51
|
Guo R, Huang X, Zhao M, Lei Y, Ke Z, Kong L. Bifurcated Hydrogen-Bond-Stabilized Boron Analogues of Carboxylic Acids. Inorg Chem 2019; 58:13370-13375. [PMID: 31553578 DOI: 10.1021/acs.inorgchem.9b02257] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The reactivity of a bulky m-terphenylboronic acid, DmpB(OH)2 [1; Dmp = 2,6-bis(2,4,6-trimethylphenyl)phenyl], toward three different N-heterocyclic carbenes has been examined. The reaction of 1 with 1 equiv of bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) leads to the formation of a hydrogen-bonded carbene boronic acid adduct, 2, featuring strong O-H···C contacts. In contrast, more basic 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (IPr2Me2) and 1,3-di-tert-butylimidazol-2-ylidene (ItBu) deprotonate 1 smoothly to afford the rare anionic boranuidacarboxylic acids 3 and 4, respectively. Structural determination reveals that 3 and 4 bear unprecedented bifurcated hydrogen bonds with a BO- unit as a double hydrogen-bond acceptor, which contribute significantly to stabilization of the highly reactive B═O double bond. Quantum-mechanical calculations were conducted to disclose the unique electronic properties of the multiple bonds, as well as the important hydrogen bonds in these compounds.
Collapse
Affiliation(s)
- Rui Guo
- School of Chemistry and Chemical Engineering, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education , Shandong University , 27 Shanda Nanlu , Jinan 250100 , P. R. China
| | - Xiao Huang
- School of Materials Science & Engineering, PCFM Laboratory , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Meihua Zhao
- School of Chemistry and Chemical Engineering, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education , Shandong University , 27 Shanda Nanlu , Jinan 250100 , P. R. China
| | - Yusheng Lei
- School of Chemistry and Chemical Engineering, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education , Shandong University , 27 Shanda Nanlu , Jinan 250100 , P. R. China
| | - Zhuofeng Ke
- School of Materials Science & Engineering, PCFM Laboratory , Sun Yat-sen University , Guangzhou 510275 , P. R. China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering, Key Laboratory of Colloid and Interface Chemistry, Ministry of Education , Shandong University , 27 Shanda Nanlu , Jinan 250100 , P. R. China.,State Key Laboratory of Elemento-Organic Chemistry , Nankai University , Tianjin 300071 , P. R. China
| |
Collapse
|
52
|
Liu LL, Zhou J, Cao LL, Stephan DW. Phosphaaluminirenes: Synthons for Main Group Heterocycles. J Am Chem Soc 2019; 141:16971-16982. [DOI: 10.1021/jacs.9b09330] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liu Leo Liu
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Jiliang Zhou
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Levy L. Cao
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Douglas W. Stephan
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| |
Collapse
|
53
|
Pranckevicius C, Herok C, Fantuzzi F, Engels B, Braunschweig H. Bindungsstärkende Rückbindung in Aminoborylen‐stabilisierten Aminoborylenen: an der Grenze zwischen Borylenen und Diborenen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Conor Pranckevicius
- Institut für anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institut für nachhaltige Chemie und Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Christoph Herok
- Institut für anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institut für nachhaltige Chemie und Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Felipe Fantuzzi
- Institut für anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institut für nachhaltige Chemie und Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institut für physikalische und theoretische Chemie Julius-Maximilians-Universität Würzburg Emil-Fischer Straße 42 97074 Würzburg Deutschland
| | - Bernd Engels
- Institut für physikalische und theoretische Chemie Julius-Maximilians-Universität Würzburg Emil-Fischer Straße 42 97074 Würzburg Deutschland
| | - Holger Braunschweig
- Institut für anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institut für nachhaltige Chemie und Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| |
Collapse
|
54
|
Pranckevicius C, Herok C, Fantuzzi F, Engels B, Braunschweig H. Bond-Strengthening Backdonation in Aminoborylene-Stabilized Aminoborylenes: At the Intersection of Borylenes and Diborenes. Angew Chem Int Ed Engl 2019; 58:12893-12897. [PMID: 31241232 DOI: 10.1002/anie.201906671] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Indexed: 12/22/2022]
Abstract
Singly NHC-coordinated (aminoboryl)aminoborenium salts react with Na2 [Fe(CO)4 ] to yield stable coordination complexes of aminoborylene-stabilized aminoborylenes, which exhibit exceptional σ-donor properties. Upon photolytic CO extrusion from the metal center, the diboron ligand adopts a novel η3 -BBN coordination mode, where bond-strengthening backdonation from the metal center into the vacant B-B π-orbital is observed. This bonding situation can be alternatively described as a Fe-diaminodiborene complex. In a related reduction of CAAC-stabilized (aminoboryl)aminoborenium with KC8 , the reduced species can be captured with nucleophiles to form three-coordinate (diaminoboryl)borylenes, where both amino groups have migrated to the distal boron atom. Collectively, these reactions illustrate the isomeric flexibility imparted by amino groups on this reduced diboron system, thus opening multiple avenues of novel reactivity.
