1
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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. [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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2
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Wang X, Rüttger F, Kretsch J, Kreyenschmidt A, Herbst-Irmer R, Stalke D. Boron bis-(4-methylbenzoxazol-2-yl)-methanide complexes. Dalton Trans 2024; 53:8264-8268. [PMID: 38656395 DOI: 10.1039/d4dt00522h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Boron compounds have attracted the attention of chemists because of their unique catalytic properties and potential wider material applications. Although group 13 metal compounds, which are based on the bis-(benzoxazol-2-yl)-methane system (Box, ({NCOC6H4}2CH2)), have been reported in the last several years, boron containing Box compounds were still missing. Now we report their successful syntheses and spectroscopic characterisation in this work. The borane compound [({NCOC6H3}2CH)BH2] (1) and haloboranes [({NCOC6H3}2CH)BF2] (2), [({NCOC6H3}2CH)BCl2] (3) and [({NCOC6H3}2CH)BBr2] (4) were characterised in the solid state by single crystal X-ray diffraction and in solution by NMR techniques. In addition, the fluorescence properties of compounds 1-4 are communicated.
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Affiliation(s)
- Xiaobai Wang
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
| | - Franziska Rüttger
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
| | - Johannes Kretsch
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
| | - Anne Kreyenschmidt
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077, Göttingen, Germany.
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3
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Cai L, Xu B, Cheng J, Cong F, Riedel S, Wang X. N 2 cleavage by silylene and formation of H 2Si(μ-N) 2SiH 2. Nat Commun 2024; 15:3848. [PMID: 38719794 PMCID: PMC11078988 DOI: 10.1038/s41467-024-48064-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
Fixation and functionalisation of N2 by main-group elements has remained scarce. Herein, we report a fixation and cleavage of the N ≡ N triple bond achieved in a dinitrogen (N2) matrix by the reaction of hydrogen and laser-ablated silicon atoms. The four-membered heterocycle H2Si(μ-N)2SiH2, the H2SiNN(H2) and HNSiNH complexes are characterized by infrared spectroscopy in conjunction with quantum-chemical calculations. The synergistic interaction of the two SiH2 moieties with N2 results in the formation of final product H2Si(μ-N)2SiH2, and theoretical calculations reveal the donation of electron density of Si to π* antibonding orbitals and the removal of electron density from the π bonding orbitals of N2, leading to cleave the non-polar and strong NN triple bond.
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Affiliation(s)
- Liyan Cai
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China
| | - Bing Xu
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China.
| | - Juanjuan Cheng
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China
| | - Fei Cong
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China
| | - Sebastian Riedel
- Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, D-14195, Berlin, Germany.
| | - Xuefeng Wang
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China.
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4
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Ready AD, Nelson YA, Torres Pomares DF, Spokoyny AM. Redox-Active Boron Clusters. Acc Chem Res 2024; 57:1310-1324. [PMID: 38619089 DOI: 10.1021/acs.accounts.4c00040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
ConspectusIn this Account, we discuss our group's research over the past decade on a class of functionalized boron clusters with tunable chemical and physical properties, with an emphasis on accessing and controlling their redox behavior. These clusters can be thought of as three-dimensional aromatic systems that have distinct redox behavior and photophysical properties compared to their two-dimensional organic counterparts. Specifically, our lab has studied the highly tunable, multielectron redox behavior of B12(OR)12 clusters and applied these molecules in various settings. We first discuss the spectroscopic and electrochemical characterization of B12(OR)12 clusters in various oxidation states, followed by their use as catholytes and/or anolytes in redox flow batteries and chemical dopants in conjugated polymers. Additionally, the high oxidizing potential and visible light-absorbing nature of fluoroaryl-functionalized B12(OR)12 clusters have been leveraged by our group to generate weakly coordinating, photoexcitable species that can promote photooxidation chemistry.We have further translated these solution-phase studies of B12(OR)12 clusters to the solid state by using the precursor [B12(OH)12]2- cluster as a robust building block for hybrid metal oxide materials. Specifically, we have shown that the boron cluster can act as a thermally stable cross-linking material, which enhances electron transport between metal oxide nanoparticles. We applied this structural motif to create TiO2- and WO3-containing materials that showed promising properties as photocatalysts and electroactive materials for supercapacitors. Building on this concept, we later discovered that B12(OCH3)12, the smallest of the B12(OR)12 family, could retain its redox behavior in the solid state, a previously unseen phenomenon. We successfully harnessed this unique behavior for solid-state energy storage by implementing this boron cluster as a cathode-active material in a Li-ion prototype cell device. Recently, our group has also explored how to tune the redox properties of clusters other than B12(OR)12 species by synthesizing a library of vertex-differentiated clusters containing both B-OR and B-halogen groups. Due to the additive qualities of different functional groups on the cluster, these species allow access to a region of electrochemical potentials previously inaccessible by fully substituted closo-dodecaborate alkoxy-based derivatives.Lastly, we discuss our research into smaller-sized redox-active polyhedral boranes (B6- and B10-based cluster cores). Interestingly, these clusters show significantly less redox stability and reversibility than their dodecaborate-based counterparts. While exploring the functionalization of closo-hexaborate to create fully substituted derivates (i.e., [B6R6Hfac]-), we observed unique oxidative decomposition pathways for this cluster system. Consequently, we leveraged this oxidative instability to generate useful alkyl boronate esters via selective chemical oxidation. We further explored a closo-decaborate cluster as a platform to access electrophilic [B10H13]+ species capable of directly borylating arene compounds with unique regioselectivity. Upon chemical oxidation of the arylated decaborate clusters, we successfully synthesized various aryl boronate esters, establishing the generality of the oxidative cluster deconstruction concept.Overall, our work shows that boron clusters are an appealing class of redox-active molecules, and this fundamental and understudied property can be leveraged for constructing novel materials with tunable physical and electrochemical properties, as well as producing unique chemical reagents for small molecule synthesis.
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Affiliation(s)
- Austin D Ready
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Yessica A Nelson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Daniel F Torres Pomares
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
- California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095, United States
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5
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Mao X, Qiu S, Guo R, Dai Y, Zhang J, Kong L, Xie Z. Cyclic (Alkyl)(Amino)Carbene-Iminoboryl Compounds with Three Formal Oxidation States. J Am Chem Soc 2024; 146:10917-10924. [PMID: 38587904 DOI: 10.1021/jacs.4c01934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
BN/CC isosterism is an effective strategy to build hybrid functional molecules with unique properties. In contrast to the alkynyl iminium salts derived from cyclic (alkyl)(amino)carbenes (CAACs) that feature only one reversible reduction wave, the isoelectronic cationic CAAC-iminoboryl adducts could be singly and doubly reduced smoothly. Both the resultant neutral radical and anionic azaborataallenes bear NBC-mixed allenic structures. The former radical has a high spin-density of 0.55e at CCAAC carbon, yet exhibits formal boron-centered radical reactivity. The latter azaborataallenes feature the nucleophilic CCAAC center and polar N(δ-)═B(δ+)═C(δ-) unit, and readily undergo nucleophilic substitution, isocyanide insertion, dipolar addition and cycloaddition reactions etc. The N-substituents have been shown to have a significant influence on the solid-state structure, thermal stability, and reactivity of azaborataallenes. This work showcases the allenic BN-unsaturated species as versatile building blocks in organic synthesis.
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Affiliation(s)
- Xiaofeng Mao
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong 999077, China
| | - Shuang Qiu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Rui Guo
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Yuyang Dai
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Jie Zhang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong 999077, China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Zuowei Xie
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong 999077, China
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
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6
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Zeng J, You F, Zhu J. Screening seven-electron boron-centered radicals for dinitrogen activation. J Comput Chem 2024; 45:648-654. [PMID: 38073508 DOI: 10.1002/jcc.27281] [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: 09/09/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 03/02/2024]
Abstract
The activation of dinitrogen is significant as nitrogen-containing compounds play an important role in industries. However, the inert NN triple bond caused by its large HOMO-LUMO gap (10.8 eV) and high bond dissociation energy (945 kJ mol-1 ) renders its activation under mild conditions particularly challenging. Recent progress shows that a few main group species can mimic transition metal complexes to activate dinitrogen. Here, we demonstrate that a series of seven-electron (7e) boron-centered radical can be used to activate N2 via density functional theory calculations. It is found that boron-centered radicals containing amine ligand perform best on the thermodynamics of dinitrogen activation. In addition, when electron-donating groups are introduced at the boron atom, these radicals can be used to activate N2 with low reaction barriers. Further analysis suggests that the electron transfer from the boron atom to the π* orbitals of dinitrogen is essential for its activation. Our findings suggest great potential of 7e boron radicals in the field of dinitrogen activation.
