1
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Sarkar N, Kumar Sahoo R, Nembenna S. Aluminium-Catalyzed Selective Hydroboration of Esters and Epoxides to Alcohols: C-O Bond Activation. Chemistry 2023; 29:e202203023. [PMID: 36226774 DOI: 10.1002/chem.202203023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 11/07/2022]
Abstract
In this work, the molecular aluminium dihydride complex bearing an N, N'-chelated conjugated bis-guanidinate (CBG) ligand is used as a catalyst for reducing a wide range of aryl and alkyl esters with good tolerance of alkene (C=C), alkyne (C≡C), halides (Cl, Br, I and F), nitrile (C≡N), and nitro (NO2 ) functionalities. Further, we investigated the catalytic application of aluminium dihydride in the C-O bond cleavage of alkyl and aryl epoxides into corresponding branched Markovnikov ring-opening products. In addition, the chemoselective intermolecular reduction of esters over other reducible functional groups, such as amides and alkenes, has been established. Intermediates are isolated and characterized by NMR and HRMS studies, which confirm the probable catalytic cycles for the hydroboration of esters and epoxides.
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Affiliation(s)
- Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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2
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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] [Grants] [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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3
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Rej S, Das A, Panda TK. Overview of Regioselective and Stereoselective Catalytic Hydroboration of Alkynes. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100950] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Supriya Rej
- Institut für Chemie Technische Universität Berlin Berlin, Strasse des 17. Juni 115 10623 Berlin Germany
| | - Amrita Das
- Department of Applied Chemistry Faculty of Engineering Osaka University 565-0871 Suita Osaka Japan
| | - Tarun K. Panda
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi 502285 Sangareddy Telangana India
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4
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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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5
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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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Sahoo RK, Sarkar N, Nembenna S. Zinc Hydride Catalyzed Chemoselective Hydroboration of Isocyanates: Amide Bond Formation and C=O Bond Cleavage. Angew Chem Int Ed Engl 2021; 60:11991-12000. [PMID: 33638314 DOI: 10.1002/anie.202100375] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/16/2021] [Indexed: 12/15/2022]
Abstract
Herein, a remarkable conjugated bis-guanidinate (CBG) supported zinc hydride, [{LZnH}2 ; L={(ArHN)(ArN)-C=N-C=(NAr)(NHAr); Ar=2,6-Et2 -C6 H3 }] (I) catalyzed partial reduction of heteroallenes via hydroboration is reported. A large number of aryl and alkyl isocyanates, including electron-donating and withdrawing groups, undergo reduction to obtain selectively N-boryl formamide, bis(boryl) hemiaminal and N-boryl methyl amine products. The compound I effectively catalyzes the chemoselective reduction of various isocyanates, in which the construction of the amide bond occurs. Isocyanates undergo a deoxygenation hydroboration reaction, in which the C=O bond cleaves, leading to N-boryl methyl amines. Several functionalities such as nitro, cyano, halide, and alkene groups are well-tolerated. Furthermore, a series of kinetic, control experiments and structurally characterized intermediates suggest that the zinc hydride species are responsible for all reduction steps and breaking the C=O bond.
