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Frey NC, Hollister KK, Müller P, Dickie DA, Webster CE, Gilliard RJ. Borafluorene-Mediated Sulfur Activation: Isolation of Boryl-Linked S 7 and S 8 Catenates and Related Chalcogenide Molecules. Inorg Chem 2024. [PMID: 39239900 DOI: 10.1021/acs.inorgchem.4c02459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
Although the activation of elemental sulfur by main group compounds is well-documented in the literature, the products of such reactions are often heterocyclic in nature. However, the isolation and characterization of sulfur catenates (i.e., acyclic sulfur chains) is significantly less common. In this study, we report the activation of elemental sulfur by the 9-CAAC-9-borafluorene radical (1) and anion (2) (CAAC = (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene) to form boron-sulfur catenates (3-6). From the isolation of the octasulfide-bridged compound 3, a sulfur extrusion reaction using 1,3,4,5-tetramethylimidazol-2-ylidene (IMe4) was used to decrease the sulfide chain length from eight to seven (4). Bonding analysis of compounds 3-6 was performed using density functional theory, which elucidated the nature of the sulfur-sulfur bonding observed within these compounds. We also report the synthesis of a series of borafluorene-chalcogenide species (7-9), via diphenyl dichalcogenide activation, which portray characteristics described by an internal heavy atom effect. Compounds 7-9 each exhibit blue fluorescence, with the lowest energy emissive process (S2 → S0) at 436 nm (7 and 8) and 431 nm (9). The S1 → S0 emission is not observed experimentally due to a Laporte forbidden transition. Density functional theory was employed to investigate the frontier molecular orbitals and absorption and emission profiles of compounds 7-9.
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Affiliation(s)
- Nathan C Frey
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Kimberly K Hollister
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Peter Müller
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Box 9573, Mississippi State, Mississippi 39762, United States
| | - Robert J Gilliard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
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2
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Rutz PM, Kleeberg C. Copper Catalyzed Borylation of Alkynes: An Experimental Mechanistic Study. Chem Asian J 2024; 19:e202400286. [PMID: 38738792 DOI: 10.1002/asia.202400286] [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: 03/14/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
The copper catalyzed hydroboration of alkynes with B2pin2 was studied by in detail studies of individual relevant steps along the catalytic pathway. A number of reaction steps were retraced by in situ NMR spectroscopy as well as central intermediates and side-products were isolated and comprehensively characterized. A copper boryl complex is central to the catalytic process by inserting the terminal alkyne substrate into the B-Cu bond. The selectivity of this step - depending on the NHC auxiliary ligand - determines the α/β selectivity observed in the product. The latter complex is protonated by the auxiliary alcohol reagent resulting in hydroboration product formation and formation of a Cu alkoxido complex. Reaction of the latter with B2pin2 results in the regeneration of the central copper boryl complex. This alcoholysis step depends on the acidity of the alcohol, in particular on the relative acidity of the alcohol vs. the alkyne substrate. A number of side reactions leading to the hydrogenation product of the alkyne substrate and a bis hydroborated product were identified and studied in some detail. It is concluded that the performance of a particular catalytic system depends crucially on the relative acidities of the reagents and generalizations may be difficult.
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Affiliation(s)
- Philipp M Rutz
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106, Braunschweig, Germany
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106, Braunschweig, Germany
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3
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Hollister KK, Wentz KE, Gilliard RJ. Redox- and Charge-State Dependent Trends in 5, 6, and 7-Membered Boron Heterocycles: A Neutral Ligand Coordination Chemistry Approach to Boracyclic Cations, Anions, and Radicals. Acc Chem Res 2024; 57:1510-1522. [PMID: 38708938 DOI: 10.1021/acs.accounts.4c00096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
ConspectusBoron heterocycles represent an important subset of heteroatom-incorporated rings, attracting attention from organic, inorganic, and materials chemists. The empty pz orbital at the boron center makes them stand out as quintessential Lewis acidic molecules, also serving as a means to modulate electronic structure and photophysical properties in a facile manner. As boracycles are ripe for extensive functionalization, they are used in catalysis, chemical biology, materials science, and continue to be explored as chemical synthons for conjugated materials and reagents. Neutral boron(III)-incorporated polycyclic molecules are some of the most studied types of boracycles, and understanding their redox transformations is important for applications relying on electron transfer and charge transport. While relevant redox species can often be electrochemically observed, it remains challenging to isolate and characterize boracycles where the boron center and/or polycyclic skeleton have been chemically reduced.We describe our recent work isolating 5-, 6-, and 7-membered boracyclic radicals, anions, and cations, focusing on stabilization strategies, ligand-mediated bonding situations, and reactivity. We present a versatile neutral ligand coordination chemistry approach that permits the transformation of boracycles from potent electrophiles to powerful nucleophilic heterocycles that facilitate diverse electron transfer and bond activation chemistry. Although there are a wide range of suitable stabilizing ligands, we have employed both diamino-N-heterocyclic carbenes (NHCs) and cyclic(alkyl)(amino) carbenes (CAACs), which led to boracycles with tunable electronic structures and aromaticity trends. We highlight successful isolation of borafluorene radicals and demonstrate their reversible redox behavior, undergoing oxidation to the cation or reduction to the anion. The borafluorene anion is a chemical synthon that has been used to prepare boryl main-group and transition-metal bonds, luminescent oxabora-spirocycles, borafluorenate-crown ethers, and CO-releasing molecules via carbon dioxide activation. We expanded to 6-membered boracycles and characterized neutral bis(NHC-supported 9-boraphenanthrene)s and the corresponding bis(CAAC-stabilized 9-boraphenanthrene) biradical. We detail the interconvertible multiredox states of boraphenalene, where the boraphenalenyl radical, anion, and cation mimic the charge-states of the all-hydrocarbon analogue. Reactivity studies of the boraphenalenyl anion displayed unusual nucleophilic reactivity at multiple sites on the periphery of the boraphenalenyl tricyclic scaffold. Reduced borepins, 7-membered boron containing heterocycles, have also been isolated. We used a stepwise one-pot synthesis combining the halo-borepin precursor, CAAC, and KC8 to afford the monomeric borepin radicals and anions. The π-system was extended to contain two borepin rings fused in a pentacyclic scaffold, which permitted isolation of diborepin biradicals and a diborepin containing a dibora-quinone core.Our goal is to provide a guide explaining the current structure-function trends and isolation strategies for redox-active boron-incorporated polycyclic molecules to initiate the rational design and use of these types of compounds across a vast chemical space.
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Affiliation(s)
- Kimberly K Hollister
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Kelsie E Wentz
- Department of Chemistry, Johns Hopkins University, Remson Hall, 3400 N Charles Street, Baltimore, Maryland 21218-2625, United States
| | - Robert J Gilliard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
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4
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He M, Hu C, Wei R, Wang XF, Liu LL. Recent advances in the chemistry of isolable carbene analogues with group 13-15 elements. Chem Soc Rev 2024; 53:3896-3951. [PMID: 38436383 DOI: 10.1039/d3cs00784g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Carbenes (R2C:), compounds with a divalent carbon atom containing only six valence shell electrons, have evolved into a broader class with the replacement of the carbene carbon or the RC moiety with main group elements, leading to the creation of main group carbene analogues. These analogues, mirroring the electronic structure of carbenes (a lone pair of electrons and an empty orbital), demonstrate unique reactivity. Over the last three decades, this area has seen substantial advancements, paralleling the innovations in carbene chemistry. Recent studies have revealed a spectrum of unique carbene analogues, such as monocoordinate aluminylenes, nitrenes, and bismuthinidenes, notable for their extraordinary properties and diverse reactivity, offering promising applications in small molecule activation. This review delves into the isolable main group carbene analogues that are in the forefront from 2010 and beyond, spanning elements from group 13 (B, Al, Ga, In, and Tl), group 14 (Si, Ge, Sn, and Pb) and group 15 (N, P, As, Sb, and Bi). Specifically, this review focuses on the potential amphiphilic species that possess both lone pairs of electrons and vacant orbitals. We detail their comprehensive synthesis and stabilization strategies, outlining the reactivity arising from their distinct structural characteristics.