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Affiliation(s)
- Jie Zeng
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China
- Pharmaceutical Research Institute, Wuhan Institute of Technology, Wuhan, China
| | - Feiying You
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Jun Zhu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
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7
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Ferrer-Bru C, Ferrer J, Passarelli V, Lahoz FJ, García-Orduña P, Carmona D. Molecular Dihydrogen Activation by (C 5Me 5)M/N (M=Rh, Ir) Transition Metal Frustrated Lewis Pairs: Reversible Proton Migration to, and Proton Abstraction from, the C 5Me 5 Ligand. Chemistry 2024; 30:e202304140. [PMID: 38323731 DOI: 10.1002/chem.202304140] [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: 12/12/2023] [Revised: 02/07/2024] [Accepted: 02/07/2024] [Indexed: 02/08/2024]
Abstract
The masked transition-metal frustrated Lewis pairs [Cp*M(κ3N,N',N''-L)][SbF6] (Cp*=η5-C5Me5; M=Ir, 1, Rh, 2; HL=pyridinyl-amidine ligand) reversibly activate H2 under mild conditions rendering the hydrido derivatives [Cp*MH(κ2N,N'-HL)][SbF6] observed as a mixture of the E and Z isomers at the amidine C=N bond (M=Ir, 3Z, 3E; M=Rh, 4Z, 4E). DFT calculations indicate that the formation of the E isomers follows a Grotthuss type mechanism in the presence of water. A mixture of Rh(I) isomers of formula [(Cp*H)Rh(κ2N,N'-HL)][SbF6] (5 a-d) is obtained by reductive elimination of Cp*H from 4. The formation of 5 a-d was elucidated by means of DFT calculations. Finally, when 2 reacts with D2, the Cp* and Cp*H ligands of the resulting rhodium complexes 4 and 5, respectively, are deuterated as a result of a reversible hydrogen abstraction from the Cp* ligand and D2 activation at rhodium.
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Affiliation(s)
- Carlos Ferrer-Bru
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Joaquina Ferrer
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Vincenzo Passarelli
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Fernando J Lahoz
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Pilar García-Orduña
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Daniel Carmona
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009, Zaragoza, Spain
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8
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Peng PK, Donald CP, Dong Z, May JA. Photoactivation of Hydrazones for the Synthesis of Diarylalkanes and Trialkylmethylboronates: The Key Role Played by Soluble Base. Org Lett 2024. [PMID: 38602322 DOI: 10.1021/acs.orglett.4c00873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
The synthesis of diaryl alkanes and tertiary organoboronates via Barluenga coupling at room temperature occurred via photoactivated conversion of aryl sulfonyl hydrazones to diazo compounds in the presence of soluble bases. The combination of arylsulfonyl hydrazone and a soluble base is necessary to provide a near-UV chromophore. Using aromatic hydrazones and aromatic boronic acids resulted in rapid deboronation because of the instability of dibenzylic boron intermediates. Alkyl hydrazones allowed the isolation of derivatives of the tertiary boronate.
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Affiliation(s)
- Po-Kai Peng
- Department of Chemistry, University of Houston, 3585 Cullen Boulevard, Fleming Building 112, Houston, Texas 77204-5003, United States
| | - Clayton P Donald
- Department of Chemistry, University of Houston, 3585 Cullen Boulevard, Fleming Building 112, Houston, Texas 77204-5003, United States
| | - Zhencheng Dong
- Department of Chemistry, University of Houston, 3585 Cullen Boulevard, Fleming Building 112, Houston, Texas 77204-5003, United States
| | - Jeremy A May
- Department of Chemistry, University of Houston, 3585 Cullen Boulevard, Fleming Building 112, Houston, Texas 77204-5003, United States
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9
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Rang M, Heinz M, Halkić A, Weber M, Dewhurst RD, Rempel A, Härterich M, Holthausen MC, Braunschweig H. Trapping of a Terminal Intermediate in the Boron-Mediated Dinitrogen Reduction: Mono-, Tri-, and Tetrafunctionalized Hydrazines in Two Steps from N 2. J Am Chem Soc 2024. [PMID: 38598273 DOI: 10.1021/jacs.4c01818] [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 addition of chlorotrimethylsilane to a boron-mediated, transition-metal-free N2 activation reaction leads to the isolation of multiple potassium boryl(silyl)hydrazido species, likely trapping products of a terminal dinitrogen complex of boron. One of these silylated N2 species can be protonated or methylated, providing access to mono- to tetrafunctionalized hydrazines in two steps from N2 and in the absence of transition metals.
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Affiliation(s)
- Maximilian Rang
- 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
| | - Myron Heinz
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Anel Halkić
- 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
| | - Marco Weber
- 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
| | - Anna Rempel
- 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
| | - Max C Holthausen
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, 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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10
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Sun C, Liu Q, Meng L, Li X. Small molecules (CO 2 , iPrNCO, and iPrNCNiPr) activation by the metallomimetics (μ-Hydrido) diborane anion: A DFT investigation on mechanism and chemoselectivity controlling. J Comput Chem 2024; 45:331-340. [PMID: 37846101 DOI: 10.1002/jcc.27240] [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: 08/18/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/18/2023]
Abstract
Main-group metallomimetics provide a new way to replace transition metal complexes to activate inert small molecules under mild conditions. In this work, the activation mechanisms of CO2 , iPrNCO, and iPrNCNiPr by (μ-Hydrido) diborane anion ([1H]- ) have been investigated by density functional theory (DFT) calculations. Two different activation sites, BB versus BH bond of [1H]- , are investigated and compared. The results show that these inert molecules can be activated by [1H]- through cycloadditions under mild conditions. The reactions with iPrNCO and iPrNCNiPr are dynamic and thermodynamic controlling, the obtained products are related not only to the energy barrier but also to the stability of the products. Moreover, the competition for BB/BH bond site activation is directly related to the steric effect of small molecules. CO2 , which is without steric hindrance, can only be activated by the BB bond, whereas iPrNCNiPr can only be activated by the BH bond due to the large steric effect. The medium iPrNCO can be activated not only by the BB bond but also by the BH bond. Our study provides theoretical explanations for the reaction activity and chemoselectivity controlling of the title reaction, and displays the potential applications for compounds containing boron-boron bonds and inert small molecule activation.
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Affiliation(s)
- ChenFei Sun
- College of Chemistry and Material Science, Hebei Key Laboratory of Inorganic and Nano-Materials, Hebei Normal University, Shijiazhuang, China
| | - Qing Liu
- College of Chemistry and Material Science, Hebei Key Laboratory of Inorganic and Nano-Materials, Hebei Normal University, Shijiazhuang, China
| | - Lingpeng Meng
- College of Chemistry and Material Science, Hebei Key Laboratory of Inorganic and Nano-Materials, Hebei Normal University, Shijiazhuang, China
| | - Xiaoyan Li
- College of Chemistry and Material Science, Hebei Key Laboratory of Inorganic and Nano-Materials, Hebei Normal University, Shijiazhuang, China
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11
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Guo X, Lin Z. Boryls, their compounds and reactivity: a structure and bonding perspective. Chem Sci 2024; 15:3060-3070. [PMID: 38425516 PMCID: PMC10901493 DOI: 10.1039/d3sc06864a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024] Open
Abstract
Boryls and their compounds are important due to their diverse range of applications in the fields of materials science and catalysis. They are an integral part of boron chemistry, which has attracted tremendous research interest over the past few decades. In this perspective, we provide an in-depth analysis of the reaction chemistry of boryl compounds from a structure and bonding perspective. We discuss the reactivity of boryls in various transition metal complexes and diborane(4) compounds towards different substrate molecules, with a focus on their nucleophilic and electrophilic properties in various reaction processes. Additionally, we briefly discuss the reactivity of boryl radicals. Our analysis sheds new light on the unique properties of boryls and their potential for catalytic applications.
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Affiliation(s)
- Xueying Guo
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong
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12
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Ahmad A, Gayen S, Mishra S, Afsan Z, Bontemps S, Ghosh S. Doubly Base-Stabilized Diborane(4) and Borato-Boronium Species and Their Chemistry with Chalcogens. Inorg Chem 2024; 63:3376-3382. [PMID: 38329931 DOI: 10.1021/acs.inorgchem.3c03961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
In an effort to isolate diborane(4) derivatives, we have developed an efficient and uncatalyzed approach using [BH3·THF] and the mercaptopyridine ligand. Thermolysis of 2-mercaptopyridine, in the presence of [BH3·THF], afforded a doubly base-stabilized diborane(4) species 1, [HB(μ-C5H4NS)]2, along with the formation of its isomeric species 2, [HB(μ-C5H4NS)]2, albeit in less yield. Based on the coordination of the boron with the mercaptopyridine ligand in 2 and its spectroscopic data, compound 2 has been designated as a borato-boronium species, in which the anionic borate and cationic boronium units are covalently bonded to each other. Furthermore, we have demonstrated the oxidative insertion of chalcogen atoms (S and Se) through the B-B bond of the base-stabilized diborane(4), 1, that yielded chalcogenido-diboron species, 3(S) and 4(Se).
