1
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Chakraborty B, González-Pinardo D, Fernández I, Phukan AK. Carbene-Decorated Geometrically Constrained Borylenes for Bond Activations. Inorg Chem 2024. [PMID: 39072652 DOI: 10.1021/acs.inorgchem.4c01697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
While metal-ligand cooperativity is well-known, studies on element-ligand cooperativity involving main group species are comparatively much less explored. In this study, we computationally designed a few geometrically constrained borylenes supported by different carbenes. Our density functional theory studies indicate that they possess enhanced nucleophilicity as well as electrophilicity, thus rendering them promising candidates for exhibiting borylene-ligand cooperativity. The cooperation between the boron and adjacent carbene centers facilitates different bond activation processes, including the cycloaddition of acetylene across the boron-carbene bond as well as B-H/Si-H bond activation reactions, which have been analyzed in detail. To the best of our knowledge, the borylenes proposed in this study represent the first examples of theoretically proposed geometrically constrained bis(carbene)-stabilized borylenes capable of cooperative activation of enthalpically strong bonds.
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Affiliation(s)
- Barsha Chakraborty
- Department of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India
| | - Daniel González-Pinardo
- Departamento de Química Orgánica 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 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, Napaam 784028, Assam, India
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2
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Lei B, Cao F, Chen M, Wang X, Mo Z. Bisgermylene-Stabilized Stannylone: Catalytic Reduction of Nitrous Oxide and Nitro Compounds via Element-Ligand Cooperativity. J Am Chem Soc 2024; 146:17817-17826. [PMID: 38780163 DOI: 10.1021/jacs.4c03227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
This study describes the synthesis, structural characterization, and catalytic application of a bis(germylene)-stabilized stannylone (2). The reduction of digermylated stannylene (1) with 2.2 equiv of potassium graphite (KC8) leads to the formation of stannylone 2 as a green solid in 78% yield. Computational studies showed that stannylone 2 possesses a formal Sn(0) center and a delocalized 3-c-2-e π-bond in the Ge2Sn core, which arises from back-donation of the p-type lone pair electrons on the Sn atom to the vacant orbitals of the Ge atoms. Stannylone 2 can serve as an efficient precatalyst for the selective reduction of nitrous oxide (N2O) and nitroarenes (ArNO2) with the formation of dinitrogen (N2) and hydrazines (ArNH-NHAr), respectively. Exposure of 2 with N2O (1 atm) resulted in the insertion of two oxygen atoms into the Ge-Ge and Ge-Sn bonds, yielding the germyl(oxyl)stannylene (3). Moreover, the stoichiometric reaction of 2 with 1-chloro-4-nitrobenzene afforded an amido(oxyl)stannylene (4) through the complete scission of the N-O bonds of the nitroarene. Stannylenes 3 and 4 serve as catalytically active species for the catalytic reduction of nitrous oxide and nitroarenes, respectively. Mechanistic studies reveal that the cooperation of the low-valent Ge and Sn centers allows for multiple electron transfers to cleave the N-O bonds of N2O and ArNO2. This approach presents a new strategy for catalyzing the deoxygenation of N2O and ArNO2 using a zerovalent tin compound.
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Affiliation(s)
- Binglin Lei
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Fanshu Cao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Ming Chen
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xuyang Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhenbo Mo
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
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3
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Karnbrock SBH, Golz C, Alcarazo M. P(V)-bis(amidophenolate) ligand cooperation: stoichiometric CO-bond cleavage in aldehydes and ketones. Chem Commun (Camb) 2024; 60:6745-6748. [PMID: 38864327 DOI: 10.1039/d4cc02202e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
The cooperation between a geometrically constrained, highly electrophilic phosphorus(V) center, and an electronically rich tetradentate bis(amidophenolate) ligand enables the cleavage of the CO bond from typical aldehydes and ketones delivering iminio phosphoramidate species. The amphiphilic nature of these products, which is demonstrated through their reaction with typical Lewis acids and bases, enables their use as a mild source of silylium cations from silanes, allowing the selective reductive coupling of aldehydes to ethers under catalytic conditions.
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Affiliation(s)
- Simon B H Karnbrock
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
| | - Christopher Golz
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
| | - Manuel Alcarazo
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
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4
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Kumar M, Nayek HP. Syntheses and exploration of the catalytic activities of organotin(IV) compounds. Dalton Trans 2024; 53:9827-9837. [PMID: 38804088 DOI: 10.1039/d4dt00646a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Six organotin(IV) compounds (1-6) have been synthesized by reaction of the polydentate pro-ligands H3L and H2L, respectively, with the corresponding diorganotin chlorides. All of the compounds were characterized by FT-IR spectroscopy, 1H, 13C{1H}, and 119Sn (1H) NMR spectroscopy, HRMS spectrometry, and single-crystal X-ray diffraction. The solid-state structures show that all of the compounds are monomeric (except compound 3) and contain a penta-coordinated tin atom. Compound 3 is a dimer with two hexa-coordinated tin atoms. Compounds 1-3 contain a non-coordinated hydroxymethyl group. All of the compounds have been screened for their catalytic efficacy in the synthesis of 1,2 disubstituted benzimidazoles using o-phenylenediamine and aldehyde derivatives. It has been observed that both the Lewis acidic Sn(IV) centre and the hydroxymethyl group (hydrogen bond donor) catalyse the reactions with a product yield of up to 92%.
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Affiliation(s)
- Manish Kumar
- Department of Chemistry & Chemical Biology, Indian Institute of Technology (Indian School of Mines), Dhanbad-826004, Jharkhand, India.
| | - Hari Pada Nayek
- Department of Chemistry & Chemical Biology, Indian Institute of Technology (Indian School of Mines), Dhanbad-826004, Jharkhand, India.
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5
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Becker S. Understanding Cooperativity in Homo- and Heterometallic Complexes: From Basic Concepts to Design. Chempluschem 2024; 89:e202300619. [PMID: 38317458 DOI: 10.1002/cplu.202300619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/12/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024]
Abstract
Cooperative effects have attracted considerable attention in recent years. These effects are ubiquitous in chemistry and biology and can govern interactions of proteins with other biomolecules, mechanisms of supramolecular recognition and polymerization, catalysis, assembly of compounds on surfaces, and physical properties such as magnetic, electronic or optical properties, e. g. Consequently, the understanding of cooperative effects can lead to a structure-property relation that can pave the way to future applications in various research areas; however, with regard to cooperative effects in homo- and heterometallic complexes, we still are at the beginning of understanding. Nevertheless, concepts to describe cooperativity of metal centers as well as methodologies to investigate and model these effects have emerged over the last years. This concept article gives an overview of these existing concepts, approaches, and strategies to understand cooperative effects in homo- and heterometallic complexes. Special emphasis is put on concepts to define cooperative effects, their quantification, as well as methods to investigate cooperative effects.
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Affiliation(s)
- Sabine Becker
- Fachbereich Chemie, RPTU Kaiserslautern-Landau, Erwin-Schroedinger-Str. 54, 67663, Kaiserslautern, Germany
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6
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Coburger P, Buzanich AG, Emmerling F, Abbenseth J. Combining geometric constraint and redox non-innocence within an ambiphilic PBiP pincer ligand. Chem Sci 2024; 15:6036-6043. [PMID: 38665539 PMCID: PMC11040644 DOI: 10.1039/d4sc00197d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/16/2024] [Indexed: 04/28/2024] Open
Abstract
The synthesis of the first pincer ligand featuring a strictly T-shaped group 15 element and its coordination behaviour towards transition metals is described. The platform is itself derived from a trianionic redox non-innocent NNN scaffold. In addition to providing a rigid coordination environment to constrain a Bi centre in a T-shaped geometry to manipulate its frontier molecular orbital constitution, the NNN chelate displays highly covalent bonding towards the geometrically constrained Bi centre. The formation of intriguing ambiphilic Bi-M bonding interactions is demonstrated upon formation of a pincer complex as well as a multimetallic cluster. All compounds are comprehensively characterised by spectroscopic methods including X-ray Absorption Near Edge Structure (XANES) spectroscopy and complemented by DFT calculations.
