1
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Choudhury D, Lam CC, Farag NL, Slaughter J, Bond AD, Goodman JM, Wright DS. Suppressing Cis/Trans 'Ring-Flipping' in Organoaluminium(III)-2-Pyridyl Dimers-Design Strategies Towards Lewis Acid Catalysts for Alkene Oligomerisation. Chemistry 2024; 30:e202303872. [PMID: 38477400 DOI: 10.1002/chem.202303872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/06/2024] [Accepted: 03/11/2024] [Indexed: 03/14/2024]
Abstract
Owing to its high natural abundance compared to the commonly used transition (precious) metals, as well as its high Lewis acidity and ability to change oxidation state, aluminium has recently been explored as the basis for a range of single-site catalysts. This paper aims to establish the ground rules for the development of a new type of cationic alkene oligomerisation catalyst containing two Al(III) ions, with the potential to act co-operatively in stereoselective assembly. Five new dimers of the type [R2Al(2-py')]2 (R=Me, iBu; py'=substituted pyridyl group) with different substituents on the Al atoms and pyridyl rings have been synthesised. The formation of the undesired cis isomers can be suppressed by the presence of substituents on the 6-position of the pyridyl ring due to steric congestion, with DFT calculations showing that the selection of the trans isomer is thermodynamically controlled. Calculations show that demethylation of the dimers [Me2Al(2-py')]2 with Ph3C+ to the cations [{MeAl(2-py')}2(μ-Me)]+ is highly favourable and that the desired trans disposition of the 2-pyridyl ring units is influenced by steric effects. Preliminary experimental studies confirm that demethylation of [Me2Al(6-MeO-2-py)]2 can be achieved using [Ph3C][B(C6F5)4].
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Affiliation(s)
- Dipanjana Choudhury
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
| | - Ching Ching Lam
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
| | - Nadia L Farag
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
| | - Jonathan Slaughter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot, OX11 0RA, United Kingdom
| | - Andrew D Bond
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
| | - Jonathan M Goodman
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
| | - Dominic S Wright
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW
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2
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Roy MMD, Omaña AA, Wilson ASS, Hill MS, Aldridge S, Rivard E. Molecular Main Group Metal Hydrides. Chem Rev 2021; 121:12784-12965. [PMID: 34450005 DOI: 10.1021/acs.chemrev.1c00278] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, and 12-16. Particular attention will be given to the emerging use of said hydrides in the rapidly expanding field of Main Group element-mediated catalysis. While this review is comprehensive in nature, focus will be given to research appearing in the open literature since 2001.
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Affiliation(s)
- Matthew M D Roy
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Alvaro A Omaña
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Andrew S S Wilson
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Michael S Hill
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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3
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Bodach A, Ortmeyer J, Herrmann B, Felderhoff M. Amino−Organolithium Compounds and their Aggregation for the Synthesis of Amino−Organoaluminium Compounds. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100224] [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)
- Alexander Bodach
- Department of Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Jochen Ortmeyer
- Department of Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Bastian Herrmann
- Department of Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Michael Felderhoff
- Department of Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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4
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Bodach A, Nöthling N, Felderhoff M. Activation of Molecular Hydrogen by Inter‐ and Intramolecular Al−N Lewis Pairs. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202001152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1
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Morris LJ, Hill MS, Mahon MF, Manners I, Patrick BO. Alkaline-Earth Derivatives of Diphenylphosphine–Borane. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Louis J. Morris
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Ian Manners
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Brian O. Patrick
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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6
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Abstract
The catalytic dehydrocoupling of amine–boranes has recently received a great deal of attention due to its potential in hydrogen storage applications. The use of aluminum catalysts for this transformation would provide an additional cost-effective and sustainable approach towards the hydrogen economy. Herein, we report the use of both N-heterocyclic imine (NHI)- and carbene (NHC)-supported Al(III) hydrides and their role in the catalytic dehydrocoupling of Me2NHBH3. Differences in the σ-donating ability of the ligand class resulted in a more stable catalyst for NHI-Al(III) hydrides, whereas a deactivation pathway was found in the case of NHC-Al(III) hydrides.