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Affiliation(s)
- Asif Ahmad
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sourav Gayen
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Shivankan Mishra
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Zeenat Afsan
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sébastien Bontemps
- LCC-CNRS, Université de Toulouse, CNRS, 205 route de Narbonne, Toulouse 31077, Cedex 04, France
| | - Sundargopal Ghosh
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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13
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Abstract
Organoboron acids are stable, organic-soluble Lewis acids with potential application as catalysts for a wide variety of chemical reactions. In this review, we summarize the utility of boronic and borinic acids, as well as boric acid, as catalysts for organic transformations. Typically, the catalytic processes exploit the Lewis acidity of trivalent boron, enabling the reversible formation of a covalent bond with oxygen. Our focus is on recent developments in the catalysis of dehydration, carbonyl condensation, acylation, alkylation, and cycloaddition reactions. We conclude that organoboron acids have a highly favorable prospectus as the source of new catalysts.
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Affiliation(s)
- Brian J Graham
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Ronald T Raines
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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14
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Parveen D, Yadav RK, Roy DK. Recent progress in beryllium organometallic chemistry. Chem Commun (Camb) 2024; 60:1663-1673. [PMID: 38260953 DOI: 10.1039/d3cc04844f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Beryllium possesses a unique amalgamation of characteristics, its electronegativity included, that not only make it a vital component in a wide range of technical sectors and consumer industries, but also make it an interesting candidate for forming covalently bonded compounds. However, the extremely toxic nature of beryllium, which can cause chronic beryllium disease, has limited the exploration of its chemistry, making beryllium one of the least studied (non-radioactive) elements. The development of selective chelating ligands, sterically encumbered substituents and, moreover, the boom of N-heterocyclic carbenes in organometallic chemistry and main group chemistry has revived the interest in beryllium chemistry. Therefore, some quite remarkable progress in the coordination and organometallic chemistry of beryllium has been made in the last two decades. For example, low oxidation state beryllium compounds, antiaromatic/aromatic beryllium compounds, where beryllium is involved in π-electron delocalization, and the isolation of beryllium-beryllium bonded species have all been achieved. This article provides an oversight over the recent developments in the organometallic chemistry of beryllium.
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Affiliation(s)
- Darakshan Parveen
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
| | - Rahul Kumar Yadav
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
| | - Dipak Kumar Roy
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
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15
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de Azevedo Santos L, Trujillo-González DE, Jiménez-Halla JOC, Bickelhaupt FM, Solà M. Stabilization of Diborynes versus Destabilization of Diborenes by Coordination of Lewis Bases: Unravelling the Dichotomy. Chemistry 2024; 30:e202303185. [PMID: 37870211 DOI: 10.1002/chem.202303185] [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: 09/29/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 10/24/2023]
Abstract
We have quantum chemically investigated the boron-boron bonds in B2 , diborynes B2 L2 , and diborenes B2 H2 L2 (L=none, OH2 , NH3 ) using dispersion-corrected relativistic density functional theory at ZORA-BLYP-D3(BJ)/TZ2P. B2 has effectively a single B-B bond provided by two half π bonds, whereas B2 H2 has effectively a double B=B bond provided by two half π bonds and one σ 2p-2p bond. This different electronic structure causes B2 and B2 H2 to react differently to the addition of ligands. Thus, in B2 L2 , electron-donating ligands shorten and strengthen the boron-boron bond whereas, in B2 H2 L2 , they lengthen and weaken the boron-boron bond. The aforementioned variations in boron-boron bond length and strength become more pronounced as the Lewis basicity of the ligands L increases.
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Affiliation(s)
- Lucas de Azevedo Santos
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Daniel E Trujillo-González
- Departamento de Química, División de Ciencias Naturales y Exactas, Unversidad de Guanajuato, Noria Alta S/N Col. Noria Alta, Guanajuato, C.P. 36050, Gto., Mexico
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany, 69, 17003, Girona, Catalonia, Spain
| | - J Oscar C Jiménez-Halla
- Departamento de Química, División de Ciencias Naturales y Exactas, Unversidad de Guanajuato, Noria Alta S/N Col. Noria Alta, Guanajuato, C.P. 36050, Gto., Mexico
| | - F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, 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
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany, 69, 17003, Girona, Catalonia, Spain
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16
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Halford-McGuff JM, Varga M, Cordes DB, McKay AP, Watson AJB. Modular Synthesis of Complex Benzoxaboraheterocycles through Chelation-Assisted Rh-Catalyzed [2 + 2 + 2] Cycloaddition. ACS Catal 2024; 14:1846-1854. [PMID: 38327642 PMCID: PMC10845118 DOI: 10.1021/acscatal.3c05766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/09/2024]
Abstract
Benzoxaboraheterocycles (BOBs) are moieties of increasing interest in the pharmaceutical industry; however, the synthesis of these compounds is often difficult or impractical due to the sensitivity of the boron moiety, the requirement for metalation-borylation protocols, and lengthy syntheses. We report a straightforward, modular approach that enables access to complex examples of the BOB framework through a Rh-catalyzed [2 + 2 + 2] cycloaddition using MIDA-protected alkyne boronic acids. The key to the development of this methodology was overcoming the steric barrier to catalysis by leveraging chelation assistance. We show the utility of the method through synthesis of a broad range of BOB scaffolds, mechanistic information on the chelation effect, intramolecular alcohol-assisted BMIDA hydrolysis, and linear/cyclic BOB limits as well as comparative binding affinities of the product BOB frameworks for ribose-derived biomolecules.
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Affiliation(s)
- John M. Halford-McGuff
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
| | - Marek Varga
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
| | - David B. Cordes
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
| | - Aidan P. McKay
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
| | - Allan J. B. Watson
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
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17
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Bonfante S, Lorber C, Lynam JM, Simonneau A, Slattery JM. Metallomimetic C-F Activation Catalysis by Simple Phosphines. J Am Chem Soc 2024; 146:2005-2014. [PMID: 38207215 PMCID: PMC10811696 DOI: 10.1021/jacs.3c10614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 01/13/2024]
Abstract
Delivering metallomimetic reactivity from simple p-block compounds is highly desirable in the search to replace expensive, scarce precious metals by cheap and abundant elements in catalysis. This contribution demonstrates that metallomimetic catalysis, involving facile redox cycling between the P(III) and P(V) oxidation states, is possible using only simple, cheap, and readily available trialkylphosphines without the need to enforce unusual geometries at phosphorus or use external oxidizing/reducing agents. Hydrodefluorination and aminodefluorination of a range of fluoroarenes was realized with good to very good yields under mild conditions. Experimental and computational mechanistic studies show that the phosphines undergo oxidative addition of the fluoroaromatic substrate via a Meisenheimer-like transition state to form a fluorophosphorane. This undergoes a pseudotransmetalation step with a silane, via initial fluoride transfer from P to Si, to give experimentally observed phosphonium ions. Hydride transfer from a hydridosilicate counterion then leads to a hydridophosphorane, which undergoes reductive elimination of the product to reform the phosphine catalyst. This behavior is analogous to many classical transition-metal-catalyzed reactions and so is a rare example of both functional and mechanistically metallomimetic behavior in catalysis by a main-group element system. Crucially, the reagents used are cheap, readily available commercially, and easy to handle, making these reactions a realistic prospect in a wide range of academic and industrial settings.
