(I). This protocol represents a distinct catalytic example where a main-group center performs three elementary organometallic steps in a low-valent redox manifold.
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Affiliation(s)
- Yue Pang
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Felix Katzenburg
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Josep Cornella
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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29
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Friedrich A, Eyselein J, Langer J, Färber C, Harder S. Cationic Heterobimetallic Mg(Zn)/Al(Ga) Combinations for Cooperative C-F Bond Cleavage. Angew Chem Int Ed Engl 2021; 60:16492-16499. [PMID: 33979476 PMCID: PMC8361950 DOI: 10.1002/anie.202103250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Indexed: 12/14/2022]
Abstract
Low-valent (Me BDI)Al and (Me BDI)Ga and highly Lewis acidic cations in [(tBu BDI)M+ ⋅C6 H6 ][(B(C6 F5 )4 - ] (M=Mg or Zn, Me BDI=HC[C(Me)N-DIPP]2 , tBu BDI=HC[C(tBu)N-DIPP]2 , DIPP=2,6-diisopropylphenyl) react to heterobimetallic cations [(tBu BDI)Mg-Al(Me BDI)+ ], [(tBu BDI)Mg-Ga(Me BDI)+ ] and [(tBu BDI)Zn-Ga(Me BDI)+ ]. These cations feature long Mg-Al (or Ga) bonds while the Zn-Ga bond is short. The [(tBu BDI)Zn-Al(Me BDI)+ ] cation was not formed. Combined AIM and charge calculations suggest that the metal-metal bonds to Zn are considerably more covalent, whereas those to Mg should be described as weak AlI (or GaI )→Mg2+ donor bonds. Failure to isolate the Zn-Al combination originates from cleavage of the C-F bond in the solvent fluorobenzene to give (tBu BDI)ZnPh and (Me BDI)AlF+ which is extremely Lewis acidic and was not observed, but (Me BDI)Al(F)-(μ-F)-(F)Al(Me BDI)+ was verified by X-ray diffraction. DFT calculations show that the remarkably facile C-F bond cleavage follows a dearomatization/rearomatization route.
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Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jonathan Eyselein
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jens Langer
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Christian Färber
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Sjoerd Harder
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
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30
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Friedrich A, Eyselein J, Langer J, Färber C, Harder S. Cationic Heterobimetallic Mg(Zn)/Al(Ga) Combinations for Cooperative C–F Bond Cleavage. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jonathan Eyselein
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Christian Färber
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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31
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Falconer RL, Nichol GS, Smolyar IV, Cockroft SL, Cowley MJ. Reversible Reductive Elimination in Aluminum(II) Dihydrides. Angew Chem Int Ed Engl 2021; 60:2047-2052. [PMID: 33022874 PMCID: PMC7894477 DOI: 10.1002/anie.202011418] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/05/2020] [Indexed: 11/12/2022]
Abstract
Oxidative addition and reductive elimination are defining reactions of transition‐metal organometallic chemistry. In main‐group chemistry, oxidative addition is now well‐established but reductive elimination reactions are not yet general in the same way. Herein, we report dihydrodialanes supported by amidophosphine ligands. The ligand serves as a stereochemical reporter for reversible reductive elimination/oxidative addition chemistry involving AlI and AlIII intermediates.
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Affiliation(s)
- Rosalyn L Falconer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Gary S Nichol
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Ivan V Smolyar
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Scott L Cockroft
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, UK
| | - Michael J Cowley
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, UK
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32
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Kysliak O, Görls H, Kretschmer R. Cooperative Bond Activation by a Bimetallic Main-Group Complex. J Am Chem Soc 2021; 143:142-148. [PMID: 33356229 DOI: 10.1021/jacs.0c12166] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inspired by natural metalloenzymes that efficiently catalyze a variety of transformations, chemists have developed large numbers of dinuclear transition-metal complexes with extraordinary properties and reactivity patterns. For main-group element compounds, however, metal-metal cooperativity is much less explored. Here we present the synthesis and characterization of a room-temperature-stable compound with two separated two-coordinated gallium(I) centers possessing both a lone pair of electrons and a vacant orbital, reminiscent of singlet carbenes. This species displays enhanced reactivity compared to its mononuclear counterpart due to bimetallic cooperativity that allows for the facile activation of strong C-F bonds across the gallium-gallium bond. Two mechanistic scenarios of the cooperative bond activation have been identified by DFT and DLPNO-CCSD(T) calculations.