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7
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Boom DHA, Jupp AR, Slootweg JC. Dehydrogenation of Amine-Boranes Using p-Block Compounds. Chemistry 2019; 25:9133-9152. [PMID: 30964220 PMCID: PMC6771515 DOI: 10.1002/chem.201900679] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Indexed: 01/11/2023]
Abstract
Amine-boranes have gained a lot of attention due to their potential as hydrogen storage materials and their capacity to act as precursors for transfer hydrogenation. Therefore, a lot of effort has gone into the development of suitable transition- and main-group metal catalysts for the dehydrogenation of amine-boranes. During the past decade, new systems started to emerge solely based on p-block elements that promote the dehydrogenation of amine-boranes through hydrogen-transfer reactions, polymerization initiation, and main-group catalysis. In this review, we highlight the development of these p-block based systems for stoichiometric and catalytic amine-borane dehydrogenation and discuss the underlying mechanisms.
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Affiliation(s)
- Devin H. A. Boom
- Van 't Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041090 GDAmsterdamThe Netherlands
| | - Andrew R. Jupp
- Van 't Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041090 GDAmsterdamThe Netherlands
| | - J. Chris Slootweg
- Van 't Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041090 GDAmsterdamThe Netherlands
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8
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Trose M, Reiß M, Reiß F, Anke F, Spannenberg A, Boye S, Lederer A, Arndt P, Beweries T. Dehydropolymerisation of methylamine borane using a dinuclear 1,3-allenediyl bridged zirconocene complex. Dalton Trans 2018; 47:12858-12862. [PMID: 30156242 DOI: 10.1039/c8dt03311k] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dinuclear zirconocene chloride complex 1 is a highly active precatalyst for the dehydropolymerisation of methylamine borane. Comparison with mononuclear Zr chlorides and related dinuclear complexes suggests that the nature of the bridging motif is essential for the unique reactivity of 1.
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Affiliation(s)
- M Trose
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - M Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - F Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - F Anke
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - A Spannenberg
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - S Boye
- Leibniz-Institut für Polymerforschung Dresden, Hohe Str. 6, 01069 Dresden, Germany
| | - A Lederer
- Leibniz-Institut für Polymerforschung Dresden, Hohe Str. 6, 01069 Dresden, Germany and Technische Universität Dresden, 01062 Dresden, Germany
| | - P Arndt
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - T Beweries
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
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9
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Turner J, Chilton NF, Kumar A, Colebatch AL, Whittell GR, Sparkes HA, Weller AS, Manners I. Iron Precatalysts with Bulky Tri(tert-butyl)cyclopentadienyl Ligands for the Dehydrocoupling of Dimethylamine-Borane. Chemistry 2018; 24:14127-14136. [PMID: 29573487 DOI: 10.1002/chem.201705316] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 03/07/2018] [Indexed: 11/11/2022]
Abstract
In an attempt to prepare new Fe catalysts for the dehydrocoupling of amine-boranes and to provide mechanistic insight, the paramagnetic FeII dimeric complex [Cp'FeI]2 (1) (Cp'=η5 -((1,2,4-tBu)3 C5 H2 )) was used as a precursor to a series of cyclopentadienyl FeII and FeIII mononuclear species. The complexes prepared were [Cp'Fe(η6 -Tol)][Cp'FeI2 ] (2) (Tol=C6 H5 Me), [Cp'Fe(η6 -Tol)][BArF4 ] (3) (BArF4 =[B(C6 H3 (m-CF3 )2 )4 ]- ), [N(nBu)4 ][Cp'FeI2 ] (4), Cp'FeI2 (5), and [Cp'Fe(MeCN)3 ][BArF4 ] (6). The electronic structure of the [Cp'FeI2 ]- anion in 2 and 4 was investigated by SQUID magnetometry, EPR spectroscopy and ab initio Complete Active Space Self Consistent Field-Spin Orbit (CASSCF-SO) calculations, and the studies revealed a strongly anisotropic S=2 ground state. Complexes 1-6 were investigated as catalysts for the dehydrocoupling of Me2 NH⋅BH3 (I) in THF at 20 °C to yield the cyclodiborazane product [Me2 N-BH2 ]2 (IV). Complexes 1-4 and 6 were active dehydrocoupling catalysts towards I (5 mol % loading), however 5 was inactive, and ultra-violet (UV) irradiation was required for the reaction mediated by 3. Complex 6 was found to be the most active precatalyst, reaching 80 % conversion to IV after 19 h at 22 °C. Dehydrocoupling of I by 1-4 proceeded via formation of the aminoborane Me2 N=BH2 (II) as the major intermediate, whereas for 6 the linear diborazane Me2 NH-BH2 -NMe2 -BH3 (III) could be detected, together with trace amounts of II. Reactions of 1 and 6 with Me3 N⋅BH3 were investigated in an attempt to identify Fe-based intermediates in the catalytic reactions. The σ-complex [Cp'Fe(MeCN)(κ2 -H2 BH⋅NMe2 H][BArF4 ] was proposed to initially form in dehydrocoupling reactions involving 6 based on ESI-MS (ESI=Electrospray Ionisation Mass Spectroscopy) and NMR spectroscopic evidence. The latter also suggests that these complexes function as precursors to iron hydrides which may be the true catalytic species.
