1
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Zhu Y, Gao H, Huang L, Lv Y, Liu P. Highly efficient selective hydrogenation of adiponitrile to hexamethylene diamine over barium and melamine formaldehyde resin-modified nickel-cobalt-based zeolitic imidazolate framework-derived catalyst. J Colloid Interface Sci 2024; 668:120-131. [PMID: 38669990 DOI: 10.1016/j.jcis.2024.04.157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024]
Abstract
In the present study, the catalyst modified with alkaline oxide can enhance the selectivity to primary amines. However, the addition of alkaline oxide inevitably reduces catalytic activity. In this study, NiCo-NC@BaO-MFC catalyst derived from zeolitic imidazolate framework-67, Ba(CH3COO)2, and melamine formaldehyde (MF) resin was prepared and used for the hydrogenation of adiponitrile (ADN) to hexamethylene diamine (HDMA). The carbon layer obtained from the MF resin effectively prevents the interaction between barium (Ba) and the active center, thus improving target product selectivity without decreasing catalytic activity. The results of the density functional theory (DFT) calculation and characterization indicated that the effect of synergy between nickel (Ni) and cobalt (Co) bimetals induces an electron density growth on the Ni surface, bringing the d-band center toward the Fermi surface. Meanwhile, the high electron density of the active center compensates for the electron-deficient state of the carbon atom in -CN, thus improving the catalytic activity. Furthermore, it was found that the introduction of Ba promotes the formation of nucleophilic hydrogen anions, which facilitates the hydrogenation of 6-aminohexylimine (AHIM) to HDMA and inhibits the intramolecular condensation of AHIM, hence improving the selectivity to HDMA. The NiCo-NC@BaO-MFC catalyst gives 98.6 % ADN conversion and 97.2 % selectivity to HDMA in an alkali-free system.
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Affiliation(s)
- Yuqin Zhu
- College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
| | - Hang Gao
- College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
| | - Lei Huang
- College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China; Engineering Research Centre for Chemical Process Simulation and Optimization of Ministry of Education, Xiangtan University, Xiangtan 411105, China; National & Local United Engineering Research Centre for Chemical Process Simulation and Intensification, Xiangtan University, Xiangtan 411105, China
| | - Yang Lv
- College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China; Engineering Research Centre for Chemical Process Simulation and Optimization of Ministry of Education, Xiangtan University, Xiangtan 411105, China; National & Local United Engineering Research Centre for Chemical Process Simulation and Intensification, Xiangtan University, Xiangtan 411105, China.
| | - Pingle Liu
- College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China; Engineering Research Centre for Chemical Process Simulation and Optimization of Ministry of Education, Xiangtan University, Xiangtan 411105, China; National & Local United Engineering Research Centre for Chemical Process Simulation and Intensification, Xiangtan University, Xiangtan 411105, China.
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2
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Žáková A, Saha P, Paparakis A, Zábranský M, Gastelu G, Kukla J, Uranga JG, Hulla M. Hexacoordinated tin complexes catalyse imine hydrogenation with H 2. Chem Commun (Camb) 2024; 60:3287-3290. [PMID: 38421350 DOI: 10.1039/d3cc05878f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Frustrated Lewis pair (FLP) hydrogenation catalysts predominantly use alkyl- and aryl-substituted Lewis acids (LA) that offer a limited number of combinations of substituents, limiting our ability to tune their properties and, ultimately, their reactivity. Nevertheless, main-group complexes have numerous ligands available for such purposes, which could enable us to broaden the range of FLP catalysis. Supporting this hypothesis, we demonstrate here that hexacoordinated tin complexes with Schiff base ligands catalyse imine hydrogenation via activation of H2(g). As shown by hydrogen-deuterium scrambling, [Sn(tBu2Salen)(OTf)2] activated H2(g) at 25 °C and 10 bar of H2. After tuning the ligands, we found that [Sn(Salen)Cl2] was the most efficient imine hydrogenation catalyst despite having the lowest activity in H2(g) activation. Moreover, various imines were hydrogenated in yields up to 98% thereby opening up opportunities for developing novel FLP hydrogenation catalysts based on hexacoordinated LA of main-group elements.
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Affiliation(s)
- Andrea Žáková
- Department of Inorganic Chemistry, Faculty of Science Charles, University Prague, 128 00, Czech Republic.
| | - Pritha Saha
- Department of Inorganic Chemistry, Faculty of Science Charles, University Prague, 128 00, Czech Republic.
| | - Alexandros Paparakis
- Department of Inorganic Chemistry, Faculty of Science Charles, University Prague, 128 00, Czech Republic.
| | - Martin Zábranský
- Department of Inorganic Chemistry, Faculty of Science Charles, University Prague, 128 00, Czech Republic.
| | - Gabriela Gastelu
- Instituto de Investigaciones en Físico-Química Córdoba Universidad Nacional de Córdoba (INFIQC-CONICET), Córdoba, 5000, Argentina
| | - Jaroslav Kukla
- Institute of Environmental Studies, Faculty of Science Charles, University Prague, 128 00, Czech Republic
| | - Jorge G Uranga
- Instituto de Investigaciones en Físico-Química Córdoba Universidad Nacional de Córdoba (INFIQC-CONICET), Córdoba, 5000, Argentina
| | - Martin Hulla
- Department of Inorganic Chemistry, Faculty of Science Charles, University Prague, 128 00, Czech Republic.
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3
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Vrána J, Růžičková Z, Růžička A, Dostál L. Synthesis and reactivity of alkali metal aluminates bearing bis(organoamido)phosphane ligand. Dalton Trans 2023; 52:12623-12631. [PMID: 37610275 DOI: 10.1039/d3dt01859h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
In this study, we report a group of alkali metal aluminates bearing bis(organoamido)phosphane ligand. The starting complex {[PhP(NtBu)2]AlMe2}Li·OEt2 (1) was prepared by stepwise deprotonation of the parent PhP(NHtBu)2 by nBuLi and AlMe3. Further derivatization of aluminate 1 was performed by the virtual substitution of lithium -{[PhP(NtBu)2]AlMe2}K (2), methyl substituents - {[PhP(NtBu)2]AlH2}Li·THF (3), modification of steric bulk and induction effects on the phosphorus atom - {[tBuP(N-2,6-iPr2C6H3)2]AlMe2}Li·(OEt2)2 (4), and phosphorus atom oxidation state {[Ph(Y)P(NtBu)2]AlMe2}Li (Y = O (5), S (6), Se (7), Te (8)). The structure causing non-covalent interactions in 1-4 were evaluated with the help of theoretical calculations and topological analysis ranging from π-electron system-metal to agostic interactions of various types. The further reactions of 1 with various nucleophiles were found to be a versatile tool for the preparation of iminophosphonamides via the formation of P-E bond (E = Si, Ge, Sn, Pb, P, and C) and followed by P(III) → P(V) tautomeric shift.