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Affiliation(s)
- Mian He
- 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.
| | - Rui Wei
- 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-Feng Wang
- 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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5
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Wang B, Zhu Z, Liang MJ, Ren YK, Xue JB, Zhang JY, Qi F, Xiao XQ. A 12-Vertex Metallacarborane of Silver(I). Inorg Chem 2024; 63:5481-5486. [PMID: 38446017 DOI: 10.1021/acs.inorgchem.3c04329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
The discovery of ferrocene in 1951 was a significant landmark in the field of organometallic chemistry, and since then, numerous sandwich- or half-sandwich metallic complexes have been reported. However, silver stands as an intriguing exception in this regard, and knowledge of its bonding situation has remained undisclosed. Herein, unprecedented 12-vertex metallacarboranes of Ag(I) (2a and 2b) were synthesized through the reaction of sodium hexamethyldisilazide (NaHMDS) with the mixture of nido-C2B9 carborane anion-supported N-heterocyclic carbene precursors (1a and 1b) and [Ag(PPh3)Cl]4. The X-ray structural analysis of the resulting metallacarboranes revealed a unique "slipped" half-sandwich structure, which is a rarity among cyclopentadienyl analogues. DFT calculations provided insights into the asymmetric π-interactions between the pentagonal C2B3 face and the silver ion.
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Affiliation(s)
- Beining Wang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Zhouli Zhu
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Mei-Juan Liang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Yun-Kang Ren
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Jin-Bian Xue
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Jia-Ying Zhang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Fan Qi
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
| | - Xu-Qiong Xiao
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Rd., Hangzhou, Zhejiang 311121, China
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6
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Charman RSC, Hobson JA, Jackson RA, Mahon MF, Neale SE, Liptrot DJ. Acyclic Boryl Complexes of Copper(I). Chemistry 2024; 30:e202302704. [PMID: 37818674 DOI: 10.1002/chem.202302704] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/12/2023]
Abstract
Reaction of (6-Dipp)CuOtBu (6-Dipp=C{NDippCH2 }2 CH2 , Dipp=2,6-iPr2 C6 H3 ) with B2 (OMe)4 provided access to (6-Dipp)CuB(OMe)2 via σ-bond metathesis. (6-Dipp)CuB(OMe)2 was characterised by NMR spectroscopy and X-ray crystallography and shown to be a monomeric acyclic boryl of copper. (6-Dipp)CuB(OMe)2 reacted with ethylene and diphenylacetylene to provide insertion compounds into the Cu-B bond which were characterised by NMR spectroscopy in both cases and X-ray crystallography in the latter. It was also competent in the rapid catalytic deoxygenation of CO2 in the presence of excess B2 (OMe)4 . Alongside π-insertion, (6-Dipp)CuB(OMe)2 reacted with LiNMe2 to provide a salt metathesis reaction at boron, giving (6-Dipp)CuB(OMe)NMe2 , a second monomeric acyclic boryl, which also cuproborated diphenylacetylene. Computational interrogation validated these acyclic boryl species to be electronically similar to (6-Dipp)CuBpin.
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Affiliation(s)
- Rex S C Charman
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Josie A Hobson
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Ross A Jackson
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Samuel E Neale
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - David J Liptrot
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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7
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O'Connell AC, Mansour PA, Maleczka RE, Smith MR. Regiochemical Switching in Ir-Catalyzed C-H Borylation by Altering Ligand Loadings of N,B-Type Diboron Species. Org Lett 2023; 25:8057-8061. [PMID: 37939287 DOI: 10.1021/acs.orglett.3c02760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Traditional reaction conditions in Ir-catalyzed C-H borylation consist of a 2:1 ligand to Ir metal ratio, affording C(sp2)-H borylation at the least sterically hindered position. We found that lowering the ligand to metal ratio of a N,B-type diboron (BB) preligand in respect to the IrI precatalyst to 0.5:1 affords the chelate controlled ortho product. Switching from steric-directed to chelate-directed products is shown for various substituted arenes and (hetero)arenes containing Lewis-basic functionalities. This work offers the first example of obtaining complementary regioisomers as the major product by altering the ligand loading in CHB.
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Affiliation(s)
- Alex C O'Connell
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing 48824-1322, Michigan United States
| | - Pauline A Mansour
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing 48824-1322, Michigan United States
| | - Robert E Maleczka
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing 48824-1322, Michigan United States
| | - Milton R Smith
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing 48824-1322, Michigan United States
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8
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Wentz KE, Molino A, Freeman LA, Dickie DA, Wilson DJD, Gilliard RJ. Systematic Electronic and Structural Studies of 9-Carbene-9-Borafluorene Monoanions and Transformations into Luminescent Boron Spirocycles. Inorg Chem 2022; 61:17049-17058. [PMID: 36259945 DOI: 10.1021/acs.inorgchem.2c01945] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The impact of the exact spatial arrangement of the alkali metal on the electronic properties of 9-carbene-9-borafluorene monoanions is assessed, and a series of [K][9-CAAC-9-borafluorene] complexes (1-4) have been isolated (CAAC = cyclic(alkyl)(amino) carbene, (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene). Compound 1, which contains [B]-K(THF)3 interactions, is compared to charge-separated 2-4, which were prepared by capturing the potassium cations with 18-crown-6, 2.2.2-cryptand, or 1,10-phenanthroline. Notably, the 11B NMR spectra of charge-separated borafluorene monoanions 2-4 show distinct low-field signatures compared to 1. Theoretical calculations indicate that charge separation may be exploited to influence the nucleophilic and electron transfer properties of 9-carbene-9-borafluorene monoanions. When [K(2.2.2-cryptand)][9-CAAC-9-borafluorene] (3) is reacted with 9,10-phenanthrenequinone and 1,10-phenanthroline-5,6-dione, the carbene ligand is displaced, and new air-stable R2BO2 spirocycles are formed (5 and 6, respectively). Remarkably, compounds 5 and 6 display fluorescence under UV light in both the solid and solution phases with quantum yields of up to 20%. In addition, a drastic red-shift in the emission color is observed in 6 because of the presence of the nitrogen atoms on the phenanthroline moiety. Mechanistic insights into the formation of these spirocycles are also described based on density functional theory calculations.
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Affiliation(s)
- Kelsie E Wentz
- Department of Chemistry, University of Virginia, Charlottesville 22904, Virginia, United States
| | - Andrew Molino
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Lucas A Freeman
- Department of Chemistry, University of Virginia, Charlottesville 22904, Virginia, United States
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, Charlottesville 22904, Virginia, United States
| | - David J D Wilson
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Robert J Gilliard
- Department of Chemistry, University of Virginia, Charlottesville 22904, Virginia, United States
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9
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Ma HZ, Canty AJ, O'Hair RAJ. Electrospray Ionization Tandem Mass Spectrometry and DFT Survey of Copper(I) Ate Complexes Containing Coordinated Borohydride Anions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1443-1452. [PMID: 35749300 DOI: 10.1021/jasms.2c00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper(I) borohydride ate complexes of the type Cat+[XCu(BH4)]- have been previously postulated as intermediates in the reactions of copper salts with borohydride. Negative ion electrospray ionization of an acetonitrile solution of copper(I) phenylacetylide with a 10-fold excess of sodium borohydride (NaBH4) revealed the formation of a diverse range of mononuclear, dinuclear and trinuclear cuprates with different numbers of BH4-, H- and CN- ligands, the latter likely being formed by abstraction of CN- from the acetonitrile solvent. Collision-induced dissociation was used to examine the fragmentation reactions of the following borohydride containing cuprates: [Cu(H)(BH4)]-, [Cu(BH4)2]-, [Cu(BH4)(CN)]-, [Cu2(H)(BH4)2]-, [Cu2(H)2(BH4)]-, [Cu2(BH4)2(CN)]-, [Cu2(H)(BH4)(CN)]-, [Cu3(H)(BH4)3]-, [Cu3(H)2(BH4)2]-, [Cu3(H)3(BH4)]-, [Cu3(BH4)2(CN)2]-, and [Cu3(H)(BH4)2(CN)]-. In all cases, BH3 loss is observed. For many of the dinuclear and trinuclear complexes cluster fragmentation by loss of CuH was also observed. In the case of [Cu2(H)2(BH4)]- and [Cu3(H)3(BH4)]-, loss of H2 was also observed. DFT calculations were used to explore potential structures of the various borohydride-containing cuprates and to predict the overall reaction energetics for the various fragmentation channels.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Allan J Canty