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Affiliation(s)
- Joshua Turner
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Nicholas F Chilton
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Amit Kumar
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | | | - George R Whittell
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Hazel A Sparkes
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Andrew S Weller
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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10
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Affiliation(s)
- Catherine Weetman
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research CenterTechnische Universität München (TUM) Lichtenbergstraße 4 Garching bei München 85748 Germany
| | - Shigeyoshi Inoue
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research CenterTechnische Universität München (TUM) Lichtenbergstraße 4 Garching bei München 85748 Germany
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11
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Kundu D, Chakma S, Pugazhenthi G, Banerjee T. Ionic Liquid Facilitated Dehydrogenation of tert-Butylamine Borane. ACS OMEGA 2018; 3:2273-2281. [PMID: 31458528 PMCID: PMC6641282 DOI: 10.1021/acsomega.7b01781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/09/2018] [Indexed: 06/10/2023]
Abstract
The current work reports ionic liquid (IL) facilitated dehydrogenation of tert-butylamine borane (TBAB) at 90 and 105 °C. For the screening of potential IL solvent, solubility predictions of TBAB in ILs were performed by the conductor-like screening model segment activity coefficient (COSMO-SAC) model. The COSMO-SAC model predicted a logarithmic infinite dilution activity coefficient of -6.66 and -7.31 for TBAB in 1-butyl-3-methylimidazolium acetate [BMIM][OAc] and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate [TDTHP][Phosph], respectively. Hydrogen (1.95 equiv) was seen to release from TBAB/[BMIM][OAc] at 105 °C, whereas TBAB/[TDTHP][Phosph] produced 1.63 equiv of hydrogen after 360 min of dehydrogenation. The proton nuclear magnetic resonance (1H NMR) characterization of TBAB/IL systems revealed the structural integrity of ILs during dehydrogenation. Further characterization through the boron NMR (11B NMR) technique disclosed the time-resolved formation and stability of the starting compound, intermediate boron moieties, and product distribution. The 11B NMR characterization also revealed the fact that the TBAB/[TDTHP][Phosph] mixture dehydrogenates via bimolecular addition of TBAB by forming borohydride anion (-BH4 -). It was seen to oligomerize with the subsequent addition of TBAB in the oligomer chain. For the TBAB/[BMIM][OAc] system, the 11B NMR characterization could not identify the borohydride anion but confirmed a faster formation of the B=N moiety when compared to the TBAB/[TDTHP][Phosph] system. On the basis of the NMR characterization, IL-facilitated dehydrogenation mechanism of TBAB is proposed.
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Affiliation(s)
- Debashis Kundu
- Department
of Chemical Engineering, Indian Institute
of Technology Guwahati, Guwahati 781039, Assam, India
| | - Sankar Chakma
- Department
of Chemical Engineering, Indian Institute
of Science Education and Research Bhopal, Bhopal 462 066, Madhya Pradesh, India
| | - Gopal Pugazhenthi
- Department
of Chemical Engineering, Indian Institute
of Technology Guwahati, Guwahati 781039, Assam, India
| | - Tamal Banerjee
- Department
of Chemical Engineering, Indian Institute
of Technology Guwahati, Guwahati 781039, Assam, India
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12
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Nolla-Saltiel R, Geer AM, Lewis W, Blake AJ, Kays DL. Dehydrogenation of dimethylamine-borane mediated by Group 1 pincer complexes. Chem Commun (Camb) 2018; 54:1825-1828. [DOI: 10.1039/c7cc08385h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alkali metal carbazolido complexes are precatalysts for the dehydrogenation of Me2NH·BH3, where the cation plays a vital role in the reaction outcome.
