1
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Jo J, Kim S, Park S, Kim S, Lee S, Choi JH, Chung WJ. Study on Pyridine-Boryl Radical-Promoted, Ketyl Radical-Mediated Carbon-Carbon Bond-Forming Reactions. J Org Chem 2024; 89:8985-9000. [PMID: 38861548 DOI: 10.1021/acs.joc.4c00946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Ketyl radicals are synthetically versatile reactive species, but their applications have been hampered by harsh generation conditions employing highly reducing metals. Recently, the pyridine-boryl radical received wide attention as a promising organic reductant because of its mildness as well as convenience in handling. While probing the utility of the pyridine-boryl radical, our group observed facile pinacol coupling reactivity that had not been known at that time. This serendipitous finding was successfully rendered into a practical synthesis of tetraaryl-1,2-diols in up to 99% yield within 1 h. Subsequently, upon examinations of various reaction manifolds, a diastereoselective ketyl-olefin cyclization was accomplished to produce cycloalkanols such as trans-2-alkyl-1-indanols. Compared to the previous methods, the stereocontrolling ability was considerably enhanced by taking advantage of the structurally modifiable boryl group that would be present near the bond-forming site. In this full account, our synthetic efforts with the O-boryl ketyl radicals are disclosed in detail, covering the discovery, optimization, scope expansion, and mechanistic analysis, including density functional theory (DFT) calculations.
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Affiliation(s)
- Junhyuk Jo
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Somi Kim
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Seonyoung Park
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Seonyul Kim
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Sunggi Lee
- Department of Physics and Chemistry, DGIST, 333 Techno jungang-daero, Hyeonpung-eup, Dalseong-gun, Daegu 42988, Republic of Korea
| | - Jun-Ho Choi
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Won-Jin Chung
- Department of Chemistry, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
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2
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van Beek CM, Swarbrook AM, Creissen CE, Hawes CS, Gazis TA, Matthews PD. Juggling Optoelectronics and Catalysis: The Dual Talents of Bench Stable 1,4-Azaborinines. Chemistry 2024; 30:e202301944. [PMID: 38050753 DOI: 10.1002/chem.202301944] [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: 06/19/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 12/06/2023]
Abstract
Boron- and nitrogen-doped polycyclic aromatic hydrocarbons (B-PAHs) have established a strong foothold in the realm of organic electronics. However, their catalytic potential remains largely untapped. In this study, we synthesise and characterise two bench stable B,N-doped PAH derivatives based on a 1,4-azaborinine motif. Most importantly, the anthracene derived structure is an efficient catalyst in the reduction of various carbonyls and imines. These results underscore the potential of B,N-PAHs in catalytic transformations, setting the stage for deeper exploration in this chemical space.
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Affiliation(s)
- Chloe M van Beek
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
| | - Amelia M Swarbrook
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
| | - Charles E Creissen
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
| | - Chris S Hawes
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
| | - Theodore A Gazis
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
| | - Peter D Matthews
- School of Chemical & Physical Sciences, Keele University, Newcastle-under-Lyme, Staffs, ST5 5BG, U.K
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3
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Timoshkin AY. The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments. Chemistry 2024; 30:e202302457. [PMID: 37752859 DOI: 10.1002/chem.202302457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 09/28/2023]
Abstract
New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.
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Affiliation(s)
- Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, 199034, Universitetskaya emb. 7/9, St. Petersburg, Russia
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4
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Krupa B, Szyling J, Walkowiak J. Pt(PPh 3) 4 and Pt(PPh 3) 4@IL catalyzed hydroboration of ketones. Sci Rep 2023; 13:20237. [PMID: 37981660 PMCID: PMC10658173 DOI: 10.1038/s41598-023-47518-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023] Open
Abstract
An efficient method for the reduction of various ketones via [Pt(PPh3)4]-catalyzed hydroboration with HBpin has been successfully developed for the first time. The protocol is suitable for symmetrical and unsymmetrical derivatives possessing electron donating or withdrawing functional groups. O-borylated products were easily converted to 2° alcohols via hydrolysis with high isolated yields. According to the low-temperature NMR spectroscopy, a reaction mechanism was proposed. Additionally, effective immobilization of the catalyst in the ionic liquid [BMIM][NTf2] was applied to increase the productivity of the process by carrying out reactions under the repetitive batch mode, obtaining higher TON values and limiting the amount of expensive Pt used. The catalyst stability and almost neglectable leaching were confirmed by ICP-MS analysis of the extracted mixture. A simple separation method via extraction with n-heptane, efficient catalyst immobilization, and the commercial availability of the Pt complex, make this protocol an attractive method for the hydroboration of ketones.