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Affiliation(s)
- Jan Vrána
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic.
| | - Zdeňka Růžičková
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic.
| | - Aleš Růžička
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic.
| | - Libor Dostál
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic.
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4
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Macdonald PA, Banerjee S, Kennedy AR, van Teijlingen A, Robertson SD, Tuttle T, Mulvey RE. Alkali Metal Dihydropyridines in Transfer Hydrogenation Catalysis of Imines: Amide Basicity versus Hydride Surrogacy. Angew Chem Int Ed Engl 2023; 62:e202304966. [PMID: 37132607 PMCID: PMC10952797 DOI: 10.1002/anie.202304966] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/04/2023]
Abstract
Catalytic reduction of a representative set of imines, both aldimines and ketimines, to amines has been studied using transfer hydrogenation from 1,4-dicyclohexadiene. Unusually, this has been achieved using s-block pre-catalysts, namely 1-metallo-2-tert-butyl-1,2-dihydropyridines, 2-tBuC5 H5 NM, M(tBuDHP), where M=Li-Cs. Reactions have been monitored in C6 D6 and tetrahydrofuran-d8 (THF-d8 ). A definite trend is observed in catalyst efficiency with the heavier alkali metal tBuDHPs outperforming the lighter congeners. In general, Cs(tBuDHP) is the optimal pre-catalyst with, in the best cases, reactions producing quantitative yields of amines in minutes at room temperature using 5 mol % catalyst. Supporting the experimental study, Density Functional Theory (DFT) calculations have also been carried out which reveal that Cs has a pathway with a significantly lower rate determining step than the Li congener. In the postulated initiation pathways DHP can act as either a base or as a surrogate hydride.
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Affiliation(s)
- Peter A. Macdonald
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Sumanta Banerjee
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | | | - Stuart D. Robertson
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Tell Tuttle
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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5
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Liang Y, Luo J, Diskin-Posner Y, Milstein D. Designing New Magnesium Pincer Complexes for Catalytic Hydrogenation of Imines and N-Heteroarenes: H 2 and N-H Activation by Metal-Ligand Cooperation as Key Steps. J Am Chem Soc 2023; 145:9164-9175. [PMID: 37068165 PMCID: PMC10141328 DOI: 10.1021/jacs.3c01091] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Utilization of main-group metals as alternatives to transition metals in homogeneous catalysis has become a hot research area in recent years. However, their application in catalytic hydrogenation is less common due to the difficulty in heterolytic cleavage of the H-H bond. Employing aromatization/de-aromatization metal-ligand cooperation (MLC) highly enhances the H2 activation process, offering an efficient approach for the hydrogenation of unsaturated molecules catalyzed by main-group metals. Herein, we report a series of new magnesium pincer complexes prepared using PNNH-type pincer ligands. The complexes were characterized by NMR and X-ray single-crystal diffraction. Reversible activation of H2 and N-H bonds by MLC employing these pincer complexes was developed. Using the new magnesium complexes, homogeneously catalyzed hydrogenation of aldimines and ketimines was achieved, affording secondary amines in excellent yields. Control experiments and DFT studies reveal that a pathway involving MLC is favorable for the hydrogenation reactions. Moreover, the efficient catalysis was extended to the selective hydrogenation of quinolines and other N-heteroarenes, presenting the first example of hydrogenation of N-heteroarenes homogeneously catalyzed by early main-group metal complexes. This study provides a new strategy for hydrogenation of C═N bonds catalyzed by magnesium compounds and enriches the research of main-group metal catalysis.
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Affiliation(s)
- Yaoyu Liang
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jie Luo
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yael Diskin-Posner
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - David Milstein
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
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6
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Sahoo RK, Patro AG, Sarkar N, Nembenna S. Zinc Catalyzed Hydroelementation (HE; E = B, C, N, and O) of Carbodiimides: Intermediates Isolation and Mechanistic Insights. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Arukela Ganesh Patro
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050, India
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7
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Synthesis and Structural Comparisons of NHC-Alanes. INORGANICS 2022. [DOI: 10.3390/inorganics11010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
N-heterocyclic carbenes (NHCs) are widely used in organometallic chemistry. Here, we examine the role of NHCs in the stabilisation of aluminium hydrides, AlH3, also known as alanes. This includes an assessment of the various synthetic strategies, comparisons of structural parameters and theoretical insight. Based on percent buried volume (%Vbur) parameters, we report the largest and smallest NHC alanes to date, with noted differences in their observed stability in both the solution and solid state.
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8
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Banerjee S, Macdonald PA, Orr SA, Kennedy AR, van Teijlingen A, Robertson SD, Tuttle T, Mulvey RE. Hydrocarbon Soluble Alkali-Metal-Aluminium Hydride Surrog[ATES]. Chemistry 2022; 28:e202201085. [PMID: 35811447 PMCID: PMC9804340 DOI: 10.1002/chem.202201085] [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: 04/08/2022] [Indexed: 01/05/2023]
Abstract
A series of group 1 hydrocarbon-soluble donor free aluminates [AM(t BuDHP)(TMP)Al(i Bu)2 ] (AM=Li, Na, K, Rb) have been synthesised by combining an alkali metal dihydropyridyl unit [(2-t BuC5 H5 N)AM)] containing a surrogate hydride (sp3 C-H) with [(i Bu)2 Al(TMP)]. These aluminates have been characterised by X-ray crystallography and NMR spectroscopy. While the lithium aluminate forms a monomer, the heavier alkali metal aluminates exist as polymeric chains propagated by non-covalent interactions between the alkali metal cations and the alkyldihydropyridyl units. Solvates [(THF)Li(t BuDHP)(TMP)Al(i Bu)2 ] and [(TMEDA)Na(t BuDHP)(TMP)Al(i Bu)2 ] have also been crystallographically characterised. Theoretical calculations show how the dispersion forces tend to increase on moving from Li to Rb, as opposed to the electrostatic forces of stabilization, which are orders of magnitude more significant. Having unique structural features, these bimetallic compounds can be considered as starting points for exploring unique reactivity trends as alkali-metal-aluminium hydride surrog[ATES].