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Affiliation(s)
| | - Ana M. Geer
- School of Chemistry
- University of Nottingham
- Nottingham
- UK
| | - William Lewis
- School of Chemistry
- University of Nottingham
- Nottingham
- UK
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13
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McLellan R, Kennedy AR, Mulvey RE, Orr SA, Robertson SD. 1-Alkali-metal-2-alkyl-1,2-dihydropyridines: Soluble Hydride Surrogates for Catalytic Dehydrogenative Coupling and Hydroboration Applications. Chemistry 2017; 23:16853-16861. [PMID: 28940713 PMCID: PMC5820744 DOI: 10.1002/chem.201703609] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Indexed: 01/27/2023]
Abstract
Equipped with excellent hydrocarbon solubility, the lithium hydride surrogate 1-lithium-2-tert-butyl-1,2-dihydropyridine (1tLi) functions as a precatalyst to convert Me2 NH⋅BH3 to [NMe2 BH2 ]2 (89 % conversion) under competitive conditions (2.5 mol %, 60 h, 80 °C, toluene solvent) to that of previously reported LiN(SiMe3 )2 . Sodium and potassium dihydropyridine congeners produce similar high yields of [NMe2 BH2 ]2 but require longer times. Switching the solvent to pyridine induces a remarkable change in the dehydrocoupling product ratio, with (NMe2 )2 BH favoured over [NMe2 BH2 ]2 (e.g., 94 %:2 % for 1tLi). Demonstrating its versatility, precatalyst 1tLi was also successful in promoting hydroboration reactions between pinacolborane and a selection of aldehydes and ketones. Most reactions gave near quantitative conversion to the hydroborated products in 15 minutes, though sterically demanding carbonyl substrates require longer times. The mechanisms of these rare examples of Group 1 metal-catalysed processes are discussed.
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Affiliation(s)
- Ross McLellan
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Samantha A. Orr
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Stuart D. Robertson
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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14
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Soluble aluminum hydrides function as catalysts in deprotonation, insertion, and activation reactions. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.03.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Less RJ, Hanf S, García-Rodríguez R, Bond AD, Wright DS. A [HN(BH═NH)2]2– Dianion, Isoelectronic with a β-Diketiminate. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert J. Less
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Schirin Hanf
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, U.K
- University of Leipzig, Department of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, D-04103 Leipzig, Germany
| | - Raúl García-Rodríguez
- GIR MIOMeT-IU Cinquima-Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel, Delibes, 47011 Valladolid, Spain
| | - Andrew D. Bond
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Dominic S. Wright
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, U.K
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16
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McLellan R, Kennedy AR, Orr SA, Robertson SD, Mulvey RE. Lithium Dihydropyridine Dehydrogenation Catalysis: A Group 1 Approach to the Cyclization of Diamine Boranes. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201610905] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ross McLellan
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; Glasgow G1 1XL UK
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; Glasgow G1 1XL UK
| | - Samantha A. Orr
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; Glasgow G1 1XL UK
| | - Stuart D. Robertson
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; Glasgow G1 1XL UK
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied Chemistry; University of Strathclyde; Glasgow G1 1XL UK
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17
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McLellan R, Kennedy AR, Orr SA, Robertson SD, Mulvey RE. Lithium Dihydropyridine Dehydrogenation Catalysis: A Group 1 Approach to the Cyclization of Diamine Boranes. Angew Chem Int Ed Engl 2016; 56:1036-1041. [PMID: 28000994 PMCID: PMC5396369 DOI: 10.1002/anie.201610905] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Indexed: 11/15/2022]
Abstract
In reactions restricted previously to a ruthenium catalyst, a 1‐lithium‐2‐alkyl‐1,2‐dihydropyridine complex is shown to be a competitive alternative dehydrogenation catalyst for the transformation of diamine boranes into cyclic 1,3,2‐diazaborolidines, which can in turn be smoothly arylated in good yields. This study established the conditions and solvent dependence of the catalysis through NMR monitoring, with mechanistic insight provided by NMR (including DOSY) experiments and X‐ray crystallographic studies of several model lithio intermediates.
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Affiliation(s)
- Ross McLellan
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Samantha A Orr
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Stuart D Robertson
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
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18
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Metters OJ, Flynn SR, Dowds CK, Sparkes HA, Manners I, Wass DF. Catalytic Dehydrocoupling of Amine–Boranes using Cationic Zirconium(IV)–Phosphine Frustrated Lewis Pairs. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02211] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Owen J. Metters
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Stephanie R. Flynn
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Christiana K. Dowds
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Hazel A. Sparkes
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Duncan F. Wass
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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19
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Cui J, Li Y, Ganguly R, Kinjo R. Reactivity Studies on a Diazadiphosphapentalene. Chemistry 2016; 22:9976-85. [PMID: 27283866 DOI: 10.1002/chem.201600935] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Indexed: 11/06/2022]
Abstract
The reactivity of diazadiphosphapentalene 1 towards various substrates was investigated. Reaction of 1 with ammonia-borane resulted in transfer hydrogenolysis concomitantly with the cleavage of a P-N bond. By treatment of 1 with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), oxidation took place at one of the phosphorus atoms of 1, and a P(V) /P(III) mixed-valence derivative was isolated. At the same time, it was demonstrated that only one of the phosphorus atoms in 1 behaves as an electron donor for electrophiles and Lewis acids. The former afforded an intramolecularly coordinated phosphine-phosphenium species, whereas the latter demonstrates the ligand property of 1. UV irradiation induced rearrangement of 1 into another example of another diazadiphosphapentalene.
