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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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2
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Roesky HW, Kushvaha SK, Mishra A, Mondal KC. Recent advances in the domain of Cyclic (alkyl)(amino) carbenes. Chem Asian J 2022; 17:e202101301. [PMID: 34989475 PMCID: PMC9307053 DOI: 10.1002/asia.202101301] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/25/2021] [Indexed: 12/03/2022]
Abstract
Isolation of cyclic (alkyl) amino carbenes (cAACs) in 2005 has been a major achievement in the field of stable carbenes due to their better electronic properties. cAACs and bicyclic(alkyl)(amino)carbene (BicAAC) in essence are the most electrophilic as well as nucleophilic carbenes are known till date. Due to their excellent electronic properties in terms of nucleophilic and electrophilic character, cAACs have been utilized in different areas of chemistry, including stabilization of low valent main group and transition metal species, activation of small molecules, and catalysis. The applications of cAACs in catalysis have opened up new avenues of research in the field of cAAC chemistry. This review summarizes the major results of cAAC chemistry published until August 2021.
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Affiliation(s)
- Herbert W Roesky
- Georg-August-Universitat Gottingen, Department of Chemistry, Tammannstrasse 4, 37077, Göttingen, GERMANY
| | | | - Ankush Mishra
- IIT Madras: Indian Institute of Technology Madras, Chemistry, INDIA
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3
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Francisco MAS, Fantuzzi F, Cardozo TM, Esteves PM, Engels B, Oliveira RR. Taming the Antiferromagnetic Beast: Computational Design of Ultrashort Mn-Mn Bonds Stabilized by N-Heterocyclic Carbenes. Chemistry 2021; 27:12126-12136. [PMID: 34114702 PMCID: PMC8456913 DOI: 10.1002/chem.202101116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Indexed: 12/26/2022]
Abstract
The development of complexes featuring low-valent, multiply bonded metal centers is an exciting field with several potential applications. In this work, we describe the design principles and extensive computational investigation of new organometallic platforms featuring the elusive manganese-manganese bond stabilized by experimentally realized N-heterocyclic carbenes (NHCs). By using DFT computations benchmarked against multireference calculations, as well as MO- and VB-based bonding analyses, we could disentangle the various electronic and structural effects contributing to the thermodynamic and kinetic stability, as well as the experimental feasibility, of the systems. In particular, we explored the nature of the metal-carbene interaction and the role of the ancillary η6 coordination to the generation of Mn2 systems featuring ultrashort metal-metal bonds, closed-shell singlet multiplicities, and positive adiabatic singlet-triplet gaps. Our analysis identifies two distinct classes of viable synthetic targets, whose electrostructural properties are thoroughly investigated.
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Affiliation(s)
- Marcos A. S. Francisco
- Instituto de QuímicaUniversidade Federal do Rio de JaneiroAv. Athos da Silveira Ramos 14921941909Rio de JaneiroBrazil
| | - Felipe Fantuzzi
- Institut für Physikalische und Theoretische ChemieJulius-Maximilians-Universität WürzburgEmil-Fischer-Straße 4297074WürzburgGermany
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Thiago M. Cardozo
- Instituto de QuímicaUniversidade Federal do Rio de JaneiroAv. Athos da Silveira Ramos 14921941909Rio de JaneiroBrazil
| | - Pierre M. Esteves
- Instituto de QuímicaUniversidade Federal do Rio de JaneiroAv. Athos da Silveira Ramos 14921941909Rio de JaneiroBrazil
| | - Bernd Engels
- Institut für Physikalische und Theoretische ChemieJulius-Maximilians-Universität WürzburgEmil-Fischer-Straße 4297074WürzburgGermany
| | - Ricardo R. Oliveira
- Instituto de QuímicaUniversidade Federal do Rio de JaneiroAv. Athos da Silveira Ramos 14921941909Rio de JaneiroBrazil
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4
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Brückner T, Fantuzzi F, Stennett TE, Krummenacher I, Dewhurst RD, Engels B, Braunschweig H. Isolierung neutraler, mono‐ und dikationischer B
2
P
2
‐Ringe durch Addition eines Diphosphans an eine Bor‐Bor‐Dreifachbindung. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tobias Brückner
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
| | - Felipe Fantuzzi
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institut für Physikalische und Theoretische Chemie Julius-Maximilians-Universität Würzburg Emil-Fischer-Straße 42 97074 Würzburg Deutschland
| | - Tom E. Stennett
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
| | - Ivo Krummenacher
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
| | - Rian D. Dewhurst
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie Julius-Maximilians-Universität Würzburg Emil-Fischer-Straße 42 97074 Würzburg Deutschland
| | - Holger Braunschweig
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97070 Würzburg Deutschland
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5
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Brückner T, Fantuzzi F, Stennett TE, Krummenacher I, Dewhurst RD, Engels B, Braunschweig H. Isolation of Neutral, Mono-, and Dicationic B 2 P 2 Rings by Diphosphorus Addition to a Boron-Boron Triple Bond. Angew Chem Int Ed Engl 2021; 60:13661-13665. [PMID: 33844394 PMCID: PMC8252364 DOI: 10.1002/anie.202102218] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/09/2021] [Indexed: 01/10/2023]
Abstract
The NHC-stabilised diboryne (B2 (SIDep)2 ; SIDep=1,3-bis(2,6-diethylphenyl)imidazolin-2-ylidene) undergoes a high-yielding P-P bond activation with tetraethyldiphosphine at room temperature to form a B2 P2 heterocycle via a diphosphoryldiborene by 1,2-diphosphination. The heterocycle can be oxidised to a radical cation and a dication, respectively, depending on the oxidant used and its counterion. Starting from the planar, neutral 1,3-bis(alkylidene)-1,3-diborata-2,4-diphosphoniocyclobutane, each oxidation step leads to decreased B-B distances and loss of planarity by cationisation. X-ray analyses in conjunction with DFT and CASSCF/NEVPT2 calculations reveal closed-shell singlet, butterfly-shaped structures for the NHC-stabilised dicationic B2 P2 rings, with their diradicaloid, planar-ring isomers lying close in energy.
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Affiliation(s)
- Tobias Brückner
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany
| | - Felipe Fantuzzi
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Physical and Theoretical Chemistry, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Strasse 42, 97074, Würzburg, Germany
| | - Tom E Stennett
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany
| | - Rian D Dewhurst
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany
| | - Bernd Engels
- Institute for Physical and Theoretical Chemistry, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Strasse 42, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97070, Würzburg, Germany
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