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Affiliation(s)
- Peter Coburger
- Department of Inorganic Chemistry, Technische Universität München Lichtenbergstr. 4 85747 Garching Germany
| | - Ana Guilherme Buzanich
- Department of Materials Chemistry, Federal Institute for Materials Research and Testing Richard-Willstätter-Str. 11 12489 Berlin Germany
| | - Franziska Emmerling
- Department of Materials Chemistry, Federal Institute for Materials Research and Testing Richard-Willstätter-Str. 11 12489 Berlin Germany
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Josh Abbenseth
- Institut für Chemie, Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
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7
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Parsons LW, Berben LA. Expanding the Scope of Aluminum Chemistry with Noninnocent Ligands. Acc Chem Res 2024; 57:1087-1097. [PMID: 38581655 PMCID: PMC11025028 DOI: 10.1021/acs.accounts.3c00714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/08/2024]
Abstract
ConspectusAluminum is the most abundant metal in the earth's crust at 8%, and it is also widely available domestically in many countries worldwide, which ensures a stable supply chain. To further the applications of aluminum (Al), such as in catalysis and electronic and energy storage materials, there has been significant interest in the synthesis and characterization of new Al coordination compounds that can support electron transfer (ET) and proton transfer (PT) chemistry. This has been achieved using redox and chemically noninnocent ligands (NILs) combined with the highly stable M(III) oxidation state of Al and in some cases the heavier group 13 ions, Ga and In.When ligands participate in redox chemistry or facilitate the breaking or making of new bonds, they are often termed redox or chemically noninnocent, respectively. Al(III) in particular supports rich ligand-based redox chemistry because it is so redox inert and will support the ligand across many charge and protonation states without entering into the reaction chemistry. To a lesser extent, we have reported on the heavier group 13 elements Ga and In, and this chemistry will also be included in this Account, where available.This Account is arranged into two technical sections, which are (1) Structures of Al-NIL complexes and (2) Reactivity of Al-NIL complexes. Highlights of the research work include reversible redox chemistry that has been enabled by ligand design to shut down radical coupling pathways and to prevent loss of H2 from unsaturated ligand sites. These reversible redox properties have in turn enabled the characterization of Class III electron delocalization through Al when two NIL are bound to the Al(III) in different charge states. Characterization of the metalloaromatic character of square planar Al and Ga complexes has been achieved, and characterization of the delocalized electronic structures has provided a model within which to understand and predict the ET and PT chemistry of the NIL group 13 compounds. The capacity of Al-NIL complexes to perform ET and PT has been employed in reactions that use ET or PT reactivity only or in reactions where coupled ET/PT affords hydride transfer chemistry. As an example, ligand-based PT reactions initiate metal-ligand cooperative bond activation pathways for catalysis: this includes acceptorless dehydrogenation of formic acid and anilines and transfer hydrogenation chemistry. In a complementary approach, ligand based ET/PT chemistry has been used in the study of dihydropyridinate (DHP-) chemistry where it was shown that N-coordination of group 13 ions lowers kinetic barriers to DHP- formation. Taken together, the discussion presented herein illustrates that the NIL chemistry of Al(III), and also of Ga(III) and In(III) holds promise for further developments in catalysis and energy storage.
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Affiliation(s)
- Leo W.
T. Parsons
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Louise A. Berben
- Department of Chemistry, University of California, Davis, California 95616, United States
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8
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Kim SG, Kim D, Oh J, Son YJ, Jeong S, Kim J, Hwang SJ. Phosphorus-Ligand Redox Cooperative Catalysis: Unraveling Four-Electron Dioxygen Reduction Pathways and Reactive Intermediates. J Am Chem Soc 2024. [PMID: 38597246 DOI: 10.1021/jacs.4c01748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The reduction of dioxygen to water is crucial in biology and energy technologies, but it is challenging due to the inertness of triplet oxygen and complex mechanisms. Nature leverages high-spin transition metal complexes for this, whereas main-group compounds with their singlet state and limited redox capabilities exhibit subdued reactivity. We present a novel phosphorus complex capable of four-electron dioxygen reduction, facilitated by unique phosphorus-ligand redox cooperativity. Spectroscopic and computational investigations attribute this cooperative reactivity to the unique electronic structure arising from the geometry of the phosphorus complex bestowed by the ligand. Mechanistic study via spectroscopic and kinetic experiments revealed the involvement of elusive phosphorus intermediates resembling those in metalloenzymes. Our result highlights the multielectron reactivity of phosphorus compound emerging from a carefully designed ligand platform with redox cooperativity. We anticipate that the work described expands the strategies in developing main-group catalytic reactions, especially in small molecule fixations demanding multielectron redox processes.
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Affiliation(s)
- Sung Gyu Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Dongyoung Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Jinrok Oh
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Yeong Jun Son
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Sangmin Jeong
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Joonghan Kim
- Department of Chemistry, The Catholic University of Korea, Bucheon 14662, Republic of Korea
| | - Seung Jun Hwang
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- Institute for Convergence Research and Education in Advanced Technology (I-CREATE), Yonsei University, Seoul 03722, Republic of Korea
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9
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Koptseva TS, Skatova AA, Moskalev MV, Rumyantcev RV, Fedushkin IL. Diversity of transformation of heteroallenes on acenaphthene-1,2-diimine aluminum oxide. Dalton Trans 2024; 53:4643-4651. [PMID: 38357860 DOI: 10.1039/d3dt04333a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The reactions of oxide [(dpp-bian)Al(μ2-O)2Al(dpp-bian)] (1) (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with phenyl- or cyclohexylisocyanates result in the formation of carbonimidate derivatives [(dpp-bian)Al(μ-O)(μ-RNCO2)Al(dpp-bian)] (R = Ph, 2; Cy, 3). Addition of N,N'-dicyclohexylcarbodiimide to compound 1 leads to the formation of ureate complex [(dpp-bian)Al(μ-O)(μ-(CyN)2CO)Al(dpp-bian)] (4). The reactions of the oxide 1 with pinacolborane and catecholborane afford oxo-bridged hydride [{(dpp-bian)Al(H)}(μ-O){Al(OBpin)(dpp-bian)}] (5) and compound [{(dpp-bian)Al(OBCat)}2(μ-O)] (7), respectively. Insertion of cyclohexylisocyanate into the Al-H bond of compound 5 gives CO insertion product [{(dpp-bian)Al(OC(H)NCy)}(μ-O){Al(OBpin)(dpp-bian)}] (6). New compounds have been characterized by ESR and IR spectroscopy; their molecular structures have been established by single-crystal X-ray analysis. The oxide 1 serves as a catalyst for the hydroboration of heteroallenes (isocyanates, carbodiimides) with pinacolborane.
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Affiliation(s)
- Tatyana S Koptseva
- G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, Tropinina Str. 49, Nizhny Novgorod, 603137, Russian Federation.
| | - Alexandra A Skatova
- G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, Tropinina Str. 49, Nizhny Novgorod, 603137, Russian Federation.
| | - Mikhail V Moskalev
- G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, Tropinina Str. 49, Nizhny Novgorod, 603137, Russian Federation.
| | - Roman V Rumyantcev
- G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, Tropinina Str. 49, Nizhny Novgorod, 603137, Russian Federation.
| | - Igor L Fedushkin
- G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences, Tropinina Str. 49, Nizhny Novgorod, 603137, Russian Federation.
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10
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Scott J, Maenaga ML, Woodside AJ, Guo VW, Cheriel AR, Gau MR, Rablen PR, Graves CR. Reversible O-H Bond Activation by Tripodal tris(Nitroxide) Aluminum and Gallium Complexes. Inorg Chem 2024; 63:4028-4038. [PMID: 38386423 PMCID: PMC10915791 DOI: 10.1021/acs.inorgchem.3c02902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
Herein, we report the preparation and characterization of the Group 13 metal complexes of a tripodal tris(nitroxide)-based ligand, designated (TriNOx3-)M (M = Al (1), Ga (2), In (3)). Complexes 1 and 2 both activate the O-H bond of a range of alcohols spanning a ∼10 pKa unit range via an element-ligand cooperative pathway to afford the zwitterionic complexes (HTriNOx2-)M-OR. Structures of these alcohol adduct products are discussed. We demonstrate that the thermodynamic and kinetic aspects of the reactions are both influenced by the identity of the metal, with 1 having higher reaction equilibrium constants and proceeding at a faster rate relative to 2 for any given alcohol. These parameters are also influenced by the pKa of the alcohol, with more acidic alcohols reacting both to more completion and faster than their less acidic counterparts. Possible mechanistic pathways for the O-H activation are discussed.
