1
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Zhao H, Ravn AK, Haibach MC, Engle KM, Johansson Seechurn CCC. Diversification of Pharmaceutical Manufacturing Processes: Taking the Plunge into the Non-PGM Catalyst Pool. ACS Catal 2024; 14:9708-9733. [PMID: 38988647 PMCID: PMC11232362 DOI: 10.1021/acscatal.4c01809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 07/12/2024]
Abstract
Recent global events have led to the cost of platinum group metals (PGMs) reaching unprecedented heights. Many chemical companies are therefore starting to seriously consider and evaluate if and where they can substitute PGMs for non-PGMs in their catalytic processes. This review covers recent highly relevant applications of non-PGM catalysts in the modern pharmaceutical industry. By highlighting these selected successful examples of non-PGM-catalyzed processes from the literature, we hope to emphasize the enormous potential of non-PGM catalysis and inspire further development within this field to enable this technology to progress toward manufacturing processes. We also present some historical contexts and review the perceived advantages and challenges of implementing non-PGM catalysts in the pharmaceutical manufacturing environment.
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Affiliation(s)
- Hui Zhao
- Sinocompound
Catalysts, Building C,
Bonded Area Technology Innovation Zone, Zhangjiagang, Jiangsu 215634, China
| | - Anne K. Ravn
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Michael C. Haibach
- Process
Research and Development, AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Keary M. Engle
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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2
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Rajput S, Sahoo RK, Sarkar N, Nembenna S. Gallium Hydride-Catalyzed Selective Hydroboration of Unsaturated Organic Substrates. Chempluschem 2024; 89:e202300737. [PMID: 38437065 DOI: 10.1002/cplu.202300737] [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: 12/13/2023] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 03/06/2024]
Abstract
The first examples of tetrasubstituted conjugated bis-guanidinate (CBG) supported monomeric and thermally stable gallium dihalides [LGaX2], (X=Cl (Ga-Cl), I (Ga-I)) and dihydride (Ga-H) [LGaH2] (where L={(ArHN)(ArN)-C=N-C=(NAr)(NHAr)}; Ar=2,6-Et2-C6H3) compounds are reported. The reaction of in situ generated LLi with 1.0 equiv. GaX3 (X=Cl, I) afforded compounds Ga-Cl and Ga-I. The reaction between Ga-Cl and Li[HBEt3] in benzene yielded the dihydride compound Ga-H. All reported compounds (Ga-Cl, Ga-I, and Ga-H) were characterized by NMR, HRMS, and single-crystal X-ray diffraction studies. Ga-H was probed for the hydroboration of carbodiimides (CDI), isocyanates, and isothiocyanates with HBpin. Compound Ga-H was also found effective for the catalytic hydroboration of imines, nitriles, alkynes, esters, and formates, affording the corresponding products in quantitative yields. Stoichiometric reactions with a CDI were performed to establish the catalytic cycle.
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Affiliation(s)
- Sagrika Rajput
- 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
| | - 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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3
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Kumar R, Mahata B, Gayathridevi S, Vipin Raj K, Vanka K, Sen SS. Lanthanide Mimicking by Magnesium for Oxazolidinone Synthesis. Chemistry 2024; 30:e202303478. [PMID: 37897110 DOI: 10.1002/chem.202303478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 10/29/2023]
Abstract
In the last decade, magnesium complexes have emerged as a viable alternative to transition-metal catalysts for the hydrofunctionalization of unsaturated bonds. However, their potential for advanced catalytic reactions has not been thoroughly investigated. To address this gap, we have developed a novel magnesium amide compound (3) using a PNP framework that is both bulky and flexible. Our research demonstrates that compound 3 can effectively catalyze the synthesis of biologically significant oxazolidinone derivatives. This synthesis involves a tandem reaction of hydroalkoxylation and cyclohydroamination of isocyanate using propargyl alcohol. Furthermore, we conducted comprehensive theoretical calculations to gain insights into the reaction mechanism. It is important to note that these types of transformations have not been reported for magnesium and would significantly enhance the catalytic portfolio of the 7th most abundant element.