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Affiliation(s)
- Oleksandr Kysliak
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
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33
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Kundu G, Ajithkumar VS, Bisai MK, Tothadi S, Das T, Vanka K, Sen SS. Diverse reactivity of carbenes and silylenes towards fluoropyridines. Chem Commun (Camb) 2021; 57:4428-4431. [PMID: 33949460 DOI: 10.1039/d1cc01401c] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of IDipp with C5F5N led to functionalization of all three carbon atoms of the imidazole ring with HF2- as the counter-anion (1). Reactivity with 2,3,5,6-tetrafluoropyridine gives only C-F bond activation leaving C-H bonds intact (5b). The reaction of SIDipp with C5F5N in the presence of BF3 afforded the ring cleavage product (3). Analogous reactions with silylene led to oxidative addition at the Si(ii) center.
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - V S Ajithkumar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Milan Kumar Bisai
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Srinu Tothadi
- Organic Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Tamal Das
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India and Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India and Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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34
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Guan Q, Lin C, Chen S, Gao F, Shen L. Palladium‐Catalyzed Selective Carbofunctionalization of Inert γ‐C(
sp
3
)−O Bonds with 4‐Hydroxypyridin‐2(
1H
)‐ones and 4‐Hydroxy‐
2H
‐pyran‐2‐ones. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202001091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Qifan Guan
- Jiangxi Engineering Laboratory of Waterborne Coatings College of Chemistry and Chemical Engineering Jiangxi Science & Technology Normal University Nanchang 330013 People's Republic of China
| | - Cong Lin
- Jiangxi Engineering Laboratory of Waterborne Coatings College of Chemistry and Chemical Engineering Jiangxi Science & Technology Normal University Nanchang 330013 People's Republic of China
| | - Sai Chen
- Jiangxi Engineering Laboratory of Waterborne Coatings College of Chemistry and Chemical Engineering Jiangxi Science & Technology Normal University Nanchang 330013 People's Republic of China
| | - Fei Gao
- Jiangxi Engineering Laboratory of Waterborne Coatings College of Chemistry and Chemical Engineering Jiangxi Science & Technology Normal University Nanchang 330013 People's Republic of China
| | - Liang Shen
- Jiangxi Engineering Laboratory of Waterborne Coatings College of Chemistry and Chemical Engineering Jiangxi Science & Technology Normal University Nanchang 330013 People's Republic of China
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35
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Falconer RL, Nichol GS, Smolyar IV, Cockroft SL, Cowley MJ. Reversible Reductive Elimination in Aluminum(II) Dihydrides. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011418] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Rosalyn L. Falconer
- School of Chemistry University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Gary S. Nichol
- School of Chemistry University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Ivan V. Smolyar
- School of Chemistry University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Scott L. Cockroft
- School of Chemistry University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
| | - Michael J. Cowley
- School of Chemistry University of Edinburgh Joseph Black Building David Brewster Road Edinburgh EH9 3FJ UK
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36
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Hicks J, Vasko P, Heilmann A, Goicoechea JM, Aldridge S. Arene C-H Activation at Aluminium(I): meta Selectivity Driven by the Electronics of S N Ar Chemistry. Angew Chem Int Ed Engl 2020; 59:20376-20380. [PMID: 32722863 PMCID: PMC7693242 DOI: 10.1002/anie.202008557] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Indexed: 12/14/2022]
Abstract
The reactivity of the electron-rich anionic AlI aluminyl compound K2 [(NON)Al]2 (NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene) towards mono- and disubstituted arenes is reported. C-H activation chemistry with n-butylbenzene gives exclusively the product of activation at the arene meta position. Mechanistically, this transformation proceeds in a single step via a concerted Meisenheimer-type transition state. Selectivity is therefore based on similar electronic factors to classical SN Ar chemistry, which implies the destabilisation of transition states featuring electron-donating groups in either ortho or para positions. In the cases of toluene and the three isomers of xylene, benzylic C-H activation is also possible, with the product(s) formed reflecting the feasibility (or otherwise) of competing arene C-H activation at a site which is neither ortho nor para to a methyl substituent.