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Affiliation(s)
- Joseph
S. Scott
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Mika L. Maenaga
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Audra J. Woodside
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Vivian W. Guo
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Alex R. Cheriel
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Michael R. Gau
- Department
of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Paul R. Rablen
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Christopher R. Graves
- Department
of Chemistry & Biochemistry, Swarthmore
College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
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11
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Moon HW, Wang F, Bhattacharyya K, Planas O, Leutzsch M, Nöthling N, Auer AA, Cornella J. Mechanistic Studies on the Bismuth-Catalyzed Transfer Hydrogenation of Azoarenes. Angew Chem Int Ed Engl 2023; 62:e202313578. [PMID: 37769154 DOI: 10.1002/anie.202313578] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 09/30/2023]
Abstract
Organobismuth-catalyzed transfer hydrogenation has recently been disclosed as an example of low-valent Bi redox catalysis. However, its mechanistic details have remained speculative. Herein, we report experimental and computational studies that provide mechanistic insights into a Bi-catalyzed transfer hydrogenation of azoarenes using p-trifluoromethylphenol (4) and pinacolborane (5) as hydrogen sources. A kinetic analysis elucidated the rate orders in all components in the catalytic reaction and determined that 1 a (2,6-bis[N-(tert-butyl)iminomethyl]phenylbismuth) is the resting state. In the transfer hydrogenation of azobenzene using 1 a and 4, an equilibrium between 1 a and 1 a ⋅ [OAr]2 (Ar=p-CF3 -C6 H4 ) is observed, and its thermodynamic parameters are established through variable-temperature NMR studies. Additionally, pKa -gated reactivity is observed, validating the proton-coupled nature of the transformation. The ensuing 1 a ⋅ [OAr]2 is crystallographically characterized, and shown to be rapidly reduced to 1 a in the presence of 5. DFT calculations indicate a rate-limiting transition state in which the initial N-H bond is formed via concerted proton transfer upon nucleophilic addition of 1 a to a hydrogen-bonded adduct of azobenzene and 4. These studies guided the discovery of a second-generation Bi catalyst, the rate-limiting transition state of which is lower in energy, leading to catalytic transfer hydrogenation at lower catalyst loadings and at cryogenic temperature.
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Affiliation(s)
- Hye Won Moon
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Feng Wang
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Kalishankar Bhattacharyya
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Oriol Planas
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Alexander A Auer
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Josep Cornella
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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12
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Lan X, Zhang X, Mei Y, Hu C, Liu LL. Utilizing bis(imino)dihydroacridanide pincer ligands in p-block chemistry: synthesis and catalysis of an antimony monocation salt. Dalton Trans 2023; 52:15660-15664. [PMID: 37859530 DOI: 10.1039/d3dt03310d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
We present the synthesis and characterization of an Sb(III) monocation salt stabilized by a bulky bis(imino)dihydroacridanide pincer ligand. The Lewis acidity of the Sb cation is quantified using the Guttmann-Beckett method and confirmed by its reaction with 4-dimethylaminopyridine, which forms a Lewis acid-base adduct. This Sb cation exhibits catalytic activity in the cyanosilylation of arylketones. The electronic structure of the Sb cation as well as the mechanism of the catalytic transformation are explored by density functional theory computations.
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Affiliation(s)
- Xiaofang Lan
- Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Xin Zhang
- Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Yanbo Mei
- Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Chaopeng Hu
- Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Liu Leo Liu
- Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.
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13
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Yadav R, Janßen P, Schorpp M, Greb L. Calix[4]pyrrolato-germane-(thf) 2: Unlocking the Anti-van't Hoff-Le Bel Reactivity of Germanium(IV) by Ligand Dissociation. J Am Chem Soc 2023; 145:17746-17754. [PMID: 37549106 PMCID: PMC10436272 DOI: 10.1021/jacs.3c04424] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 08/09/2023]
Abstract
Anti-van't Hoff-Le Bel configured p-block element species possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept to reach anti-van't Hoff-Le Bel reactivity by ligand dissociation from a rigid calix[4]pyrrole germane in its bis(thf) adduct. While the macrocyclic ligand assures square-planar coordination in the uncomplexed form, the labile thf donors provide robustness for isolation on a multigram scale. Unique properties of a low-lying acceptor orbital imparted to germanium(IV) can be verified, e.g., by isolating an elusive anionic hydrido germanate and exploiting it for challenging bond activations. Aldehydes, water, alcohol, and a CN triple bond are activated for the first time by germanium-ligand cooperativity. Unexpected behaviors against fluoride ion donors disclose critical interferences of a putative redox-coupled fluoride ion transfer during the experimental determination of Lewis acidity. Overall, we showcase how ligand lability grants access to the uncharted chemistry of anti-van't Hoff-Le Bel germanium(IV) and line up this element as a member in the emerging class of structurally constrained p-block elements.
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Affiliation(s)
| | | | | | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
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14
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King AJ, Abbenseth J, Goicoechea JM. Reactivity of a Strictly T-Shaped Phosphine Ligated by an Acridane Derived NNN Pincer Ligand. Chemistry 2023; 29:e202300818. [PMID: 37042718 PMCID: PMC10947599 DOI: 10.1002/chem.202300818] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/13/2023]
Abstract
The steric tuning of a tridentate acridane-derived NNN pincer ligand allows for the isolation of a strictly T-shaped phosphine that exhibits ambiphilic reactivity. Well-defined phosphorus-centered reactivity towards nucleophiles and electrophiles is reported, contrasting with prior reports on this class of compounds. Reactions towards oxidants are also described. The latter result in the two-electron oxidation of the phosphorus atom from +III to +V and are accompanied by a strong geometric distortion of the NNN pincer ligand. By contrast, cooperative activation of E-H (HCl, HBcat, HOMe) bonds proceeds with retention of the phosphorus redox state. When using H2 O as a substrate, the reaction results in the full disassembly of H2 O to its constituent atoms, highlighting the potential of this platform for small molecule activation reactions.
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Affiliation(s)
- Aaron J. King
- Department of ChemistryUniversity of OxfordChemistry Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
| | - Josh Abbenseth
- Department of ChemistryUniversity of OxfordChemistry Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Straße 212489BerlinGermany
| | - Jose M. Goicoechea
- Department of ChemistryIndiana University800 E. Kirkland Ave.Bloomington, In47401USA
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15
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Yang D, Zhang S, Zeng G, Chen ZX. Metal-free catalytic hydroboration of imine with pinacolborane using a pincer-type phosphorus compound: mechanistic insight and improvement of the reaction. Phys Chem Chem Phys 2023. [PMID: 37378853 DOI: 10.1039/d3cp01709e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
A mechanistic study of the catalytic hydroboration of imine using a pincer-type phosphorus compound 1NP was performed through the combination of DFT and DLPNO-CCSD(T) calculations. The reaction proceeds through a phosphorus-ligand cooperative catalytic cycle, where the phosphorus center and triamide ligand work in a synergistic manner. First, the pinB-H bond activation by 1NP occurs through the cooperative functions of the phosphorus center and the triamide ligand, leading to a phosphorus-hydride intermediate 2NP. This is the rate-determining step, with the Gibbs energy barrier and Gibbs reaction energy of 25.3 and -17.0 kcal mol-1, respectively. Subsequently, the hydroboration of phenylmethanimine takes place through a concerted transition state through the cooperative function of the phosphorus center and the triamide ligand. It leads to the final hydroborated product 4 with the regeneration of 1NP. Our computational results reveal that the experimentally isolated intermediate 3NP is a resting state of the reaction. It is formed through the B-N bond activation of 4 by 1NP, rather than via the insertion of the CN double bond of phenylmethanimine into the P-H bond of 2NP. However, this side reaction can be suppressed by utilizing a planar phosphorus compound AcrDipp-1NP as the catalyst, which features steric-demanding substituents on the chelated N atom of the ligand.
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Affiliation(s)
- Deshuai Yang
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Shuoqi Zhang
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Guixiang Zeng
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Zhao-Xu Chen
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
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16
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Ghara M, Mondal H, Pal R, Chattaraj PK. Frustrated Lewis Pairs: Bonding, Reactivity, and Applications. J Phys Chem A 2023. [PMID: 37216335 DOI: 10.1021/acs.jpca.3c02141] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The outstanding capability of Frustrated Lewis Pair (FLP) catalysts to activate small molecules has gained significant attention in recent times. Reactivity of FLP is further extended toward the hydrogenation of various unsaturated species. Over the past decade, this unique catalysis concept has been successfully expanded to heterogeneous catalysis as well. The present review article gives a brief survey on several studies on this field. A thorough discussion on quantum chemical studies concerning the activation of H2 is provided. The role of aromaticity and boron-ligand cooperation on the reactivity of FLP is discussed in the Review. How FLP can activate other small molecules by cooperative action of its Lewis centers is also discussed. Further, the discussion is shifted to the hydrogenation of various unsaturated species and the mechanism regarding this process. It also discusses the latest theoretical advancements in the application of FLP in heterogeneous catalysis across various domains, such as two-dimensional materials, functionalized surfaces, and metal oxides. A deeper understanding of the catalytic process may assist in devising new heterogeneous FLP catalysts through experimental design.