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Affiliation(s)
- Rajata Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Nabin Sarkar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
| | - Sharanappa Nembenna
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Homi Bhabha National Institute (HBNI), Bhubaneswar, 752050, India
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7
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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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8
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Zinc Hydride Catalyzed Chemoselective Hydroboration of Isocyanates: Amide Bond Formation and C=O Bond Cleavage. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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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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10
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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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11
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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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12
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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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13
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Whitelaw MT, Kennedy AR, Mulvey RE. Structural Similarity in a Series of Alkali Metal Aluminates with Heteroleptic
tert
‐Butoxide–Isobutyl Ligand Sets. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Michael T. Whitelaw
- WestCHEM Department of Pure and Applied Chemistry University of Strathclyde 295 Cathedral Street G1 1XL Glasgow U.K
| | - Alan R. Kennedy
- WestCHEM Department of Pure and Applied Chemistry University of Strathclyde 295 Cathedral Street G1 1XL Glasgow U.K
| | - R. E. Mulvey
- WestCHEM Department of Pure and Applied Chemistry University of Strathclyde 295 Cathedral Street G1 1XL Glasgow U.K
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14
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Stanford MW, Bismuto A, Cowley MJ. Silyl Anion Initiated Hydroboration of Aldehydes and Ketones. Chemistry 2020; 26:9855-9858. [PMID: 32304609 PMCID: PMC7496802 DOI: 10.1002/chem.202000897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Indexed: 11/09/2022]
Abstract
Hydroboration is an emerging method for mild and selective reduction of carbonyl compounds. Typically, transition-metal or reactive main-group hydride catalysts are used in conjunction with a mild reductant such as pinacolborane. The reactivity of the main-group catalysts is a consequence of the nucleophilicity of their hydride ligands. Silicon hydrides are significantly less reactive and are therefore not efficient hydroboration catalysts. Here, a readily prepared silyl anion is reported to be an effective initiator for the reduction of aldehydes and ketones requiring mild conditions, low catalyst loadings and with a good substrate scope. The silyl anion it is shown to activate HBpin to generate a reactive borohydride in situ which reacts with aldehydes and ketones to afford the hydroboration product.
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Affiliation(s)
- Martin W. Stanford
- School of ChemistryUniversity of EdinburghJoseph Black Building, David Brewster RoadEdinburghEH9, 3FJUnited Kingdom
| | - Alessandro Bismuto
- School of ChemistryUniversity of EdinburghJoseph Black Building, David Brewster RoadEdinburghEH9, 3FJUnited Kingdom
| | - Michael J. Cowley
- School of ChemistryUniversity of EdinburghJoseph Black Building, David Brewster RoadEdinburghEH9, 3FJUnited Kingdom
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15
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Sarkar N, Mahato M, Nembenna S. Palladium‐Catalyzed Selective Reduction of Carbonyl Compounds. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000310] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Nabin Sarkar
- School of Chemical Sciences National Institute of Science Education and Research (NISER) Homi Bhabha National Institute (HBNI) 752050 Bhubaneswar India
| | - Mamata Mahato
- School of Chemical Sciences National Institute of Science Education and Research (NISER) Homi Bhabha National Institute (HBNI) 752050 Bhubaneswar India
| | - Sharanappa Nembenna
- School of Chemical Sciences National Institute of Science Education and Research (NISER) Homi Bhabha National Institute (HBNI) 752050 Bhubaneswar India
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16
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Kumar GS, Harinath A, Narvariya R, Panda TK. Homoleptic Zinc‐Catalyzed Hydroboration of Aldehydes and Ketones in the Presence of HBpin. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.201901276] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Gobbilla Sai Kumar
- Department of Chemistry Indian Institute of Technology Hyderabad, Kandi ‐502 285 Sangareddy Telangana India
| | - Adimulam Harinath
- Department of Chemistry Indian Institute of Technology Hyderabad, Kandi ‐502 285 Sangareddy Telangana India
| | - Rajrani Narvariya
- Department of Chemistry Indian Institute of Technology Hyderabad, Kandi ‐502 285 Sangareddy Telangana India
| | - Tarun K. Panda
- Department of Chemistry Indian Institute of Technology Hyderabad, Kandi ‐502 285 Sangareddy Telangana India
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17
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Liu X, Ming W, Friedrich A, Kerner F, Marder TB. Copper-Catalyzed Triboration of Terminal Alkynes Using B 2 pin 2 : Efficient Synthesis of 1,1,2-Triborylalkenes. Angew Chem Int Ed Engl 2020; 59:304-309. [PMID: 31502712 PMCID: PMC6972586 DOI: 10.1002/anie.201908466] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/31/2019] [Indexed: 02/04/2023]
Abstract
We report herein the catalytic triboration of terminal alkynes with B2 pin2 (bis(pinacolato)diboron) using readily available Cu(OAc)2 and Pn Bu3 . Various 1,1,2-triborylalkenes, a class of compounds that have been demonstrated to be potential matrix metalloproteinase (MMP-2) inhibitors, were obtained directly in moderate to good yields. The process features mild reaction conditions, a broad substrate scope, and good functional group tolerance. This copper-catalyzed reaction can be conducted on a gram scale to produce the corresponding 1,1,2-triborylalkenes in modest yields. The utility of these products was demonstrated by further transformations of the C-B bonds to prepare gem-dihaloborylalkenes (F, Cl, Br), monohaloborylalkenes (Cl, Br), and trans-diaryldiborylalkenes, which serve as important synthons and have previously been challenging to prepare.