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Affiliation(s)
- Jamie Hicks
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
- Research School of ChemistryAustralian National University, Building 137Sullivan's Creek RoadActonACT2601Australia
| | - Petra Vasko
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
- Department of ChemistryNanoscience CenterUniversity of JyväskyläP. O. Box 3540014JyväskyläFinland
| | - Andreas Heilmann
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Jose M. Goicoechea
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
| | - Simon Aldridge
- Inorganic Chemistry LaboratoryDepartment of ChemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QRUK
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37
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Helling C, Wölper C, Cutsail GE, Haberhauer G, Schulz S. A Mechanistic Study on Reactions of Group 13 Diyls LM with Cp*SbX 2 : From Stibanyl Radicals to Antimony Hydrides. Chemistry 2020; 26:13390-13399. [PMID: 32428370 PMCID: PMC7693246 DOI: 10.1002/chem.202001739] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Indexed: 01/17/2023]
Abstract
Oxidative addition of Cp*SbX2 (X=Cl, Br, I; Cp*=C5 Me5 ) to group 13 diyls LM (M=Al, Ga, In; L=HC[C(Me)N (Dip)]2 , Dip=2,6-iPr2 C6 H3 ) yields elemental antimony (M=Al) or the corresponding stibanylgallanes [L(X)Ga]Sb(X)Cp* (X=Br 1, I 2) and -indanes [L(X)In]Sb(X)Cp* (X=Cl 5, Br 6, I 7). 1 and 2 react with a second equivalent of LGa to eliminate decamethyl-1,1'-dihydrofulvalene (Cp*2 ) and form stibanyl radicals [L(X)Ga]2 Sb. (X=Br 3, I 4), whereas analogous reactions of 5 and 6 with LIn selectively yield stibanes [L(X)In]2 SbH (X=Cl 8, Br 9) by elimination of 1,2,3,4-tetramethylfulvene. The reactions are proposed to proceed via formation of [L(X)M]2 SbCp* as reaction intermediate, which is supported by the isolation of [L(Cl)Ga]2 SbCp (11, Cp=C5 H5 ). The reaction mechanism was further studied by computational calculations using two different models. The energy values for the Ga- and the In-substituted model systems showing methyl groups instead of the very bulky Dip units are very similar, and in both cases the same products are expected. Homolytic Sb-C bond cleavage yields van der Waals complexes from the as-formed radicals ([L(Cl)M]2 Sb. and Cp*. ), which can be stabilized by hydrogen atom abstraction to give the corresponding hydrides, whereas the direct formation of Sb hydrides starting from [L(Cl)M]2 SbCp* via concerted β-H elimination is unlikely. The consideration of the bulky Dip units reveals that the amount of the steric overload in the intermediate I determines the product formation (radical vs. hydride).