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Affiliation(s)
- Manas Ghara
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Himangshu Mondal
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Ranita Pal
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302, India
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17
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Oberdorf K, Hanft A, Xie X, Bickelhaupt FM, Poater J, Lichtenberg C. Insertion of CO 2 and CS 2 into Bi-N bonds enables catalyzed CH-activation and light-induced bismuthinidene transfer. Chem Sci 2023; 14:5214-5219. [PMID: 37206406 PMCID: PMC10189873 DOI: 10.1039/d3sc01635h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023] Open
Abstract
The uptake and release of small molecules continue to be challenging tasks of utmost importance in synthetic chemistry. The combination of such small molecule activation with subsequent transformations to generate unusual reactivity patterns opens up new prospects for this field of research. Here, we report the reaction of CO2 and CS2 with cationic bismuth(iii) amides. CO2-uptake gives isolable, but metastable compounds, which upon release of CO2 undergo CH activation. These transformations could be transferred to the catalytic regime, which formally corresponds to a CO2-catalyzed CH activation. The CS2-insertion products are thermally stable, but undergo a highly selective reductive elimination under photochemical conditions to give benzothiazolethiones. The low-valent inorganic product of this reaction, Bi(i)OTf, could be trapped, showcasing the first example of light-induced bismuthinidene transfer.
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Affiliation(s)
- Kai Oberdorf
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Str. 4 35043 Marburg Germany
| | - Anna Hanft
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Str. 4 35043 Marburg Germany
| | - Xiulan Xie
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Str. 4 35043 Marburg Germany
| | - F Matthias Bickelhaupt
- Theoretical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam The Netherlands
- Institute for Molecules and Materials, Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
- Department of Chemical Sciences, University of Johannesburg Auckland Park Johannesburg 2006 South Africa
| | - Jordi Poater
- Departament de Química Inorgànica i Orgànica, IQTCUB, Universitat de Barcelona, ICREA Pg. Lluís Companys 23 08010 Barcelona Spain
| | - Crispin Lichtenberg
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Str. 4 35043 Marburg Germany
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18
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Eickhoff L, Kramer P, Bresien J, Michalik D, Villinger A, Schulz A. On the Dynamic Behavior of Pacman Phosphanes─A Case of Cooperativity and Redox Isomerism. Inorg Chem 2023; 62:6768-6778. [PMID: 37068163 DOI: 10.1021/acs.inorgchem.3c00481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
In solution, the Pacman chlorophosphane (2Cl) shows fast exchange of the endo/exo-orientation of the two P-Cl bonds in the molecule featuring cooperativity. Experimental and quantum mechanical investigations of the inversion on the phosphorus(III) centers reveal a crucial role of chloride ions in the dynamic process. To confirm the results, the homologous Pacman halogen-phosphanes 2X were prepared by halogen exchange reactions (X = F, Br, and I). Besides accelerated dynamic behavior for the heavier analogues, significant differences in the molecular structure are caused by the halogen exchange reactions, including the formation of an endo-endo substituted Pacman fluorophosphane as well as dicationic species by phosphorus halogen bond dissociation. The latter process can be regarded as redox isomerism since two PIII atoms in 2X become PV centers in the dications.
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Affiliation(s)
- Liesa Eickhoff
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
| | - Pascal Kramer
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
| | - Jonas Bresien
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
| | - Dirk Michalik
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 29a, D-18059 Rostock, Germany
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
| | - Axel Schulz
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 29a, D-18059 Rostock, Germany
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19
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Cooperative Bond Activation and Catalytic CO 2 Functionalization with a Geometrically Constrained Bis(silylene)-Stabilized Borylene. J Am Chem Soc 2023; 145:7011-7020. [PMID: 36939300 DOI: 10.1021/jacs.3c00949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Metal-ligand cooperativity has emerged as an important strategy to tune the reactivity of transition-metal complexes for the catalysis and activation of small molecules. Studies of main-group compounds, however, are scarce. Here, we report the synthesis, structural characterization, and reactivity of a geometrically constrained bis(silylene)-stabilized borylene. The one-pot reaction of [(SiNSi)Li(OEt2)] (SiNSi = 4,5-bis(silylene)-2,7,9,9-tetramethyl-9H-acridin-10-ide) with 1 equiv of [BBr3(SMe2)] in toluene at room temperature followed by reduction with 2 equiv of potassium graphite (KC8) leads to borylene [(SiNSi)B] (1), isolated as blue crystals in 45% yield. X-ray crystallography shows that borylene (1) has a tricoordinate boron center with a distorted T-shaped geometry. Computational studies reveal that the HOMO of 1 represents the lone pair orbital on the boron center and is delocalized over the Si-B-Si unit, while the geometric perturbation significantly increases its energy. Borylene (1) shows single electron transfer reactivity toward tris(pentafluorophenyl)borane (B(C6F5)3), forming a frustrated radical pair [(SiNSi)B]•+[B(C6F5)3]•-, which can be trapped by its reaction with PhSSPh, affording an ion pair [(SiNSi)BSPh][PhSB(C6F5)3] (3). Remarkably, the cooperation between borylene and silylene allows the facile cleavage of the N-H bond of aniline, the P-P bond in white phosphorus, and the C═O bond in ketones and carbon dioxide, thus representing a new type of main-group element-ligand cooperativity for the activation of small molecules. In addition, 1 is a strikingly effective catalyst for carbon dioxide reduction. Computational studies reveal that the cooperation between borylene and silylene plays a key role in the catalytic chemical bond activation process.
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20
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Shaves CL, Villegas-Escobar N, Clark ER, Riddlestone IM. Diverse Cooperative Reactivity at a Square Planar Aluminium Complex and Catalytic Reduction of CO 2. Chemistry 2023; 29:e202203806. [PMID: 36511153 DOI: 10.1002/chem.202203806] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
The use of a sterically demanding pincer ligand to prepare an unusual square planar aluminium complex is reported. Due to the constrained geometry imposed by the ligand scaffold, this four-coordinate aluminium centre remains Lewis acidic and reacts via differing metal-ligand cooperative pathways for activating ketones and CO2 . It is also a rare example of a single-component aluminium system for the catalytic reduction of CO2 to a methanol equivalent at room temperature.
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Affiliation(s)
- Chloe L Shaves
- Department of Chemistry, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Nery Villegas-Escobar
- Departamento de Físico-Química, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, 4070386, Chile
| | - Ewan R Clark
- School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
| | - Ian M Riddlestone
- Department of Chemistry, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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21
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Roth D, Thorwart T, Douglas C, Greb L. Bis(amidophenolato)phosphonium: Si-H Hydride Abstraction and Phosphorus-Ligand Cooperative Activation of C-C Multiple Bonds. Chemistry 2023; 29:e202203024. [PMID: 36367087 PMCID: PMC10107512 DOI: 10.1002/chem.202203024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 11/13/2022]
Abstract
The first bis(amidophenolato)phosphonium salts are prepared and fully characterized. The perfluorinated derivative represents the strongest monocationic phosphorus Lewis acid on the fluoride and hydride ion affinity scale isolable to date. This affinity enables new reactions, such as hydride abstraction from Et3 SiH, the first phosphaalkoxylation of an alkyne or a phosphorus catalyzed intramolecular hydroarylation. All properties and reactions are scrutinized by theory and experiment. Substantial σ- and π-acidity provides the required affinity for substrate activation, while phosphorus-ligand cooperativity substantially enriches the reactivity portfolio of phosphonium ions.
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Affiliation(s)
- Daniel Roth
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Thaddäus Thorwart
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Clara Douglas
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,Department of Chemistry and Biochemistry - Inorganic Chemistry, Freie Universität Berlin, Fabeckstr. 34/36, 14195, Berlin, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,Department of Chemistry and Biochemistry - Inorganic Chemistry, Freie Universität Berlin, Fabeckstr. 34/36, 14195, Berlin, Germany
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22
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Chulsky K, Malahov I, Bawari D, Dobrovetsky R. Metallomimetic Chemistry of a Cationic, Geometrically Constrained Phosphine in the Catalytic Hydrodefluorination and Amination of Ar-F Bonds. J Am Chem Soc 2023; 145:3786-3794. [PMID: 36738474 PMCID: PMC9936586 DOI: 10.1021/jacs.2c13318] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The synthesis, isolation, and reactivity of a cationic, geometrically constrained σ3-P compound in the hexaphenyl-carbodiphosphoranyl-based pincer-type ligand (1+) are reported. 1+ reacts with electron-poor fluoroarenes via an oxidative addition-type reaction of the C-F bond to the PIII-center, yielding new fluorophosphorane-type species (PV). This reactivity of 1+ was used in the catalytic hydrodefluorination of Ar-F bonds with PhSiH3, and in a catalytic C-N bond-forming cross-coupling reactions between fluoroarenes and aminosilanes. Importantly, 1+ in these catalytic reactions closely mimics the mode of action of the transition metal-based catalysts.