Collapse
Affiliation(s)
- Conor Pranckevicius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Christoph Herok
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Felipe Fantuzzi
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Institute for Physical and Theoretical Chemistry, Julius-Maximilians-Universität Würzburg, Emil-Fischer Strasse 42, 97074, Würzburg, Germany
| | - Bernd Engels
- Institute for Physical and Theoretical Chemistry, Julius-Maximilians-Universität Würzburg, Emil-Fischer Strasse 42, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| |
Collapse
|
55
|
Wang J, Cui Y, Ye Q. Bis(alkynyl)borane: A New Class of Acyclic Boron-Containing π Ligands in η 5-Coordination Mode. Inorg Chem 2019; 58:11279-11283. [PMID: 31424208 DOI: 10.1021/acs.inorgchem.9b02089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions between Rosenthal's zirconocene synthon, [Cp2Zr(py)Me3SiC≡CSiMe3] (py = pyridine), and two different types of bis(alkynyl) boranes, (Me3Si)2NB(C≡CSiMe3)2 and MesB(C≡CSiMe3)2 (Mes = 2,4,6-trimethylphenyl), both resulting in the formation of η5-coordinated bis(alkynyl)borane zirconocene complexes. X-ray diffraction analysis revealed their six-membered cyclic structures featuring a boat conformation with considerable Zr-B interactions. The Zr-B bonding strength and conformational lability of the ZrC4B ring are dependent on the π basicity of the exocyclic B substituent. These compounds represent the first examples of η5-coordinated acyclic boron-containing π ligands.
Collapse
Affiliation(s)
- Junyi Wang
- Department of Chemistry , Southern University of Science and Technology , 518055 Shenzhen , P. R. China
| | - Yunshu Cui
- Department of Chemistry , Southern University of Science and Technology , 518055 Shenzhen , P. R. China
| | - Qing Ye
- Department of Chemistry , Southern University of Science and Technology , 518055 Shenzhen , P. R. China
| |
Collapse
|
56
|
Yang X, Kalita SJ, Maheshuni S, Huang YY. Recent advances on transition-metal-catalyzed asymmetric tandem reactions with organoboron reagents. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
57
|
Maser L, Schneider C, Vondung L, Alig L, Langer R. Quantifying the Donor Strength of Ligand-Stabilized Main Group Fragments. J Am Chem Soc 2019; 141:7596-7604. [DOI: 10.1021/jacs.9b02598] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Leon Maser
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Christian Schneider
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Lisa Vondung
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Lukas Alig
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Robert Langer
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| |
Collapse
|
58
|
Lee K, Kim CW, Buckley JL, Vlaisavljevich B, Daly SR. Isolation of ligand-centered borocations in molybdenum complexes containing a triaminoborane-bridged diphosphorus ligand. Dalton Trans 2019; 48:3777-3785. [PMID: 30810573 DOI: 10.1039/c9dt00733d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Metal complexes that form isolable, ligand-centered borenium ions (i.e. reactive three-coordinate boron cations) are rare, especially with highly-versatile diphosphorus ligands. Here we report the first structurally-characterized examples of ligand-centered borocations in a class of diphosphorus ligands derived from the bicyclic triaminoborane 1,8,10,9-triazaboradecalin (TBD). Treating (PhTBDPhos)Mo(CO)4 (1) with HOTf or HNTf2 resulted in protonation of the bridgehead α-nitrogen on the TBD backbone and formation of ligand-centered borenium ions (1-HOTf and 1-HNTf2, respectively), whereas reaction of 1 with HBF4·Et2O resulted in protonation of two α-nitrogen atoms and fluoride abstraction from BF4- to form a four-coordinate borocation in [1-H2F][BF4]. Single-crystal XRD data confirmed the formation of the borocations, and multinuclear NMR and IR spectroscopy studies were used to interrogate the electronic environment at molybdenum and boron. The 11B NMR resonances for the borenium ions in 1-HOTf and 1-HNTf2 (δ 29.5 and 29.6 ppm) were more deshielded than the resonance for 1 (δ 25.9 ppm), consistent with the decreased electron density at boron. The 31P NMR data revealed similar trends in response to increasing protonation on the TBD backbone, and aligned well with small, stepwise increases in Mo-CO stretching frequencies that followed the order borane (1) < borenium (1-HOTf and 1-HNTf2) < boronium ([1-H2F][BF4]). Density functional theory calculations conducted on 1, 1-HOTf, and [1-H2F][BF4] revealed subtle changes in boron and nitrogen atomic charges consistent with those calculated for more well-established borenium ions in metal-free systems. Overall, the results confirm previous observations of latent borenium ion reactivity in TBDPhos complexes.
Collapse
Affiliation(s)
- Kyounghoon Lee
- The University of Iowa, Department of Chemistry, E331 Chemistry Building, Iowa City, IA 52242, USA.
| | | | | | | | | |
Collapse
|
59
|
Abstract
Most of the chemical and biological processes involving the fixation and transformation of small molecules have long been exclusive for metal complexes. Meanwhile, the last decades have seen a significant advance in main group chemistry that mimics transition-metal complexes, among which various boron-containing systems have been successful in mediating the small molecule activation. In this review, we focus on boron-containing heterocycles enabling the activation of σ- and π-bonds in small molecules, in conjunction with the proposed mechanisms.
Collapse
Affiliation(s)
- Yuanting Su
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore.
| | | |
Collapse
|
60
|
Lu D, He Y, Wu C. Electronic structure of mono(Lewis base)-stabilized borylenes. Phys Chem Chem Phys 2019; 21:23533-23540. [DOI: 10.1039/c9cp04653d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mono(Lewis base)-stabilized 3c-6e borylenes are found to have multiple ground state electronic structures.
Collapse
Affiliation(s)
- Dongmei Lu
- Department of Chemistry
- School of Science
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Yijin He
- Department of Chemistry
- School of Science
- Xi'an Jiaotong University
- Xi'an 710049
- China
| | - Chao Wu
- Frontier Institute of Science and Technology
- Xi'an Jiaotong University
- Xi'an 710054
- China
| |
Collapse
|