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Affiliation(s)
- Jingjing Cui
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore, 637371, Singapore
| | - Yongxin Li
- NTU-CBC Crystallography Facility, Nanyang Technological University, Singapore
| | - Rakesh Ganguly
- NTU-CBC Crystallography Facility, Nanyang Technological University, Singapore
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore, 637371, Singapore.
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20
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Mo Z, Rit A, Campos J, Kolychev EL, Aldridge S. Catalytic B-N Dehydrogenation Using Frustrated Lewis Pairs: Evidence for a Chain-Growth Coupling Mechanism. J Am Chem Soc 2016; 138:3306-9. [PMID: 26918906 DOI: 10.1021/jacs.6b01170] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The catalytic dehydrogenation of ammonia- and amine-boranes by a dimethylxanthene-derived frustrated Lewis pair is described. Turnover is facilitated on a thermodynamic basis by the ready release of H2 from the weakly basic PPh2-containing system. In situ NMR studies and the isolation of intermediates from stoichiometric reactions support a mechanism initiated by B-H activation, followed by end-growth BN coupling involving the terminal NH bond of the bound BN fragment and a BH bond of the incoming borane monomer.
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Affiliation(s)
- Zhenbo Mo
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Arnab Rit
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Jesús Campos
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Eugene L Kolychev
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom
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21
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Metal-Free Dehydrogenation of Amine-Boranes by Tunable N-Heterocyclic Iminoboranes. Chemistry 2016; 22:2134-2145. [DOI: 10.1002/chem.201503528] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 01/11/2023]
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22
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Bellham P, Anker MD, Hill MS, Kociok-Köhn G, Mahon MF. The significance of secondary interactions during alkaline earth-promoted dehydrogenation of dialkylamine-boranes. Dalton Trans 2016; 45:13969-78. [DOI: 10.1039/c6dt03185d] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reactions of anilidoimine magnesium n-butyl and calcium bis(trimethylsilyl)amide derivatives with Me2NH·BH3 at 25 °C resulted in the isolation of complexes containing [NMe2BH2NMe2BH3]− and [NMe2BH3]− anions respectively.
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23
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Melen RL. Dehydrocoupling routes to element–element bonds catalysed by main group compounds. Chem Soc Rev 2016; 45:775-88. [DOI: 10.1039/c5cs00521c] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This Tutorial Review focuses on recent applications of main group compounds in the catalytic synthesis of heteronuclear element–element bonds within the p-block.
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24
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Fernández-Millán M, Allen LK, García-Rodríguez R, Bond AD, Mosquera MEG, Wright DS. Formation of a unique ‘unsupported’ hydridic stannate(ii). Chem Commun (Camb) 2016; 52:5993-6. [DOI: 10.1039/c6cc01885h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The reaction of the amido-stannate LiSn(NMe2)3 with the phosphine–borane tBu2PHBH3 gives the SnII hydride [(Me2NH)2Li{BH3P(tBu)2}2Sn(H)] (1); the first example of a hydridic stannate(ii) that is not supported by transition metal or ligand bonding.
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Affiliation(s)
| | - Lucy K. Allen
- Chemistry Department
- Cambridge University
- Cambridge CB2 1EW
- UK
| | | | - Andrew D. Bond
- Chemistry Department
- Cambridge University
- Cambridge CB2 1EW
- UK
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25
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Less RJ, García-Rodríguez R, Simmonds HR, Allen LK, Bond AD, Wright DS. Use of crown ethers to isolate intermediates in ammonia-borane dehydrocoupling reactions. Chem Commun (Camb) 2016; 52:3650-2. [DOI: 10.1039/c6cc00088f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The presence of 18-crown-6 in the Lewis acid-promoted dehydrocoupling reaction of ammonia borane permits isolation of [(THF)BH2NH3]+ cation.