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23
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Zechovský J, Kertész E, Erben M, Jambor R, Růžička A, Benkö Z, Dostál L. Oxidations of N-coordinated Arsinidene and Stibinidene by Substituted Quinones: A Remarkable Follow-Up Reactivity. Chempluschem 2023; 88:e202300018. [PMID: 36756773 DOI: 10.1002/cplu.202300018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/10/2023]
Abstract
The reactivity of pnictinidenes [2-(DippN=CH)-6-(DippNHCH2 )C6 H3 ]E (where E=As (1) or Sb (2)) toward substituted ortho- and para-quinones is reported. The central pnictogen atom is easily oxidized by ortho-quinones closing five-membered EO2 C2 ring. The oxidized antimony derivatives are stable species, while in the case of arsenic compounds the hydrogen of the pendant amino NHCH2 group cleaves one newly formed As-O bonds leading to the closure of a new azaarsole ring. Furthermore, a heating of these arsenic heterocycles resulted in a C-H bond activation at the NCH2 group involved in this heterocycle followed by a reductive elimination of corresponding catechols and arsinidene [2,6-(DippN=CH)C6 H3 ]As. Using of para-quinones, resulted in the oxidation of the central atom with a concomitant hydrogen migration from NHCH2 group even in the case of the antimony derivatives. The reductive elimination of hydroquinones is in this case feasible for all compounds. Studied compounds were characterized by multi-nuclear NMR, IR and Raman spectroscopy and single-crystal X-ray diffraction analysis. The theoretical study focusing the key compounds and reactions is also included.
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Affiliation(s)
- Jan Zechovský
- Department of General and Inorganic Chemistry FCHT, University of Pardubice, Studentská 573, Pardubice, 532 10, Czech Republic
| | - Erik Kertész
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111, Budapest, Hungary
| | - Milan Erben
- Department of General and Inorganic Chemistry FCHT, University of Pardubice, Studentská 573, Pardubice, 532 10, Czech Republic
| | - Roman Jambor
- Department of General and Inorganic Chemistry FCHT, University of Pardubice, Studentská 573, Pardubice, 532 10, Czech Republic
| | - Aleš Růžička
- Department of General and Inorganic Chemistry FCHT, University of Pardubice, Studentská 573, Pardubice, 532 10, Czech Republic
| | - Zoltán Benkö
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111, Budapest, Hungary
| | - Libor Dostál
- Department of General and Inorganic Chemistry FCHT, University of Pardubice, Studentská 573, Pardubice, 532 10, Czech Republic
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24
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Zhu Q, Zhang S, Ma J, Zhu J, Li S, Zeng G. Catalytic Mechanisms of Transfer Hydrogenation of Azobenzene with Ammonia Borane by Pincer Bismuth Complex: Crucial Role of C=N Functional Group on the Pincer Ligand. Chem Asian J 2023; 18:e202201069. [PMID: 36398781 DOI: 10.1002/asia.202201069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/17/2022] [Indexed: 11/19/2022]
Abstract
Transfer hydrogenation of azobenzene with ammonia borane mediated by pincer bismuth complex 1 was systematically investigated through density functional theory calculations. An unusual metal-ligand cooperation mechanism was disclosed, in which the saturation/regeneration of the C=N functional group on the pincer ligand plays an essential role. The reaction is initiated by the hydrogenation of the C=N bond (saturation) with ammonia borane to afford 3CN , which is the rate-determining step with Gibbs energy barrier (ΔG≠ ) and Gibbs reaction energy (ΔG) of 25.6 and -7.3 kcal/mol, respectively. 3CN is then converted to a Bi-H intermediate through a water-bridged pathway, which is followed up with the transfer hydrogenation of azobenzene to produce the final product N,N'-diphenylhydrazine and regenerate the catalyst. Finally, the catalyst could be improved by substituting the phenyl group for the tert-butyl group on the pincer ligand, where the ΔG≠ value (rate-determining step) decreases to 24.0 kcal/mol.
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Affiliation(s)
- Qin Zhu
- Kuang Yaming Honors School, Nanjing University, Nanjing, 210093, P. R. China.,School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing, 210093, P. R. China.,State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChem), Fujian Provincial Key Laboratory of Theoretical Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Shuoqi Zhang
- Kuang Yaming Honors School, Nanjing University, Nanjing, 210093, P. R. China
| | - Jing Ma
- School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing, 210093, P. R. China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChem), Fujian Provincial Key Laboratory of Theoretical Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Shuhua Li
- School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing, 210093, P. R. China
| | - Guixiang Zeng
- Kuang Yaming Honors School, Nanjing University, Nanjing, 210093, P. R. China
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25
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Hollingsworth WM, Hill EA. Exploring the potential role of heavy pnictogen elements in ligand design for new metal-ligand cooperative chemistry. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2124863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- W. M. Hollingsworth
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
| | - E. A. Hill
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA
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26
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Zechovský J, Kertész E, Kremláček V, Hejda M, Mikysek T, Erben M, Růžička A, Jambor R, Benkő Z, Dostál L. Exploring Differences between Bis(aldimino)- and amino-aldimino- N, C, N-Pincer-Stabilized Pnictinidenes: Limits of Synthesis, Structure, and Reversible Tautomerization-Controlled Oxidation. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jan Zechovský
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Erik Kertész
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, H-1111 Budapest, Hungary
| | - Vít Kremláček
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Martin Hejda
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Tomáš Mikysek
- Department of Analytical Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Milan Erben
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Aleš Růžička
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Roman Jambor
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
| | - Zoltán Benkő
- Department of Inorganic and Analytical Chemistry and ELKH-BME Computation Driven Chemistry Research Group, Budapest University of Technology and Economics, Szent Gellért tér 4, H-1111 Budapest, Hungary
| | - Libor Dostál
- Department of General and Inorganic Chemistry, University of Pardubice, Studentská 573, CZ 532 10 Pardubice, Czech Republic
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27
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Volodarsky S, Bawari D, Dobrovetsky R. Dual Reactivity of a Geometrically Constrained Phosphenium Cation. Angew Chem Int Ed Engl 2022; 61:e202208401. [PMID: 35830679 PMCID: PMC9541694 DOI: 10.1002/anie.202208401] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Indexed: 01/08/2023]
Abstract
A geometrically constrained phosphenium cation in bis(pyrrolyl)pyridine based NNN pincer type ligand (1+) was synthesized, isolated and its preliminary reactivity was studied with small molecules. 1+ reacts with MeOH and Et2NH, activating the O−H and N−H bonds via a P‐center/ligand assisted path. The reaction of 1+ with one equiv. of H3NBH3 leads to its dehydrogenation producing 5. Interestingly, reaction of 1+ with an excess H3NBH3 leads to phosphinidene (PI) species coordinating to two BH3 molecules (6). In contrast, [1+][OTf] reacts with Et3SiH by hydride abstraction yielding 1‐H and Et3SiOTf, while [1+][B(C6F5)4] reacts with Et3SiH via an oxidative addition type reaction of Si−H bond to P‐center, affording a new PV compound (8). However, 8 is not stable over time and degrades to a complex mixture of compounds in matter of minutes. Despite this, the ability of [1+][B(C6F5)4] to activate Si−H bond could still be tested in catalytic hydrosilylation of benzaldehyde, where 1+ closely mimics transition metal behaviour.
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Affiliation(s)
- Solomon Volodarsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
| | - Deependra Bawari
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
| | - Roman Dobrovetsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University Department Tel Aviv 69978 Israel
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28
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Yang X, Reijerse EJ, Bhattacharyya K, Leutzsch M, Kochius M, Nöthling N, Busch J, Schnegg A, Auer AA, Cornella J. Radical Activation of N-H and O-H Bonds at Bismuth(II). J Am Chem Soc 2022; 144:16535-16544. [PMID: 36053726 PMCID: PMC9479083 DOI: 10.1021/jacs.2c05882] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The development of unconventional strategies for the activation of ammonia (NH3) and water (H2O) is of capital importance for the advancement of sustainable chemical strategies. Herein we provide the synthesis and characterization of a radical equilibrium complex based on bismuth featuring an extremely weak Bi-O bond, which permits the in situ generation of reactive Bi(II) species. The ensuing organobismuth(II) engages with various amines and alcohols and exerts an unprecedented effect onto the X-H bond, leading to low BDFEX-H. As a result, radical activation of various N-H and O-H bonds─including ammonia and water─occurs in seconds at room temperature, delivering well-defined Bi(III)-amido and -alkoxy complexes. Moreover, we demonstrate that the resulting Bi(III)-N complexes engage in a unique reactivity pattern with the triad of H+, H-, and H• sources, thus providing alternative pathways for main group chemistry.