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Affiliation(s)
- Barbara Krupa
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614, Poznan, Poland
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614, Poznan, Poland
| | - Jakub Szyling
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614, Poznan, Poland
| | - Jędrzej Walkowiak
- Center for Advanced Technology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614, Poznan, Poland.
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5
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Paskaruk KM, Emslie DJH, Britten JF. A comparison of the coordination behaviour of R 2PCH 2BMe 2 (R = Me vs. Ph) ambiphilic ligands with late transition metals. Dalton Trans 2023; 52:15712-15724. [PMID: 37815843 DOI: 10.1039/d3dt02538a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
A new synthesis that avoids the use of Me2PH is reported for (Me2PCH2BMe2)2, and this method was extended to the synthesis of (Ph2PCH2BMe2)2. The ligand precursor (Me2PCH2BMe2)2 did not react with [{M(μ-Cl)(cod)}2] (cod = 1,5-cyclooctadiene; M = Ir and Rh) or [PtCl2(cod)] at room temperature. However, after 12-48 hours at 65-70 °C, these reactions afforded (a) [Ir(cod)(μ-Cl)(Me2PCH2BMe2)] (1), (b) an equilibrium mixture of (Me2PCH2BMe2)2, [{Rh(μ-Cl)(cod)}2] and [Rh(cod)(μ-Cl)(Me2PCH2BMe2)] (2), and (c) cis-[Pt(μ-Cl)2(Me2PCH2BMe2)2] (3), respectively. By contrast, reactions between the phenyl-substituted analogue, (Ph2PCH2BMe2)2, and [{M(μ-Cl)(cod)}2] (cod = 1,5-cyclooctadiene; M = Ir and Rh) proceeded over the course of 1 hour at 20 °C to generate [M(cod)(μ-Cl)(Ph2PCH2BMe2)] (M = Ir (4) and Rh (5)), indicative of room temperature (Ph2PCH2BMe2)2 dissociation. Room temperature reactions of (Ph2PCH2BMe2)2 with [{Rh(μ-Cl)(coe)2}2] (coe = cyclooctene) using a 1 : 1 or 3 : 1 stoichiometry also afforded [{Rh(coe)(μ-Cl)(Ph2PCH2BMe2)}2] (6) or [RhCl(Ph2PCH2BMe2)3] (7), respectively, where the latter is a borane-appended analogue of Wilkinson's catalyst, and reactions of (Ph2PCH2BMe2)2 with [PtX2(cod)] (X = Cl or Me) yielded cis-[Pt(μ-Cl)2(Ph2PCH2BMe2)2] (8) and cis-[PtMe2(Ph2PCH2BMe2)2] (9). Compounds 1-9, (Me2PCH2BMe2)2 and (Ph2PCH2BMe2)2 were crystallographically characterized. In compounds 1-5 and 8, each chloride co-ligand is coordinated by the borane of an R2PCH2BMe2 ligand. Additionally, in the solid state structure of 6, each bridging chloride ligand interacts weakly with a pendent borane, and in 7, the chloride ligand is tightly coordinated to the borane of one Ph2PCH2BMe2 ligand and weakly coordinated to the borane of a second Ph2PCH2BMe2 ligand. By contrast, both boranes in 9 (and one of the three boranes in 7) are non-coordinated.
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Affiliation(s)
- Katia M Paskaruk
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
| | - David J H Emslie
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
| | - James F Britten
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
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6
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Bohlen JL, Endres L, Drescher R, Radacki K, Dietz M, Krummenacher I, Braunschweig H. Boroles from alumoles: accessing boroles with alkyl-substituted backbones via transtrielation. Chem Sci 2023; 14:9010-9015. [PMID: 37655034 PMCID: PMC10466280 DOI: 10.1039/d3sc02668j] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/14/2023] [Indexed: 09/02/2023] Open
Abstract
The alumole Cp3tAlC4Et4 (Cp3t = 1,2,4-tris(tert-butyl)cyclopentadienyl) is reported to be capable of transferring its butadiene moiety to aryl(dihalo)boranes to generate boroles through aluminum-boron exchange. The products feature a rare alkyl-substituted backbone, which, as shown in other examples, often leads to dimerization due to insufficient steric protection of the antiaromatic borole ring. Sterically crowded aryl groups bound to the boron atom are shown to prevent dimerization, allowing access to the first monomeric derivatives of this type. Results from UV-vis spectroscopy, electrochemistry, and DFT calculations reveal that the alkyl substituents cause remarkable modifications in the optical and electronic properties of the boroles compared to their perarylated counterparts.