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26
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Stubbs NE, Schäfer A, Robertson APM, Leitao EM, Jurca T, Sparkes HA, Woodall CH, Haddow MF, Manners I. B-Methylated Amine-Boranes: Substituent Redistribution, Catalytic Dehydrogenation, and Facile Metal-Free Hydrogen Transfer Reactions. Inorg Chem 2015; 54:10878-89. [DOI: 10.1021/acs.inorgchem.5b01946] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Naomi E. Stubbs
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - André Schäfer
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | | | - Erin M. Leitao
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - Titel Jurca
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - Hazel A. Sparkes
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | | | - Mairi F. Haddow
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - Ian Manners
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
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27
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Bellham P, Hill MS, Kociok-Köhn G. Alkali metal-mediated dehydrocoupling of Me2NH·BH3. Dalton Trans 2015; 44:12078-81. [PMID: 25789721 DOI: 10.1039/c5dt00178a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bis(trimethylsilyl)amide derivatives of the group 1 elements (Li, Na, K) are competent pre-catalysts for the dehydrocoupling of Me2NH·BH3 via the formation of intermediates containing [H3BNMe2BH2Me2N](-) anions.
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Affiliation(s)
- Peter Bellham
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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28
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Erickson KA, Stelmach JPW, Mucha NT, Waterman R. Zirconium-Catalyzed Amine Borane Dehydrocoupling and Transfer Hydrogenation. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00415] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Karla A. Erickson
- Department of Chemistry, University of Vermont, Burlington, Vermont 05401, United States
| | - John P. W. Stelmach
- Department of Chemistry, University of Vermont, Burlington, Vermont 05401, United States
| | - Neil T. Mucha
- Department of Chemistry, University of Vermont, Burlington, Vermont 05401, United States
| | - Rory Waterman
- Department of Chemistry, University of Vermont, Burlington, Vermont 05401, United States
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29
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Metters OJ, Chapman AM, Robertson APM, Woodall CH, Gates PJ, Wass DF, Manners I. Generation of aminoborane monomers RR'N=BH2 from amine-boronium cations [RR'NH-BH2L](+): metal catalyst-free formation of polyaminoboranes at ambient temperature. Chem Commun (Camb) 2015; 50:12146-9. [PMID: 25177756 DOI: 10.1039/c4cc05145a] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Protonation of MeRNH·BH3 (R = Me or H) with HX (X = B(C6F5)4, OTf, or Cl), followed by immediate, spontaneous H2 elimination, yielded the amine-boronium cation salt [MeRNH·BH2(OEt2)][B(C6F5)4] and related polar covalent analogs, MeRNH·BH2X (X = OTf or Cl). These species can be deprotonated to conveniently generate reactive aminoborane monomers MeRN=BH2 which oligomerize or polymerize; in the case of MeNH2·BH3, the two step process gave poly(N-methylaminoborane), [MeNH-BH2]n.
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Affiliation(s)
- Owen J Metters
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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30
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Allen LK, García-Rodríguez R, Wright DS. Stoichiometric and catalytic Si–N bond formation using the p-block base Al(NMe2)3. Dalton Trans 2015; 44:12112-8. [DOI: 10.1039/c5dt00662g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aluminium reagent Al(NMe2)3 acts as a stoichiometric or catalytic reagent in dehydrogenic Si–N bond formation using amines and silanes. The observed catalytic rate law suggests a mechanism involving the silane component in the deprotonation of the amine.
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31
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Less RJ, Allen LK, Steiner A, Wright DS. Multiple deprotonation of primary aromatic diamines by LiAlH4. Dalton Trans 2015; 44:4141-7. [DOI: 10.1039/c4dt03802a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction of LiAlH4with 1,2-phenylenediamine (1H4) in THF gives [{Al(1H2)}2{Al(1H)2}2][Li(THF)2]4, containing the largest aluminate of its type so far reported.
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32
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Roberts AJ, Clegg W, Kennedy AR, Probert MR, Robertson SD, Hevia E. Two alternative approaches to access mixed hydride-amido zinc complexes: synthetic, structural and solution implications. Dalton Trans 2015; 44:8169-77. [DOI: 10.1039/c5dt00312a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the presence of a bulky N-heterocyclic carbene, Zn(HMDS)2can be converted in to either a mononuclear amido/hydride complex or a tetranuclear hydride rich cluster depending on the hydride source and reaction conditions employed.