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Affiliation(s)
- Sumanta Banerjee
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Peter A. Macdonald
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Samantha A. Orr
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Alan R. Kennedy
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | | | - Stuart D. Robertson
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Tell Tuttle
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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9
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Zhang G, Zeng H, Zheng S, Neary MC, Dub PA. Markovnikov alcohols via epoxide hydroboration by molecular alkali metal catalysts. iScience 2022; 25:105119. [PMID: 36185366 PMCID: PMC9515598 DOI: 10.1016/j.isci.2022.105119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/29/2022] [Accepted: 09/08/2022] [Indexed: 11/28/2022] Open
Affiliation(s)
- Guoqi Zhang
- Department of Sciences, John Jay College and PhD in Chemistry Program, the Graduate Center of City University of New York, New York, NY 10019, USA
- Corresponding author
| | - Haisu Zeng
- Department of Sciences, John Jay College and PhD in Chemistry Program, the Graduate Center of City University of New York, New York, NY 10019, USA
- Department of Chemistry, Hunter College, City University of New York, New York, NY 10065, USA
| | - Shengping Zheng
- Department of Chemistry, Hunter College, City University of New York, New York, NY 10065, USA
| | - Michelle C. Neary
- Department of Chemistry, Hunter College, City University of New York, New York, NY 10065, USA
| | - Pavel A. Dub
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- Corresponding author
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10
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Pölker J, Schaarschmidt D, Bernauer J, Villa M, Jacobi von Wangelin A. BIAN‐Aluminium‐Catalyzed Imine Hydrogenation. ChemCatChem 2022; 14:e202200144. [PMID: 36032039 PMCID: PMC9401587 DOI: 10.1002/cctc.202200144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/07/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Jennifer Pölker
- University of Hamburg: Universitat Hamburg Dept. of Chemistry GERMANY
| | | | - Josef Bernauer
- University of Hamburg: Universitat Hamburg Dept. of Chemistry GERMANY
| | - Matteo Villa
- University of Regensburg: Universitat Regensburg Dept. of Chemistry GERMANY
| | - Axel Jacobi von Wangelin
- Universitat Hamburg Institute of Inorganic and Applied Chemistry Martin Luther King Pl 6 20146 Hamburg GERMANY
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11
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Qu ZW, Zhu H, Streubel R, Grimme S. C‐H Deprotonation and C=C Hydrogenation of N‐heterocyclic Olefin with Calcium Hydride Complexes: Cooperative Ca‐H‐Ca Bridge versus Terminal Ca‐H bond. ChemCatChem 2022. [DOI: 10.1002/cctc.202200508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Zheng-Wang Qu
- University of Bonn: Rheinische Friedrich-Wilhelms-Universitat Bonn Mulliken Center for Theoretical Chemistry Beringstr. 4 D-53115 Bonn GERMANY
| | - Hui Zhu
- Rheinische Friedrich-Wilhelms-Universitat Bonn Mulliken Center for Theoretical Chemsitry Bonn GERMANY
| | - Rainer Streubel
- University of Bonn: Rheinische Friedrich-Wilhelms-Universitat Bonn Institut für Anorganische Chemie Bonn GERMANY
| | - Stefan Grimme
- University of Bonn: Rheinische Friedrich-Wilhelms-Universitat Bonn Mulliken Center for Theoretical Chemistry Bonn GERMANY
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12
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Evans MJ, Anker MD, Gardiner MG, McMullin CL, Coles MP. Controlling Al- M Interactions in Group 1 Metal Aluminyls ( M = Li, Na, and K). Facile Conversion of Dimers to Monomeric and Separated Ion Pairs. Inorg Chem 2021; 60:18423-18431. [PMID: 34807607 DOI: 10.1021/acs.inorgchem.1c03012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aluminyl compounds [M{Al(NONDipp)}]2 (NONDipp = [O(SiMe2NDipp)2]2-, Dipp = 2,6-iPr2C6H3), which exist as contacted dimeric pairs in both the solution and solid states, have been converted to monomeric ion pairs and separated ion pairs for each of the group 1 metals, M = Li, Na, and K. The monomeric ion pairs contain discrete, highly polarized Al-M bonds between the aluminum and the group 1 metal and have been isolated with monodentate (THF, M = Li and Na) or bidentate (TMEDA, M = Li, Na, and K) ligands at M. The separated ion pairs comprise group 1 cations that are encapsulated by polydentate ligands, rendering the aluminyl anion, [Al(NONDipp)]- "naked". For M = Li, this structure type was isolated as the [Li(TMEDA)2]+ salt directly from a solution of the corresponding contacted dimeric pair in neat TMEDA, while the polydentate [2.2.2]cryptand ligand was used to generate the separated ion pairs for the heavier group 1 metals M = Na and K. This work shows that starting from the corresponding contacted dimeric pairs, the extent of the Al-M interaction in these aluminyl systems can be readily controlled with appropriate chelating reagents.