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Affiliation(s)
- Christoph Helling
- Institute for Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (Cenide)University of Duisburg-EssenUniversitätsstraße 5–745117EssenGermany
| | - Christoph Wölper
- Institute for Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (Cenide)University of Duisburg-EssenUniversitätsstraße 5–745117EssenGermany
| | - George E. Cutsail
- Max Planck Institute for Chemical Energy Conversion (CEC)Stiftstrasse 34–36/45470Mülheim an der RuhrGermany
| | - Gebhard Haberhauer
- Institute of Organic ChemistryUniversity of Duisburg-EssenUniversitätsstraße 5–745117EssenGermany
| | - Stephan Schulz
- Institute for Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (Cenide)University of Duisburg-EssenUniversitätsstraße 5–745117EssenGermany
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38
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Lim S, Radosevich AT. Round-Trip Oxidative Addition, Ligand Metathesis, and Reductive Elimination in a PIII/PV Synthetic Cycle. J Am Chem Soc 2020; 142:16188-16193. [DOI: 10.1021/jacs.0c07580] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Soohyun Lim
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Alexander T. Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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39
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Dmitrienko A, Pilkington M, Britten JF, Gabidullin BM, Est A, Nikonov GI. Shedding Light on the Diverse Reactivity of NacNacAl with N‐Heterocycles. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anton Dmitrienko
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - Melanie Pilkington
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - James F. Britten
- Department of Chemistry & Biology McMaster University 1280 Main Street West Hamilton Ontario L8S 4L8 Canada
| | - Bulat M. Gabidullin
- X-Ray Core Facility University of Ottawa 150 Louis Pasteur Ottawa Ontario K1N 6N5 Canada
| | - Art Est
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - Georgii I. Nikonov
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
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40
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Grams S, Eyselein J, Langer J, Färber C, Harder S. Boosting Low-Valent Aluminum(I) Reactivity with a Potassium Reagent. Angew Chem Int Ed Engl 2020; 59:15982-15986. [PMID: 32449816 PMCID: PMC7540686 DOI: 10.1002/anie.202006693] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Indexed: 12/11/2022]
Abstract
The reagent RK [R=CH(SiMe3 )2 or N(SiMe3 )2 ] was expected to react with the low-valent (DIPP BDI)Al (DIPP BDI=HC[C(Me)N(DIPP)]2 , DIPP=2,6-iPr-phenyl) to give [(DIPP BDI)AlR]- K+ . However, deprotonation of the Me group in the ligand backbone was observed and [H2 C=C(N-DIPP)-C(H)=C(Me)-N-DIPP]Al- K+ (1) crystallized as a bright-yellow product (73 %). Like most anionic AlI complexes, 1 forms a dimer in which formally negatively charged Al centers are bridged by K+ ions, showing strong K+ ⋅⋅⋅DIPP interactions. The rather short Al-K bonds [3.499(1)-3.588(1) Å] indicate tight bonding of the dimer. According to DOSY NMR analysis, 1 is dimeric in C6 H6 and monomeric in THF, but slowly reacts with both solvents. In reaction with C6 H6 , two C-H bond activations are observed and a product with a para-phenylene moiety was exclusively isolated. DFT calculations confirm that the Al center in 1 is more reactive than that in (DIPP BDI)Al. Calculations show that both AlI and K+ work in concert and determines the reactivity of 1.