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Affiliation(s)
- Sara Bonfante
- Department
of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 Route de Narbonne,
BP44099, Toulouse Cedex 4 F-31077, France
| | - Christian Lorber
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 Route de Narbonne,
BP44099, Toulouse Cedex 4 F-31077, France
| | - Jason M. Lynam
- Department
of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
| | - Antoine Simonneau
- LCC−CNRS, Université de Toulouse, CNRS, UPS, 205 Route de Narbonne,
BP44099, Toulouse Cedex 4 F-31077, France
| | - John M. Slattery
- Department
of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
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18
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Bairagi S, Giri S, Patel DK, Luong D, Fokwa BPT, Ghosh S. Hetero-trimetallic complexes comprising bridging boryl and borylene ligands: an experimental and theoretical study. Dalton Trans 2024. [PMID: 38247401 DOI: 10.1039/d3dt03907b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
In an effort to explore the coordination chemistry of the coordinative sulfur centers in arachno-ruthenaborane [(Cp*Ru)2(B3H8)(CS2H)] (arachno-1), we have thermolyzed arachno-1 with group-6 metal carbonyls [M(CO)5·THF] (M = Cr, Mo and W). The reaction of arachno-1 with [Cr(CO)5·THF] resulted in the formation of hetero-trimetallic triply bridging borylene [(Cp*Ru)2(μ-CO)(μ3-CH2S2-κ2S':κ2S''){Cr(CO)3}(μ3-BH)] (2), bridging boryl-borylene [(Cp*Ru)2(μ-CO){(μ3-BH(CH2S2)-κ2B:κ2S':κ1S'')}{Cr(CO)3}(μ3-BH)] (3), and sulfido bridged hetero-trimetallic complex [(Cp*Ru)2(μ-CO)3{Cr(CO)3}(μ3-S)] (4). In 2, one side of Ru2Cr-triangle features a μ3-BH ligand while the other side is quadruply bridged by a methanedithiolato ligand in an unsymmetrical fashion. Unlike 2, in complex 3, one side of the Ru2Cr-triangle has a μ3-BH ligand while the opposite side is bridged by a boryl ligand BH(CH2S2) in an unsymmetrical way (μ3-κ2:κ2:κ1) to the metal centers. Interestingly, when the similar reactions of arachno-1 were performed with heavier group-6 metal carbonyls [M(CO)5·THF] (M = Mo and W), it led to the formation of methanedithiolato bridged hetero-trimetallic chain complexes, [{Cp*Ru(CO)}2(μ-CO)2(μ3-CH2S2-κ2S':κ2S''){M(CO)2}] (5, M = Mo; 6, M = W) and sulfido-bridged hetero-trimetallic complexes [(Cp*Ru)2(μ-CO)3{M(CO)3}(μ3-S)] (7, M = Mo; 8, M = W), analogous to 4. In complexes 5 and 6, a Ru2M-chain is symmetrically bridged by a methanedithiolato ligand. On the other hand, in complexes 4, 7, and 8, a sulfido ligand coordinates to two ruthenium and one group-6 metal atoms in μ3-fashion. All the complexes have been characterized by 1H NMR, 13C NMR, UV-vis, IR spectroscopy, and mass spectrometry and their structural architectures have been unambiguously established by single crystal X-ray diffraction studies. In addition, theoretical investigations provided valuable insights into their electronic structures and bonding properties.
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Affiliation(s)
- Subhash Bairagi
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Soumen Giri
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Deepak Kumar Patel
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Diana Luong
- Department of Chemistry, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA.
| | - Boniface P T Fokwa
- Department of Chemistry, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA.
| | - Sundargopal Ghosh
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
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19
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Dietz M, Arrowsmith M, Braunschweig H. CAAC-stabilised 9,10-diboraanthracene: an electronically and structurally flexible platform for small-molecule activation and metal complexation. Dalton Trans 2024; 53:449-453. [PMID: 38062986 DOI: 10.1039/d3dt03787h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
A biradical cyclic alkyl(amino)carbene-stabilised 9,10-diboraanthracene (DBA) activates small molecules such as hydrogen, phenyl azide or TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl) across its two boron atoms, while reactions with [(MeCN)3M(CO)3] (M = Cr, Mo, W) yield the first half-sandwich DBA complexes of the form [(η6-DBA)M(CO)3].
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Affiliation(s)
- Maximilian Dietz
- 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
| | - Merle Arrowsmith
- 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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20
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Filbeck E, Cremer S, Jansen MCF, Kaifer E, Himmel HJ. Halide-Coupled Double Electron Transfer with Electron-Rich Diboranes. Chemistry 2023; 29:e202302911. [PMID: 37728170 DOI: 10.1002/chem.202302911] [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: 09/15/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/21/2023]
Abstract
The ditriflato-diborane B2 (μ-hpp)2 (OTf)2 (hpp=1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate) acts as a stable surrogate of the elusive dication [B2 (hpp)2 ]2+ , being both electrophilic (vacant boron p orbitals) and nucleophilic (filled B-B bond orbital). This combination of seemingly contrasting behaviors could be used to develop a metallomimetic diborane chemistry, with Lewis σ-basic and π-acidic substrates being bound and reduced at the diborane. Here, we report on a novel reaction type within this general theme, in which double electron transfer from the diboron unit to the boron-bound organic substrate is coupled with halide transfer in the other direction. Novel diborylated dienamines are synthesized in this way. The scope of this unprecedented reaction motif and the reaction pathways are elucidated.
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Affiliation(s)
- Erik Filbeck
- Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Sebastian Cremer
- Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Moritz C F Jansen
- Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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21
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Kawa S, Knorke H, Jin J, Rohdenburg M, Asmis KR, Tonner-Zech R, Bernhardt E, Jenne C, Finze M, Warneke J. Binding Properties of Small Electrophilic Anions [B 6 X 5 ] - and [B 10 X 9 ] - (X=Cl, Br, I): Activation of Small Molecules Based on π-Backbonding. Chemistry 2023; 29:e202302247. [PMID: 37749942 DOI: 10.1002/chem.202302247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 09/27/2023]
Abstract
Superelectrophilic anions constitute a special class of molecular anions that show strong binding of weak nucleophiles despite their negative charge. In this study, the binding characteristics of smaller gaseous electrophilic anions of the types [B6 X5 ]- and [B10 X9 ]- (with X=Cl, Br, I) were computationally and experimentally investigated and compared to those of the larger analogues [B12 X11 ]- . The positive charge of vacant boron increases from [B6 X5 ]- via [B10 X9 ]- to [B12 X11 ]- , as evidenced by increasing attachment enthalpies towards typical σ-donor molecules (noble gases, H2 O). However, this behavior is reversed for σ-donor-π-acceptor molecules. [B6 Cl5 ]- binds most strongly to N2 and CO, even more strongly than to H2 O. Energy decomposition analysis confirms that the orbital interaction is responsible for this opposite trend. The extended transition state natural orbitals for chemical valence method shows that the π-backdonation order is [B6 X5 ]- >[B10 X9 ]- >[B12 X11 ]- . This predicted order explains the experimentally observed red shifts of the CO and N2 stretching fundamentals compared to those of the unbound molecules, as measured by infrared photodissociation spectroscopy. The strongest red shift is observed for [B6 Cl5 N2 ]- : 222 cm-1 . Therefore, strong activation of unreactive σ-donor-π-acceptor molecules (commonly observed for cationic transition metal complexes) is achieved with metal-free molecular anions.
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Affiliation(s)
- Sebastian Kawa
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Jiaye Jin
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Markus Rohdenburg
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Ralf Tonner-Zech
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
| | - Eduard Bernhardt
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Carsten Jenne
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Maik Finze
- Institut für Anorganische Chemie, Institut für Nachhaltige Chemie & Katalyse mit Bor (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jonas Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318, Leipzig, Germany
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22
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Ahmed S, Das H, González-Pinardo D, Fernández I, Phukan AK. Mono(Lewis Base)-Stabilized Gallium Iodide: An Unexplored Class of Promising Ligands. Chemistry 2023:e202303746. [PMID: 38109193 DOI: 10.1002/chem.202303746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/03/2023] [Accepted: 12/18/2023] [Indexed: 12/19/2023]
Abstract
Quantum-chemical (DFT) calculations on hitherto unknown base(carbene)-stabilized gallium monoiodides (LB→GaI) suggest that these systems feature one lone pair of electrons and a formally vacant p-orbital - both centered at the central gallium atom - and exhibit metallomimetic behavior. The calculated reaction free energies as well as bond dissociation energies suggest that these LB→GaI systems are capable of forming stable donor-acceptor complexes with group 13 trichlorides. Examination of the ligand exchange reactions with iron and nickel complexes indicates their potential use as ligands in transition metal chemistry. In addition, it is found that the title compounds are also able to activate various enthalpically robust bonds. Further, a detailed mechanistic investigation of these small molecule activation processes reveals the non-innocent behavior of the carbene (base) moiety attached to the GaI fragment, thereby indicating the cooperative nature of these bond activation processes. The energy decomposition analysis (EDA) and activation strain model (ASM) of reactivity were also employed to quantitatively understand and rationalize the different activation processes.
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Affiliation(s)
- Sahtaz Ahmed
- Department of Chemical Sciences, Tezpur University Napam, 784028, Assam, India
| | - Himashri Das
- Department of Chemical Sciences, Tezpur University Napam, 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 Napam, 784028, Assam, India
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23
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Briand GG. Redox-active ligands - a viable route to reactive main group metal compounds. Dalton Trans 2023; 52:17666-17678. [PMID: 37994106 DOI: 10.1039/d3dt03100d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Anionic redox-active ligands such as o-amidophenolates, catecholates, dithiolenes, 1,2-benzendithiolates, 2-amidobenzenethiolates, reduced α-diimines, ferrocenyl and porphyrinates are capable of reversible oxidation and thus have the ability to act as sources of electrons for metal centres. These and other non-innocent ligands have been employed in coordination complexes of base transition metals to influence their redox chemistry and afford compounds with useful catalytic, optical, magnetic and conducting properties. Despite the focus in contemporary main group chemistry on designing reactive compounds with potential catalytic activity, comparatively few studies exploring the chemistry of main group metal complexes incorporating redox-active ligands have been reported. This article highlights relevant chemical reactivity and electrochemical studies that probe the oxidation/reduction of main group metal compounds possessing redox-active ligands and comments on the prospects for this relatively untapped avenue of research.
