1
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Franke M, Ens T, Mix A, Neumann B, Stammler HG, Mitzel NW. Host-guest chemistry of tridentate Lewis acids based on tribenzotriquinacene. Dalton Trans 2024; 53:11970-11980. [PMID: 38961795 DOI: 10.1039/d4dt01558d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Flexible poly-Lewis acids (PLA) based on the tribenzotriquinacene (TBTQ) scaffold have been synthesised. Hydrosilylation of 4b,8b,12b-triallyltribenzotriquinacene and subsequent exchange of the chlorine substituents with weaker coordinating triflate groups afforded a novel triple silyl-functionalised PLA. By regioselective hydroboration of triallyl-TBTQ with various organoboranes, PLAs with different Lewis acidities were obtained. The synthesised PLAs were combined with neutral bases in host-guest experiments. DOSY NMR spectroscopy was performed to elucidate the complexation process in solution. These experiments revealed a highly dynamic interaction between the boron-functionalised PLA and triazine. However, the addition of one equivalent of tris(dimethylphosphino(methyl))phenylsilane led to the formation of a 1 : 1 adduct, which was confirmed by diffusion experiments.
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Affiliation(s)
- Maurice Franke
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Tobin Ens
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Andreas Mix
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Beate Neumann
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Hans-Georg Stammler
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
| | - Norbert W Mitzel
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstraße 25, D-33615 Bielefeld, Germany.
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2
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Sigmund LM, S SS, Albers A, Erdmann P, Paton RS, Greb L. Predicting Lewis Acidity: Machine Learning the Fluoride Ion Affinity of p-Block-Atom-Based Molecules. Angew Chem Int Ed Engl 2024; 63:e202401084. [PMID: 38452299 DOI: 10.1002/anie.202401084] [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: 01/19/2024] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024]
Abstract
"How strong is this Lewis acid?" is a question researchers often approach by calculating its fluoride ion affinity (FIA) with quantum chemistry. Here, we present FIA49k, an extensive FIA dataset with 48,986 data points calculated at the RI-DSD-BLYP-D3(BJ)/def2-QZVPP//PBEh-3c level of theory, including 13 different p-block atoms as the fluoride accepting site. The FIA49k dataset was used to train FIA-GNN, two message-passing graph neural networks, which predict gas and solution phase FIA values of molecules excluded from training with a mean absolute error of 14 kJ mol-1 (r2=0.93) from the SMILES string of the Lewis acid as the only input. The level of accuracy is notable, given the wide energetic range of 750 kJ mol-1 spanned by FIA49k. The model's value was demonstrated with four case studies, including predictions for molecules extracted from the Cambridge Structural Database and by reproducing results from catalysis research available in the literature. Weaknesses of the model are evaluated and interpreted chemically. FIA-GNN and the FIA49k dataset can be reached via a free web app (www.grebgroup.de/fia-gnn).
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Affiliation(s)
- Lukas M Sigmund
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Shree Sowndarya S
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Andreas Albers
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Philipp Erdmann
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Robert S Paton
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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3
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Timoshkin AY. The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments. Chemistry 2024; 30:e202302457. [PMID: 37752859 DOI: 10.1002/chem.202302457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 09/28/2023]
Abstract
New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.
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Affiliation(s)
- Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, 199034, Universitetskaya emb. 7/9, St. Petersburg, Russia
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4
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Tania, Sceney M, Bennetts JD, Barwise L, White KF, Dutton JL. C-H, Si-H and C-F abstraction with an extremely electron poor I(III) reagent. Dalton Trans 2023; 52:15866-15870. [PMID: 37830138 DOI: 10.1039/d3dt03266c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The recently discovered I(III) reagent NO2-C6H4-I(OTf)2 is found to rapidly react with hydride sources, including HSiEt3 and relatively hydridic C-H precursors. These represent the first distinct reactions involving direct hydride abstraction by I(III) under ambient conditions. Direct C-F abstraction is also demonstrated, as well as oxidation of cyclic alkenes to aromatic rings, all representing new reactions for I(III) demonstrating the very high reactivity of NO2-C6H4-I(OTf)2.