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Affiliation(s)
- Samuel Grams
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jonathan Eyselein
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jens Langer
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Christian Färber
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
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41
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Hicks J, Vasko P, Heilmann A, Goicoechea JM, Aldridge S. Arene C−H Activation at Aluminium(I):
meta
Selectivity Driven by the Electronics of S
N
Ar Chemistry. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008557] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jamie Hicks
- Inorganic Chemistry Laboratory Department of Chemistry University of Oxford South Parks Road Oxford OX1 3QR UK
- Research School of Chemistry Australian National University, Building 137 Sullivan's Creek Road Acton ACT 2601 Australia
| | - Petra Vasko
- Inorganic Chemistry Laboratory Department of Chemistry University of Oxford South Parks Road Oxford OX1 3QR UK
- Department of Chemistry Nanoscience Center University of Jyväskylä P. O. Box 35 40014 Jyväskylä Finland
| | - Andreas Heilmann
- Inorganic Chemistry Laboratory Department of Chemistry University of Oxford South Parks Road Oxford OX1 3QR UK
| | - Jose M. Goicoechea
- Inorganic Chemistry Laboratory Department of Chemistry University of Oxford South Parks Road Oxford OX1 3QR UK
| | - Simon Aldridge
- Inorganic Chemistry Laboratory Department of Chemistry University of Oxford South Parks Road Oxford OX1 3QR UK
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42
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Cabrera-Trujillo JJ, Fernández I. Rationalizing the Al I -Promoted Oxidative Addition of C-C Versus C-H Bonds in Arenes. Chemistry 2020; 26:11806-11813. [PMID: 32329537 DOI: 10.1002/chem.202000921] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/22/2020] [Indexed: 01/17/2023]
Abstract
The factors controlling the oxidative addition of C-C and C-H bonds in arenes mediated by AlI have been computationally explored by means of Density Functional Theory calculations. To this end, we compared the processes involving benzene, naphthalene and anthracene which are promoted by a recently prepared anionic AlI -carbenoid. It is found that this species exhibits a strong tendency to oxidatively activate C-H bonds over C-C bonds, with the notable exception of benzene, where the C-C bond activation is feasible but only under kinetic control reaction conditions. State-of-the-art computational methods based on the combination of the Activation Strain Model of reactivity and the Energy Decomposition Analysis have been used to rationalize the competition between both bond activation reactions as well as to quantitatively analyze in detail the ultimate factors controlling these transformations.
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Affiliation(s)
- Jorge Juan Cabrera-Trujillo
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
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43
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Rekhroukh F, Chen W, Brown RK, White AJP, Crimmin MR. Palladium-catalysed C-F alumination of fluorobenzenes: mechanistic diversity and origin of selectivity. Chem Sci 2020; 11:7842-7849. [PMID: 34094156 PMCID: PMC8163258 DOI: 10.1039/d0sc01915a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
A palladium pre-catalyst, [Pd(PCy3)2] is reported for the efficient and selective C–F alumination of fluorobenzenes with the aluminium(i) reagent [{(ArNCMe)2CH}Al] (1, Ar = 2,6-di-iso-propylphenyl). The catalytic protocol results in the transformation of sp2 C–F bonds to sp2 C–Al bonds and provides a route to reactive organoaluminium complexes (2a–h) from fluorocarbons. The catalyst is highly active. Reactions proceed within 5 minutes at 25 °C (and at appreciable rates at even −50 °C) and the scope includes low-fluorine-content substrates such as fluorobenzene, difluorobenzenes and trifluorobenzenes. The reaction proceeds with complete chemoselectivity (C–F vs. C–H) and high regioselectivities (>90% for C–F bonds adjacent to the most acidic C–H sites). The heterometallic complex [Pd(PCy3)(1)2] was shown to be catalytically competent. Catalytic C–F alumination proceeds with a KIE of 1.1–1.3. DFT calculations have been used to model potential mechanisms for C–F bond activation. These calculations suggest that two competing mechanisms may be in operation. Pathway 1 involves a ligand-assisted oxidative addition to [Pd(1)2] and leads directly to the product. Pathway 2 involves a stepwise C–H → C–F functionalisation mechanism in which the C–H bond is broken and reformed along the reaction coordinate, guiding the catalyst to an adjacent C–F site. This second mechanism explains the experimentally observed regioselectivity. Experimental support for this C–H activation playing a key role in C–F alumination was obtained by employing [{(MesNCMe)2CH}AlH2] (3, Mes = 2,4,6-tri-methylphenyl) as a reagent in place of 1. In this instance, the kinetic C–H alumination intermediate could be isolated. Under catalytic conditions this intermediate converts to the thermodynamic C–F alumination product. A palladium pre-catalyst, [Pd(PCy3)2] is reported for the efficient and selective C–F alumination of fluorobenzenes with the aluminium(i) reagent [{(ArNCMe)2CH}Al] (Ar = 2,6-di-iso-propylphenyl).![]()