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Affiliation(s)
- Glen G Briand
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, New Brunswick E4L 1G8, Canada.
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24
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Chen M, Zhang Z, Liu J, Li G, Zhao L, Mo Z. Isolation and Reactivity of Homoleptic Diphosphene Lead Complexes. Angew Chem Int Ed Engl 2023; 62:e202312837. [PMID: 37837247 DOI: 10.1002/anie.202312837] [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: 08/30/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/15/2023]
Abstract
Due to their limited capacity for π-backdonation, isolation of π-complexes of main-group elements remains a great challenge. We report herein the synthesis of a homoleptic diphosphene lead complex (2) from the degradation of P4 with a bis(germylene)-stabilized Pb(0) complex. Structural and computational studies showed that 2 possesses significant π bonding interactions between Pb atom and diphosphene ligands, which is reminiscent of transition-metal diphosphene complexes. Consistent with its unique electronic structure, complex 2 can deliver Pb(0) atoms to perform redox reaction with an iminoquinone to produce a cyclic plumbylene (4) and perform 2,5-dimethyl-3,4-dimethylimidazol-1-ylidene (IMe2 Me2 ) induced phosphorus cation abstraction to give an anionic PbP3 complex (6).
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Affiliation(s)
- 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
| | - Zhaoyin Zhang
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Jun Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Gongyu Li
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Lili Zhao
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, 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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25
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Yadav R, Das B, Singh A, Anmol, Sharma A, Majumder C, Kundu S. Bicyclic (alkyl)(amino)carbene (BICAAC)-supported phosphinidenes. Dalton Trans 2023; 52:16680-16687. [PMID: 37960973 DOI: 10.1039/d3dt02765a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Herein, the synthesis and characterization of bicyclic (alkyl)(amino)carbene (BICAAC)-stabilized phosphinidenes (1-4) are reported. Compounds 1-3 were obtained by reacting trihalophosphine [PX3, X = Cl (1), Br (2), I (3)] with BICAAC in THF. A BICAAC-stabilized bis-phosphinidene (4) was obtained from the reduction of compound 2. All four compounds were characterized by X-ray crystallography and heteronuclear NMR spectroscopy. Theoretical calculations indicated the predominant C(carbene)P double bond characteristic in compounds 1-4.
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Affiliation(s)
- Ritu Yadav
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Bindusagar Das
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Ashi Singh
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Anmol
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Ankita Sharma
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Chinmoy Majumder
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Subrata Kundu
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
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26
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Han J, Hu C, Li Q, Liu LL, Tung CH, Cui P, Kong L. Derivatization of an Alkylideneborane with B═C Bond Cleavage. Inorg Chem 2023; 62:18820-18824. [PMID: 37935044 DOI: 10.1021/acs.inorgchem.3c03232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
We present the synthesis, structural characterization, and reactivity of alkylideneborane 2, supported by π-donating N-heterocyclic imino and σ-donating N-heterocyclic carbene (NHC) ligands. The incorporation of these ligands effectively weakens the B═C bond strength, leading to enhanced reactivity. Consequently, selective cleavage of the B═C bond can be achieved using pyridine-N-oxide, sulfur, and selenium, resulting in the formation of 1,3-dioxa-2,4-diboretane 3, thioxoborane 4, and selenoborane 5, respectively. Furthermore, intriguing B═C bond insertions with CO2 and CS2 are observed, affording zwitterionic borenium/fluorenide 6 and dithiaboretane 7. The former species 6 is readily converted to transient oxoborane and imidazolium enolate, showcasing the bora-Wittig reaction of alkylideneborane. This investigation highlights the potential of alkylideneborane as a versatile building block for synthesizing novel organoboron compounds through unconventional transformations.
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Affiliation(s)
- Jixing Han
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Chaopeng Hu
- Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Qianli Li
- School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China
| | - Liu Leo Liu
- Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chen-Ho Tung
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Ping Cui
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
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27
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Chen J, Wang J, Wang X, Wei D, Duan Z. π-Electron Fluctuation-Induced P + /C - Ambiphilic Interaction for Intramolecular C Ar -H Bond Activation. Chemistry 2023:e202302889. [PMID: 37974486 DOI: 10.1002/chem.202302889] [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: 09/05/2023] [Revised: 11/06/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023]
Abstract
Herein, we describe how computational mechanistic understanding has led directly to the discovery of new 2H-phosphindole for C-CAr bond activation and dearomatization reaction. We uncover an unexpected intramolecular C-H bond activation with a 2H-phosphindole derivative. This new intriguing experimental observation and further theoretical studies led to an extension of the reaction mechanism with 2H-phosphindole. Through DFT calculations, we confirm that within a five-membered ring, the polarizable PC3 unit orchestrates the formation of an electrophilic phosphorus atom (P+ ) and a nucleophilic carbon atom (C- ). This kinetically accessible ambiphilic phosphorus/carbon couple is spatially separated by geometric constraints, and their reactivity is modulated through structural resonance.
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Affiliation(s)
- Jianzhou Chen
- College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, Zhengzhou University, 450001, Zhengzhou, China
| | - Junjian Wang
- College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, Zhengzhou University, 450001, Zhengzhou, China
| | - Xinghua Wang
- College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, Zhengzhou University, 450001, Zhengzhou, China
| | - Donghui Wei
- College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, Zhengzhou University, 450001, Zhengzhou, China
| | - Zheng Duan
- College of Chemistry, Green Catalysis Center, International Phosphorus Laboratory, Zhengzhou University, 450001, Zhengzhou, China
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28
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Roth D, Radosevich AT, Greb L. Reversible Oxidative Addition of Nonactivated C-H Bonds to Structurally Constrained Phosphenium Ions. J Am Chem Soc 2023; 145:24184-24190. [PMID: 37877607 PMCID: PMC10842376 DOI: 10.1021/jacs.3c08456] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
A series of structurally constrained phosphenium ions based on pyridinylmethylamidophenolate scaffolds are shown to undergo P(III)/P(V) oxidative addition with C-H bonds of alkynes, alkenes, and arenes. Nonactivated substrates such as benzene, toluene, and deactivated chlorobenzene are phosphorylated in quantitative yields. Computational and spectroscopic studies suggest a low-barrier isomerization from a bent to a T-shaped isomer that initiates a phosphorus-ligand-cooperative pathway and subsequent ring-chain tautomerism. Remarkably, C-H bond activations occur reversibly, allowing for reductive elimination back to P(III) at elevated temperatures or the exchange with other substrates.
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Affiliation(s)
- Daniel Roth
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
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29
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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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30
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Loh YK, Melaimi M, Gembicky M, Munz D, Bertrand G. A crystalline doubly oxidized carbene. Nature 2023; 623:66-70. [PMID: 37730995 DOI: 10.1038/s41586-023-06539-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/14/2023] [Indexed: 09/22/2023]
Abstract
The chemistry of carbon is governed by the octet rule, which refers to its tendency to have eight electrons in its valence shell. However, a few exceptions do exist, for example, the trityl radical (Ph3C∙) (ref. 1) and carbocation (Ph3C+) (ref. 2) with seven and six valence electrons, respectively, and carbenes (R2C:)-two-coordinate octet-defying species with formally six valence electrons3. Carbenes are now powerful tools in chemistry, and have even found applications in material and medicinal sciences4. Can we undress the carbene further by removing its non-bonding electrons? Here we describe the synthesis of a crystalline doubly oxidized carbene (R2C2+), through a two-electron oxidation/oxide-ion abstraction sequence from an electron-rich carbene5. Despite a cumulenic structure and strong delocalization of the positive charges, the dicoordinate carbon centre maintains significant electrophilicity, and possesses two accessible vacant orbitals. A two-electron reduction/deprotonation sequence regenerates the parent carbene, fully consistent with its description as a doubly oxidized carbene. This work demonstrates that the use of bulky strong electron-donor substituents can simultaneously impart electronic stabilization and steric protection to both vacant orbitals on the central carbon atom, paving the way for the isolation of a variety of doubly oxidized carbenes.
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Affiliation(s)
- Ying Kai Loh
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA.
| | - Mohand Melaimi
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Milan Gembicky
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Dominik Munz
- Coordination Chemistry, Saarland University, Saarbrücken, Germany
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA.