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Affiliation(s)
- Matthew J Evans
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Kelburn, Wellington 6012, New Zealand
| | - Mathew D Anker
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Kelburn, Wellington 6012, New Zealand
| | - Michael G Gardiner
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | | | - Martyn P Coles
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Kelburn, Wellington 6012, New Zealand
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13
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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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14
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15
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Wiesinger M, Knüpfer C, Elsen H, Mai J, Langer J, Harder S. Heterometallic Mg−Ba Hydride Clusters in Hydrogenation Catalysis. ChemCatChem 2021. [DOI: 10.1002/cctc.202101071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michael Wiesinger
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Christian Knüpfer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jonathan Mai
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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16
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Moskalev MV, Sokolov VG, Koptseva TS, Skatova AA, Bazanov AA, Baranov EV, Fedushkin IL. Reactivity of aluminum hydrides supported with sterically hindered acenaphthene-1,2-diimines towards CO2. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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17
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Qu Z, Zhu H, Grimme S. LiAlH
4
‐catalyzed Imine Hydrogenation with Dihydrogen: New DFT Mechanistic Insights. ChemCatChem 2021. [DOI: 10.1002/cctc.202100674] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Zheng‐Wang Qu
- Mulliken Center for Theoretical Chemistry University of Bonn Beringstr. 4 53115 Bonn Germany
| | - Hui Zhu
- Mulliken Center for Theoretical Chemistry University of Bonn Beringstr. 4 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry University of Bonn Beringstr. 4 53115 Bonn Germany
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18
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Friedrich A, Eyselein J, Langer J, Färber C, Harder S. Cationic Heterobimetallic Mg(Zn)/Al(Ga) Combinations for Cooperative C-F Bond Cleavage. Angew Chem Int Ed Engl 2021; 60:16492-16499. [PMID: 33979476 PMCID: PMC8361950 DOI: 10.1002/anie.202103250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Indexed: 12/14/2022]
Abstract
Low-valent (Me BDI)Al and (Me BDI)Ga and highly Lewis acidic cations in [(tBu BDI)M+ ⋅C6 H6 ][(B(C6 F5 )4 - ] (M=Mg or Zn, Me BDI=HC[C(Me)N-DIPP]2 , tBu BDI=HC[C(tBu)N-DIPP]2 , DIPP=2,6-diisopropylphenyl) react to heterobimetallic cations [(tBu BDI)Mg-Al(Me BDI)+ ], [(tBu BDI)Mg-Ga(Me BDI)+ ] and [(tBu BDI)Zn-Ga(Me BDI)+ ]. These cations feature long Mg-Al (or Ga) bonds while the Zn-Ga bond is short. The [(tBu BDI)Zn-Al(Me BDI)+ ] cation was not formed. Combined AIM and charge calculations suggest that the metal-metal bonds to Zn are considerably more covalent, whereas those to Mg should be described as weak AlI (or GaI )→Mg2+ donor bonds. Failure to isolate the Zn-Al combination originates from cleavage of the C-F bond in the solvent fluorobenzene to give (tBu BDI)ZnPh and (Me BDI)AlF+ which is extremely Lewis acidic and was not observed, but (Me BDI)Al(F)-(μ-F)-(F)Al(Me BDI)+ was verified by X-ray diffraction. DFT calculations show that the remarkably facile C-F bond cleavage follows a dearomatization/rearomatization route.
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Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jonathan Eyselein
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jens Langer
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Christian Färber
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Sjoerd Harder
- Inorganic and Organometallic ChemistryUniversität Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
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19
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Friedrich A, Eyselein J, Langer J, Färber C, Harder S. Cationic Heterobimetallic Mg(Zn)/Al(Ga) Combinations for Cooperative C–F Bond Cleavage. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jonathan Eyselein
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Christian Färber
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Universität Erlangen-Nürnberg Egerlandstrasse 1 91058 Erlangen Germany
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20
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Dub PA, Tkachenko NV. Mechanism of Potassium tert-Butoxide-Catalyzed Ketones Hydrogenation in the Solution Phase. J Phys Chem A 2021; 125:5726-5737. [PMID: 34184903 DOI: 10.1021/acs.jpca.1c02516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanism of ketones homogeneous hydrogenation with t-BuOK in tert-butanol is currently portrayed as the one proceeding via a six-membered [2 + 2 + 2] cyclic transition state involving the H2 molecule, the base, and a ketone. However, the concerted nature of the reaction is inconsistent with a number of experimental observations. Here we reanalyze available experimental data and revise the mechanism of this paradigmatic reaction based on the static and dynamic density functional theory (DFT) calculations in solution phase. In contrast to the gas-phase profile where the overall reaction occurs in two elementary steps, there are three consecutive steps in solution: cleavage of the H-H bond in basic tert-butanol to afford potassium hydride, addition of potassium hydride across the C═O bond of a ketone through the rate-determining transition state, and rapid product formation through K/H exchange. Potassium hydride is therefore an important intermediate of the catalytic process. The free energy profile for the prophetic ester homogeneous hydrogenation with t-BuOK in tert-butanol is also computed herein. The reaction seems to be kinetically possible, but slightly harsher conditions need to be applied, consistent with rate-determining nature of the potassium hydride addition.
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Affiliation(s)
- Pavel A Dub
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Nikolay V Tkachenko
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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21
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Friedrich A, Eyselein J, Elsen H, Langer J, Pahl J, Wiesinger M, Harder S. Cationic Aluminium Complexes as Catalysts for Imine Hydrogenation. Chemistry 2021; 27:7756-7763. [PMID: 33780071 PMCID: PMC8252007 DOI: 10.1002/chem.202100641] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Indexed: 12/14/2022]
Abstract
Strongly Lewis acidic cationic aluminium complexes, stabilized by β–diketiminate (BDI) ligands and free of Lewis bases, have been prepared as their B(C6F5)4− salts and were investigated for catalytic activity in imine hydrogenation. The backbone (R1) and N (R2) substituents on the R1,R2BDI ligand (R1,R2BDI=HC[C(R1)N(R2)]2) influence sterics and Lewis acidity. Ligand bulk increases along the row Me,DIPPBDI<Me,DIPePBDI≈tBu,DIPPBDI<tBu,DIPePBDI; DIPP=2,6‐C(H)Me2‐phenyl, DIPeP=2,6‐C(H)Et2‐phenyl. The Gutmann‐Beckett test showed acceptor numbers of: (tBu,DIPPBDI)AlMe+ 85.6, (tBu,DIPePBDI)AlMe+ 85.9, (Me,DIPPBDI)AlMe+ 89.7, (Me,DIPePBDI)AlMe+ 90.8, (Me,DIPPBDI)AlH+ 95.3. Steric and electronic factors need to be balanced for catalytic activity in imine hydrogenation. Open, highly Lewis acidic, cations strongly coordinate imine rendering it inactive as a Frustrated Lewis Pair (FLP). The bulkiest cations do not coordinate imine but its combination is also not an active catalyst. The cation (tBu,DIPPBDI)AlMe+ shows the best catalytic activity for various imines and is also an active catalyst for the Tishchenko reaction of benzaldehyde to benzylbenzoate. DFT calculations on the mechanism of imine hydrogenation catalysed by cationic Al complexes reveal two interconnected catalytic cycles operating in concert. Hydrogen is activated either by FLP reactivity of an Al⋅⋅⋅imine couple or, after formation of significant quantities of amine, by reaction with an Al⋅⋅⋅amine couple. The latter autocatalytic Al⋅⋅⋅amine cycle is energetically favoured.