- School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
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10
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Ríos P, See MS, Handford RC, Teat SJ, Tilley TD. Robust dicopper(i) μ-boryl complexes supported by a dinucleating naphthyridine-based ligand. Chem Sci 2022; 13:6619-6625. [PMID: 35756530 PMCID: PMC9172574 DOI: 10.1039/d2sc00848c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/05/2022] [Indexed: 12/11/2022] Open
Abstract
Copper boryl species have been widely invoked as reactive intermediates in Cu-catalysed C–H borylation reactions, but their isolation and study have been challenging. Use of the robust dinucleating ligand DPFN (2,7-bis(fluoro-di(2-pyridyl)methyl)-1,8-naphthyridine) allowed for the isolation of two very thermally stable dicopper(i) boryl complexes, [(DPFN)Cu2(μ-Bpin)][NTf2] (2) and [(DPFN)Cu2(μ-Bcat)][NTf2] (4) (pin = 2,3-dimethylbutane-2,3-diol; cat = benzene-1,2-diol). These complexes were prepared by cleavage of the corresponding diborane via reaction with the alkoxide [(DPFN)Cu2(μ-OtBu)][NTf2] (3). Reactivity studies illustrated the exceptional stability of these boryl complexes (thermal stability in solution up to 100 °C) and their role in the activation of C(sp)–H bonds. X-ray diffraction and computational studies provide a detailed description of the bonding and electronic structures in these complexes, and suggest that the dinucleating character of the naphthyridine-based ligand is largely responsible for their remarkable stability. Cu(i) boryl species have been widely invoked as reactive intermediates in Cu-catalysed C–H borylations, but their isolation has been challenging. In this work, thermally robust dicopper(I) boryl complexes have been synthesized and studied in detail.![]()
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Affiliation(s)
- Pablo Ríos
- Department of Chemistry, University of California Berkeley USA
| | - Matthew S See
- Department of Chemistry, University of California Berkeley USA
| | - Rex C Handford
- Department of Chemistry, University of California Berkeley USA
| | - Simon J Teat
- Advanced Light Source, Lawrence Berkeley National Laboratory Berkeley CA 94720-1460 USA
| | - T Don Tilley
- Department of Chemistry, University of California Berkeley USA
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11
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Structure and reactivity of germylene-bridged digold complexes. Nat Commun 2022; 13:1785. [PMID: 35379820 PMCID: PMC8979951 DOI: 10.1038/s41467-022-29476-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
The bonding between gold and main-group metallic elements (M) featuring Auδ−−Mδ+ polarity, has been studied recently. The gold in the bonds is expected to have the oxidation number of −1, and hence, nucleophilic. However, the knowledge of the reactivity of the gold-metal bonds remains limited. Here, we report digold-substituted germanes of the form of R’2Ge(AuPR3)(AuGeR’2) (3a; R = Me, 3b; R = Et), featuring two Au-Ge(IV) and one Au-Ge(II) bonds. DFT calculations of 3a revealed the existence of high-lying σ(Ge-Au) type HOMO and low-lying LUMO with germylene pπ nature. A pendular motion of AuPR3 group between Ge(IV) and Ge(II) of 3 occurs in the NMR time scale, suggesting that the Ge(II) center has an enhanced electrophilicity to be attacked by the nucleophilic gold (−I) atom. 3a reacts with nucleophilic Cl− and electrophilic MeOTf reagents at Ge(II) and Ge(IV) centers, respectively. The number of metal complexes featuring gold-germanium bonds is limited. Here the authors report the preparation of germylene-bridged digold complexes complexes and study their structure, bonding, and reactivity.
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12
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Mao X, Zhang J, Lu Z, Xie Z. A (μ-hydrido)diborane(4) anion and its coordination chemistry with coinage metals. Chem Sci 2022; 13:3009-3013. [PMID: 35382458 PMCID: PMC8905795 DOI: 10.1039/d2sc00318j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/10/2022] [Indexed: 11/21/2022] Open
Abstract
A tetra(o-tolyl) (μ-hydrido)diborane(4) anion 1, an analogue of [B2H5]- species, was facilely prepared through the reaction of tetra(o-tolyl)diborane(4) with sodium hydride. Unlike common sp2-sp3 diborane species, 1 exhibited a σ-B-B bond nucleophilicity towards NHC-coordinated transition-metal (Cu, Ag, and Au) halides, resulting in the formation of η2-B-B bonded complexes 2 as confirmed by single-crystal X-ray analyses. Compared with 1, the structural data of 2 imply significant elongations of B-B bonds, following the order Au > Cu > Ag. DFT studies show that the diboron ligand interacts with the coinage metal through a three-center-two-electron B-M-B bonding mode. The fact that the B-B bond of the gold complex is much prolonged than the related Cu and Ag compounds might be ascribed to the superior electrophilicity of the gold atom.
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Affiliation(s)
- Xiaofeng Mao
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Jie Zhang
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Zhenpin Lu
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Zuowei Xie
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
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13
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Liu HY, Neale SE, Hill MS, Mahon MF, McMullin CL. On the reactivity of Al-group 11 (Cu, Ag, Au) bonds. Dalton Trans 2022; 51:3913-3924. [PMID: 35169824 DOI: 10.1039/d2dt00404f] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reactions of the seven-membered heterocyclic potassium diamidoalumanyl, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2; Dipp = 2,6-di-isopropylphenyl), with a variety of Cu(I), Ag(I) and Au(I) chloride N-heterocyclic carbene (NHC) adducts are described. The resultant group 11-Al bonded derivatives have been characterised in solution by NMR spectroscopy and, in the case of [{SiNDipp}Al-Au(NHCiPr)] (NHCiPr = N,N'-di-isopropyl-4,5-dimethyl-2-ylidene), by single crystal X-ray diffraction. Although similar reactions of LAgCl and LAuCl, where L is a more basic cyclic alkyl amino carbene (CAAC), generally resulted in reduction of the group 11 cations to the base metals, X-ray analysis of [(CyCAAC)AgAl(SiNDipp)] (CyCAAC = 2-[2,6-bis(1-methylethyl)phenyl]-3,3-dimethyl-2-azaspiro[4.5]dec-1-ylidene) provides the first solid-state authentication of an Ag-Al σ bond. The reactivity of the NHC-supported Cu, Ag and Au alumanyl derivatives was assayed with the isoelectronic unsaturated small molecules, N,N'-di-isopropylcarbodiimide and CO2. While these reactions generally provided products consistent with nucleophilic attack of the group 11 atom at the electrophilic heteroallene carbon centre, treatment of the NHC-supported copper and silver alumanyls with N,N'-di-isopropylcarbodiimide yielded less symmetric Cu-C and Ag-C-bonded isomers. In contrast to the previously described copper and silver alumanyl derivatives, [(NON)Al(O2C)M(Pt-Bu3)] (M = Cu or Ag; NON = 4,5-bis(2,6-di-isopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), which were prone to facile CO extrusion and formation of carbonate derivatives, the NHC-supported dioxocarbene species, [(NHCiPr)M(CO2)Al(SiNDipp)] (M = Cu, Ag, Au), are all stable at room and moderately elevated temperatures. The stabilising role of the NHC co-ligand was, thus, assessed by preparation of the t-Bu3P adducted copper-alumanyl, [(t-Bu3P)CuAl(SiNDipp)]. Treatment of this latter compound, which was also structurally characterised by X-ray analysis, with both N,N'-di-isopropylcarbodiimide and CO2 again provided smooth heteroallene insertion and formation of the relevant Cu-C-bonded products. Although both compounds were quite stable at room temperature, heating of [(t-Bu3P)Cu(CO2)Al(SiNDipp)] at 60 °C induced elimination of CO and formation of the analogous carbonate, [(t-Bu3P)Cu(OCO2)Al(SiNDipp)], which was identified by 13C and 31P NMR spectroscopy. Reflective of the more reliable nucleophilic behaviour of the gold centres in these group 11 alumanyls, computational (QTAIM and NBO) analysis highlighted a lower level of covalency of the Al-Au linkage in comparison to the analogous Al-Cu and Al-Ag interactions. Although substitution of the co-ligand significantly perturbs the charge distribution across the Cu-Al bond of [LCuAl(SiNDipp)] (L = NHCiPr or t-Bu3P), only a negligible difference is observed between the phosphine-coordinated copper systems derived from either the [SiNDipp]- or (NON)-based alumanyl ligands. Computational mapping of the reaction profiles arising from treatment of the various group 11 alumanyls with N,N'-di-isopropylcarbodiimide indicates that the observed formation of the Cu-N and Ag-N bound isomers do not provide the thermodynamic reaction outcome. In contrast, examination of the CO2-derived reactions, and their potential toward CO extrusion and subsequent carbonate formation, implies that the identity of the co-ligand exerts a greater influence on this aspect of reactivity than the architecture of the diamidoalumanyl anion.