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31
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Heinz M, Arrowsmith M, Schweizer JI, Krummenacher I, Holthausen MC, Braunschweig H. Experimental and Computational Study of a Confirmed Borylene-to-Diborene Dimerization. J Am Chem Soc 2023; 145:22685-22696. [PMID: 37802099 DOI: 10.1021/jacs.3c07979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
Abstract
While the dimerization of heavier group 13 carbene analogues to the corresponding alkene analogues is known and relatively well understood, the dimerization of dicoordinate borylenes (LRB:, L = neutral donor; R = anionic substituent) to the corresponding diborenes (LRB═BRL) has never been directly observed. In this study we present the first example of a formal borylene-to-diborene dimerization through abstraction of a labile phosphine ligand from the tricoordinate hydroborylene precursor (CAAC)(Me3P)BH (CAAC = cyclic alkyl(amino)carbene) by bulky Lewis-acidic dihaloboranes (BX2Y, X = Cl, Br, Y = aryl, boryl), generating the corresponding dihydrodiborene (CAAC)HB═BH(CAAC) and (Me3P)BX2Y as the byproduct. An in-depth experimental and computational mechanistic analysis shows that this seemingly simple process (2 LL'BH + 2 BX2Y → LHB═BHL + 2 L'BX2Y) is in fact based on a complex sequence of finely tuned processes, involving the one-electron oxidation of and PMe3 abstraction from the borylene precursor by BX2Y, multiple halide transfers between (di)boron intermediates and BX2Y/[BX3Y]-, and multiple one-electron redox processes between diboron intermediates and the borylene precursor, which make the reaction ultimately autocatalytic in [(CAAC)(Me3P)BH]•+. The findings suggest that [LBXR]• boryl radicals are more likely coupling partners than dicoordinate LRB: borylenes in the reductive coupling of base-stabilized LBX2R boranes to LRB═BRL diborenes.
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Affiliation(s)
- Myron Heinz
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Merle Arrowsmith
- 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
| | - Julia I Schweizer
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Ivo Krummenacher
- 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
| | - Max C Holthausen
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, 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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32
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Trujillo-González DE, González-García G, Jiménez-Halla JOC, Solà M. Beryllium compounds for the carbon-halogen bond activation of phenyl halides: the role of non-innocent ligands. Dalton Trans 2023; 52:13068-13078. [PMID: 37700680 DOI: 10.1039/d3dt02251j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Beryllium is a metallomimetic main-group element, i.e., it behaves similarly to transition metals (TMs) in some bond activation processes. To investigate the ability of Be compounds to activate C-X bonds (X = F-I), we have computationally investigated, using DFT methods, the reaction of (CAAC)2Be (CAAC = 1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) and a series of five-membered heterocyclic beryllium bidentate ligands with phenyl halides. We have analysed all plausible reaction mechanisms and our results show that, after the initial C-X oxidative addition, migration of the phenyl group occurs towards the less electronegative heteroatom. Our theoretical study highlights the important role of bidentate non-innocent ligands in providing the required electrons for the initial Ph-X oxidative addition. In contrast, the monodentate ligand, CAAC, does not favour this oxidative addition.
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Affiliation(s)
- Daniel E Trujillo-González
- Departamento de Química, Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, CP 36050, Guanajuato, Gto, Mexico.
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany, 69, 17003 Girona, Catalonia, Spain.
| | - Gerardo González-García
- Departamento de Química, Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, CP 36050, Guanajuato, Gto, Mexico.
| | - J Oscar C Jiménez-Halla
- Departamento de Química, Campus Guanajuato, Universidad de Guanajuato, Noria Alta S/N, CP 36050, Guanajuato, Gto, Mexico.
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany, 69, 17003 Girona, Catalonia, Spain.
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33
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Ghosh S, Bhardwaj A, Mondal B. Revisiting the electronic structure of N 2-bound cAAC-borylene at the CASSCF level: a detailed bonding picture of borylene-N 2 interaction. Dalton Trans 2023; 52:12517-12525. [PMID: 37606083 DOI: 10.1039/d3dt01155k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
A base-trapped borylene species featuring a cyclic-(alkyl)(amino)carbene (cAAC) has shown unique bonding interactions with dinitrogen, thereby, opening a new avenue for N2 activation by main-group compounds. The detailed electronic structure and qualitative bonding picture between cAAC-trapped borylene and N2 remain to be fully understood. This work presents a multiconfigurational complete active space self-consistent field (CASSCF)-based electronic structure investigation on the N2-bound cAAC-borylene species (1) isolated by Braunschweig et al. Specifically, the synergistic bonding between the borylene units and N2 involving the donation from the N-N σ to the unoccupied orbital of borylene and back-donation from the occupied orbital of borylene to the N-N π* has been unequivocally established using CASSCF-derived natural orbitals and electronic configuration. Bonding interactions between the HOMO of the borylene units and the N-N π* (HOMOcAAC-B + π*NN) and the LUMO of the borylene units and the N-N σ (LUMOcAAC-B + σNN) in 1 were apparent through the CASSCF-derived natural orbitals. The unique bonding of the B-N-N-B core in 1 and the resulting geometry have also been compared with the M-N-N-M core of a prototypical transition metal(M)-N2 complex. Finally, the change in the electronic structure and geometry of the N2-bound borylene species 1 on two-electron reduction has been investigated in the context of N2 activation.
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Affiliation(s)
- Susovon Ghosh
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh 175005, India.
| | - Akhil Bhardwaj
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh 175005, India.
| | - Bhaskar Mondal
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh 175005, India.
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34
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Lv W, Dai Y, Guo R, Su Y, Ruiz DA, Liu LL, Tung CH, Kong L. Geometrically Constrained Organoboron Species as Lewis Superacids and Organic Superbases. Angew Chem Int Ed Engl 2023; 62:e202308467. [PMID: 37395499 DOI: 10.1002/anie.202308467] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/03/2023] [Accepted: 07/03/2023] [Indexed: 07/04/2023]
Abstract
This report unveils an advancement in the formation of a Lewis superacid (LSA) and an organic superbase by the geometrical deformation of an organoboron species towards a T-shaped geometry. The boron dication [2]2+ supported by an amido diphosphine pincer ligand features both a large fluoride ion affinity (FIA>SbF5 ) and hydride ion affinity (HIA>B(C6 F5 )3 ), which qualifies it as both a hard and soft LSA. The unusual Lewis acidic properties of [2]2+ are further showcased by its ability to abstract hydride and fluoride from Et3 SiH and AgSbF6 respectively, and effectively catalyze the hydrodefluorination, defluorination/arylation, as well as reduction of carbonyl compounds. One and two-electron reduction of [2]2+ affords stable boron radical cation [2]⋅+ and borylene 2, respectively. The former species has an extremely high spin density of 0.798e at the boron atom, whereas the latter compound has been demonstrated to be a strong organic base (calcd. pKBH + (MeCN)=47.4) by both theoretical and experimental assessment. Overall, these results demonstrate the strong ability of geometric constraining to empower the central boron atom.
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Affiliation(s)
- Weiwei Lv
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China
| | - Yuyang Dai
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China
| | - Rui Guo
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China
| | - Yuanting Su
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - David A Ruiz
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Liu Leo Liu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Chen-Ho Tung
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
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35
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Guo R, Hu C, Li Q, Liu LL, Tung CH, Kong L. BN Analogue of Butadiyne: A Platform for Dinitrogen Release and Reduction. J Am Chem Soc 2023; 145:18767-18772. [PMID: 37582249 DOI: 10.1021/jacs.3c07469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Exploration of the metallomimetic chemistry of main group elements is of the utmost importance from the perspective of both fundamental research and potential applications. Here, we report the synthesis, bonding analysis, and reactivities of an isolable diiminoborane, Mes*B≡N─N≡BMes* (Mes* = 2,4,6-tri-tert-butylphenyl) (1), a BN analogue of butadiyne. This species is characterized by a conjugated B≡N─N≡B moiety, a structural feature that enables the controlled release of N2 when it is exposed to organic nitriles. Furthermore, the N2 unit in 1 could be reduced to an ammonium salt via cleavage of the BN triple bond. Our work shows a rare example of an unsaturated BN system, serving as a platform for both the release and reduction of N2. This discovery opens new pathways and holds substantial influence on the future design of functional main group N2 species.
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Affiliation(s)
- Rui Guo
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Chaopeng Hu
- Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Qianli Li
- School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China
| | - Liu Leo Liu
- Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chen-Ho Tung
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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36
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Zhu L, Kinjo R. Insertion of carbon monoxide into an unsymmetrical diborene to form an oxaborirane. Chem Commun (Camb) 2023; 59:10436-10439. [PMID: 37555354 DOI: 10.1039/d3cc02844e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
The insertion of carbon monoxide (CO) into an unsymmetrical diborene, concomitant with B-O bond formation under ambient conditions, gives an oxaborirane species. A similar insertion reaction with isocyanide, the isoelectronic species of CO, generates azaboriridine derivatives.
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Affiliation(s)
- Lizhao Zhu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore.
| | - Rei Kinjo
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore.