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Affiliation(s)
- Alexander Friedrich
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jonathan Eyselein
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jürgen Pahl
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Michael Wiesinger
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
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Gentner TX, Mulvey RE. Alkali-Metal Mediation: Diversity of Applications in Main-Group Organometallic Chemistry. Angew Chem Int Ed Engl 2021; 60:9247-9262. [PMID: 33017511 PMCID: PMC8247348 DOI: 10.1002/anie.202010963] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Indexed: 12/23/2022]
Abstract
Organolithium compounds have been at the forefront of synthetic chemistry for over a century, as they mediate the synthesis of myriads of compounds that are utilised worldwide in academic and industrial settings. For that reason, lithium has always been the most important alkali metal in organometallic chemistry. Today, that importance is being seriously challenged by sodium and potassium, as the alkali-metal mediation of organic reactions in general has started branching off in several new directions. Recent examples covering main-group homogeneous catalysis, stoichiometric organic synthesis, low-valent main-group metal chemistry, polymerization, and green chemistry are showcased in this Review. Since alkali-metal compounds are often not the end products of these applications, their roles are rarely given top billing. Thus, this Review has been written to alert the community to this rising unifying phenomenon of "alkali-metal mediation".
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Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Robert E. Mulvey
- Department of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
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23
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Gentner TX, Kennedy AR, Hevia E, Mulvey RE. Alkali Metal (Li, Na, K, Rb, Cs) Mediation in Magnesium Hexamethyldisilazide [Mg(HMDS)
2
] Catalysed Transfer Hydrogenation of Alkenes. ChemCatChem 2021. [DOI: 10.1002/cctc.202100218] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied Chemistry University of Strathclyde G1 1XL Glasgow UK
| | - Alan R. Kennedy
- Department of Pure and Applied Chemistry University of Strathclyde G1 1XL Glasgow UK
| | - Eva Hevia
- Department für Chemie und Biochemie und Pharmazie Universität Bern Freiestrasse 3 CH-3012 Bern Switzerland
| | - Robert E. Mulvey
- Department of Pure and Applied Chemistry University of Strathclyde G1 1XL Glasgow UK
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24
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Sequential hydroaminomethylation/Pd-catalyzed hydrogenolysis as an atom efficient route to valuable primary and secondary amines. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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25
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Chia CC, Teo YC, Cham N, Ho SYF, Ng ZH, Toh HM, Mézailles N, So CW. Aluminum-Hydride-Catalyzed Hydroboration of Carbon Dioxide. Inorg Chem 2021; 60:4569-4577. [PMID: 33733776 DOI: 10.1021/acs.inorgchem.0c03507] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This study describes the first use of a bis(phosphoranyl)methanido aluminum hydride, [ClC(PPh2NMes)2AlH2] (2, Mes = Me3C6H2), for the catalytic hydroboration of CO2. Complex 2 was synthesized by the reaction of a lithium carbenoid [Li(Cl)C(PPh2NMes)2] with 2 equiv of AlH3·NEtMe2 in toluene at -78 °C. 2 (10 mol %) was able to catalyze the reduction of CO2 with HBpin in C6D6 at 110 °C for 2 days to afford a mixture of methoxyborane [MeOBpin] (3a; yield: 78%, TOF: 0.16 h-1) and bis(boryl)oxide [pinBOBpin] (3b). When more potent [BH3·SMe2] was used instead of HBpin, the catalytic reaction was extremely pure, resulting in the formation of trimethyl borate [B(OMe)3] (3e) [catalytic loading: 1 mol % (10 mol %); reaction time: 60 min (5 min); yield: 97.6% (>99%); TOF: 292.8 h-1 (356.4 h-1)] and B2O3 (3f). Mechanistic studies show that the Al-H bond in complex 2 activated CO2 to form [ClC(PPh2NMes)2Al(H){OC(O)H}] (4), which was subsequently reacted with BH3·SMe2 to form 3e and 3f, along with the regeneration of complex 2. Complex 2 also shows good catalytic activity toward the hydroboration of carbonyl, nitrile, and alkyne derivatives.
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Affiliation(s)
- Cher-Chiek Chia
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Yeow-Chuan Teo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Ning Cham
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Samuel Ying-Fu Ho
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.,Laboratoire Hétérochimie Fondamentale et Appliquée, CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Zhe-Hua Ng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Hui-Min Toh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Nicolas Mézailles
- Laboratoire Hétérochimie Fondamentale et Appliquée, CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Cheuk-Wai So
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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26
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Orr SA, Andrews PC, Blair VL. Main Group Metal-Mediated Transformations of Imines. Chemistry 2021; 27:2569-2588. [PMID: 32761667 DOI: 10.1002/chem.202003108] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/02/2020] [Indexed: 12/20/2022]
Abstract
Main-group-metal-mediated transformations of imines have earned a valued place in the synthetic chemist's toolbox. Their versatility allows the simple preparation of various nitrogen containing compounds. This review will outline the early discoveries including metallation, addition/cyclisation and metathesis pathways, followed by the modern-day use of imines in synthetic methodology. Recent advances in imine C-F activation protocols are discussed, alongside revisiting "classic" imine reactivity from a sustainable perspective. Developments in catalytic methods for hydroelementation of imines have been reviewed, highlighting the importance of s-block metals in the catalytic arena. Whilst stoichiometric transformations in alternative reaction media such as deep eutectic solvents or water have been summarised. The incorporation of imines into flow chemistry has received recent attention and is summarised within.