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Affiliation(s)
- Xiuxiu Yang
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Edward J Reijerse
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | | | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Markus Kochius
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Julia Busch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Alexander Schnegg
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Alexander A Auer
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Josep Cornella
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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29
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Culpepper JD, Lee K, Portis W, Swenson DC, Daly SR. Fluorination and hydrolytic stability of water-soluble platinum complexes with a borane-bridged diphosphoramidite ligand. Dalton Trans 2022; 51:12895-12903. [PMID: 35942906 DOI: 10.1039/d2dt01482c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The high fluorophilicity of borane-containing ligands offers promise for accessing new metallodrug candidates capable of bifunctional [18F]-positron emission tomography (PET) imaging, but this requires water soluble and hydrolytically stable ligands that can be fluorinated under mild conditions. Toward this goal, here we report the synthesis and characterization of water-soluble Pt(II) complexes containing a triaminoborane-bridged diphosphoramidite ligand called MeOTBDPhos that can be fluorinated using simple fluoride salts. NMR and XRD studies show that (MeOTBDPhos)PtCl2 (1) dissolves in water with cooperative H-OH addition across the bridgehead N-B bond to form 1-H2O. The B-OH bond in 1-H2O undergoes rapid displacement with fluoride (<10 min) when treated with CsF in MeCN to form 1-HF. 1-HF can also be prepared in <10 min by addition of KF to 1 in the presence Kryptofix® 222 and (HNEt3)Cl in MeCN. In addition to using fluoride salts, we show how mononuclear 1 can be fluorinated with HBF4·Et2O to form dinuclear [(MeOTBDPhos-HF)Pt(μ-Cl)]2(BF4)2 (4-HF). Comparative studies show that the B-F bond in 1-HF undergoes hydrolysis as soon as it is dissolved in water or saline, but the B-F bond persists for hours when the pH of the solution is lowered to pH ≤ 2. In contrast to 1-HF, the B-F bond in dinuclear 4-HF persists for days when dissolved in water, which may be attributed to slow, sacrificial release of fluoride from the BF4- anion. The results show how cooperative N-B reactivity on the ligand can be leveraged to rapidly fluorinate water-soluble MeOTBDPhos complexes under mild conditions and afford suggestions for how to enhance hydrolytic B-F stability, as required for use in biomedical applications.
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Affiliation(s)
- Johnathan D Culpepper
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
| | - Kyounghoon Lee
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
| | - William Portis
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
| | - Dale C Swenson
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
| | - Scott R Daly
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, USA.
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30
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Karnbrock SBH, Golz C, Mata RA, Alcarazo M. Ligand‐Enabled Disproportionation of 1,2‐Diphenylhydrazine at a P
V
‐Center**. Angew Chem Int Ed Engl 2022; 61:e202207450. [PMID: 35714171 PMCID: PMC9542402 DOI: 10.1002/anie.202207450] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 12/02/2022]
Abstract
We present herein the synthesis of a nearly square‐pyramidal chlorophosphorane supported by the tetradentate bis(amidophenolate) ligand, N,N′‐bis(3,5‐di‐tert‐butyl‐2‐phenoxy)‐1,2‐phenylenediamide. After chloride abstraction the resulting phosphonium cation efficiently promotes the disproportionation of 1,2‐diphenylhydrazine to aniline and azobenzene. Mechanistic studies, spectroscopic analyses and theoretical calculations suggest that this unprecedented reactivity mode for PV‐centres is induced by the high electrophilicity at the cationic PV‐center, which originates from the geometry constraints imposed by the rigid pincer ligand, combined with the ability of the o‐amidophenolate moieties to act as electron reservoir. This study illustrates the promising role of cooperativity between redox‐active ligands and phosphorus for the design of organocatalysts able to promote redox processes.
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Affiliation(s)
- Simon B. H. Karnbrock
- Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
| | - Christopher Golz
- Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
| | - Ricardo A. Mata
- Institut für Physikalische Chemie Georg-August-Universität Göttingen Tammannstr. 6 37077 Göttingen Germany
| | - Manuel Alcarazo
- Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
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31
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Banerjee S, Vanka K. Computational insights into hydroboration with acyclic α-Borylamido-germylene and stannylene catalysts: Cooperative dual catalysis the key to system efficiency. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Volodarsky S, Bawari D, Dobrovetsky R. Dual Reactivity of a Geometrically Constrained Phosphenium Cation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | | | - Roman Dobrovetsky
- Tel Aviv University School of Chemistry Tel Aviv University, Shenkar Chemistry building, room 105 69978 Tel Aviv ISRAEL
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34
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Alcarazo M, Karnbrock SBH, Golz C, Mata RA. Ligand Enabled Disproportionation of 1,2‐Diphenylhydrazine at a P(V)‐Center. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Manuel Alcarazo
- Georg-August-Universität Göttingen Organic chemistry Tammannstr 2 37007 Göttingen GERMANY
| | - Simon B. H. Karnbrock
- Georg-August-Universität Göttingen: Georg-August-Universitat Gottingen Institut für organische und Biomolekulare Chemie GERMANY
| | - Christopher Golz
- Georg-August-Universität Göttingen: Georg-August-Universitat Gottingen Institu für Organische und Biomolekulare Chemie GERMANY
| | - Ricardo A. Mata
- Georg-August-Universität Göttingen: Georg-August-Universitat Gottingen Institut für Physikalische Chemie GERMANY
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35
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Volodarsky S, Malahov I, Bawari D, Diab M, Malik N, Tumanskii B, Dobrovetsky R. Geometrically constrained square pyramidal phosphoranide. Chem Sci 2022; 13:5957-5963. [PMID: 35685804 PMCID: PMC9132080 DOI: 10.1039/d2sc01060g] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/27/2022] [Indexed: 02/03/2023] Open
Abstract
Geometrical constriction of main group elements leading to a change in the reactivity of these main group centers has recently become an important tool in main group chemistry. A lot of focus on using this modern method is dedicated to group 15 elements and especially to phosphorus. In this work, we present the synthesis, isolation and preliminary reactivity study of the geometrically constrained, square pyramidal (SP) phosphoranide anion (1-). Unlike, trigonal bipyramidal (TBP) phosphoranides that were shown to react as nucleophiles while their redox chemistry was not reported, 1- reacts both as a nucleophile and reductant. The chemical oxidation of 1- leads to a P-P dimer (1-1) that is formed via the dimerization of unstable SP phosphoranyl radical (1˙), an unprecedented decay pathway for phosphoranyl radicals. Reaction of 1- with benzophenone leads via a single electron transfer (SET) to 1-OK and corresponding tetraphenyl epoxide (4).
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Affiliation(s)
- Solomon Volodarsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
| | - Irina Malahov
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
| | - Deependra Bawari
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
| | - Mohand Diab
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
| | - Naveen Malik
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science Rehovot 7610001 Israel
| | - Boris Tumanskii
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
| | - Roman Dobrovetsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University Department Tel Aviv 69978 Israel
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36
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Schön F, Sigmund LM, Schneider F, Hartmann D, Wiebe MA, Manners I, Greb L. Calix[4]pyrrolato Aluminate Catalyzes the Dehydrocoupling of Phenylphosphine Borane to High Molar Weight Polymers. Angew Chem Int Ed Engl 2022; 61:e202202176. [PMID: 35235698 PMCID: PMC9313825 DOI: 10.1002/anie.202202176] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Indexed: 01/13/2023]
Abstract
High molar weight polyphosphinoboranes represent materials with auspicious properties, but their preparation requires transition metal‐based catalysts. Here, calix[4]pyrrolato aluminate is shown to induce the dehydropolymerization of phosphine boranes to high molar mass polyphosphinoboranes (up to Mn=43 000 Da). Combined GPC and 31P DOSY NMR spectroscopic analyses, quantum chemical computations, and stoichiometric reactions disclose a P−H bond activation by the cooperative action of the square‐planar aluminate and the electron‐rich ligand framework. This first transition metal‐free catalyst for P−B dehydrocoupling overcomes the problem of residual d‐block metal impurities in the resulting polymers that might interfere with the reproducibility of the properties for this emerging class of inorganic materials.