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Affiliation(s)
- Xiaocui Liu
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Wenbo Ming
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Florian Kerner
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Todd B. Marder
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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18
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Liu X, Ming W, Friedrich A, Kerner F, Marder TB. Kupfer‐katalysierte Triborierung terminaler Alkine mit B
2
pin
2
: Effiziente Synthese von 1,1,2‐Triborylalkenen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908466] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Xiaocui Liu
- Institut für Anorganische Chemie und Institut für Nachhaltige Chemie & Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Wenbo Ming
- Institut für Anorganische Chemie und Institut für Nachhaltige Chemie & Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Alexandra Friedrich
- Institut für Anorganische Chemie und Institut für Nachhaltige Chemie & Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Florian Kerner
- Institut für Anorganische Chemie und Institut für Nachhaltige Chemie & Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Todd B. Marder
- Institut für Anorganische Chemie und Institut für Nachhaltige Chemie & Katalyse mit Bor Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
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Pandey VK, Donthireddy SNR, Rit A. Catalyst-Free and Solvent-Free Facile Hydroboration of Imines. Chem Asian J 2019; 14:3255-3258. [PMID: 31430049 DOI: 10.1002/asia.201901016] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/19/2019] [Indexed: 11/06/2022]
Abstract
A facile process for the catalyst-free and solvent-free hydroboration of aromatic as well as heteroaromatic imines is reported. This atom-economic methodology is scalable, compatible with sterically and electronically diverse imines, displaying excellent tolerance towards various functional groups, and works efficiently at ambient temperature in most of the cases, affording secondary amines in good to excellent yield after hydrolysis.
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Affiliation(s)
- Vipin K Pandey
- Department of Chemistry, Indian Institute of Technology Madras, Chennai-, 600036, India
| | | | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology Madras, Chennai-, 600036, India
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20
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Shen Q, Ma X, Li W, Liu W, Ding Y, Yang Z, Roesky HW. Organoaluminum Compounds as Catalysts for Monohydroboration of Carbodiimides. Chemistry 2019; 25:11918-11923. [PMID: 31291029 PMCID: PMC6771511 DOI: 10.1002/chem.201902000] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/24/2019] [Indexed: 11/26/2022]
Abstract
The effective catalytic activity of organoaluminum compounds for the monohydroboration of carbodiimides has been demonstrated. Two aluminum complexes, 2 and 3, were synthesized and characterized. The efficient catalytic performances of four aluminum hydride complexes L1 AlH2 (L1 =HC(CMeNAr)2 , Ar=2,6-Et2 C6 H3 ; 1), L2 AlH2 (NMe3 ) (L2 =o-C6 H4 F(CH=N-Ar), Ar=2,6-Et2 C6 H3 ; 2), L3 AlH (L3 =2,6-bis(1-methylethyl)-N-(2-pyridinylmethylene)phenylamine; 3), and L4 AlH(NMe3 ) (L4 =o-C6 H4 (N-Dipp)(CH=N-Dipp), Dipp=2,6-iPr2 C6 H3 ; 4), and an aluminum alkyl complex L1 AlMe2 (5) were used for the monohydroboration of carbodiimides investigated under solvent-free and mild conditions. Compounds 1-3 and 5 can produce monohydroborated N-borylformamidine, whereas 4 can afford the C-borylformamidine product. A suggested mechanism of this reaction was explored, and the aluminum formamidinate compound 6 was characterized by single-crystal X-ray, also a stoichiometric reaction was investigated.
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Affiliation(s)
- Qiumiao Shen
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Xiaoli Ma
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Wenling Li
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Wenqing Liu
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Yi Ding
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Zhi Yang
- School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081P. R. China
| | - Herbert W. Roesky
- Institute of Inorganic ChemistryGeorg-August-Universität GöttingenTammannstrasse 437077GöttingenGermany
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21
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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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22
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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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