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Affiliation(s)
- Josina L Bohlen
- 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
| | - Lukas Endres
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Regina Drescher
- 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
| | - Krzysztof Radacki
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Maximilian Dietz
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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7
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Zapf L, Riethmann M, Föhrenbacher SA, Finze M, Radius U. An easy-to-perform evaluation of steric properties of Lewis acids. Chem Sci 2023; 14:2275-2288. [PMID: 36873848 PMCID: PMC9977453 DOI: 10.1039/d3sc00037k] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/04/2023] [Indexed: 02/08/2023] Open
Abstract
Steric and electronic effects play a very important role in chemistry, as these effects influence the shape and reactivity of molecules. Herein, an easy-to-perform approach to assess and quantify steric properties of Lewis acids with differently substituted Lewis acidic centers is reported. This model applies the concept of the percent buried volume (%V Bur) to fluoride adducts of Lewis acids, as many fluoride adducts are crystallographically characterized and are frequently calculated to judge fluoride ion affinities (FIAs). Thus, data such as cartesian coordinates are often easily available. A list of 240 Lewis acids together with topographic steric maps and cartesian coordinates of an oriented molecule suitable for the SambVca 2.1 web application is provided, together with different FIA values taken from the literature. Diagrams of %V Bur as a scale for steric demand vs. FIA as a scale for Lewis acidity provide valuable information about stereo-electronic properties of Lewis acids and an excellent evaluation of steric and electronic features of the Lewis acid under consideration. Furthermore, a novel LAB-Rep model (Lewis acid/base repulsion model) is introduced, which judges steric repulsion in Lewis acid/base pairs and helps to predict if an arbitrary pair of Lewis acid and Lewis base can form an adduct with respect to their steric properties. The reliability of this model was evaluated in four selected case studies, which demonstrate the versatility of this model. For this purpose, a user-friendly Excel spreadsheet was developed and is provided in the ESI, which works with listed buried volumes of Lewis acids %V Bur_LA and of Lewis bases %V Bur_LB, and no results from experimental crystal structures or quantum chemical calculations are necessary to evaluate steric repulsion in these Lewis acid/base pairs.
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Affiliation(s)
- Ludwig Zapf
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Melanie Riethmann
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Steffen A Föhrenbacher
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group
| | - Maik Finze
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Udo Radius
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group
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8
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Alharbi MM, van Ingen Y, Roldan A, Kaehler T, Melen RL. Synthesis and lewis acidity of fluorinated triaryl borates. Dalton Trans 2023; 52:1820-1825. [PMID: 36661186 DOI: 10.1039/d2dt04095f] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A series of fluorinated triaryl borates B(OArF)3 (ArF = 2-FC6H4, 3-FC6H4, 4-FC6H4, 2,4-F2C6H3, 3,5-F2C6H3, 2,3,4-F3C6H2, 2,4,6-F3C6H2, 3,4,5-F3C6H2) have been prepared and isolated from the reactions of the mono-, di-, or tri-fluorophenol with BCl3. The Lewis acidity of these borates has been determined by NMR spectroscopic and theoretical methods and compared to their well-established borane counterpart.
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Affiliation(s)
- Mashael M Alharbi
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Cymru/Wales, UK. .,Department of Chemistry, King Faisal University, College of Science, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia
| | - Yara van Ingen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Cymru/Wales, UK.
| | - Alberto Roldan
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Cymru/Wales, UK.
| | - Tanja Kaehler
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Cymru/Wales, UK.
| | - Rebecca L Melen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Cymru/Wales, UK.
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9
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Sarkar N, Kumar Sahoo R, Nembenna S. Aluminium-Catalyzed Selective Hydroboration of Esters and Epoxides to Alcohols: C-O Bond Activation. Chemistry 2023; 29:e202203023. [PMID: 36226774 DOI: 10.1002/chem.202203023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 11/07/2022]
Abstract
In this work, the molecular aluminium dihydride complex bearing an N, N'-chelated conjugated bis-guanidinate (CBG) ligand is used as a catalyst for reducing a wide range of aryl and alkyl esters with good tolerance of alkene (C=C), alkyne (C≡C), halides (Cl, Br, I and F), nitrile (C≡N), and nitro (NO2 ) functionalities. Further, we investigated the catalytic application of aluminium dihydride in the C-O bond cleavage of alkyl and aryl epoxides into corresponding branched Markovnikov ring-opening products. In addition, the chemoselective intermolecular reduction of esters over other reducible functional groups, such as amides and alkenes, has been established. Intermediates are isolated and characterized by NMR and HRMS studies, which confirm the probable catalytic cycles for the hydroboration of esters and epoxides.