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Affiliation(s)
- Han-Ying Liu
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Samuel E Neale
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Michael S Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Claire L McMullin
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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14
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Seidel FW, Nozaki K. A Ni
0
σ‐Borane Complex Bearing a Rigid Bidentate Borane/Phosphine Ligand: Boryl Complex Formation by Oxidative Dehydrochloroborylation and Catalytic Activity for Ethylene Polymerization. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202111691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Falk William Seidel
- Department of Chemistry and Biotechnology Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo Japan
| | - Kyoko Nozaki
- Department of Chemistry and Biotechnology Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo Japan
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15
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Sorbelli D, Belpassi L, Belanzoni P. What Singles out Aluminyl Anions? A Comparative Computational Study of the Carbon Dioxide Insertion Reaction in Gold-Aluminyl, -Gallyl, and -Indyl Complexes. Inorg Chem 2022; 61:1704-1716. [PMID: 34986633 PMCID: PMC8790757 DOI: 10.1021/acs.inorgchem.1c03579] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Indexed: 11/29/2022]
Abstract
Anionic aluminum(I) anions ("aluminyls") are the most recent discovery along Group 13 anions, and the understanding of the unconventional reactivity they are able to induce at a coordinated metal site is at an early stage. A striking example is the efficient insertion of carbon dioxide into the Au-Al bond of a gold-aluminyl complex. The reaction occurs via a cooperative mechanism, with the gold-aluminum bond being the actual nucleophile and the Al site also behaving as an electrophile. In the complex, the Au-Al bond has been shown to be mainly of an electron-sharing nature, with the two metal fragments displaying a diradical-like reactivity with CO2. In this work, the analogous reactivity with isostructural Au-X complexes (X = Al, Ga, and In) is computationally explored. We demonstrate that a kinetically and thermodynamically favorable reactivity with CO2 may only be expected for the gold-aluminyl complex. The Au-Al bond nature, which features the most (nonpolar) electron-sharing character among the Group 13 anions analyzed here, is responsible for its highest efficiency. The radical-like reactivity appears to be a key ingredient to stabilize the CO2 insertion product. This investigation elucidates the special role of Al in these hetero-binuclear compounds, providing new insights into the peculiar electronic structure of aluminyls, which may help for the rational control of their unprecedented reactivity toward carbon dioxide.
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Affiliation(s)
- Diego Sorbelli
- Department
of Chemistry, Biology and Biotechnologies, University of Perugia, Via Elce di Sotto, 8, 06123 Perugia, Italy
| | - Leonardo Belpassi
- CNR
Institute of Chemical Science and Technologies “Giulio Natta”
(CNR-SCITEC), Via Elce
di Sotto, 8, 06123 Perugia, Italy
| | - Paola Belanzoni
- Department
of Chemistry, Biology and Biotechnologies, University of Perugia, Via Elce di Sotto, 8, 06123 Perugia, Italy
- CNR
Institute of Chemical Science and Technologies “Giulio Natta”
(CNR-SCITEC), Via Elce
di Sotto, 8, 06123 Perugia, Italy
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16
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Alam S, Karim R, Khan A, Pal AK, Maruani A. Copper‐Catalyzed Preparation of Alkenylboronates and Arylboronates. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Safiul Alam
- Department of Chemistry Aliah University IIA/27, New Town Kolkata 700160 India
| | - Rejaul Karim
- Department of Chemistry Aliah University IIA/27, New Town Kolkata 700160 India
| | - Aminur Khan
- Department of Chemistry Aliah University IIA/27, New Town Kolkata 700160 India
| | - Amarta Kumar Pal
- Centre for Advance Studies in Chemistry North-Eastern Hill University Mawlai Campus Shillong 793022 India
| | - Antoine Maruani
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques – UMR 8601 Université de Paris UFR Biomédicale 45 rue des Saints Pères Paris 75006 France
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17
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Seidel FW, Nozaki K. A Ni 0 σ-Borane Complex Bearing a Rigid Bidentate Borane/Phosphine Ligand: Boryl Complex Formation by Oxidative Dehydrochloroborylation and Catalytic Activity for Ethylene Polymerization. Angew Chem Int Ed Engl 2021; 61:e202111691. [PMID: 34854528 DOI: 10.1002/anie.202111691] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Indexed: 11/08/2022]
Abstract
While of interest, synthetically feasible access to boryl ligands and complexes remains limited, meaning such complexes remain underexploited in catalysis. For bidentate boryl ligands, oxidative addition of boranes to low-valent IrI or Pt0 are the only examples yet reported. As part of our interest in developing improved group 10 ethylene polymerization catalysts, we present here an optimized synthesis of a novel, rigid borane/phosphine ligand and its Ni0 σ-borane complex. From the latter, an unprecedented oxidative dehydrochloroborylation, to give a NiII boryl complex, was achieved. Furthermore, this new B/P ligand allowed the nickel-catalyzed polymerization of ethylene, which suggests that Ni0 σ-hydroborane complexes act as masked NiII boryl hydride reagents.
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Affiliation(s)
- Falk William Seidel
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kyoko Nozaki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
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18
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Horsley Downie TM, Charman RSC, Hall JW, Mahon MF, Lowe JP, Liptrot DJ. A stable ring-expanded NHC-supported copper boryl and its reactivity towards heterocumulenes. Dalton Trans 2021; 50:16336-16342. [PMID: 34734620 DOI: 10.1039/d1dt03540a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Reaction of bis(pinacolato)diboron with (6-Dipp)CuOtBu generates a ring-expanded N-heterocyclic carbene supported copper(I) boryl, (6-Dipp)CuBpin. This compound showed remarkable stability and was characterised by NMR spectroscopy and X-ray crystallography. (6-Dipp)CuBpin readily dechalcogenated a range of heterocumulenes such as CO2, isocyanates and isothiocyanates to yield (6-Dipp)CuXBpin (X = O, S). In the case of CO2 catalytic reduction to CO is viable in the presence of excess bis(pinacolato)diboron. In contrast, in the case of iso(thio)cyanates, the isocyanide byproduct of dechalcogenation reacted with (6-Dipp)CuBpin to generate a copper(I) borylimidinate, (6-Dipp)CuC(NR)Bpin, which went on to react with heterocumulenes. This off-cycle reactivity gives selective access to a range of novel boron-containing heterocycles bonded to copper, but precludes catalytic reactivity.
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Affiliation(s)
| | - Rex S C Charman
- Department of Chemistry, University of Bath. Claverton Down, Bath, BA2 7AY, UK.
| | - Jonathan W Hall
- Department of Chemistry, University of Bath. Claverton Down, Bath, BA2 7AY, UK.
| | - Mary F Mahon
- Department of Chemistry, University of Bath. Claverton Down, Bath, BA2 7AY, UK.
| | - John P Lowe
- Department of Chemistry, University of Bath. Claverton Down, Bath, BA2 7AY, UK.
| | - David J Liptrot
- Department of Chemistry, University of Bath. Claverton Down, Bath, BA2 7AY, UK.
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19
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Eleazer BJ, Jayaweera HDAC, Gange GB, Smith MD, Martin CR, Park KC, Popov AA, Peryshkov DV. Bimetallic Ru-Pd and Trimetallic Ru-Pd-Cu Assemblies on the Carborane Cluster Surface. Inorg Chem 2021; 60:16911-16916. [PMID: 34710327 DOI: 10.1021/acs.inorgchem.1c02799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of well-defined heterometallic complexes remains a frontier challenge in inorganic chemistry. We report an approach that relies on the sequential insertion of electrophilic metal fragments into electron-rich Ru-B bonds of the η2-BB-carboryne complex (POBBOP)Ru(CO)2 [POBBOP = 1,7-OP(iPr)2-m-2,6-dehydrocarborane]. Utilizing this synthetic strategy, bimetallic (POBBOP)(Ru)(CO)2[Pd(PtBu3)] and trimetallic (POBBOP)(Ru)(CO)2[Pd(PtBu3)](CuBr) complexes were selectively prepared. Structural and theoretical analysis of the features of chemical bonding within Ru-B-B-Cu and Ru-B-B-Pd fragments is presented.