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Affiliation(s)
- Samantha A Orr
- School of Chemistry, Monash University, Wellington Road, Clayton, Melbourne, VIC, 3800, Australia
| | - Philip C Andrews
- School of Chemistry, Monash University, Wellington Road, Clayton, Melbourne, VIC, 3800, Australia
| | - Victoria L Blair
- School of Chemistry, Monash University, Wellington Road, Clayton, Melbourne, VIC, 3800, Australia
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27
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Pollard VA, Kennedy AR, McLellan R, Ross D, Tuttle T, Mulvey RE. Structurally Defined Ring‐Opening and Insertion of Pinacolborane into Aluminium‐Nitrogen Bonds of Sterically Demanding Dialkylaluminium Amides. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202000919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Victoria A. Pollard
- 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
| | - Ross McLellan
- WestCHEM Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL UK
| | - Duncan Ross
- WestCHEM Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL UK
| | - Tell Tuttle
- 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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28
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Elsen H, Langer J, Ballmann G, Wiesinger M, Harder S. Insights into LiAlH 4 Catalyzed Imine Hydrogenation. Chemistry 2021; 27:401-411. [PMID: 32869898 PMCID: PMC7839755 DOI: 10.1002/chem.202003862] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 08/31/2020] [Indexed: 01/22/2023]
Abstract
Commercial LiAlH4 can be used in catalytic quantities in the hydrogenation of imines to amines with H2 . Combined experimental and theoretical investigations give deeper insight in the mechanism and identifies the most likely catalytic cycle. Activity is lost when Li in LiAlH4 is exchanged for Na or K. Exchanging Al for B or Ga also led to dramatically reduced activities. This indicates a heterobimetallic mechanism in which cooperation between Li and Al is crucial. Potential intermediates on the catalytic pathway have been isolated from reactions of MAlH4 (M=Li, Na, K) and different imines. Depending on the imine, double, triple or quadruple imine insertion has been observed. Prolonged reaction of LiAlH4 with PhC(H)=NtBu led to a side-reaction and gave the double insertion product LiAlH2 [N]2 ([N]=N(tBu)CH2 Ph) which at higher temperature reacts further by ortho-metallation of the Ph ring. A DFT study led to a number of conclusions. The most likely catalyst for hydrogenation of PhC(H)=NtBu with LiAlH4 is LiAlH2 [N]2 . Insertion of a third imine via a heterobimetallic transition state has a barrier of +23.2 kcal mol-1 (ΔH). The rate-determining step is hydrogenolysis of LiAlH[N]3 with H2 with a barrier of +29.2 kcal mol-1 . In agreement with experiment, replacing Li for Na (or K) and Al for B (or Ga) led to higher calculated barriers. Also, the AlH4 - anion showed very high barriers. Calculations support the experimentally observed effects of the imine substituents at C and N: the lowest barriers are calculated for imines with aryl-substituents at C and alkyl-substituents at N.
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Affiliation(s)
- Holger Elsen
- Inorganic and Organometallic ChemistryUniversity Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Jens Langer
- Inorganic and Organometallic ChemistryUniversity Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Gerd Ballmann
- Inorganic and Organometallic ChemistryUniversity Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Michael Wiesinger
- Inorganic and Organometallic ChemistryUniversity Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
| | - Sjoerd Harder
- Inorganic and Organometallic ChemistryUniversity Erlangen-NürnbergEgerlandstrasse 191058ErlangenGermany
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29
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Gentner TX, Mulvey RE. Alkalimetall‐Mediatoren: Vielfältige Anwendungen in der metallorganischen Chemie der Hauptgruppenelemente. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010963] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Thomas X. Gentner
- Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
| | - Robert E. Mulvey
- Department of Pure and Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
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30
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Gil-Negrete JM, Hevia E. Main group bimetallic partnerships for cooperative catalysis. Chem Sci 2020; 12:1982-1992. [PMID: 34163960 PMCID: PMC8179316 DOI: 10.1039/d0sc05116k] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/16/2020] [Indexed: 11/21/2022] Open
Abstract
Over the past decade s-block metal catalysis has undergone a transformation from being an esoteric curiosity to a well-established and consolidated field towards sustainable synthesis. Earth-abundant metals such as Ca, Mg, and Al have shown eye-opening catalytic performances in key catalytic processes such as hydrosilylation, hydroamination or alkene polymerization. In parallel to these studies, s-block mixed-metal reagents have also been attracting widespread interest from scientists. These bimetallic reagents effect many cornerstone organic transformations, often providing enhanced reactivities and better chemo- and regioselectivities than conventional monometallic reagents. Despite a significant number of synthetic advances to date, most efforts have focused primarily on stoichiometric transformations. Merging these two exciting areas of research, this Perspective Article provides an overview on the emerging concept of s/p-block cooperative catalysis. Showcasing recent contributions from several research groups across the world, the untapped potential that these systems can offer in catalytic transformations is discussed with special emphasis placed on how synergistic effects can operate and the special roles played by each metal in these transformations. Advancing the understanding of the ground rules of s-block cooperative catalysis, the application of these bimetalic systems in a critical selection of catalytic transformations encompassing hydroamination, cyclisation, hydroboration to C-C bond forming processes are presented as well as their uses in important polymerization reactions.
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Affiliation(s)
- Jose M Gil-Negrete
- Department für Chemie und Biochemie, Universität Bern CH3012 Bern Switzerland
| | - Eva Hevia
- Department für Chemie und Biochemie, Universität Bern CH3012 Bern Switzerland
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31
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Nasrollahzadeh M, Shafiei N, Maham M, Issaabadi Z, Nezafat Z, Varma RS. Polymer surfaces adorning ligand-coordinated palladium for hydrogenation reactions. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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32
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Panda TK, Banerjee I, Sagar S. Alkali Metal–Promoted Facile Synthesis of Secondary Amines from Imines and Carbodiimides. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5765] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tarun K. Panda
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi Sangareddy Telangana 502285 India
| | - Indrani Banerjee
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi Sangareddy Telangana 502285 India
| | - Shweta Sagar
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi Sangareddy Telangana 502285 India
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33
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Elsen H, Langer J, Wiesinger M, Harder S. Alkaline Earth Metal Aluminates as Catalysts for Imine Hydrogenation. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00226] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Holger Elsen
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Michael Wiesinger
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
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34
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Sarkar N, Bera S, Nembenna S. Aluminum-Catalyzed Selective Hydroboration of Nitriles and Alkynes: A Multifunctional Catalyst. J Org Chem 2020; 85:4999-5009. [DOI: 10.1021/acs.joc.0c00234] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050 India
| | - Subhadeep Bera
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050 India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar 752 050 India
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35
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Zhang XY, Du HZ, Zhai DD, Guan BT. Combined KH/alkaline-earth metal amide catalysts for hydrogenation of alkenes. Org Chem Front 2020. [DOI: 10.1039/d0qo00383b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Breaking saline KH: The combined KH/alkaline-earth metal amide catalysts display much better catalytic activity than their components in the hydrogenation of alkenes, suggesting the degradation and activation of saline KH with the metal amides.