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Affiliation(s)
- Tania
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
| | - Marcus Sceney
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
| | - Jason D Bennetts
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
| | - Lachlan Barwise
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
| | - Keith F White
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
| | - Jason L Dutton
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia.
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5
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Wohltmann WM, Schmidtmann M, Müller T. Covalent triflates as synthons for silolyl- and germolyl cations. Dalton Trans 2022; 51:9836-9842. [PMID: 35708108 DOI: 10.1039/d2dt01446g] [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 synthesis of 1-silolyl and 1-germolyl triflates from the corresponding chlorides by salt metathesis reaction is reported. These covalent triflates are ideal starting materials for the preparation of ionic silolyl- and germolyl-imidazolium triflates by their reaction with N-heterocyclic carbenes. Similarily, ionic silolyl- and germolyl-oxophosphonium triflates are obtained by substitution of the triflate group by triethylphosphane oxide Et3PO. The analysis of their 31P NMR chemical shifts according to the Gutmann-Beckett method reveal the high Lewis acidity of the underlying silolyl and germolyl cations. Further analysis of structural and NMR parameters of the silolyl- and germolyl-imidazolium and oxophosphonium triflates indicates that these compounds are covalently bonded silole and germole derivatives with insignificant contributions from silolyl- or germolyl cations. Silolyl and germolyl triflates are however synthetic equivalents of these cations and might serve as a source for electrophilic silolyl and germolyl units.
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Affiliation(s)
- Wiebke Marie Wohltmann
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany.
| | - Marc Schmidtmann
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany.
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany.
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6
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Barthélemy A, Glootz K, Scherer H, Hanske A, Krossing I. Ga +-catalyzed hydrosilylation? About the surprising system Ga +/HSiR 3/olefin, proof of oxidation with subvalent Ga + and silylium catalysis with perfluoroalkoxyaluminate anions. Chem Sci 2022; 13:439-453. [PMID: 35126976 PMCID: PMC8729802 DOI: 10.1039/d1sc05331k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/21/2021] [Indexed: 12/19/2022] Open
Abstract
Already 1 mol% of subvalent [Ga(PhF)2]+[pf]- ([pf]- = [Al(ORF)4]-, RF = C(CF3)3) initiates the hydrosilylation of olefinic double bonds under mild conditions. Reactions with HSiMe3 and HSiEt3 as substrates efficiently yield anti-Markovnikov and anti-addition products, while bulkier substrates such as HSiiPr3 are less reactive. Investigating the underlying mechanism by gas chromatography and STEM analysis, we unexpectedly found that H2 and metallic Ga0 formed. Without the addition of olefins, the formation of R3Si-F-Al(ORF)3 (R = alkyl), a typical degradation product of the [pf]- anion in the presence of a small silylium ion, was observed. Electrochemical analysis revealed a surprisingly high oxidation potential of univalent [Ga(PhF)2]+[pf]- in weakly coordinating, but polar ortho-difluorobenzene of E 1/2(Ga+/Ga0; oDFB) = +0.26-0.37 V vs. Fc+/Fc (depending on the scan rate). Apparently, subvalent Ga+, mainly known as a reductant, initially oxidizes the silane and generates a highly electrophilic, silane-supported, silylium ion representing the actual catalyst. Consequently, the [Ga(PhF)2]+[pf]-/HSiEt3 system also hydrodefluorinates C(sp3)-F bonds in 1-fluoroadamantane, 1-fluorobutane and PhCF3 at room temperature. In addition, both catalytic reactions may be initiated using only 0.2 mol% of [Ph3C]+[pf]- as a silylium ion-generating initiator. These results indicate that silylium ion catalysis is possible with the straightforward accessible weakly coordinating [pf]- anion. Apparently, the kinetics of hydrosilylation and hydrodefluorination are faster than that of anion degradation under ambient conditions. These findings open up new windows for main group catalysis.