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Affiliation(s)
- Bennett J Eleazer
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - H D A Chathumal Jayaweera
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Gayathri B Gange
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Mark D Smith
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Corey R Martin
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Kyoung Chul Park
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
| | - Alexey A Popov
- Leibniz Institute for Solid State and Materials Research, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Dmitry V Peryshkov
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States
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20
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21
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McManus C, Hicks J, Cui X, Zhao L, Frenking G, Goicoechea JM, Aldridge S. Coinage metal aluminyl complexes: probing regiochemistry and mechanism in the insertion and reduction of carbon dioxide. Chem Sci 2021; 12:13458-13468. [PMID: 34777765 PMCID: PMC8528051 DOI: 10.1039/d1sc04676d] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 09/16/2021] [Indexed: 01/13/2023] Open
Abstract
The synthesis of coinage metal aluminyl complexes, featuring M-Al covalent bonds, is reported via a salt metathesis approach employing an anionic Al(i) ('aluminyl') nucleophile and group 11 electrophiles. This approach allows access to both bimetallic (1 : 1) systems of the type ( t Bu3P)MAl(NON) (M = Cu, Ag, Au; NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene) and a 2 : 1 di(aluminyl)cuprate system, K[Cu{Al(NON)}2]. The bimetallic complexes readily insert heteroallenes (CO2, carbodiimides) into the unsupported M-Al bonds to give systems containing a M(CE2)Al bridging unit (E = O, NR), with the μ-κ1(C):κ2(E,E') mode of heteroallene binding being demonstrated crystallographically for carbodiimide insertion in the cases of all three metals, Cu, Ag and Au. The regiochemistry of these processes, leading to the formation of M-C bonds, is rationalized computationally, and is consistent with addition of CO2 across the M-Al covalent bond with the group 11 metal acting as the nucleophilic partner and Al as the electrophile. While the products of carbodiimide insertion are stable to further reaction, their CO2 analogues have the potential to react further, depending on the identity of the group 11 metal. ( t Bu3P)Au(CO)2Al(NON) is inert to further reaction, but its silver counterpart reacts slowly with CO2 to give the corresponding carbonate complex (and CO), and the copper system proceeds rapidly to the carbonate even at low temperatures. Experimental and quantum chemical investigations of the mechanism of the CO2 to CO/carbonate transformation are consistent with rate-determining extrusion of CO from the initially-formed M(CO)2Al fragment to give a bimetallic oxide that rapidly assimilates a second molecule of CO2. The calculated energetic barriers for the most feasible CO extrusion step (ΔG ‡ = 26.6, 33.1, 44.5 kcal mol-1 for M = Cu, Ag and Au, respectively) are consistent not only with the observed experimental labilities of the respective M(CO)2Al motifs, but also with the opposing trends in M-C (increasing) and M-O bond strengths (decreasing) on transitioning from Cu to Au.
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Affiliation(s)
- Caitilín McManus
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road Oxford OX1 3QR UK
| | - Jamie Hicks
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road Oxford OX1 3QR UK
| | - Xianlu Cui
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University Nanjing 211816 P. R. 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 P. R. China
| | - Gernot Frenking
- Fachbereich Chemie, Philipps-Universität, Marburg D-35043 Marburg Germany
| | - Jose M Goicoechea
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road Oxford OX1 3QR UK
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road Oxford OX1 3QR UK
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22
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Wentz KE, Molino A, Freeman LA, Dickie DA, Wilson DJD, Gilliard RJ. Reactions of 9-Carbene-9-Borafluorene Monoanion and Selenium: Synthesis of Boryl-Substituted Selenides and Diselenides. Inorg Chem 2021; 60:13941-13949. [PMID: 34472333 DOI: 10.1021/acs.inorgchem.1c02124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions of 9-carbene-9-borafluorene monoanion (1) with elemental selenium and selenium-containing reagents are reported. When compound 1 is reacted with grey selenium in THF, various boryl-substituted selenides and diselenides are produced (2-6), including molecules resulting from migration of the carbene ligand Dipp group (Dipp = 2,6-diisopropylphenyl). However, when a similar reaction between 1 and grey selenium is performed in toluene in the presence of 18-crown-6, boryl-substituted selenide 7 is obtained as the sole boron-containing product. As compound 7 is the monomeric variant of organoselenide 3, 18-crown-6 promotes both product selectivity and solubility in a nonpolar solvent. Diselenide 5, which features a trans-bent B-Se-Se-B core, was directly isolated via reaction of 1 with Se2Cl2 in THF. Computational modeling suggests that the formation of 5 proceeds via a radical mechanism. This was supported by an experiment demonstrating that the CAAC-borafluorene radical also reacts with SeCl2 to yield 5 [CAAC = (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene]. Energy decomposition analysis of 5 indicates a covalent borafluorene-diselenide bond (ΔEint, -168.9 kcal mol-1). All of the new compounds were fully characterized via single-crystal X-ray diffraction and multinuclear nuclear magnetic resonance (1H, 13C, 11B, and 77Se).
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Affiliation(s)
- Kelsie E Wentz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Andrew Molino
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Lucas A Freeman
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - David J D Wilson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Robert J Gilliard
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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23
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Suzuki A, Wu L, Lin Z, Yamashita M. Isomerization of a cis-(2-Borylalkenyl)Gold Complex via a Retro-1,2-Metalate Shift: Cleavage of a C-C/C-Si Bond trans to a C-Au Bond. Angew Chem Int Ed Engl 2021; 60:21007-21013. [PMID: 34288308 DOI: 10.1002/anie.202108530] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Indexed: 01/27/2023]
Abstract
This manuscript describes the first example of an alkyne insertion to the Au-B bond of a di(o-tolyl)borylgold complex to afford a cis-2-borylalkenylgold complex, and its isomerization to result in interchanging substituents on the alkenyl carbon atom and the boron atom. The former reaction is the first example of an alkyne insertion to a Au-B bond. In the latter reaction, the regiochemistry of the isomerized alkenylgold products varied depending on the substituents. DFT calculations revealed the formation of gold alkynylborates as a common intermediate via a "retro-1,2-metalate shift", which can be considered as an anti-β-carbon/silicon elimination, and identified a subsequent 1,2-metalate shift as the regiochemistry-determining step. Relative energies of the transition states to each isomer and natural-bond-orbital (NBO) analyses were used to clearly rationalize the regiochemistry of the products.
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Affiliation(s)
- Akane Suzuki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho Chikusa-ku, Nagoya, 464-8603, Aichi, Japan
| | - Linlin Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Hong Kong
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho Chikusa-ku, Nagoya, 464-8603, Aichi, Japan
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24
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Suzuki A, Wu L, Lin Z, Yamashita M. Isomerization of a
cis
‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond
trans
to a C−Au Bond. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Akane Suzuki
- Department of Molecular and Macromolecular Chemistry Graduate School of Engineering Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
| | - Linlin Wu
- Department of Chemistry The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Hong Kong
| | - Zhenyang Lin
- Department of Chemistry The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Hong Kong
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry Graduate School of Engineering Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
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25
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Hara N, Yamamoto K, Tanaka Y, Saito T, Sakaki S, Nakao Y. Synthesis, Electronic Properties, and Lewis Acidity of Rhodium Complexes Bearing X-Type PBP, PAlP, and PGaP Pincer Ligands. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Naofumi Hara
- Department of Material Chemistry, Institution Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Konosuke Yamamoto
- Department of Material Chemistry, Institution Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yuuki Tanaka
- Department of Material Chemistry, Institution Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Teruhiko Saito
- Department of Material Chemistry, Institution Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Shigeyoshi Sakaki
- Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Kyoto 615-8510, Japan
| | - Yoshiaki Nakao
- Department of Material Chemistry, Institution Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
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26
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Lai S, Takaesu N, Lin WX, Perrin DM. Suzuki coupling of aroyl-MIDA boronate esters – A preliminary report on scope and limitations. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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Wentz KE, Molino A, Weisflog SL, Kaur A, Dickie DA, Wilson DJD, Gilliard RJ. Stabilization of the Elusive 9-Carbene-9-Borafluorene Monoanion. Angew Chem Int Ed Engl 2021; 60:13065-13072. [PMID: 33780572 DOI: 10.1002/anie.202103628] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Indexed: 01/09/2023]
Abstract
Two-electron reduction of carbene-supported 9-bromo-9-borafluorenes with excess KC8 , Na, or Li-naphthalenide affords six N-heterocyclic carbene (NHC)- or cyclic(alkyl)(amino) carbene (CAAC)-stabilized borafluorene anions (3-8)-the first isolated and structurally authenticated examples of the elusive 9-carbene-9-borafluorene monoanion. The electronic structure, bonding, and aromaticity of the boracyclic anions were comprehensively investigated via computational studies. Compounds 5 and 8 react with metal halides via salt elimination to give new B-E (E=Au, Se, Ge)-containing materials (9-12). Upon reaction with diketones, the carbene ligand cleanly dissociates from 5 or 8 to yield new B-O containing spirocycles (13-14) that cannot be easily obtained using "normal" valent borafluorene compounds. Collectively, these results support the notion that carbene-stabilized monoanionic borafluorenes may serve as a new platform for the one-step construction of higher-value boracyclic materials.