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Affiliation(s)
- Rohit Kumar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Biplab Mahata
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - S Gayathridevi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - K Vipin Raj
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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4
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Janda BA, Tran JA, Chang DK, Nerhood GC, Maduka Ogba O, Liberman-Martin AL. Carbodiimide and Isocyanate Hydroboration by a Cyclic Carbodiphosphorane Catalyst. Chemistry 2024; 30:e202303095. [PMID: 37847813 DOI: 10.1002/chem.202303095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 10/19/2023]
Abstract
We report hydroboration of carbodiimide and isocyanate substrates catalyzed by a cyclic carbodiphosphorane catalyst. The cyclic carbodiphosphorane outperformed the other Lewis basic carbon species tested, including other zerovalent carbon compounds, phosphorus ylides, an N-heterocyclic carbene, and an N-heterocyclic olefin. Hydroborations of seven carbodiimides and nine isocyanates were performed at room temperature to form N-boryl formamidine and N-boryl formamide products. Intermolecular competition experiments demonstrated the selective hydroboration of alkyl isocyanates over carbodiimide and ketone substrates. DFT calculations support a proposed mechanism involving activation of pinacolborane by the carbodiphosphorane catalyst, followed by hydride transfer and B-N bond formation.
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Affiliation(s)
- Ben A Janda
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
| | - Julie A Tran
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
| | - Daniel K Chang
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
| | - Gabriela C Nerhood
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
| | - O Maduka Ogba
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
| | - Allegra L Liberman-Martin
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 450 North Center Street, Orange, CA 92866, USA
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5
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Brouillet EV, Brown SA, Kennedy AR, Rae A, Walton HP, Robertson SD. Atom-economic access to cationic magnesium complexes. Dalton Trans 2023; 52:13332-13338. [PMID: 37671570 DOI: 10.1039/d3dt02669h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Cationic alkaline-earth complexes attract interest for their enhanced Lewis acidity and reactivity compared with their neutral counterparts. Synthetic protocols to these complexes generally utilize expensive specialized reagents in reactions generating multiple by-products. We have studied a simple ligand transfer approach to these complexes using (NacNac)MgR and ER3 (NacNac = β-diketiminate anion; E = group 13 element; R = aryl/amido anion) which demonstrates high atom economy, opening up the ability to target these species in a more sustainable manner. The success of this methodology is dependent on the identity of the group 13 element with the heavier elements facilitating faster ligand exchange. Furthermore, while this reaction is successful with aromatic ligands such as phenyl and pyrrolyl, the secondary amide piperidide (pip) fails to transfer, which we attribute to the stronger 3-centre-4-electron dimerization interaction of Al2(pip)6.
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Affiliation(s)
- Etienne V Brouillet
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Scott A Brown
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Alan R Kennedy
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Annabel Rae
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Heather P Walton
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
| | - Stuart D Robertson
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
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6
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Evans MJ, Jones C. Synthesis and Reactivity of Alkali Metal Hydrido-Magnesiate Complexes which Exhibit Group 1 Metal Counter-Cation Specific Stability. Inorg Chem 2023; 62:14393-14401. [PMID: 37602922 DOI: 10.1021/acs.inorgchem.3c02086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Reactions of the series of alkali metal amides M(HMDS) (M = Li-Cs; HMDS = [N(SiMe3)2]-) with the neutral magnesium(II) hydride compound [Mg(BDIDipp)(μ-H)]2 (BDIDipp = [CH{C(Me)NDipp}2], Dipp = 2,6-iPr2-C6H3) have been carried out. When M = Li or Na, the reactions yielded Mg(BDIDipp)(HMDS) and MH as the primary products. In the sodium amide reaction, [Na2(HMDS)][{Mg(BDIDipp)}2(H)3] was obtained as a low-yield by-product. When M = K-Cs, the reactions gave the group 1 metal hydrido-magnesiates, M2[Mg(BDIDipp)(HMDS)(H)]2·(benzene)n (n = 0 or 1), the thermal stability of which increases with the increasing molecular weight of the alkali metal involved. Reactions of Cs2[Mg(BDIDipp)(HMDS)(H)]2·(benzene) with 18-crown-6 and CO gave the first monomeric alkali metal hydrido-magnesiate [Cs(18-crown-6)][Mg(BDIDipp)(HMDS)(H)] and the ethenediolate complex Cs2[{Mg(BDIDipp)(HMDS)}2(μ-C2H2O2)], respectively. The new synthetic route to alkali metal hydrido-magnesiates described herein may facilitate further reactivity studies of this rare compound class.