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Affiliation(s)
- Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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10
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Hoffmann KF, Wiesner A, Steinhauer S, Riedel S. Insights on the Lewis Superacid Al(OTeF 5 ) 3 : Solvent Adducts, Characterization and Properties. Chemistry 2022; 28:e202201958. [PMID: 35901430 PMCID: PMC9804164 DOI: 10.1002/chem.202201958] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Indexed: 01/05/2023]
Abstract
Preparation and characterization of the dimeric Lewis superacid [Al(OTeF5 )3 ]2 and various solvent adducts is presented. The latter range from thermally stable adducts to highly reactive, weakly bound species. DFT calculations on the ligand affinity of these Lewis acids were performed in order to rank their remaining Lewis acidity. An experimental proof of the Lewis acidity is provided by the reaction of solvent-adducts of Al(OTeF5 )3 with [PPh4 ][SbF6 ] and OPEt3 , respectively. Furthermore, their reactivity towards chloride and pentafluoroorthotellurate salts as well as (CH3 )3 SiCl and (CH3 )3 SiF is shown. This includes the formation of the dianion [Al(OTeF5 )5 ]2- .
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Affiliation(s)
- Kurt F. Hoffmann
- Fachbereich für BiologieChemiePharmazieInstitut für Chemie und Biochemie – Anorganische ChemieFabeckstraße 34/3614195BerlinGermany
| | - Anja Wiesner
- Fachbereich für BiologieChemiePharmazieInstitut für Chemie und Biochemie – Anorganische ChemieFabeckstraße 34/3614195BerlinGermany
| | - Simon Steinhauer
- Fachbereich für BiologieChemiePharmazieInstitut für Chemie und Biochemie – Anorganische ChemieFabeckstraße 34/3614195BerlinGermany
| | - Sebastian Riedel
- Fachbereich für BiologieChemiePharmazieInstitut für Chemie und Biochemie – Anorganische ChemieFabeckstraße 34/3614195BerlinGermany
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11
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Paskaruk K, Emslie DJH, Britten JF. Coordination chemistry and structural rearrangements of the Me 2PCH 2AlMe 2 ambiphilic ligand. Dalton Trans 2022; 51:15040-15048. [PMID: 36112126 DOI: 10.1039/d2dt02519a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction of 2 equivalents of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] (cod = 1,5-cyclooctadiene) afforded [{κ2P,P-(Me3Al)ClMeAl(CH2PMe2)2}Rh(cod)] (1), which features a κ2-coordinated bis(phosphino)aluminate anion. In compound 1, an Al-Cl substituent bridges to a molecule of AlMe3, which could be removed in vacuo to provide [{κ2P,P-ClMeAl(CH2PMe2)2}Rh(cod)] (2). By contrast, reaction of 1 equiv. of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] yielded [Rh(cod)(μ-Cl)(Me2PCH2AlMe2)] (3) as the major product, where the phosphine donor of an intact Me2PCH2AlMe2 ligand is coordinated to rhodium and a chloride ligand bridges between Rh and Al. [Rh(cod)(μ-Cl)(Me2PCH2AlClMe)] (3A) and 2 were also formed as minor products. The aforementioned reactions were carried out in benzene or toluene, whereas the 1 : 1 reaction of (Me2PCH2AlMe2)2 with [{RhCl(cod)}2] in THF afforded [{Rh(μ-CH2PMe2)(cod)}2] (4). Reactions of (Me2PCH2AlMe2)2 with iridium(I), gold(I) and platinum(II) precursors were also explored. A 1 : 1 reaction of (Me2PCH2AlMe2)2 with [{IrCl(cod)}2] afforded [{κ2P,P-Cl2Al(CH2PMe2)2}Ir(cod)] (5) as one of two major phosphine-containing products; unlike 3, this compound features two chlorine substituents on aluminium. For comparison, the rhodium analogue of 5, [{κ2P,P-Cl2Al(CH2PMe2)2}Rh(cod)] (6), was also synthesized via the 1 : 1 reaction of {ClAl(CH2PMe2)2}2 with [{RhCl(cod)}2]. Reactions of (Me2PCH2AlMe2)2 with [AuCl(CO)] or [PtCl2(cod)] also resulted in chloride-methyl group exchange between the transition metal and aluminium. However, these reactions generated free (Me2PCH2AlClMe)2 accompanied by gold and ethane, or [PtMe2(cod)], respectively. Reaction of 1.5 equivalents of (Me2PCH2AlMe2)2 with [PtMe2(cod)] at 75 °C afforded zwitterionic [(PtMe{μ-κ1P:κ2P,P-MeAl(CH2PMe2)3})2] (7) which features two tris(phosphino)aluminate anions bridging between PtMe units. Compounds 1-2, 3/3A, 4-7 and (Me2PCH2AlClMe)2 were crystallographically characterized.