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Affiliation(s)
- Kelsie E Wentz
- Department of Chemistry, University of Virginia, 409 McCormick Rd./ PO Box 400319, Charlottesville, VA, 22904, USA
| | - Andrew Molino
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, Latrobe University, Melbourne, 3086, Victoria, Australia
| | - Sarah L Weisflog
- Department of Chemistry, University of Virginia, 409 McCormick Rd./ PO Box 400319, Charlottesville, VA, 22904, USA
| | - Aishvaryadeep Kaur
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, Latrobe University, Melbourne, 3086, Victoria, Australia
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, 409 McCormick Rd./ PO Box 400319, Charlottesville, VA, 22904, USA
| | - David J D Wilson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, Latrobe University, Melbourne, 3086, Victoria, Australia
| | - Robert J Gilliard
- Department of Chemistry, University of Virginia, 409 McCormick Rd./ PO Box 400319, Charlottesville, VA, 22904, USA
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28
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Liu H, Schwamm RJ, Hill MS, Mahon MF, McMullin CL, Rajabi NA. Ambiphilic Al−Cu Bonding. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104658] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Han‐Ying Liu
- Department of Chemistry University of Bath Bath BA2 7AY UK
| | | | | | - Mary F. Mahon
- Department of Chemistry University of Bath Bath BA2 7AY UK
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29
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Liu HY, Schwamm RJ, Hill MS, Mahon MF, McMullin CL, Rajabi NA. Ambiphilic Al-Cu Bonding. Angew Chem Int Ed Engl 2021; 60:14390-14393. [PMID: 33899319 PMCID: PMC8252794 DOI: 10.1002/anie.202104658] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Indexed: 11/07/2022]
Abstract
Copper-alumanyl complexes, [LCu-Al(SiNDipp )], where L=carbene=NHCiPr (N,N'-diisopropyl-4,5-dimethyl-2-ylidene) and Me2 CAAC (1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene) and featuring unsupported Al-Cu bonds, have been prepared. Divergent reactivity observed with carbodiimides and CO2 implies an ambiphilicity in the Cu-Al interaction that is dependent on the identity of the carbene co-ligand.
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Affiliation(s)
- Han-Ying Liu
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | - Ryan J Schwamm
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | - Michael S Hill
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | | | - Nasir A Rajabi
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
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30
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Wentz KE, Molino A, Weisflog SL, Kaur A, Dickie DA, Wilson DJD, Gilliard RJ. Stabilization of the Elusive 9‐Carbene‐9‐Borafluorene Monoanion. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103628] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kelsie E. Wentz
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Andrew Molino
- Department of Chemistry and Physics La Trobe Institute for Molecular Science Latrobe University Melbourne 3086 Victoria Australia
| | - Sarah L. Weisflog
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Aishvaryadeep Kaur
- Department of Chemistry and Physics La Trobe Institute for Molecular Science Latrobe University Melbourne 3086 Victoria Australia
| | - Diane A. Dickie
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - David J. D. Wilson
- Department of Chemistry and Physics La Trobe Institute for Molecular Science Latrobe University Melbourne 3086 Victoria Australia
| | - Robert J. Gilliard
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
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31
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Schmid P, Fantuzzi F, Klopf J, Schröder NB, Dewhurst RD, Braunschweig H, Engel V, Engels B. Twisting versus Delocalization in CAAC- and NHC-Stabilized Boron-Based Biradicals: The Roles of Sterics and Electronics. Chemistry 2021; 27:5160-5170. [PMID: 33225473 PMCID: PMC8048672 DOI: 10.1002/chem.202004619] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Indexed: 11/06/2022]
Abstract
Twisted boron-based biradicals featuring unsaturated C2 R2 (R=Et, Me) bridges and stabilization by cyclic (alkyl)(amino)carbenes (CAACs) were recently prepared. These species show remarkable geometrical and electronic differences with respect to their unbridged counterparts. Herein, a thorough computational investigation on the origin of their distinct electrostructural properties is performed. It is shown that steric effects are mostly responsible for the preference for twisted over planar structures. The ground-state multiplicity of the twisted structure is modulated by the σ framework of the bridge, and different R groups lead to distinct multiplicities. In line with the experimental data, a planar structure driven by delocalization effects is observed as global minimum for R=H. The synthetic elusiveness of C2 R2 -bridged systems featuring N-heterocyclic carbenes (NHCs) was also investigated. These results could contribute to the engineering of novel main group biradicals.
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Affiliation(s)
- Paul Schmid
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Felipe Fantuzzi
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Jonas Klopf
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Niklas B. Schröder
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Rian D. Dewhurst
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Volker Engel
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Bernd Engels
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
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32
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Shere H, Hill MS, Pécharman AF, Mahon MF. Reactivity of a magnesium diboranate with organic nitriles. Dalton Trans 2021; 50:1283-1292. [PMID: 33393542 DOI: 10.1039/d0dt04016a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A series of complexes generated through reactions of the β-diketiminato magnesium diboranate species, [(BDI)Mg{(n-Bu)pinB-Bpin}] (BDI = HC{(Me)CNDipp}2; Dipp = 2,6-di-iso-propylphenyl), and a variety of organic nitriles are reported. Although, in every case, the diboranate anion acts as a surrogate source of the {Bpin} nucleophile, resulting in B-C bond formation at the electrophilic sp-hydridised nitrile carbon, the resultant compounds display a variable propensity to undergo subsequent reaction with additional nitrile equivalents. This behaviour is rationalised to be a consequence of substituent-dependent modulation in the basicity and resultant electrophilicity of magnesium-coordinated nitrile intermediates.
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Affiliation(s)
- Henry Shere
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Michael S Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | | | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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33
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Drescher W, Borner C, Kleeberg C. Stability and decomposition of copper( i) boryl complexes: [(IDipp)Cu–Bneop], [(IDipp*)Cu–Bneop] and copper clusters. NEW J CHEM 2021. [DOI: 10.1039/d0nj03166f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterisation of NHC copper boryl complexes [(NHC)Cu–Bneop] and their decomposition to low-valent copper clusters.
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Affiliation(s)
- Wiebke Drescher
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Corinna Borner
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
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34
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Suzuki A, Guo X, Lin Z, Yamashita M. Nucleophilic reactivity of the gold atom in a diarylborylgold(i) complex toward polar multiple bonds. Chem Sci 2020; 12:917-928. [PMID: 34163858 PMCID: PMC8179162 DOI: 10.1039/d0sc05478j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
A di(o-tolyl)borylgold complex was synthesized via the metathesis reaction of a gold alkoxide with tetra(o-tolyl)diborane(4). The resulting diarylborylgold complex exhibited a Lewis acidic boron center and a characteristic visible absorption that arises from its HOMO-LUMO excitation, which is narrower than that of a previously reported dioxyborylgold complex. The diarylborylgold complex reacted with isocyanide in a stepwise fashion to afford single- and double-insertion products and a C-C coupled product. Reactions of this diarylborylgold complex with C[double bond, length as m-dash]O/N double bond species furnished addition products under concomitant formation of Au-C and B-O/N bonds, which suggests nucleophilic reactivity of the gold metal center. DFT calculations provided details of the underlying reaction mechanism, which involves an initial coordination of the C[double bond, length as m-dash]O/N bond to the boron vacant p-orbital of the diarylboryl ligand followed by a migration of the gold atom from the tetracoordinate sp3-hybridized boron center, which is analogous to the reactivity of the conventional sp3-hybridized borate species. The DFT calculations also suggested a stepwise mechanism for the reaction of this diarylborylgold complex with isocyanide, which afforded three different reaction products depending on the applied reaction conditions.