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Affiliation(s)
- Matthew J Evans
- School of Chemistry, Monash University, P.O. Box 23, Melbourne, Victoria 3800, Australia
| | - Cameron Jones
- School of Chemistry, Monash University, P.O. Box 23, Melbourne, Victoria 3800, Australia
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7
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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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8
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Prey SE, Herok C, Fantuzzi F, Bolte M, Lerner HW, Engels B, Wagner M. Multifaceted behavior of a doubly reduced arylborane in B-H-bond activation and hydroboration catalysis. Chem Sci 2023; 14:849-860. [PMID: 36755708 PMCID: PMC9890859 DOI: 10.1039/d2sc05518j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Alkali-metal salts of 9,10-dimethyl-9,10-dihydro-9,10-diboraanthrancene (M2[DBA-Me2]; M+ = Li+, Na+, K+) activate the H-B bond of pinacolborane (HBpin) in THF already at room temperature. For M+ = Na+, K+, the addition products M2[4] are formed, which contain one new H-B and one new B-Bpin bond; for M+ = Li+, the H- ion is instantaneously transferred from the DBA-Me2 unit to another equivalent of HBpin to afford Li[5]. Although Li[5] might commonly be considered a [Bpin]- adduct of neutral DBA-Me2, it donates a [Bpin]+ cation to Li[SiPh3], generating the silyl borane Ph3Si-Bpin; Li2[DBA-Me2] with an aromatic central B2C4 ring acts as the leaving group. Furthermore, Li2[DBA-Me2] catalyzes the hydroboration of various unsaturated substrates with HBpin in THF. Quantum-chemical calculations complemented by in situ NMR spectroscopy revealed two different mechanistic scenarios that are governed by the steric demand of the substrate used: in the case of the bulky Ph(H)C[double bond, length as m-dash]NtBu, the reaction requires elevated temperatures of 100 °C, starts with H-Bpin activation which subsequently generates Li[BH4], so that the mechanism eventually turns into "hidden borohydride catalysis". Ph(H)C[double bond, length as m-dash]NPh, Ph2C[double bond, length as m-dash]O, Ph2C[double bond, length as m-dash]CH2, and iPrN[double bond, length as m-dash]C[double bond, length as m-dash]NiPr undergo hydroboration already at room temperature. Here, the active hydroboration catalyst is the [4 + 2] cycloadduct between the respective substrate and Li2[DBA-Me2]: in the key step, attack of HBpin on the bridging unit opens the bicyclo[2.2.2]octadiene scaffold and gives the activated HBpin adduct of the Lewis-basic moiety that was previously coordinated to the DBA-B atom.