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Affiliation(s)
- Feriel Rekhroukh
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Wenyi Chen
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Ryan K Brown
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Andrew J P White
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
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44
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Hooper TN, Brown RK, Rekhroukh F, Garçon M, White AJP, Costa PJ, Crimmin MR. Catalyst control of selectivity in the C-O bond alumination of biomass derived furans. Chem Sci 2020; 11:7850-7857. [PMID: 34094157 PMCID: PMC8163288 DOI: 10.1039/d0sc01918f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Non-catalysed and catalysed reactions of aluminium reagents with furans, dihydrofurans and dihydropyrans were investigated and lead to ring-expanded products due to the insertion of the aluminium reagent into a C–O bond of the heterocycle. Specifically, the reaction of [{(ArNCMe)2CH}Al] (Ar = 2,6-di-iso-propylphenyl, 1) with furans proceeded between 25 and 80 °C leading to dearomatised products due to the net transformation of a sp2 C–O bond into a sp2 C–Al bond. The kinetics of the reaction of 1 with furan were found to be 1st order with respect to 1 with activation parameters ΔH‡ = +19.7 (±2.7) kcal mol−1, ΔS‡ = −18.8 (±7.8) cal K−1 mol−1 and ΔG‡298 K = +25.3 (±0.5) kcal mol−1 and a KIE of 1.0 ± 0.1. DFT calculations support a stepwise mechanism involving an initial (4 + 1) cycloaddition of 1 with furan to form a bicyclic intermediate that rearranges by an α-migration. The selectivity of ring-expansion is influenced by factors that weaken the sp2 C–O bond through population of the σ*-orbital. Inclusion of [Pd(PCy3)2] as a catalyst in these reactions results in expansion of the substrate scope to include 2,3-dihydrofurans and 3,4-dihydropyrans and improves selectivity. Under catalysed conditions, the C–O bond that breaks is that adjacent to the sp2C–H bond. The aluminium(iii) dihydride reagent [{(MesNCMe)2CH}AlH2] (Mes = 2,4,6-trimethylphenyl, 2) can also be used under catalytic conditions to effect a dehydrogenative ring-expansion of furans. Further mechanistic analysis shows that C–O bond functionalisation occurs via an initial C–H bond alumination. Kinetic products can be isolated that are derived from installation of the aluminium reagent at the 2-position of the heterocycle. C–H alumination occurs with a KIE of 4.8 ± 0.3 consistent with a turnover limiting step involving oxidative addition of the C–H bond to the palladium catalyst. Isomerisation of the kinetic C–H aluminated product to the thermodynamic C–O ring expansion product is an intramolecular process that is again catalysed by [Pd(PCy3)2]. DFT calculations suggest that the key C–O bond breaking step involves attack of an aluminium based metalloligand on the 2-palladated heterocycle. The new methodology has been applied to important platform chemicals from biomass. Non-catalysed and catalysed reactions of aluminium reagents with furans, dihydrofurans and dihydropyrans were investigated and lead to ring-expanded products due to the insertion of the aluminium reagent into a C–O bond of the heterocycle.![]()
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Affiliation(s)
- Thomas N Hooper
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Ryan K Brown
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Feriel Rekhroukh
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK .,BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa 1749-016 Lisboa Portugal
| | - Martí Garçon
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Andrew J P White
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
| | - Paulo J Costa
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa 1749-016 Lisboa Portugal
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London 80 Wood Lane, Shepherds Bush London W12 0BZ UK
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Grams S, Eyselein J, Langer J, Färber C, Harder S. Boosting Low‐Valent Aluminum(I) Reactivity with a Potassium Reagent. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006693] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Samuel Grams