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Affiliation(s)
- Xiang-Yu Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Hui-Zhen Du
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Dan-Dan Zhai
- Department of chemistry
- Fudan University
- Shanghai 200438
- China
| | - Bing-Tao Guan
- Department of chemistry
- Fudan University
- Shanghai 200438
- China
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36
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Kannan R, Chambenahalli R, Kumar S, Krishna A, Andrews AP, Jemmis ED, Venugopal A. Organoaluminum cations for carbonyl activation. Chem Commun (Camb) 2019; 55:14629-14632. [PMID: 31746857 DOI: 10.1039/c9cc08272g] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In search of stable, yet reactive aluminum Lewis acids, we have isolated an organoaluminum cation, [(Me2NC6H4)2Al(C4H8O)2]+, coordinated with two labile tetrahydrofuran ligands. Its catalytic performance in aldehyde dimerization reveals turn-over frequencies reaching up to 6000 h-1, exceeding that of the reported main group catalysts. The cation is further demonstrated to catalyze hydroelementation of ketones. Mechanistic investigations reveal that aldehyde dimerization and ketone hydrosilylation occur through carbonyl activation.
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Affiliation(s)
- Ramkumar Kannan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram 695551, India.
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37
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Falconer RL, Nichol GS, Cowley MJ. Flexible Coordination of N,P-Donor Ligands in Aluminum Dimethyl and Dihydride Complexes. Inorg Chem 2019; 58:11439-11448. [PMID: 31411460 PMCID: PMC6727621 DOI: 10.1021/acs.inorgchem.9b01061] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Aluminum hydrides, once a simple
class of stoichiometric reductants, are now emerging as powerful catalysts
for organic transformations such as the hydroboration or hydrogenation
of unsaturated bonds. The coordination chemistry of aluminum hydrides
supported by P donors is relatively underexplored. Here, we report
aluminum dihydride and dimethyl complexes supported by amidophosphine
ligands and study their coordination behavior in solution and in the
solid state. All complexes exist as κ2-N,P complexes
in the solid state. However, we find that for amidophosphine ligands
bearing bulky aminophosphine donors, aluminum dihydride and dimethyl
complexes undergo a “ligand-slip” rearrangement in solution
to generate κ2-N,N complexes. Thus, importantly for
catalytic activity, we find that the coordination behavior of the
P donor can be modulated by controlling its steric bulk. We show that
the reported aluminum hydrides catalyze the hydroboration of alkynes
by HBPin and that the variable coordination mode exhibited by the
amidophosphine ligand modulates the catalytic activity. Mixed N,P-donor-stabilized
aluminum dimethyl and dihydride complexes were synthesized. Variation
of the ligand’s phosphine donor group enables control over
the coordination mode at aluminum.
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Affiliation(s)
- Rosalyn L Falconer
- School of Chemistry , University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , U.K
| | - Gary S Nichol
- School of Chemistry , University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , U.K
| | - Michael J Cowley
- School of Chemistry , University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , U.K
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38
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Zhai DD, Du HZ, Zhang XY, Liu YF, Guan BT. Potassium Yttrium Ate Complexes: Synergistic Effect Enabled Reversible H2 Activation and Catalytic Hydrogenation. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Dan-Dan Zhai
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Hui-Zhen Du
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xiang-Yu Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yu-Feng Liu
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Bing-Tao Guan
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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39
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Pollard VA, Young A, McLellan R, Kennedy AR, Tuttle T, Mulvey RE. Lithium-Aluminate-Catalyzed Hydrophosphination Applications. Angew Chem Int Ed Engl 2019; 58:12291-12296. [PMID: 31260154 PMCID: PMC6771573 DOI: 10.1002/anie.201906807] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Indexed: 01/23/2023]
Abstract
Synthesized, isolated, and characterized by X‐ray crystallography and NMR spectroscopic studies, lithium phosphidoaluminate iBu3AlPPh2Li(THF)3 has been tested as a catalyst for hydrophosphination of alkynes, alkenes, and carbodiimides. Based on the collective evidence of stoichiometric reactions, NMR monitoring studies, kinetic analysis, and DFT calculations, a mechanism involving deprotonation, alkyne insertion, and protonolysis is proposed for the [iBu3AlHLi]2 aluminate catalyzed hydrophosphination of alkynes with diphenylphosphine. This study enhances further the development of transition‐metal‐free, atom‐economical homogeneous catalysis using common sustainable main‐group metals.
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Affiliation(s)
- Victoria A Pollard
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Allan Young
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - 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
| | - Tell Tuttle
- 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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40
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Pollard VA, Young A, McLellan R, Kennedy AR, Tuttle T, Mulvey RE. Lithium‐Aluminate‐Catalyzed Hydrophosphination Applications. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906807] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Victoria A. Pollard
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Allan Young
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Ross McLellan
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Alan R. Kennedy
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Tell Tuttle
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Robert E. Mulvey
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
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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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42
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Fairley M, Davin L, Hernán-Gómez A, García-Álvarez J, O'Hara CT, Hevia E. s-Block cooperative catalysis: alkali metal magnesiate-catalysed cyclisation of alkynols. Chem Sci 2019; 10:5821-5831. [PMID: 31293771 PMCID: PMC6568277 DOI: 10.1039/c9sc01598a] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/26/2019] [Indexed: 01/04/2023] Open
Abstract
Through mixed metal cooperativity, alkali metal magnesiates efficiently catalyse the cyclisation of alkynols.