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Affiliation(s)
- Sven E. Prey
- Institut für Anorganische und Analytische Chemie, Goethe-Universität FrankfurtFrankfurt am Main D-60438Germany
| | - Christoph Herok
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany
| | - Felipe Fantuzzi
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany .,School of Chemistry and Forensic Science, University of Kent Canterbury CT2 7NH UK
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
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9
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Nayak DK, Sarkar N, Sampath CM, Sahoo RK, Nembenna S. Organoaluminum Catalyzed Guanylation and Hydroboration Reactions of Carbodiimides. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Deepak Kumar Nayak
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Nabin Sarkar
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Chabathula Manoj Sampath
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Rajata Kumar Sahoo
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
| | - Sharanappa Nembenna
- School of Chemical Sciences National Institute of Science Education and Research (NISER), HBNI Bhubaneswar 752 050 India
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10
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Rezaei Bazkiaei A, Findlater M, Gorden AEV. Applications of catalysis in hydroboration of imines, nitriles, and carbodiimides. Org Biomol Chem 2022; 20:3675-3702. [PMID: 35451449 DOI: 10.1039/d2ob00162d] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The catalytic hydroboration of imines, nitriles, and carbodiimides is a powerful method of preparing amines which are key synthetic intermediates in the synthesis of many value-added products. Imine hydroboration has perennially featured in notable reports while nitrile and carbodiimide hydroboration have gained attention recently. Initial developments in catalytic hydroboration of imines and nitriles employed precious metals and typically required harsh reaction conditions. More recent advances have shifted toward the use of base metal and main group element catalysis and milder reaction conditions. In this survey, we review metal and nonmetal catalyzed hydroboration of these unsaturated organic molecules and group them into three distinct categories: precious metals, base metals, and main group catalysts. The TON and TOF of imine hydroboration catalysts are reported and summarized with a brief overview of recent advances in the field. Mechanistic and kinetic studies of some of these protocols are also presented.
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Affiliation(s)
- Adineh Rezaei Bazkiaei
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA.
| | - Michael Findlater
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, USA.
| | - Anne E V Gorden
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA.
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11
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Abstract
The addition of a B-H bond to an unsaturated bond (polarized or unpolarized) is a powerful and atom-economic tool for the synthesis of organoboranes. In recent years, s-block organometallics have appeared as alternative catalysts to transition-metal complexes, which traditionally catalyze the hydroboration of unsaturated bonds. Because of the recent and rapid development in the field of hydroboration of unsaturated bonds catalyzed by alkali (Li, Na, K) and alkaline earth (Mg, Ca, Sr, Ba) metals, we provide a detailed and updated comprehensive review that covers the synthesis, reactivity, and application of s-block metal catalysts in the hydroboration of polarized as well as unsaturated carbon-carbon bonds. Moreover, we describe the main reaction mechanisms, providing valuable insight into the reactivity of the s-block metal catalysts. Finally, we compare these s-block metal complexes with other redox-neutral catalytic systems based on p-block metals including aluminum complexes and f-block metal complexes of lanthanides and early actinides. In this review, we aim to provide a comprehensive, authoritative, and critical assessment of the state of the art within this highly interesting research area.
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Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Marcin Szewczyk
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Magnus Rueping
- Chemical Science Program, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center, Thuwal 23955-6900, Kingdom of Saudi Arabia
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12
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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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13
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Liu L, Lo SK, Smith C, Goicoechea JM. Pincer-Supported Gallium Complexes for the Catalytic Hydroboration of Aldehydes, Ketones and Carbon Dioxide. Chemistry 2021; 27:17379-17385. [PMID: 34623001 PMCID: PMC9297891 DOI: 10.1002/chem.202103009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 12/16/2022]
Abstract
Gallium hydrides stabilised by primary and secondary amines are scarce due to their propensity to eliminate dihydrogen. Consequently, their reactivity has received limited attention. The synthesis of two novel gallium hydride complexes HGa(THF)[ON(H)O] and H2Ga[μ2‐ON(H)O]Ga[ON(H)O] ([ON(H)O]2−=N,N‐bis(3,5‐di‐tert‐butyl‐2‐phenoxy)amine) is described and their reactivity towards aldehydes and ketones is explored. These reactions afford alkoxide‐bridged dimers through 1,2‐hydrogallation reactions. The gallium hydrides can be regenerated through Ga−O/B−H metathesis from the reaction of such dimers with pinacol borane (HBpin) or 9‐borabicyclo[3.3.1]nonane (9‐BBN). These observations allowed us to target the catalytic reduction of carbonyl substrates (aldehydes, ketones and carbon dioxide) with low catalyst loadings at room temperature.