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jonathan Eyselein
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Christian Färber
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Chair of Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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46
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Dmitrienko A, Pilkington M, Britten JF, Gabidullin BM, van der Est A, Nikonov GI. Shedding Light on the Diverse Reactivity of NacNacAl with N-Heterocycles. Angew Chem Int Ed Engl 2020; 59:16147-16153. [PMID: 32436289 DOI: 10.1002/anie.202005925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 01/09/2023]
Abstract
The aluminum(I) compound NacNacAl (NacNac=[ArNC(Me)CHC(Me)NAr]- , Ar=2,6-iPr2 C6 H3 , 1) shows diverse and substrate-controlled reactivity in reactions with N-heterocycles. 4-Dimethylaminopyridine (DMAP), a basic substrate in which the 4-position is blocked, induces rearrangement of NacNacAl by shifting a hydrogen atom from the methyl group of the NacNac backbone to the aluminum center. In contrast, C-H activation of the methyl group of 4-picoline takes place to produce a species with a reactive terminal methylene. Reaction of 1 with 3,5-lutidine results in the first example of an uncatalyzed, room-temperature cleavage of an sp2 C-H bond (in the 4-position) by an AlI species. Another reactivity mode was observed for quinoline, which undergoes 2,2'-coupling. Finally, the reaction of 1 with phthalazine produces the product of N-N bond cleavage.
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Affiliation(s)
- Anton Dmitrienko
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Melanie Pilkington
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - James F Britten
- Department of Chemistry & Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L8, Canada
| | - Bulat M Gabidullin
- X-Ray Core Facility, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5, Canada
| | - Art van der Est
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Georgii I Nikonov
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
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Mandal D, Chandra S, Neuman NI, Mahata A, Sarkar A, Kundu A, Anga S, Rawat H, Schulzke C, Mote KR, Sarkar B, Chandrasekhar V, Jana A. Activation of Aromatic C-F Bonds by a N-Heterocyclic Olefin (NHO). Chemistry 2020; 26:5951-5955. [PMID: 32027063 PMCID: PMC7317942 DOI: 10.1002/chem.202000276] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 11/09/2022]
Abstract
A N-heterocyclic olefin (NHO), a terminal alkene selectively activates aromatic C-F bonds without the need of any additional catalyst. As a result, a straightforward methodology was developed for the formation of different fluoroaryl-substituted alkenes in which the central carbon-carbon double bond is in a twisted geometry.
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Affiliation(s)
- Debdeep Mandal
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Shubhadeep Chandra
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Institut für Anorganische ChemieLehrstuhl für Anorganische KoordinationschemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Nicolás I. Neuman
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Instituto de Desarrollo Tecnológico para la Industria QuímicaCCT Santa Fe CONICET-UNLColectora Ruta Nacional 168, Km 472, Paraje El Pozo3000Santa FeArgentina
| | - Alok Mahata
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Arighna Sarkar
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Abhinanda Kundu
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Srinivas Anga
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Hemant Rawat
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Carola Schulzke
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Kaustubh R. Mote
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Biprajit Sarkar
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Institut für Anorganische ChemieLehrstuhl für Anorganische KoordinationschemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
- Department of ChemistryIndian Institute of Technology KanpurKanpur208016India
| | - Anukul Jana
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
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48