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Nussbaum BC, Humphries AL, Gange GB, Peryshkov DV. Redox-active carborane clusters in bond activation chemistry and ligand design. Chem Commun (Camb) 2023; 59:9918-9928. [PMID: 37522167 DOI: 10.1039/d3cc03011c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Icosahedral closo-dodecaboranes have the ability to accept two electrons, opening into a dianionic nido-cluster. This transformation can be utilized to store electrons, drive bond activation, or alter coordination to metal cations. In this feature article, we present cases for each of these applications, wherein the redox activity of carborane facilitates the generation of unique products. We highlight the effects of exohedral substituents on reactivity and the stability of the products through conjugation between the cluster and exohedral substituents. Futher, the utilization of the redox properties and geometry of carborane clusters in the ligand design is detailed, both in the stabilization of low-valent complexes and in the tuning of ligand geometry.
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Affiliation(s)
- Bryce C Nussbaum
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Amanda L Humphries
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Gayathri B Gange
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
| | - Dmitry V Peryshkov
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, South Carolina 29208, USA.
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38
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Abdou-Mohamed A, Aupic C, Fournet C, Parrain JL, Chouraqui G, Chuzel O. Stereoselective formation of boron-stereogenic organoboron derivatives. Chem Soc Rev 2023. [PMID: 37325998 DOI: 10.1039/d3cs00163f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Four-coordinate organoboron derivatives present interesting chemical, physical, biological, electronical, and optical properties. Given the increasing demand for the synthesis of smart functional materials based on chiral organoboron compounds, the exploration of stereoselective synthesis of boron-stereogenic organo-derivatives is highly desirable. However, the stereoselective construction of organoboron compounds stereogenic at boron has been far less studied than other elements of the main group due to configurational stability concerns. Nowadays, these species are no longer elusive and configurationally stable compounds have been highlighted. The idea is to show the potential of the stereoselective building of the four-coordinate boron centre and encourage future endeavors and developments in the field.
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Affiliation(s)
| | - Clara Aupic
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
| | - Corentin Fournet
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
| | - Jean-Luc Parrain
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
| | - Gaëlle Chouraqui
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
| | - Olivier Chuzel
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
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Fan J, Koh AP, Zhou J, Zhang ZF, Wu CS, Webster RD, Su MD, So CW. Tetrakis( N-heterocyclic Carbene)-Diboron(0): Double Single-Electron-Transfer Reactivity. J Am Chem Soc 2023; 145:11669-11677. [PMID: 37201187 DOI: 10.1021/jacs.3c01801] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The use of 1,3,4,5-tetramethylimidazol-2-ylidene (IMe) to coordinate with diatomic B2 species afforded a tetrakis(N-heterocyclic carbene)-diboron(0) [(IMe)2B-B(IMe)2] (2). The singly bonded B2 moiety therein possesses a valence electronic configuration 1σg21πu21πg*2 with four vacant molecular orbitals (1σu*, 2σg, 1πu', 1πg'*) coordinated with IMe. Its unprecedented electronic structure is analogous to the energetically unfavorable planar hydrazine with a D2h symmetry. The two highly reactive πg* antibonding electrons enable double single-electron-transfer (SET) reactivity in small-molecule activation. Compound 2 underwent a double SET reduction with CO2 to form two carbon dioxide radical anions CO2•-, which then reduced pyridine to yield a carboxylated pyridine reductive coupling dianion [O2CNC5(H)5-C5(H)5NCO2]2- and converted compound 2 to the tetrakis(N-heterocyclic carbene)-diborene dication [(IMe)2B═B(IMe)2]2+ (32+). This is a remarkable transition-metal-free SET reduction of CO2 without ultraviolet/visible (UV/vis) light conditions.
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Affiliation(s)
- Jun Fan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
| | - An-Ping Koh
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
| | - Jingsong Zhou
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
| | - Zheng-Feng Zhang
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Chi-Shiun Wu
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Richard D Webster
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Cheuk-Wai So
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
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40
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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: 2] [Impact Index Per Article: 2.0] [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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41
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Das S, Devi K, Suthar S, Mondal KC. Bonding and stability of elusive silaboryne (SiB) and germaboryne (GeB) with donor base ligands. J Comput Chem 2023. [PMID: 37177883 DOI: 10.1002/jcc.27118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 03/28/2023] [Accepted: 04/06/2023] [Indexed: 05/15/2023]
Abstract
Stabilizing the exotic chemical species possessing multiple bonds is often extremely challenging due to insufficient orbital overlap, especially involving one heavier element. Bulky aryl groups and/or carbene as ligand have previously stabilized the SiSi, GeGe, and BB triple bonds. Herein, theoretical calculations have been carried out to shed light on the stability and bonding of elusive silaboryne/germaboryne (Si/GeB triple bond) stabilized by donor base ligands ((cAAC)BE(Me)(L); E = Si, L = cAACMe , NHCMe , PMe3 ; E = Ge, L = cAACMe ). The heavier analogues (Sn, Pb) have been further studied for comparison. Additionally, the effects of bulky substituents at the Si and N atoms on the structural parameters and stability of those species have been investigated. Energy decomposition analysis coupled with natural orbital for chemical valence (EDA-NOCV; for Si) showed that cAAC/NHC ligands could stabilize the exotic BSi-Me species more efficiently than PMe3 ligands. The BSi partial triple bond of the corresponding species possesses a mixture of one covalent electron sharing BSi σ-bond and two dative π-bonds (B ← Si, B → Si).
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Affiliation(s)
- Sujit Das
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
| | - Kavita Devi
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
| | - Sonam Suthar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
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Härterich M, Matler A, Dewhurst RD, Sachs A, Oppel K, Stoy A, Braunschweig H. A step-for-step main-group replica of the Fischer carbene synthesis at a borylene carbonyl. Nat Commun 2023; 14:2764. [PMID: 37179413 PMCID: PMC10183005 DOI: 10.1038/s41467-023-36251-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/23/2023] [Indexed: 05/15/2023] Open
Abstract
The Fischer carbene synthesis, involving the conversion of a transition metal (TM)-bound CO ligand to a carbene ligand of the form [=C(OR')R] (R, R' = organyl groups), is one of the seminal reactions in the history of organometallic chemistry. Carbonyl complexes of p-block elements, of the form [E(CO)n] (E = main-group fragment), are much less abundant than their TM cousins; this scarcity and the general instability of low-valent p-block species means that replicating the historical reactions of TM carbonyls is often very difficult. Here we present a step-for-step replica of the Fischer carbene synthesis at a borylene carbonyl involving nucleophilic attack at the carbonyl carbon followed by electrophilic quenching at the resultant acylate oxygen atom. These reactions provide borylene acylates and alkoxy-/silyloxy-substituted alkylideneboranes, main-group analogues of the archetypal transition metal acylate and Fischer carbene families, respectively. When either the incoming electrophile or the boron center has a modest steric profile, the electrophile instead attacks at the boron atom, leading to carbene-stabilized acylboranes - boron analogues of the well-known transition metal acyl complexes. These results constitute faithful main-group replicas of a number of historical organometallic processes and pave the way to further advances in the field of main-group metallomimetics.
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Affiliation(s)
- 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
| | - Alexander Matler
- 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
| | - Andreas Sachs
- 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
| | - Kai Oppel
- 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
| | - 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
| | - 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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43
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Gärtner A, Karaca US, Rang M, Heinz M, Engel PD, Krummenacher I, Arrowsmith M, Hermann A, Matler A, Rempel A, Witte R, Braunschweig H, Holthausen MC, Légaré MA. Achieving Control over the Reduction/Coupling Dichotomy of N 2 by Boron Metallomimetics. J Am Chem Soc 2023; 145:8231-8241. [PMID: 36977310 DOI: 10.1021/jacs.3c01762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
We report a detailed computational and experimental study of the fixation and reductive coupling of dinitrogen with low-valent boron compounds. Consistent with our mechanistic findings, the selectivity toward nitrogen fixation or coupling can be controlled through either steric bulk or the reaction conditions, allowing for the on-demand synthesis of nitrogen chains. The electronic structure and intriguing magnetic properties of intermediates and products of the reaction of dinitrogen with borylenes are also elucidated using high-level computational approaches.