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Affiliation(s)
- Lingyu Liu
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Rd., Oxford, OX1 3TA, UK
| | - Siu-Kwan Lo
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Rd., Oxford, OX1 3TA, UK
| | - Cory Smith
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Rd., Oxford, OX1 3TA, UK
| | - Jose M Goicoechea
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Rd., Oxford, OX1 3TA, UK
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14
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Li M, Liu X, Cui D. Catalytic hydroboration of carbonyl derivatives by using phosphinimino amide ligated magnesium complexes. Dalton Trans 2021; 50:13037-13041. [PMID: 34581349 DOI: 10.1039/d1dt00143d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reduction of carbonyl derivatives by using Earth-abundant, cheap, and environmentally benign metal-based catalysts through an atom-efficient method is a challenging task. Herein, we report the synthesis and characterization of dinuclear magnesium complexes 1-3 chelated by a phosphinimino amide skeleton. In combination with pinacolborane (HBpin) as a reducing agent, complex 1 bearing an ortho-methyl substituent on the phenyl ring of the ligand showed excellent reduction capability for a broad range of carbonyl derivatives under mild reaction conditions. Aldehydes, ketones, and acrolein substrates were efficiently reduced to the corresponding alkoxy-borane products with a record high TOF. Besides, acrolein derivatives were exclusively reduced to 1,2-regioselective products. Using two equiv. of HBpin, ester substrates were reduced to two kinds of alkoxy-borane products. Carbonate reduction accomplished by using complex 1 and three equiv. of HBpin afforded diols and a methanol precursor, respectively. When chiral substrates such as (S)-1,2-propanediol carbonate and L-lactide or polymeric P(L-LA) were employed, the chirality was almost retained in their reductive products.
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Affiliation(s)
- Min Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China. .,University of Science and Technology of China, Hefei 230026, China
| | - Xinli Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Dongmei Cui
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China. .,University of Science and Technology of China, Hefei 230026, China
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15
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Ankur, Kannan R, Chambenahalli R, Banerjee S, Yang Y, Maron L, Venugopal A. [(Me
6
TREN)MgOCHPh
2
][B(C
6
F
5
)
4
]: A Model Complex to Explore the Catalytic Activity of Magnesium Alkoxides in Ketone Hydroboration. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ankur
- School of Chemistry Indian Institute of Science Education and Research Thiruvananthapuram Vithura Thiruvananthapuram 695551 India
| | - Ramkumar Kannan
- School of Chemistry Indian Institute of Science Education and Research Thiruvananthapuram Vithura Thiruvananthapuram 695551 India
| | - Raju Chambenahalli
- School of Chemistry Indian Institute of Science Education and Research Thiruvananthapuram Vithura Thiruvananthapuram 695551 India
| | - Sumanta Banerjee
- School of Chemistry Indian Institute of Science Education and Research Thiruvananthapuram Vithura Thiruvananthapuram 695551 India
| | - Yan Yang
- LPCNO, UMR 5215, INSA, UPS Université de Toulouse-CNRS 31000 Toulouse France
| | - Laurent Maron
- LPCNO, UMR 5215, INSA, UPS Université de Toulouse-CNRS 31000 Toulouse France
| | - Ajay Venugopal
- School of Chemistry Indian Institute of Science Education and Research Thiruvananthapuram Vithura Thiruvananthapuram 695551 India
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16