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Affiliation(s)
- Andrew J. Roberts
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - William Clegg
- School of Chemistry
- Newcastle University
- Newcastle upon Tyne
- UK
| | - Alan R. Kennedy
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | | | - Stuart D. Robertson
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
| | - Eva Hevia
- WestCHEM
- Department of Pure and Applied Chemistry
- University of Strathclyde
- Glasgow
- UK
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33
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34
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Berben LA. Catalysis by Aluminum(III) Complexes of Non-Innocent Ligands. Chemistry 2014; 21:2734-42. [DOI: 10.1002/chem.201405400] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Indexed: 12/20/2022]
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35
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Wu D, Li Y, Ganguly R, Kinjo R. Synthesis and structural characterization of a C₄ cumulene including 4-pyridylidene units, and its reactivity towards ammonia-borane. Chem Commun (Camb) 2014; 50:12378-81. [PMID: 25185673 DOI: 10.1039/c4cc05886k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel type of C4 cumulene derivative featuring 4-pyridylidene units has been synthesized. X-ray diffraction analysis revealed the presence of consecutive C=C double bonds in the C4 backbone as well as the quinoidal pyridylidene structure. This C4 cumulene derivative readily reacted with ammonia-borane, which resulted in transfer hydrogenation of the central C=C double bond.
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Affiliation(s)
- Di Wu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore 637371, Singapore.
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36
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Nako AE, Gates SJ, Schädel N, White AJP, Crimmin MR. Yttrium-catalysed dehydrocoupling of alanes with amines. Chem Commun (Camb) 2014; 50:9536-8. [DOI: 10.1039/c4cc04484c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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37
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Bellham P, Hill MS, Kociok-Köhn G. Stoichiometric and Catalytic Reactivity of tert-Butylamine–Borane with Calcium Silylamides. Organometallics 2014. [DOI: 10.1021/om500467b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter Bellham
- Department of Chemistry, University of Bath, Claverton
Down, Bath BA2 7AY, U.K
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton
Down, Bath BA2 7AY, U.K
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38
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Johnson HC, Leitao EM, Whittell GR, Manners I, Lloyd-Jones GC, Weller AS. Mechanistic Studies of the Dehydrocoupling and Dehydropolymerization of Amine–Boranes Using a [Rh(Xantphos)]+ Catalyst. J Am Chem Soc 2014; 136:9078-93. [DOI: 10.1021/ja503335g] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Heather C. Johnson
- Department
of Chemistry, Chemistry Research Laboratories, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Erin M. Leitao
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - George R. Whittell
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Ian Manners
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Guy C. Lloyd-Jones
- School
of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom
| | - Andrew S. Weller
- Department
of Chemistry, Chemistry Research Laboratories, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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39
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Stubbs NE, Jurca T, Leitao EM, Woodall CH, Manners I. Polyaminoborane main chain scission using N-heterocyclic carbenes; formation of donor-stabilised monomeric aminoboranes. Chem Commun (Camb) 2014; 49:9098-100. [PMID: 23982163 DOI: 10.1039/c3cc44373f] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The reaction of N-heterocyclic carbenes with polyaminoboranes [MeNH-BH2]n or [NH2-BH2]n at 20 °C led to depolymerisation and the formation of labile, monomeric aminoborane-NHC adducts, RNH-BH2-NHC (R = Me or H); a similar NHC adduct of Ph2N=BCl2 was characterized by single crystal X-ray diffraction.
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Affiliation(s)
- Naomi E Stubbs
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
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40
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Butera V, Russo N, Sicilia E. Hydrogen Release from Dialkylamine-Boranes Promoted by Mg and Ca Complexes: A DFT Analysis of the Reaction Mechanism. Chemistry 2014; 20:5967-76. [DOI: 10.1002/chem.201304329] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Indexed: 11/06/2022]
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41
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He G, Shynkaruk O, Lui MW, Rivard E. Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities. Chem Rev 2014; 114:7815-80. [DOI: 10.1021/cr400547x] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gang He
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Olena Shynkaruk
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Melanie W. Lui
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
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42
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Chong CC, Hirao H, Kinjo R. A Concerted Transfer Hydrogenolysis: 1,3,2-Diazaphospholene-Catalyzed Hydrogenation of NN Bond with Ammonia-Borane. Angew Chem Int Ed Engl 2014; 53:3342-6. [DOI: 10.1002/anie.201400099] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Indexed: 11/05/2022]
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43
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Chong CC, Hirao H, Kinjo R. A Concerted Transfer Hydrogenolysis: 1,3,2-Diazaphospholene-Catalyzed Hydrogenation of NN Bond with Ammonia-Borane. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400099] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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44
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Vance JR, Schäfer A, Robertson APM, Lee K, Turner J, Whittell GR, Manners I. Iron-Catalyzed Dehydrocoupling/Dehydrogenation of Amine–Boranes. J Am Chem Soc 2014; 136:3048-64. [DOI: 10.1021/ja410129j] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- James R. Vance
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - André Schäfer
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | | | - Kajin Lee
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Joshua Turner
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - George R. Whittell
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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45
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46
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Myers TW, Berben LA. Aluminium–ligand cooperation promotes selective dehydrogenation of formic acid to H2 and CO2. Chem Sci 2014. [DOI: 10.1039/c4sc01035c] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Selective conversion of formic acid to H2 and CO2 is catalysed by a molecular aluminum complex. Metal–ligand cooperative interactions stabilize a transition state for an outer-sphere β-hydride abstraction mechanism for catalysis.