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Affiliation(s)
- Florian Schön
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Lukas M. Sigmund
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Friederike Schneider
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Deborah Hartmann
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Matthew A. Wiebe
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Ian Manners
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Lutz Greb
- Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Germany
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37
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Schön F, Sigmund LM, Schneider F, Hartmann D, Wiebe MA, Manners I, Greb L. Calix[4]pyrrolato Aluminate Catalyzes the Dehydrocoupling of Phenylphosphine Borane to High Molar Weight Polymers. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202202176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Florian Schön
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Lukas M. Sigmund
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Friederike Schneider
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Deborah Hartmann
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
- Anorganisch-Chemisches Institut Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Matthew A. Wiebe
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Ian Manners
- Department of Chemistry University of Victoria Victoria BC, V8P 5C2 Canada
| | - Lutz Greb
- Anorganische Chemie, Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Germany
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38
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Ataie S, Hogeterp S, Ovens JS, Baker RT. SNS ligand-assisted catalyst activation in Zn-catalysed carbonyl hydroboration. Chem Commun (Camb) 2022; 58:3795-3798. [PMID: 35234221 DOI: 10.1039/d1cc06981k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ligands that include Lewis acid/base functionality have extensive applications in bifunctional catalysis using first row metals. In this work, zinc bis(amido), bis(thiolate) and amido-thiolate SNS complexes were prepared and compared as precatalysts for carbonyl hydroboration using pinacolborane. Mechanistic studies revealed two different ligand-assisted precatalyst activation pathways, both leading to an active and robust zinc alkoxide catalyst. This work furthers our understanding of metal-ligand cooperation in first-row metal catalysis.
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Affiliation(s)
- Saeed Ataie
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
| | - Seth Hogeterp
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
| | - Jeffrey S Ovens
- Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - R Tom Baker
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
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39
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Stoy A, Härterich M, Dewhurst RD, Jiménez-Halla JOC, Endres P, Eyßelein M, Kupfer T, Deissenberger A, Thiess T, Braunschweig H. Evidence for Borylene Carbonyl (LHB═C═O) and Base-Stabilized (LHB═O) and Base-Free Oxoborane (RB≡O) Intermediates in the Reactions of Diborenes with CO 2. J Am Chem Soc 2022; 144:3376-3380. [PMID: 35179031 DOI: 10.1021/jacs.2c00479] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Doubly N-heterocyclic-carbene-stabilized diborenes undergo facile reactions with CO2, initially providing dibora-β-lactones. These lactones convert over time to their 2,4-diboraoxetan-3-one isomers through a presumed dissociative pathway and hypovalent boron species borylene carbonyls (LHB═C═O) and base-stabilized oxoboranes (LHB═O). Repeating these reactions with doubly cyclic(alkyl)(amino)carbene-stabilized diborenes allowed the isolation of a borylene carbonyl intermediate, whereas a base-stabilized oxoborane could be inferred by the isolation of a boroxine from the reaction mixture. These results, supported by calculations, confirm the presumed mechanism of the diboralactone-to-diboraoxetanone isomerization while also establishing a surprising level of stability for three unknown or very rare hypovalent boron species: base-stabilized derivatives of the parent borylene carbonyl (LHB═C═O) and parent oxoborane (LHB═O) as well as base-free oxoboranes (RB≡O).
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Affiliation(s)
- Andreas Stoy
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marcel Härterich
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Rian D Dewhurst
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - J Oscar C Jiménez-Halla
- Department of Chemistry, Division of Natural and Exact Sciences, University of Guanajuato, Campus Gto, Noria Alta s/n, 36050 Guanajuato, Mexico
| | - Peter Endres
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Maximilian Eyßelein
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Kupfer
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Andrea Deissenberger
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Torsten Thiess
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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40
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Spielvogel KD, Stumme NC, Fetrow TV, Wang L, Luna JA, Keith JM, Shaw SK, Daly SR. Quantifying Variations in Metal–Ligand Cooperative Binding Strength with Cyclic Voltammetry and Redox-Active Ligands. Inorg Chem 2022; 61:2391-2401. [DOI: 10.1021/acs.inorgchem.1c03014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Kyle D. Spielvogel
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Nathan C. Stumme
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Taylor V. Fetrow
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Li Wang
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Javier A. Luna
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Jason M. Keith
- Department of Chemistry, Colgate University, 13 Oak Drive, Hamilton, New York 13346, United States
| | - Scott K. Shaw
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Scott R. Daly
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
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41
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Sigmund LM, Engels E, Richert N, Greb L. Calix[4]pyrrolato gallate: square planar-coordinated gallium( iii) and its metal–ligand cooperative reactivity with CO 2 and alcohols. Chem Sci 2022; 13:11215-11220. [PMID: 36320463 PMCID: PMC9516954 DOI: 10.1039/d2sc03054c] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
Forcing a priori tetracoordinate atoms into planar configuration represents a promising concept for enhanced reactivity of p-block element-based systems. Herein, the synthesis, characterization, and reactivity of calix[4]pyrrolato gallates, constituting square planar-coordinated gallium(iii) atoms, are reported. Unusual structural constraint-induced Lewis acidity against neutral and anionic donors is disclosed by experiment and rationalized by computations. An energetically balanced dearomatization/rearomatization of a pyrrole unit enables fully reversible metal–ligand cooperative capture of CO2. While alcohols are found unreactive against the gallates, a rapid and selective OH-bond activation can be triggered upon protonation of the ligand. Secondary ligand–sphere modification adds a new avenue to structurally-constrained complexes that unites functional group tolerance with unconventional reactivity. Ideally square-planar coordinated gallium(iii) species is isolated and fully characterized. Spontaneous metal–ligand cooperative reactivity towards CO2 is observed, while OH-bond activation of alcohols can be triggered by protonation of the ligand.![]()
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Affiliation(s)
- Lukas M. Sigmund
- Ruprecht-Karls-Universität Heidelberg, Anorganisch-Chemisches Institut, Im Neuenheimer Feld 270, Heidelberg 69120, Germany
| | - Eliane Engels
- Ruprecht-Karls-Universität Heidelberg, Anorganisch-Chemisches Institut, Im Neuenheimer Feld 270, Heidelberg 69120, Germany
| | - Nick Richert
- Ruprecht-Karls-Universität Heidelberg, Anorganisch-Chemisches Institut, Im Neuenheimer Feld 270, Heidelberg 69120, Germany
| | - Lutz Greb
- Freie Universität Berlin, Anorganische Chemie, Fabeckstraße 34-36, Berlin 14195, Germany
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Ruppert H, Sigmund LM, Greb L. Calix[4]pyrroles as ligands: recent progress with a focus on the emerging p-block element chemistry. Chem Commun (Camb) 2021; 57:11751-11763. [PMID: 34661225 DOI: 10.1039/d1cc05120b] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Calix[4]pyrroles are readily synthesized in one step from pyrroles and ketones. For several decades, these macrocycles have been exploited as powerful anion receptors or ligands for transition and rare-earth metals. In contrast, calix[4]pyrrolates as ligands for p-block elements were established only in 2018. The present feature article reviews these developments, together with the recent progress on s-, d-, and f-block element complexes of the calix[4]pyrroles. Particular focus is given on the calix[4]pyrrolato aluminate and the corresponding silane, both featuring square planar-coordinated p-block elements in their highest oxidation states. These unique "anti-van't-Hoff-Le-Bel" structures introduce valuable characteristics into main-group element chemistry, such as agostic interactions or ligand-to-metal charge transfer absorptions. The most vital reactivities are highlighted, which rely on properties ranging from amphoterism, redox-activity, and a small HOMO-LUMO gap up to the ability to provide a platform for additional external stimuli. Overall, these developments underscore the beneficial impact of structural constraint of p-block elements and element-ligand cooperativity to enhance the functionality of the most abundant elements in their native oxidation states.
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Affiliation(s)
- Heiko Ruppert
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Lukas M Sigmund
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
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43
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Steinert H, Löffler J, Gessner VH. Single‐Site and Cooperative Bond Activation Reactions with Ylide‐Functionalized Tetrylenes: A Computational Study. Eur J Inorg Chem 2021; 2021:5004-5013. [PMID: 35874088 PMCID: PMC9298247 DOI: 10.1002/ejic.202100816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/08/2021] [Indexed: 11/22/2022]
Abstract
Due to their transition metal‐like behavior divalent group 14 compounds bear huge potential for their application in bond activation reactions and catalysis. Here we report on detailed computational studies on the use of ylide‐substituted tetrylenes in the activation of dihydrogen and phenol. A series of acyclic and cyclic ylidyltetrylenes featuring various α‐substituents with different σ‐ and π‐donating capabilities have been investigated which demonstrate that particularly π‐accepting boryl groups lead to beneficial properties and low barriers for single‐site activation reactions, above all in the case of silylenes. In contrast, for the thermodynamically more stable germylenes and stannylenes an alternative mechanism involving the active participation of the ylide ligand in the E−H bond (E=H or PhO) activation process by addition across the element carbon linkage was found to be energetically favored. Furthermore, the boryl substituted tetrylenes allowed for a further activation pathway involving the active participation of the boron element bond. These cooperative mechanisms are especially attractive for the heavier cyclic ylidyltetrylenes in which the loss of the protonated ylide group is prevented due to the cyclic framework. Overall, the present studies suggest that cyclic ylide‐substituted germylenes and stannylenes bear huge potential for cooperative bond activations at mild conditions which should be experimentally addressed in the future.