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Bole LJ, Uzelac M, Hernán-Gómez A, Kennedy AR, O'Hara CT, Hevia E. Progressing the Frustrated Lewis Pair Abilities of N-Heterocyclic Carbene/GaR 3 Combinations for Catalytic Hydroboration of Aldehydes and Ketones. Inorg Chem 2021; 60:13784-13796. [PMID: 34191489 DOI: 10.1021/acs.inorgchem.1c01276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Exploiting the steric incompatibility of the tris(alkyl)gallium GaR3 (R = CH2SiMe3) and the bulky N-heterocyclic carbene (NHC) 1,3-bis(tert-butyl)imidazol-2-ylidene (ItBu), here we report the B-H bond activation of pinacolborane (HBPin), which has led to the isolation and structural authentication of a novel ion pair, [{ItBu-BPin}+{GaR3(μ-H)GaR3}-] (2). Contrastingly, neither ItBu or GaR3 was able to react with HBPin under the conditions of this study. Combining an NHC-stabilized borenium cation, [{ItBu-BPin}+], with an anionic dinuclear gallate, [{GaR3(μ-H)GaR3}-], 2 proved to be unstable in solution at room temperature, evolving to the abnormal NHC-Ga complex [BPinC{{N(tBu)]2CHCGa(R)3}] (3). Interestingly, the structural isomer of 2, with the borenium cation residing at the C4 position of the carbene, [{aItBu-BPin}+{GaR3(μ-H)GaR3}-] (4), was obtained when the abnormal NHC complex [aItBu·GaR3] (1) was heated to 70 °C with HBPin, demonstrating that, under these forced conditions, it is possible to induce thermal frustration of the Lewis base/Lewis acid components of 1, enabling the activation of HBPin. Building on these stoichiometric studies, the frustrated Lewis pair (FLP) reactivity observed for the GaR3/ItBu combination with HBPin could then be upgraded to catalytic regimes, allowing the efficient hydroboration of a range of aldehydes and ketones under mild reaction conditions. Mechanistic insights into the possible reaction pathway involved in this process have been gained by combining kinetic investigations with a comparative study of the catalytic capabilities of several gallium and borenium species related to 2. Disclosing a new cooperative partnership, reactions are proposed to occur via the formation of a highly reactive monomeric hydride gallate, [{ItBu-BPin}+{GaR3(H)}-] (I). Each anionic and cationic component of I plays a key role for success of the hydroboration, with the nucleophilic monomeric gallate anion favoring the transfer of its hydride to the C═O bond of the organic substate, which in turn is activated by coordination to the borenium cation.
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Affiliation(s)
- Leonie J Bole
- Department für Chemie, Biochemie und Pharmazie, Universität Bern, Bern CH3012, Switzerland
| | - Marina Uzelac
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, United Kingdom
| | - Alberto Hernán-Gómez
- Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, Alcalá de Henares-Madrid 28805, Spain
| | - Alan R Kennedy
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, United Kingdom
| | - Charles T O'Hara
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, United Kingdom
| | - Eva Hevia
- Department für Chemie, Biochemie und Pharmazie, Universität Bern, Bern CH3012, Switzerland
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17
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Li J, Ma X, Peng Y, He X, Du Z, Yang Z. Solubility of mono-alkyl magnesium complex in pure and binary solvents: Measurement, correlation, thermodynamics from 268.15 K to 318.15 K. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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18
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Bisai MK, Gour K, Das T, Vanka K, Sen SS. Readily available lithium compounds as catalysts for the hydroboration of carbodiimides and esters. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121924] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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19
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Banerjee I, Panda TK. Recent advances in the carbon-phosphorus (C-P) bond formation from unsaturated compounds by s- and p-block metals. Org Biomol Chem 2021; 19:6571-6587. [PMID: 34231617 DOI: 10.1039/d1ob01019k] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Researchers around the globe have witnessed several breakthroughs in s- and p-block metal chemistry. Over the past few years, several applications in catalysis associated with these main group metals have been established, and owing to their abundance and low cost and they have proved to be essential alternatives to transition metal catalysts. In this review, we present a detailed discussion on the catalytic addition of P-H bonds from various phosphine reagents to multiple bonds of unsaturated substrates for the synthesis of organophosphorus compounds with C-P bonds promoted by various s- and p-block metal catalysts, as published in the last decade.