Mixed s-block metal organometallic reagents have been successfully utilised in the catalytic intramolecular hydroalkoxylation of alkynols. This success has been attributed to the unique manner in which these reagents can overcome the challenges of the reaction: namely OH activation and coordination to and then addition across a C
Created by potrace 1.16, written by Peter Selinger 2001-2019
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C bond. In order to optimise the reaction conditions and to garner vital catalytic system requirements, a series of alkali metal magnesiates were enlisted for the catalytic intramolecular hydroalkoxylation of 4-pentynol. In a prelude to the main investigation, the homometallic magnesium dialkyl reagent MgR2 (where R = CH2SiMe3) was utilised. This reagent was unsuccessful in cyclising the alcohol into 2-methylenetetrahydrofuran 2a or 5-methyl-2,3-dihydrofuran 2b, even in the presence of multidentate Lewis donor molecules such as N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA). Alkali metal magnesiates MIMgR3 (when MI = Li, Na or K) performed the cyclisation unsatisfactorily both in the absence/presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) or PMDETA. When higher-order magnesiates (i.e., MI2MgR4) were employed, in general a marked increase in yield was observed for MI = Na or K; however, the reactions were still sluggish with long reaction times (22–36 h). A major improvement in the catalytic activity of the magnesiates was observed when the crown ether molecule 15-crown-5 was combined with sodium magnesiate Na2MgR4(TMEDA)2 furnishing yields of 87% with 2a : 2b ratios of 95 : 5 after 5 h. Similar high yields of 88% with 2a : 2b ratios of 90 : 10 after 3 h were obtained combining 18-crown-6 with potassium magnesiate K2MgR4(PMDETA)2. Having optimised these systems, substrate scope was examined to probe the range and robustness of 18-crown-6/K2MgR4(PMDETA)2 as a catalyst. A wide series of alkynols, including terminal and internal alkynes which contain a variety of potentially reactive functional groups, were cyclised. In comparison to previously reported monometallic systems, bimetallic 18-crown-6/K2MgR4(PMDETA)2 displays enhanced reactivity towards internal alkynol-cyclisation. Kinetic studies revealed an inhibition effect of substrate on the catalysts via adduct formation and requiring dissociation prior to the rate limiting cyclisation step.
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Affiliation(s)
- Michael Fairley
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Laia Davin
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Alberto Hernán-Gómez
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Joaquín García-Álvarez
- Departamento de Química Orgánica e Inorgánica , Facultad de Química , Universidad de Oviedo , E-33071 Oviedo , Spain
| | - Charles T O'Hara
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
| | - Eva Hevia
- WestCHEM , Department of Pure and Applied Chemistry , University of Strathclyde , Glasgow , G1 1XL , UK .
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43
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Abstract
Abstract
This review focuses on the selective catalytic hydrogenation of nitriles to primary amines both homogeneously and heterogeneously with transition metal-based catalysts in the view of nitriles as hydrogen carriers. Nitriles can be reduced with two equivalents of H2 to primary amines, thus having a great potential to serve as liquid organic hydrogen carriers (LOHCs) for hydrogen storage. Imines are intermediates in the hydrogenation of nitriles to amines, thus they can also serve as potential LOHCs, however with a lower hydrogen storage capacity (HSC).
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44
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Robertson SD, Uzelac M, Mulvey RE. Alkali-Metal-Mediated Synergistic Effects in Polar Main Group Organometallic Chemistry. Chem Rev 2019; 119:8332-8405. [DOI: 10.1021/acs.chemrev.9b00047] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Stuart D. Robertson
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, U.K
| | - Marina Uzelac
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, U.K
| | - Robert E. Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, U.K
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45
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Elliott DC, Marti A, Mauleón P, Pfaltz A. H
2
Activation by Non‐Transition‐Metal Systems: Hydrogenation of Aldimines and Ketimines with LiN(SiMe
3
)
2. Chemistry 2019; 25:1918-1922. [DOI: 10.1002/chem.201805549] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Daniel C. Elliott
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Alex Marti
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Pablo Mauleón
- Department of Organic ChemistryUniversidad Autónoma de Madrid c/ Fco. Tomás y Valiente 7, Cantoblanco 28049 Madrid Spain
| | - Andreas Pfaltz
- Department of ChemistryUniversity of Basel St. Johanns-Ring 19 4056 Basel Switzerland
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46
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Lam J, Szkop KM, Mosaferi E, Stephan DW. FLP catalysis: main group hydrogenations of organic unsaturated substrates. Chem Soc Rev 2019; 48:3592-3612. [PMID: 30178796 DOI: 10.1039/c8cs00277k] [Citation(s) in RCA: 235] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This article is focused on recent developments in main group mediated hydrogenation chemistry and catalysis using "frustrated Lewis pairs" (FLPs). The broading range of substrates and catalyst systems is reviewed and the advances in catalytic reductions and the development of stereoselective, asymmetric reductions made since 2012 is considered.
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Affiliation(s)
- Jolie Lam
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario M5S3H6, Canada.
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47
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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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48
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Pollard VA, Fuentes MÁ, Kennedy AR, McLellan R, Mulvey RE. Comparing Neutral (Monometallic) and Anionic (Bimetallic) Aluminum Complexes in Hydroboration Catalysis: Influences of Lithium Cooperation and Ligand Set. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806168] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Victoria A. Pollard
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - M. Ángeles Fuentes
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Alan R. Kennedy
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Ross McLellan
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
| | - Robert E. Mulvey
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of Strathclyde Glasgow G1 1XL UK
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49
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Pollard VA, Fuentes MÁ, Kennedy AR, McLellan R, Mulvey RE. Comparing Neutral (Monometallic) and Anionic (Bimetallic) Aluminum Complexes in Hydroboration Catalysis: Influences of Lithium Cooperation and Ligand Set. Angew Chem Int Ed Engl 2018; 57:10651-10655. [PMID: 29906339 PMCID: PMC6099445 DOI: 10.1002/anie.201806168] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Indexed: 12/14/2022]
Abstract
Bimetallic lithium aluminates and neutral aluminum counterparts are compared as catalysts in hydroboration reactions with aldehydes, ketones, imines and alkynes. Possessing Li–Al cooperativity, ate catalysts are found to be generally superior. Catalytic activity is also influenced by the ligand set, alkyl and/or amido. Devoid of an Al−H bond, iBu2Al(TMP) operates as a masked hydride reducing benzophenone through a β‐Η transfer process. This catalyst library therefore provides an entry point into the future design of Al catalysts targeting substrate specific transformations.
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Affiliation(s)
- Victoria A Pollard
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - M Ángeles Fuentes
- 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
| | - Ross McLellan
- 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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50
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