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Affiliation(s)
- Antoine Barthélemy
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Kim Glootz
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Harald Scherer
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Annaleah Hanske
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie, Freiburger Materialforschungszentrum (FMF), Universität Freiburg Albertstr. 21 79104 Freiburg Germany
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7
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Schäfer F, Mix A, Cati N, Lamm JH, Neumann B, Stammler G, Mitzel NW. Host guest chemistry of a bidentate silyl-triflate bis-Lewis-acid – complex complexation behaviour unravelled by diffusion NMR spectroscopy. Dalton Trans 2022; 51:7164-7173. [DOI: 10.1039/d2dt00583b] [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 bidentate silicon-based Lewis acid, bis(dimethyl-(trifluoromethylsulfonyl)silylethyl)dimethylsilane, Me2Si[(CH2)2SiMe2-OTf]2, was prepared by a two-step synthesis starting from dimethyldivinylsilane by hydrosilylation with dimethylchlorosilane and subsequent Lewis acidity enhancement of the terminal silicon atoms...
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8
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Roy MMD, Omaña AA, Wilson ASS, Hill MS, Aldridge S, Rivard E. Molecular Main Group Metal Hydrides. Chem Rev 2021; 121:12784-12965. [PMID: 34450005 DOI: 10.1021/acs.chemrev.1c00278] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, and 12-16. Particular attention will be given to the emerging use of said hydrides in the rapidly expanding field of Main Group element-mediated catalysis. While this review is comprehensive in nature, focus will be given to research appearing in the open literature since 2001.
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Affiliation(s)
- Matthew M D Roy
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Alvaro A Omaña
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Andrew S S Wilson
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Michael S Hill
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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9
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Olaru M, Mebs S, Beckmann J. Kationische Carben‐Analoga: Donorfreie Phosphenium‐ und Arsenium‐Ionen. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107975] [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)
- Marian Olaru
- Institut für Anorganische Chemie und Kristallographie Universität Bremen Leobener Straße 7 28359 Bremen Germany
| | - Stefan Mebs
- Institut für Experimentalphysik Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Jens Beckmann
- Institut für Anorganische Chemie und Kristallographie Universität Bremen Leobener Straße 7 28359 Bremen Germany
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10
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Olaru M, Mebs S, Beckmann J. Cationic Carbene Analogues: Donor-Free Phosphenium and Arsenium Ions. Angew Chem Int Ed Engl 2021; 60:19133-19138. [PMID: 34219354 PMCID: PMC8456819 DOI: 10.1002/anie.202107975] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 06/30/2021] [Indexed: 01/08/2023]
Abstract
Carbenes and their analogues have constantly enthralled chemists with their intriguing reactivity of ambiphilic character stemming from their electronic structures. Phosphenium and arsenium ions are fiercely reactive cationic species, the stabilization of which has been so far achieved in the condensed phase by dispersing the positive charge through electromeric conjugation with at least one electron-rich substituent (frequently amido groups). Although observed in the gas phase, the isolation of dicoordinate phosphenium and arsenium ions lacking such stabilizing ligands has eluded chemists for decades. Herein we show that by judicious choice of aromatic substituents, dicoordinate, donor-free, Lewis-superacidic phosphenium and arsenium ions can be kinetically stabilized. They feature singlet electronic ground states possessing a vacant p-orbital and an electron lone pair with predominantly s-character.
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Affiliation(s)
- Marian Olaru
- Institut für Anorganische Chemie und KristallographieUniversität BremenLeobener Straße 728359BremenGermany
| | - Stefan Mebs
- Institut für ExperimentalphysikFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Jens Beckmann
- Institut für Anorganische Chemie und KristallographieUniversität BremenLeobener Straße 728359BremenGermany
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11
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Burton KI, Elser I, Waked AE, Wagener T, Andrews RJ, Glorius F, Stephan DW. Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity. Chemistry 2021; 27:11730-11737. [PMID: 34107119 DOI: 10.1002/chem.202101534] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Indexed: 01/06/2023]
Abstract
The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10 H6 R2 N2 CH2 CH2 ]2+ (R=H [1 a]2+ , Me [1 f]2+ , tBu [1 g]2+ ), and [C12 H4 R4 N2 CH2 CH2 ]2+ (R=H [2 a]2+ , Me [2 b]2+ ) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3 (C-F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3 )3 C6 H9 . The dications are shown to act as hydride acceptors with the isolation of neutral species C16 H14 N2 (3 a) and C16 H10 Me4 N2 (3 b) and monocationic species [C14 H13 N2 ]+ ([4 a]+ ) and [C18 H21 N2 ]+ ([4 b]+ ). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.