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Affiliation(s)
- Annalena Gärtner
- 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
| | - Uhut S Karaca
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Maximilian Rang
- 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
| | - Myron Heinz
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Philipp D Engel
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Ivo Krummenacher
- 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
| | - Merle Arrowsmith
- 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
| | - Alexander Hermann
- 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
| | - Alexander Matler
- 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
| | - Anna Rempel
- 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
| | - Robert Witte
- 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
| | - Max C Holthausen
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Marc-André Légaré
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal H3A 0B8, Québec, Canada
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44
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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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Witte R, Arrowsmith M, Lamprecht A, Schorr F, Krummenacher I, Braunschweig H. C-C and C-N Bond Activation, Lewis-Base Coordination and One- and Two-Electron Oxidation at a Linear Aminoborylene. Chemistry 2023; 29:e202203663. [PMID: 36562195 DOI: 10.1002/chem.202203663] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
A cyclic alkyl(amino)carbene (CAAC)-stabilized dicoordinate aminoborylene is synthesized by the twofold reduction of a [(CAAC)BCl2 (TMP)] (TMP=2,6-tetramethylpiperidyl) precursor. NMR-spectroscopic, X-ray crystallographic and computational analyses confirm the cumulenic nature of the central C=B=N moiety. Irradiation of [(CAAC)B(TMP)] (2) resulted in an intramolecular C-C bond activation, leading to a doubly-fused C10 BN heterocycle, while the reaction with acetonitrile resulted in an aryl migration from the CAAC to the acetonitrile nitrogen atom, concomitant with tautomerization of the latter to a boron-bound allylamino ligand. One-electron oxidation of 2 with CuX (X=Cl, Br) afforded the corresponding amino(halo)boryl radicals, which were characterized by EPR spectroscopy and DFT calculations. Placing 2 under an atmosphere of CO afforded the tricoordinate (CAAC,CO)-stabilized aminoborylene. Finally, the twofold oxidation of 2 with chalcogens led, in the case of N2 O and sulfur, to the splitting of the B-CCAAC bond and formation of the 2,4-diamino-1,3,2,4-dichalcogenadiboretanes and CAAC-chalcogen adducts, whereas with selenium a monomeric boraselenone was isolated, which showed some degree of B-Se multiple bonding.
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Affiliation(s)
- Robert Witte
- 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
| | - Merle Arrowsmith
- 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
| | - Anna Lamprecht
- 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
| | - Fabian Schorr
- 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
| | - Ivo Krummenacher
- 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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46
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Francis M, Roy S. Stabilisation and reactivity studies of donor-base ligand-supported gallium-phosphides with stronger binding energy: a theoretical approach. RSC Adv 2023; 13:7738-7751. [PMID: 36909773 PMCID: PMC9993238 DOI: 10.1039/d2ra06001a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 02/17/2023] [Indexed: 03/14/2023] Open
Abstract
Gallium phosphide is a three-dimensional polymeric material of the hetero-diatomic GaP unit, which has a wurtzite type structure, and captivating application as a light emitting diode (LED). As a result, there is a constant search for suitable precursors to synthesise GaP-based materials. However, the corresponding monomeric species is exotic in nature due to the expected Ga[triple bond, length as m-dash]P multiple bond. Herein, we report on the theoretical studies of stability, chemical bonding, and reactivity of the monomeric gallium phosphides with two donor base ligands having tuneable binding energies. We have performed detailed investigations using density functional theory at three different levels (BP86/def2-TZVPP, B3LYP/def2-TZVPP, M06-2X/def2-TZVPP), QTAIM and EDA-NOCV (BP86-D3(BJ)/TZ2P, M06-2X/TZ2P) to analyse various ligand-stabilised GaP monomers, which revealed the synthetic viability of such species in the presence of stable singlet carbenes, e.g., cAAC, and NHC as ligands [cAAC = cyclic alkyl(amino) carbene, NHC = N-heterocyclic carbene] due to the larger bond dissociation energy compared to a phosphine ligand (PMe3). The calculated bond dissociation energies between a pair of ligands and the monomeric GaP unit are found to be in the range of 87 to 137 kcal mol-1, predicting their possible syntheses in the laboratory. Further, the reactivity of such species with metal carbonyls [Fe(CO)4, and Ni(CO)3] have been theoretically investigated.
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Affiliation(s)
- Maria Francis
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati 517507 India
| | - Sudipta Roy
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati Tirupati 517507 India
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47
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Zhang Y, Wu L, Wang H. Application of N-heterocyclic silylenes in low-valent group 13, 14 and 15 chemistry. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Fan J, Yang MC, Su MD, So CW. N-Phosphinoamidinato Silylene- and Phosphine-Borylborylene Complexes. Inorg Chem 2023; 62:863-870. [PMID: 36600552 DOI: 10.1021/acs.inorgchem.2c03660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This work describes a straightforward method to synthesize a borylborylene without proceeding via the rearrangement of a diborene. An amidinato amidosilylene [LSiNMe2] (L = PhC(NtBu)2) and PMe3 were reacted with an N-phosphinoamidinato diborane 1 and KC8 to form a stable silylene-borylborylene 2 and a persistent phosphine-borylborylene 3, respectively. Compound 2 is stable as the borylene center is well stabilized by the silylene donor and boryl substituent, whereas compound 3 is unstable in solution due to labile PMe3. The latter was illustrated by reacting compound 3 with Ar'NC (Ar' = 2,6-Me2C6H3), where Ar'NC displaced PMe3 and inserted into the N-phosphinoamidinate ligand and B-B bond to form compound 4.
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Affiliation(s)
- Jun Fan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
| | - Ming-Chung Yang
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.,Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Cheuk-Wai So
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 637371 Singapore
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Zhang H, Wang Y, Lu Q, Song J, Duan Y, Zeng Y, Mo Y. Captodative Effect Facilitates the Excitation in Diboron Molecule (CAAC) 2 B 2 (SH) 2. Chemistry 2023; 29:e202203817. [PMID: 36624078 DOI: 10.1002/chem.202203817] [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: 12/06/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
Given the extraordinary versatility in chemical reactions and applications, boron compounds have gained increasing attentions in the past two decades. One of the remarkable advances is the unprecedented preparation of unsaturated boron species. Notably, Braunschweig et al. found that the cyclic (alkyl)(amino) carbenes (CAACs) stabilized diboron molecules (CAAC)2 B2 (SR)2 host unpaired electrons and exist in the 90°-twisted diradical form, while other analogues, such as N-heterocyclic carbenes (NHCs), stabilized diboron molecules prefer a conventional B=B double bond. Since previous studies recognized the differences in the steric effect between CAAC and NHC carbenes, here we focused on the role of thiol substituents in (CAAC)2 B2 (SR)2 by gradually localizing involved electrons. The co-planarity of the thiol groups and the consequent captodative effect were found to be the culprit for the 90°-twisted diradical form of (CAAC)2 B2 (SR)2 . Computational analyses identified two forces contributing to the π electron movements. One is the "push" effect of lone pairs on the sulfur atoms which boosts the π electron delocalization between the BB center and CAACs. The other is the π electron delocalization within each (CAAC)B(SR) fragment where the pull effect originates from the π electron withdrawal by CAACs. There are two such independent and orthogonal push-pull channels which function mainly in individual (CAAC)B(SR) fragments. This enhanced π push-pull effect in the triplet state facilitates the electronic excitation in (CAAC)2 B2 (SR)2 by reducing the singlet-triplet gap.
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Affiliation(s)
- Huaiyu Zhang
- Institute of Computational Quantum Chemistry, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Yating Wang
- Institute of Computational Quantum Chemistry, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Qingrui Lu
- Institute of Computational Quantum Chemistry, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Jinshuai Song
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China
| | - Yandong Duan
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, School of Sciences, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Yanli Zeng
- Institute of Computational Quantum Chemistry, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Yirong Mo
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA
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Li Z, Song G, Li ZH. Theoretical investigation of borane compounds mimicking transition metals for N 2 fixation and activation. Phys Chem Chem Phys 2023; 25:1331-1341. [PMID: 36533691 DOI: 10.1039/d2cp04560e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
N2 fixation is very difficult because of the nonpolarity and high stability of N2. Traditionally, it is achieved by transition metal (TM) systems utilizing the back donation from the d orbitals of the TM to the antibonding π* orbitals of N2 to activate N2. This back donation is rare for main group compounds due to the lack of high-lying valence d orbitals. In the present study, we show that borane compounds with weak B-X (X = H, Si, Ge, and Sb) bonds can mimic TM systems and be used to fix and activate N2. This is achieved by the back donation from the σ bonding orbitals of the B-X bonds to the antibonding π* and σ* orbitals of N2. There is even a linear relationship between the number of B-X bonds and the binding potential energy of N2 with BR1R2R3 (R1, R2, R3 = H, CH3, SiH3, GeH3, and SbH2). Based on these findings, we designed several stable silylborane compounds that are feasible for N2 fixation and activation under mild reaction conditions, i.e., room temperature and 1 atm. In some sandwich-like complexes formed between N2 and silylborane compounds, N2 is even activated from the triple bond to double bond.
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Affiliation(s)
- Zhipeng Li
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Shanghai, 200438, China.
| | - Guoliang Song
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Shanghai, 200438, China.
| | - Zhen Hua Li
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Department of Chemistry, Fudan University, Shanghai, 200438, China.
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