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Affiliation(s)
- Henning Steinert
- Faculty of Chemistry and Biochemistry Ruhr-Universität Bochum Universitätsstraße 150 44780 Bochum Germany
| | - Julian Löffler
- Faculty of Chemistry and Biochemistry Ruhr-Universität Bochum Universitätsstraße 150 44780 Bochum Germany
| | - Viktoria H. Gessner
- Faculty of Chemistry and Biochemistry Ruhr-Universität Bochum Universitätsstraße 150 44780 Bochum Germany
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44
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Abbenseth J, Townrow OPE, Goicoechea JM. Thermoneutral N−H Bond Activation of Ammonia by a Geometrically Constrained Phosphine. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Josh Abbenseth
- Department of Chemistry University of Oxford 12 Mansfield Road OX1 3TA Oxford UK
| | - Oliver P. E. Townrow
- Department of Chemistry University of Oxford 12 Mansfield Road OX1 3TA Oxford UK
| | - Jose M. Goicoechea
- Department of Chemistry University of Oxford 12 Mansfield Road OX1 3TA Oxford UK
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45
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Abbenseth J, Townrow OPE, Goicoechea JM. Thermoneutral N-H Bond Activation of Ammonia by a Geometrically Constrained Phosphine. Angew Chem Int Ed Engl 2021; 60:23625-23629. [PMID: 34478227 PMCID: PMC8596738 DOI: 10.1002/anie.202111017] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Indexed: 01/07/2023]
Abstract
A geometrically constrained phosphine bearing a tridentate NNS pincer ligand is reported. The effect of the geometric constraint on the electronic structure was probed by theoretical calculations and derivatization reactions. Reactions with N−H bonds result in formation of cooperative addition products. The thermochemistry of these transformations is strongly dependent on the substrate, with ammonia activation being thermoneutral. This represents the first example of a molecular compound that reversibly activates ammonia via N−H bond scission in solution upon mild heating.
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Affiliation(s)
- Josh Abbenseth
- Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, UK
| | - Oliver P E Townrow
- Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, UK
| | - Jose M Goicoechea
- Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, UK
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46
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Kremláček V, Hejda M, Rychagova E, Ketkov S, Jambor R, Růžička A, Dostál L. Probing Limits of a C=C Bond Activation by N‐Coordinated Organopnictogen(I) Compounds. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Vít Kremláček
- Department of General and Inorganic Chemistry FCHT University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic
| | - Martin Hejda
- Department of General and Inorganic Chemistry FCHT University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic
| | - Elena Rychagova
- G.A.Razuvaev Institute of Organometallic Chemistry RAS 49 Tropinin St. 603950 Nizhny Novgorod Russian Federation
| | - Sergey Ketkov
- G.A.Razuvaev Institute of Organometallic Chemistry RAS 49 Tropinin St. 603950 Nizhny Novgorod Russian Federation
| | - Roman Jambor
- Department of General and Inorganic Chemistry FCHT University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic
| | - Aleš Růžička
- Department of General and Inorganic Chemistry FCHT University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic
| | - Libor Dostál
- Department of General and Inorganic Chemistry FCHT University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic
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47
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Roth D, Stirn J, Stephan DW, Greb L. Lewis Superacidic Catecholato Phosphonium Ions: Phosphorus-Ligand Cooperative C-H Bond Activation. J Am Chem Soc 2021; 143:15845-15851. [PMID: 34521202 DOI: 10.1021/jacs.1c07905] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of catecholato phosphonium ions, including the first stable bis(catecholato)-substituted derivatives, are isolated and fully characterized. The cations rank among the most potent literature-known Lewis acids on the Gutmann-Beckett and ion affinity scales. In contrast to halogenated or multiply charged phosphorus cations, Lewis superacidity is imparted by structural constraints, as disclosed by energy decomposition analysis. The modular access provides a tunable scaffold while maintaining extreme affinity, demonstrated by the synthesis of a chiral Lewis superacid. The combination of electrophilic phosphorus and basic oxygen substituents leverages new reactivity modes by phosphorus-ligand cooperativity. With this, a phosphorus-mediated C-H bond activation is accomplished.
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Affiliation(s)
- Daniel Roth
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg 69120, Germany
| | - Judith Stirn
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg 69120, Germany.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Canada
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Canada
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg 69120, Germany
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48
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Somerville RJ, Campos J. Cooperativity in Transition Metal Tetrylene Complexes. Eur J Inorg Chem 2021; 2021:3488-3498. [PMID: 34690540 PMCID: PMC8518731 DOI: 10.1002/ejic.202100460] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/02/2021] [Indexed: 12/20/2022]
Abstract
Cooperative reactivity between transition metals and ligands, or between two metals, has created significant opportunities for the development of new transformations that would be difficult to carry out with a single metal. Here we explore cooperativity between transition metals and divalent heavier group 14 elements (tetrylenes), a less-explored facet of the field of cooperativity. Tetrylenes combine their strong σ-donor properties with an empty p-orbital that can accept electron density. This ambiphilicity has allowed them to form metal tetrylene and metallotetrylene complexes that place a reactive site adjacent to the metal. We have selected examples to demonstrate what has been achieved so far regarding cooperative reactivity, as this already spans metal-, tetrylene- or multi-site-centred bond cleavage, cycloaddition, migration, metathesis, and insertion. We also highlight some challenges that need to be overcome for this cooperativity to make it to catalysis.
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Affiliation(s)
- Rosie J. Somerville
- Instituto de Investigaciones Químicas (IIQ)Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA)Consejo Superior de Investigaciones Científicas (CSIC) andUniversity of SevillaAvenida Américo Vespucio 4941092SevillaSpain
| | - Jesús Campos
- Instituto de Investigaciones Químicas (IIQ)Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA)Consejo Superior de Investigaciones Científicas (CSIC) andUniversity of SevillaAvenida Américo Vespucio 4941092SevillaSpain
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49
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Ebner F, Greb L. An isolable, crystalline complex of square-planar silicon(IV). Chem 2021; 7:2151-2159. [PMID: 34435162 PMCID: PMC8367297 DOI: 10.1016/j.chempr.2021.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/01/2021] [Accepted: 05/04/2021] [Indexed: 12/16/2022]
Abstract
The structure and reactivity of silicon(IV), the second most abundant element in our Earth's crust, is determined by its invariant tetrahedral coordination geometry. Silicon(IV) with a square-planar configuration (ptSi IV ) represents a transition state. Quantum theory supported the feasibility of stabilizing ptSi IV by structural constraint, but its isolation has not been achieved yet. Here, we present the synthesis and full characterization of the first square-planar coordinated silicon(IV). The planarity provokes an extremely low-lying unoccupied molecular orbital that induces unusual silicon redox chemistry and CH-agostic interactions. The small separation of the frontier molecular orbitals enables visible-light ligand-element charge transfer and bond-activation reactivity. Previously, such characteristics have been reserved for d-block metals or low-valent p-block elements. Planarization transfers them, for the first time, to a p-block element in the normal valence state.
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Affiliation(s)
- Fabian Ebner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
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50
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Ota K, Kinjo R. Heavier element-containing aromatics of [4 n+2]-electron systems. Chem Soc Rev 2021; 50:10594-10673. [PMID: 34369490 DOI: 10.1039/d0cs01354d] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While the implication of the aromaticity concept has been dramatically expanded to date since its emergence in 1865, the classical [4n+2]/4n-electron counting protocol still plays an essential role in evaluating the aromatic nature of compounds. Over the last few decades, a variety of heavier heterocycles featuring the formal [4n+2] π-electron arrangements have been developed, which allows for assessing their aromatic nature. In this review, we present recent developments of the [4n+2]-electron systems of heavier heterocycles involving group 13-15 elements. The synthesis, spectroscopic data, structural parameters, computational data, and reactivity are introduced.
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Affiliation(s)
- Kei Ota
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore
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