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Affiliation(s)
- Akane Suzuki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
| | - 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
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Aichi Japan
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35
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Krantz KE, Weisflog SL, Frey NC, Yang W, Dickie DA, Webster CE, Gilliard RJ. Planar, Stair‐Stepped, and Twisted: Modulating Structure and Photophysics in Pyrene‐ and Benzene‐Fused N‐Heterocyclic Boranes. Chemistry 2020; 26:10072-10082. [DOI: 10.1002/chem.202002118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Indexed: 01/23/2023]
Affiliation(s)
- Kelsie E. Krantz
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Sarah L. Weisflog
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Nathan C. Frey
- Department of Chemistry Mississippi State University, Box 9573 Mississippi State MS 39762 USA
| | - Wenlong Yang
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Diane A. Dickie
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
| | - Charles Edwin Webster
- Department of Chemistry Mississippi State University, Box 9573 Mississippi State MS 39762 USA
| | - Robert J. Gilliard
- Department of Chemistry University of Virginia 409 McCormick Rd./ PO Box 400319 Charlottesville VA 22904 USA
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36
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Akiyama S, Ikemoto S, Muratsugu S, Tada M, Yamashita M. Copper Complexes Bearing a Dianionic Diborane(4) Ligand: Synthesis and Evaluation of the Donor Property. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Seiji Akiyama
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan
| | - Satoru Ikemoto
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan
| | - Satoshi Muratsugu
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan
| | - Mizuki Tada
- Department of Chemistry, Graduate School of Science, Integrated Research Consortium on Chemical Science (IRCCS), Institute for Advanced Science (IAS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 Aichi, Japan
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37
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Schröder J, Böttcher T. 2,6‐Bis(diazaboryl)pyridine – A Ligand with Hemilabile Donor and Lewis Acid Functionalities. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201901164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jan Schröder
- Institut für Anorganische und Analytische Chemie Universität Freiburg Albertstr. 19 79104 Freiburg Germany
| | - Tobias Böttcher
- Institut für Anorganische und Analytische Chemie Universität Freiburg Albertstr. 19 79104 Freiburg Germany
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38
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Romeo LJ, Kaur A, Wilson DJD, Martin CD, Dutton JL. Evaluation of the σ-Donating and π-Accepting Properties of N-Heterocyclic Boryl Anions. Inorg Chem 2019; 58:16500-16509. [DOI: 10.1021/acs.inorgchem.9b02433] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lorenzo J. Romeo
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Aishvaryadeep Kaur
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - David J. D. Wilson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Caleb D. Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Jason L. Dutton
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
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39
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Joost M, Saffon-Merceron N, Amgoune A, Bourissou D. Synthesis, Structure, and Reactivity of an NHC Silyl Gold(I) Complex. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00574] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Maximilian Joost
- CNRS, Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069), 118 Route de Narbonne, 31062 Toulouse Cedex 09, France
| | | | - Abderrahmane Amgoune
- CNRS, Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069), 118 Route de Narbonne, 31062 Toulouse Cedex 09, France
| | - Didier Bourissou
- CNRS, Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069), 118 Route de Narbonne, 31062 Toulouse Cedex 09, France
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40
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Tan DH, Cai YH, Zeng YF, Lv WX, Yang L, Li Q, Wang H. Diversity-Oriented Synthesis of α-Functionalized Acylborons and Borylated Heteroarenes by Nucleophilic Ring Opening of α-Chloroepoxyboronates. Angew Chem Int Ed Engl 2019; 58:13784-13788. [PMID: 31347254 DOI: 10.1002/anie.201907349] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/24/2019] [Indexed: 12/22/2022]
Abstract
The ring-opening reactions of N-methyliminodiacetyl (MIDA) α-chloroepoxyboronates with different nucleophiles allow the modular synthesis of a diverse array of organoboronates. These include seven types of α-functionalized acylboronates and seven types of borylated heteroarenes, some of which are difficult-to-access products using alternative methods. The common synthons, α-chloroepoxyboronates, could be viably synthesized by a two-step procedure from the corresponding alkenyl MIDA boronates. Mild reaction conditions, good functional-group tolerance, and generally good efficiency were observed. The utility of the products was also demonstrated.
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Affiliation(s)
- Dong-Hang Tan
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yuan-Hong Cai
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yao-Fu Zeng
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Wen-Xin Lv
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ling Yang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Qingjiang Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Honggen Wang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences of, Guangxi Normal University, Guilin, 541004, China
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41
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Tan D, Cai Y, Zeng Y, Lv W, Yang L, Li Q, Wang H. Diversity‐Oriented Synthesis of α‐Functionalized Acylborons and Borylated Heteroarenes by Nucleophilic Ring Opening of α‐Chloroepoxyboronates. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Dong‐Hang Tan
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Yuan‐Hong Cai
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Yao‐Fu Zeng
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Wen‐Xin Lv
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Ling Yang
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Qingjiang Li
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
| | - Honggen Wang
- Guangdong Key Laboratory of Chiral Molecule and Drug DiscoverySchool of Pharmaceutical SciencesSun Yat-sen University Guangzhou 510006 China
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal ResourcesSchool of Chemistry and Pharmaceutical Sciences ofGuangxi Normal University Guilin 541004 China
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42
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Pécharman AF, Hill MS, McMullon G, McMullin CL, Mahon MF. Snapshots of magnesium-centred diborane heterolysis by an outer sphere S N2 process. Chem Sci 2019; 10:6672-6682. [PMID: 31367321 PMCID: PMC6624991 DOI: 10.1039/c9sc02087j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 05/24/2019] [Indexed: 01/07/2023] Open
Abstract
Reactions of a magnesium diboranate as a source of [Bpin]– anions are initiated by ‘outer sphere’ attack of C
Created by potrace 1.16, written by Peter Selinger 2001-2019
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N bonded substrates.
Reactions of the β-diketiminato magnesium diboranate derivative, [(BDI)Mg{pinB(n-Bu)Bpin}] (BDI = HC{(Me)CNDipp}2; Dipp = 2,6-i-Pr2C6H3), with N,N′-dialkyl and N,N′-diaryl carbodiimides provided the corresponding C-borylated magnesium borylamidinates. This reactivity occurs with the displacement of n-BuBpin and with the apparent addition of a nucleophilic {Bpin} anion to the electrophilic unsaturated carbodiimide carbon centres. In contrast, while analogous reactions of [(BDI)Mg{pinB(n-Bu)Bpin}] with N-alkyl or N-aryl aldimines and ketimines also resulted in facile displacement of n-BuBpin, they provided the organomagnesium products of {Bpin} addition to the imine nitrogen atom rather than the more electrophilic trigonal imine carbon. Computational assessment by density functional theory (DFT) indicated that, although the energetic differences are marginal, the organomagnesium products may be considered as the kinetic outcome of these reactions with respect to the generation of alternative amidomagnesium regioisomers. This latter deduction was borne out by the thermally-induced conversion of two such organomagnesium species to their C-borylated amidomagnesium isomers, both of which occur with negligible entropies of activation indicative of purely intramolecular processes. Detailed analysis by DFT of the reaction of [(BDI)Mg{pinB(n-Bu)Bpin}] with PhN
Created by potrace 1.16, written by Peter Selinger 2001-2019
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CHPh indicated that B–N bond formation is initiated by attack of the imine nitrogen at the three-coordinate boron atom of the diboranate anion rather than the more crowded magnesium centre. Consistent with an effectively spontaneous reaction, the resultant cleavage of the B–B bond of the diboranate unit is accomplished via the traversal of two very modest barriers of only 8.3 and 6.7 kcal mol–1. This analysis was also supportive of a subsequent intramolecular B–N to B–C isomerisation process. Of greater general significance, however, the addition of the {Bpin}– anion to the reducible aldimine is best rationalised as a consequence of the electrophilic character of this three-coordinate boron centre rather than any intrinsic nucleophilicity associated with the B–B bond of the [pinBB(n-Bu)pin]– anion.
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Affiliation(s)
| | - Michael S Hill
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Grace McMullon
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Claire L McMullin
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Mary F Mahon
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
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Imperio D, Del Grosso E, Fallarini S, Lombardi G, Panza L. Anomeric sugar boronic acid analogues as potential agents for boron neutron capture therapy. Beilstein J Org Chem 2019; 15:1355-1359. [PMID: 31293685 PMCID: PMC6604725 DOI: 10.3762/bjoc.15.135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 06/11/2019] [Indexed: 11/24/2022] Open
Abstract
After the development of accelerators as neutron source, the access to new suitable agents for boron neutron capture therapy (BNCT) became a major need. Among many others, sugar boronic acids have recently attracted attention as boron carriers. Herein we report the synthesis and preliminary biological studies of two new sugar analogues containing a boronic acid at the anomeric position. The analogues were obtained by hydroboration of proper open-chain terminal alkenes that, after quenching with water, spontaneously afforded cyclic boronic acids with hemiacetal-like structures.