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Affiliation(s)
- Katherine I Burton
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Iris Elser
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Alexander E Waked
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Tobias Wagener
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Ryan J Andrews
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Douglas W Stephan
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
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12
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Hermannsdorfer A, Driess M. Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid. Angew Chem Int Ed Engl 2021; 60:13656-13660. [PMID: 33826216 PMCID: PMC8252640 DOI: 10.1002/anie.202103414] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/01/2021] [Indexed: 11/10/2022]
Abstract
A facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)4, is reported, acting as the first neutral silicon‐based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)4 leads to [L2Si(OTf)4] complexes (L=isocyanide, thioether and carbonyl compounds) with retention of all Si−OTf bonds. In contrast, it can cleave C−X bonds (X=F, Cl) of hard organic Lewis bases with a high tendency to form SiX4 (X=F, Cl) after halide/triflate exchange. Most notable, Si(OTf)4 allows a gentle oxydefluorination of mono‐ and bis(trifluoromethyl)benzenes, resulting in the formation of the corresponding benzoylium species, which are stabilized by the weakly coordinating [Si(OTf)6] dianion.
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Affiliation(s)
- André Hermannsdorfer
- Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, 10623, Berlin, Germany
| | - Matthias Driess
- Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, 10623, Berlin, Germany
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13
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Hermannsdorfer A, Driess M. Siliciumtetrakis(trifluormethansulfonat): Ein einfaches, neutrales Silan als weiche und harte Lewis‐Supersäure. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103414] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- André Hermannsdorfer
- Institut für Chemie, Metallorganische Chemie und anorganische Materialien Technische Universität Berlin Straße des 17. Juni 115, Sekr. C2 10623 Berlin Deutschland
| | - Matthias Driess
- Institut für Chemie, Metallorganische Chemie und anorganische Materialien Technische Universität Berlin Straße des 17. Juni 115, Sekr. C2 10623 Berlin Deutschland
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14
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Hermannsdorfer A, Driess M. Isolable Silicon-Based Polycations with Lewis Superacidity. Angew Chem Int Ed Engl 2020; 59:23132-23136. [PMID: 32935903 PMCID: PMC7756528 DOI: 10.1002/anie.202011696] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Indexed: 12/31/2022]
Abstract
Molecular silicon polycations of the types R2 Si2+ and RSi3+ (R=H, organic groups) are elusive Lewis superacids and currently unknown in the condensed phase. Here, we report the synthesis of a series of isolable terpyridine-stabilized R2 Si2+ and RSi3+ complexes, [R2 Si(terpy)]2+ (R=Ph 12+ ; R2 =C12 H8 22+ , (CH2 )3 32+ ) and [RSi(terpy)]3+ (R=Ph 43+ , cyclohexyl 53+ , m-xylyl 63+ ), in form of their triflate salts. The stabilization of the latter is achieved through higher coordination and to the expense of reduced fluoride-ion affinities, but a significant level of Lewis superacidity is nonetheless retained as verified by theory and experiment. The complexes activate C(sp3 )-F bonds, as showcased by stoichiometric fluoride abstraction from 1-fluoroadamantane (AdF) and the catalytic hydrodefluorination of AdF. The formation of the crystalline adducts [2(F)]+ and [5(H)]2+ documents in particular the high reactivity towards fluoride and hydride donors.
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Affiliation(s)
- André Hermannsdorfer
- Department of Chemistry: Metalorganics and Inorganic MaterialsTechnische Universität BerlinStrasse des 17. Juni 115, Sekr. C210623BerlinGermany
| | - Matthias Driess
- Department of Chemistry: Metalorganics and Inorganic MaterialsTechnische Universität BerlinStrasse des 17. Juni 115, Sekr. C210623BerlinGermany
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