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Affiliation(s)
- T. W. Myers
- Department of Chemistry
- University of California Davis
- , USA
| | - L. A. Berben
- Department of Chemistry
- University of California Davis
- , USA
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47
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Less RJ, Simmonds HR, Wright DS. Reactivity and catalytic activity of tert-butoxy-aluminium hydride reagents. Dalton Trans 2014; 43:5785-92. [DOI: 10.1039/c4dt00152d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity and catalytic activity of thetert-butoxy aluminium hydride reagents [(tBuO)xAlH3−x] [x= 1 (1), 2 (2)] and (L)Li[(tBuO)2AlH2] [L = THF (3), 1,4-dioxane (4)] were investigated. These reagents exhibit interesting reactivity and catalyse the dehydrocoupling reaction of the amine–borane Me2NHBH3into the ring compound [Me2NBH2]2.
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Affiliation(s)
- Robert J. Less
- Chemistry Department
- Cambridge University
- Cambridge CB2 1EW, UK
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48
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Less RJ, Simmonds HR, Dane SBJ, Wright DS. Stoichiometric and catalytic reactions of LiAlH4 with Me2NHBH3. Dalton Trans 2013; 42:6337-43. [PMID: 23302951 DOI: 10.1039/c2dt32569a] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structural and in situ NMR spectroscopic studies show that N-H deprotonation, B-N bond cleavage and B-N bond formation can occur in the stoichiometric and catalytic reactions of LiAlH4 with Me2NHBH3.
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Affiliation(s)
- Robert J Less
- Chemistry Department, Cambridge University, Cambridge, UK
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49
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Leitao EM, Jurca T, Manners I. Catalysis in service of main group chemistry offers a versatile approach to p-block molecules and materials. Nat Chem 2013; 5:817-29. [DOI: 10.1038/nchem.1749] [Citation(s) in RCA: 226] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/07/2013] [Indexed: 12/22/2022]
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50
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Sabourin KJ, Malcolm AC, McDonald R, Ferguson MJ, Rivard E. Metal-free dehydrogenation of amine-boranes by an N-heterocyclic carbene. Dalton Trans 2013; 42:4625-32. [PMID: 23358571 DOI: 10.1039/c3dt32988g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The dehydrogenation of primary and secondary amine-boranes (RNH(2)·BH(3) and R(2)NH·BH(3); R = alkyl groups) was studied using the bulky N-heterocyclic carbene IPr (IPr = [(HCNDipp)C:]; Dipp = 2,6-(i)Pr(2)C(6)H(3)) as a stoichiometric dehydrogenation agent. In the case of primary amine-boranes, carbene-bound adducts IPr·BH(2)-NH(R)-BH(3) were obtained in place of the desired polymers [RNH-BH(2)](n). The secondary amine-borane (i)Pr(2)NH·BH(3) participated in dehydrogenation chemistry with IPr to afford the aminoborane [(i)Pr(2)N=BH(2)] and the dihydroaminal IPrH(2) as products. Attempts to induce H(2) elimination from the arylamine-borane DippNH(2)·BH(3) yielded a reaction mixture containing the known species IPr·BH(2)NHDipp, IPr·BH(2)NH(Dipp)-BH(3), free DippNH(2) and IPrH(2). The new hindered aryl-amine borane adduct Ar*NH(2)·BH(3) [Ar* = 2,6-(Ph(2)CH)(2)-4-MeC(6)H(2)] underwent a reaction with IPr to give IPr·BH(3) and free Ar*NH(2), consistent with the presence of a weaker N-B dative bond in Ar*NH(2)·BH(3) relative to its less hindered amine-borane analogues.
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Affiliation(s)
- Kyle J Sabourin
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, AB, Canada T6G 2G2
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