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Lee E, Pietrasiak E. Activation of C–F, Si–F, and S–F Bonds by N-Heterocyclic Carbenes and Their Isoelectronic Analogues. Synlett 2020. [DOI: 10.1055/s-0040-1707106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Reactions involving C–F, Si–F, and S–F bond cleavage with N-heterocyclic carbenes and isoelectronic species are reviewed. Most examples involve activation of aromatic C–F bond via an SNAr pathway and nucleophilic substitution of fluorine in electron-deficient olefins. The mechanism of the C–F bond activation depends on the reaction partners and the reaction can proceed via addition–elimination, oxidative addition (concerted or stepwise) or metathesis. The adducts formed upon substitution find applications in organic synthesis, as ligands and as stable radical precursors, but in most cases, their full potential remains unexplored.1 Introduction1.1 The C–F Bond1.2 C–F Bond Activation: A Short Summary1.3 C–F Bond Activation: A Special Case of SNAr1.4 N-Heterocyclic Carbenes (NHCs)1.5 The Purpose of this Article2 C–F bond Activation in Acyl Fluorides3 Activation of Vinylic C–F Bonds4 Activation of Aromatic C–F Bonds5 X–F Bond Activation (X = S or Si)6 C–F Bond Activation by Main Group Compounds Isoelectronic with NHCs7 Conclusions and Outlook
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Affiliation(s)
- Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology
- Division of Advanced Materials Science, Pohang University of Science and Technology
| | - Ewa Pietrasiak
- Department of Chemistry, Pohang University of Science and Technology
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Schwamm RJ, Coles MP, Hill MS, Mahon MF, McMullin CL, Rajabi NA, Wilson ASS. A Stable Calcium Alumanyl. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 132:3956-3960. [PMID: 32313322 PMCID: PMC7159353 DOI: 10.1002/ange.201914986] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Indexed: 11/18/2022]
Abstract
A seven-membered N,N'-heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg-Al and Ca-Al bonded derivatives. Both species have been characterised by experimental and theoretical means, allowing a rationalisation of the greater reactivity of the heavier group 2 species implied by an initial assay of their reactivity.
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Affiliation(s)
| | - Martyn P. Coles
- School of Chemical and Physical SciencesVictoria University of WellingtonPO Box 600WellingtonNew Zealand
| | | | - Mary F. Mahon
- Department of ChemistryUniversity of BathBathBA2 7AYUK
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50
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Villegas-Escobar N, Schaefer HF, Toro-Labbé A. Formation of Formic Acid Derivatives through Activation and Hydroboration of CO 2 by Low-Valent Group 14 (Si, Ge, Sn, Pb) Catalysts. J Phys Chem A 2020; 124:1121-1133. [PMID: 31948229 DOI: 10.1021/acs.jpca.9b11648] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The chemistry of low-valent main group elements has attracted much attention in the past decade. These species are relevant because they have been able to mimic transition metal behavior in catalytic applications, with decreased material costs and diminished toxicity. In this contribution, we study the L1EH catalysts (E = Si(II), Ge(II), Sn(II), and Pb(II); L1 = [ArNC(Me)CHC(Me)NAr] with Ar = 2,6-iPr2C6H3) for the formation of formic acid derivatives through hydroboration of CO2. Detailed characterization of relevant structures on the potential energy surface enabled us to rationalize different paths for the hydroboration of CO2. Interestingly, it was found that according to the activation energies for the whole catalytic cycle, the process of transformation of CO2 becomes more favored going down group 14. However, an effective energetic decrease for the process (taking as the reference the uncatalyzed reaction between CO2 and HBpin) is evidenced just from the germanium analogue. The trend in reactivity found in the present study is a direct consequence of the change in the central main group element, enabling enhanced polar character of the E-H (L1EH in the CO2 activation step) and E-O (metal formates in the hydroboration step) bonds as the atomic radius increases. The transient stabilization of reaction intermediates found in the hydroboration step was rationalized through the non-covalent interaction index (NCI) and symmetry-adapted perturbation theory (SAPT). This computational study highlights the reactivity trends in group-14-based hydride catalysts in hydrometalation and posterior hydroboration to form formic acid intermediates. We hope that this study will motivate further experimental work in low-valent lead chemistry.
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Affiliation(s)
- Nery Villegas-Escobar
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 , United States.,Laboratorio de Quı́mica Teórica Computacional (QTC), Facultad de Quı́mica , Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna 4860 , 9820436 Santiago , Chile
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - Alejandro Toro-Labbé
- Laboratorio de Quı́mica Teórica Computacional (QTC), Facultad de Quı́mica , Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna 4860 , 9820436 Santiago , Chile
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