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Affiliation(s)
- Katarina Paskaruk
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
| | - David J H Emslie
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
| | - James F Britten
- Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
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12
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Abstract
This review highlights the hydroelementation reactions of conjugated and separated diynes, which depending on the process conditions, catalytic system, as well as the type of reagents, leads to the formation of various products: enynes, dienes, allenes, polymers, or cyclic compounds. The presence of two triple bonds in the diyne structure makes these compounds important reagents but selective product formation is often difficult owing to problems associated with maintaining appropriate reaction regio- and stereoselectivity. Herein we review this topic to gain knowledge on the reactivity of diynes and to systematise the range of information relating to their use in hydroelementation reactions. The review is divided according to the addition of the E-H (E = Mg, B, Al, Si, Ge, Sn, N, P, O, S, Se, Te) bond to the triple bond(s) in the diyne, as well as to the type of the reagent used, and the product formed. Not only are the hydroelementation reactions comprehensively discussed, but the synthetic potential of the obtained products is also presented. The majority of published research is included within this review, illustrating the potential as well as limitations of these processes, with the intent to showcase the power of these transformations and the obtained products in synthesis and materials chemistry.
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Affiliation(s)
- Jędrzej Walkowiak
- Adam Mickiewicz University in Poznan, Center for Advanced Technology, Uniwersytetu Poznanskiego 10, 61-614, Poznan.
| | - Jakub Szyling
- Adam Mickiewicz University in Poznan, Center for Advanced Technology, Uniwersytetu Poznanskiego 10, 61-614, Poznan. .,Adam Mickiewicz University in Poznan, Faculty of Chemistry, Uniwersytetu Poznanskiego 8, 61-614, Poznan, Poland
| | - Adrian Franczyk
- Adam Mickiewicz University in Poznan, Center for Advanced Technology, Uniwersytetu Poznanskiego 10, 61-614, Poznan.
| | - Rebecca L Melen
- Cardiff Catalysis Institute, Cardiff University, School of Chemistry, Park Place, Main Building, Cardiff CF10 3AT, Cymru/Wales, UK.
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Affiliation(s)
- Congjian Ni
- Beijing Institute of Technology School of chemistry CHINA
| | - Xiaoli Ma
- Beijing Institute of Technology School of Chemistry and Chemical Engineering CHINA
| | - Zhi Yang
- Beijing Institute of Technology School of Chemistry and Chemical Engineering CHINA
| | - Herbert W. Roesky
- Georg-August-Universitat Gottingen Department of Chemistry Tammannstrasse 4 37077 Göttingen GERMANY
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14
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Kamal MM, Liu Z, Zhai S, Vidović D. Imine Reduction with Me 2S-BH 3. Molecules 2021; 26:5443. [PMID: 34576911 PMCID: PMC8467297 DOI: 10.3390/molecules26185443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 11/25/2022] Open
Abstract
Although there exists a variety of different catalysts for hydroboration of organic substrates such as aldehydes, ketones, imines, nitriles etc., recent evidence suggests that tetra-coordinate borohydride species, formed by activation, redistribution, or decomposition of boron reagents, are the true hydride donors. We then proposed that Me2S-BH3 could also act as a hydride donor for the reduction of various imines, as similar compounds have been observed to reduce carbonyl substrates. This boron reagent was shown to be an effective and chemoselective hydroboration reagent for a wide variety of imines.
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Affiliation(s)
- Mohammad M. Kamal
- School of Chemistry, Faculty of Sciences, Monash University, Clayton 3800, Australia; (M.M.K.); (Z.L.); (S.Z.)
| | - Zhizhou Liu
- School of Chemistry, Faculty of Sciences, Monash University, Clayton 3800, Australia; (M.M.K.); (Z.L.); (S.Z.)
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Siyuan Zhai
- School of Chemistry, Faculty of Sciences, Monash University, Clayton 3800, Australia; (M.M.K.); (Z.L.); (S.Z.)
| | - Dragoslav Vidović
- School of Chemistry, Faculty of Sciences, Monash University, Clayton 3800, Australia; (M.M.K.); (Z.L.); (S.Z.)
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