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Affiliation(s)
- Daniela Imperio
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Erika Del Grosso
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Silvia Fallarini
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Grazia Lombardi
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Luigi Panza
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
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Drescher W, Kleeberg C. Terminal versus Bridging Boryl Coordination in N-Heterocyclic Carbene Copper(I) Boryl Complexes: Syntheses, Structures, and Dynamic Behavior. Inorg Chem 2019; 58:8215-8229. [PMID: 31148446 DOI: 10.1021/acs.inorgchem.9b01041] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The B-B bond activation of the diborane(4) derivatives B2cat2 with the copper(I) alkoxido complex [(SIDipp)Cu-O tBu] delivers, depending on the solvent, either the linear boryl complex [(SIDipp)Cu-Bcat] from PhMe or the μ-boryl complex [((SIDipp)Cu)2Bcat][cat2B] from THF. The relevant conversion of the linear boryl complex to the μ-boryl complex occurs in the polar solvent via formal boryl anion abstraction by the Lewis acid catB-O tBu, concomitantly formed during the B-B activation. With Lewis acids such as BPh3 or [CPh3][BArF] (reversible), boryl abstraction from the linear complexes [(SIDipp)Cu-Bcat] or [(SIDipp)Cu-Bdmab] occurs and results in the μ-boryl complexes [((SIDipp)Cu)2Bcat/dmab][Ph3B-Bcat/dmab] and [((SIDipp)Cu)2Bcat][BArF]. The formation of [((SIDipp)Cu)2Bcat][cat2B] is generally accompanied by the concomitant formation of the μ-hydrido complex [((SIDipp)Cu)2H][cat2B]. The spiroborate [cat2B]- is formed from the initially formed Lewis acid/base adduct [catB-B(O tBu)cat]- presumably in a process that involves the glass surface of the reaction vessel. All complexes are thoroughly characterized structurally as well as spectroscopically, in particular with respect to the dynamic behavior of the μ-boryl complexes in solution.
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Affiliation(s)
- Wiebke Drescher
- Institut für Anorganische und Analytische Chemie , Technische Universität Carolo-Wilhelmina zu Braunschweig , 38106 Braunschweig , Germany
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie , Technische Universität Carolo-Wilhelmina zu Braunschweig , 38106 Braunschweig , Germany
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Doddi A, Peters M, Tamm M. N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry. Chem Rev 2019; 119:6994-7112. [PMID: 30983327 DOI: 10.1021/acs.chemrev.8b00791] [Citation(s) in RCA: 309] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
N-Heterocyclic carbenes (NHC) are nowadays ubiquitous and indispensable in many research fields, and it is not possible to imagine modern transition metal and main group element chemistry without the plethora of available NHCs with tailor-made electronic and steric properties. While their suitability to act as strong ligands toward transition metals has led to numerous applications of NHC complexes in homogeneous catalysis, their strong σ-donating and adaptable π-accepting abilities have also contributed to an impressive vitalization of main group chemistry with the isolation and characterization of NHC adducts of almost any element. Formally, NHC coordination to Lewis acids affords a transfer of nucleophilicity from the carbene carbon atom to the attached exocyclic moiety, and low-valent and low-coordinate adducts of the p-block elements with available lone pairs and/or polarized carbon-element π-bonds are able to act themselves as Lewis basic donor ligands toward transition metals. Accordingly, the availability of a large number of novel NHC adducts has not only produced new varieties of already existing ligand classes but has also allowed establishment of numerous complexes with unusual and often unprecedented element-metal bonds. This review aims at summarizing this development comprehensively and covers the usage of N-heterocyclic carbene adducts of the p-block elements as ligands in transition metal chemistry.
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Affiliation(s)
- Adinarayana Doddi
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Marius Peters
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
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NNB-Type Tridentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C⁻H Borylation. Molecules 2019; 24:molecules24071434. [PMID: 30979032 PMCID: PMC6479588 DOI: 10.3390/molecules24071434] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/05/2019] [Accepted: 04/05/2019] [Indexed: 11/17/2022] Open
Abstract
Boryl ligands play a very important role in catalysis because of their very high electron-donating property. In this paper, NNB-type boryl anions were designed as tridentate ligands to promote aryl C-H borylation. In combination with [IrCl(COD)]₂, they generate a highly active catalyst for a broad range of (hetero)arene substrates, including highly electron-rich and/or sterically hindered ones. This work provides a new NNB-type tridentate boryl ligand to support homogeneous organometallic catalysis.
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Danopoulos AA, Simler T, Braunstein P. N-Heterocyclic Carbene Complexes of Copper, Nickel, and Cobalt. Chem Rev 2019; 119:3730-3961. [PMID: 30843688 DOI: 10.1021/acs.chemrev.8b00505] [Citation(s) in RCA: 272] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The emergence of N-heterocyclic carbenes as ligands across the Periodic Table had an impact on various aspects of the coordination, organometallic, and catalytic chemistry of the 3d metals, including Cu, Ni, and Co, both from the fundamental viewpoint but also in applications, including catalysis, photophysics, bioorganometallic chemistry, materials, etc. In this review, the emergence, development, and state of the art in these three areas are described in detail.
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Affiliation(s)
- Andreas A Danopoulos
- Laboratory of Inorganic Chemistry , National and Kapodistrian University of Athens , Panepistimiopolis Zografou , Athens GR 15771 , Greece.,Université de Strasbourg, CNRS, Institut de Chimie UMR 7177 , Laboratoire de Chimie de Coordination , Strasbourg 67081 Cedex , France
| | - Thomas Simler
- Université de Strasbourg, CNRS, Institut de Chimie UMR 7177 , Laboratoire de Chimie de Coordination , Strasbourg 67081 Cedex , France
| | - Pierre Braunstein
- Université de Strasbourg, CNRS, Institut de Chimie UMR 7177 , Laboratoire de Chimie de Coordination , Strasbourg 67081 Cedex , France
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Abstract
Solid-state auride salts featuring the negatively charged Au- ion are known to be stable in the presence of alkali metal counterions. While such electron-rich species might be expected to be nucleophilic (in the same manner as I-, for example), their instability in solution means that this has not been verified experimentally. Here we report a two-coordinate gold complex (NON)AlAuPtBu3 (where NON is the chelating tridentate ligand 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene) that features a strongly polarized bond, Auδ--Alδ+. This is synthesized by reaction of the potassium aluminyl compound [K{Al(NON)}]2 with tBu3PAuI. Computational studies of the complex, including quantum theory of atoms in molecules charge analysis, imply a charge at gold (-0.82) that is in line with the relative electronegativities of the two metals (Au: 2.54; Al: 1.61 on the Pauling scale). Consistently, the complex is found to act as a nucleophilic source of gold, reacting with diisopropylcarbodiimide and CO2 to give the Au-C bonded insertion products (NON)Al(X2C)AuPtBu3 (X = NiPr, 4; X = O, 5).
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50
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Zinser CM, Nahra F, Falivene L, Brill M, Cordes DB, Slawin AMZ, Cavallo L, Cazin CSJ, Nolan SP. Synthesis and reactivity of [Au(NHC)(Bpin)] complexes. Chem Commun (Camb) 2019; 55:6799-6802. [DOI: 10.1039/c9cc03171e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A new class of [Au(NHC)(Bpin)] complexes has been synthesized and their unusual reactivity was investigated using computational and experimental methods.
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Affiliation(s)
| | - Fady Nahra
- Department of Chemistry and Center for Sustainable Chemistry
- Ghent University
- Ghent
- Belgium
- VITO (Flemish Institute for Technological Research)
| | - Laura Falivene
- Department KAUST Catalysis Centre
- KCC
- King Abdullah University of Science and Technology
- Thuwal-23955-6900
- Saudi Arabia
| | - Marcel Brill
- EaStCHEM School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - David B. Cordes
- EaStCHEM School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | | | - Luigi Cavallo
- Department KAUST Catalysis Centre
- KCC
- King Abdullah University of Science and Technology
- Thuwal-23955-6900
- Saudi Arabia
| | - Catherine S. J. Cazin
- Department of Chemistry and Center for Sustainable Chemistry
- Ghent University
- Ghent
- Belgium
| | - Steven P. Nolan
- Department of Chemistry and Center for Sustainable Chemistry
- Ghent University
- Ghent
- Belgium
- Department of Chemistry
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