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Affiliation(s)
- Indrani Banerjee
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi - 502 285, Sangareddy, Telangana, India. and School of Basic and Applied Sciences, Raffles University, Neemrana - 301705, Alwar, Rajasthan, India
| | - Tarun K Panda
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi - 502 285, Sangareddy, Telangana, India.
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20
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Ghosh P, Jacobi von Wangelin A. Manganese‐Catalyzed Hydroborations with Broad Scope. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103550] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Pradip Ghosh
- Dept. of Chemistry University of Hamburg Martin Luther King Pl 6 20146 Hamburg Germany
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21
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Ghosh P, Jacobi von Wangelin A. Manganese-Catalyzed Hydroborations with Broad Scope. Angew Chem Int Ed Engl 2021; 60:16035-16043. [PMID: 33894033 PMCID: PMC8362021 DOI: 10.1002/anie.202103550] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/22/2021] [Indexed: 12/29/2022]
Abstract
Reductive transformations of easily available oxidized matter are at the heart of synthetic manipulation and chemical valorization. The applications of catalytic hydrofunctionalization benefit from the use of liquid reducing agents and operationally facile setups. Metal‐catalyzed hydroborations provide a highly prolific platform for reductive valorizations of stable C=X electrophiles. Here, we report an especially facile, broad‐scope reduction of various functions including carbonyls, carboxylates, pyridines, carbodiimides, and carbonates under very mild conditions with the inexpensive pre‐catalyst Mn(hmds)2. The reaction could be successfully applied to depolymerizations.
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Affiliation(s)
- Pradip Ghosh
- Dept. of Chemistry, University of Hamburg, Martin Luther King Pl 6, 20146, Hamburg, Germany
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22
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Revathi S, Raja P, Saha S, Eisen MS, Ghatak T. Recent developments in highly basic N-heterocyclic iminato ligands in actinide chemistry. Chem Commun (Camb) 2021; 57:5483-5502. [PMID: 34008633 DOI: 10.1039/d1cc00933h] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the last decade, major conceptual advances in the chemistry of actinide molecules and materials have been made to demonstrate their distinct reactivity profiles as compared to lanthanide and transition metal compounds, but some difficult questions remain concerning the intriguing stability of low-valent actinide complexes, and the importance of the 5f-orbitals in reactivity and bonding. The imidazolin-2-iminato moiety has been extensively used in ligands for the advancement of actinide chemistry owing to its unique capability of stabilizing the reactive and highly electrophilic metal ions by virtue of its strong electron donation and steric tunability. The current review article describes recent developments in the chemistry of light actinide metal ions (thorium and uranium) bearing these N-heterocyclic iminato moieties as supporting ligands. In addition, the effect of ring expansion of the N-heterocycle on the catalytic aptitude of the organoactinides is also described herein. The synthesis and reactivity of actinide complexes bearing N-heterocyclic iminato ligands are presented, and promising apposite applications are also presented. The current review focuses on addressing the catalytic behavior of actinide complexes with oxygen-containing substrates such as in the Tishchenko reaction, hydroelementation processes, and polymerization reactions. Actinide complexes have also found new catalytic applications, as demonstrated by the potent chemoselective carbonyl hydroboration and tandem proton-transfer esterification (TPTE) reaction, featuring coupling between an aldehyde and alcohol.
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Affiliation(s)
- Shanmugam Revathi
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
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23
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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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24
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Gauld RM, Lynch JR, Kennedy AR, Barker J, Reid J, Mulvey RE. Expected and Unexpected Reactivities of Homoleptic LiNacNac and Heteroleptic NacNacMg(TMP) β-Diketiminates toward Various Small Unsaturated Organic Molecules. Inorg Chem 2021; 60:6057-6064. [PMID: 33830739 PMCID: PMC8154426 DOI: 10.1021/acs.inorgchem.1c00549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Homoleptic LiNacNac forms simple donor-acceptor complexes with N,N'-dicyclohexylcarbodiimide (CyN═C═NCy), triphenylphosphine oxide (Ph3P═O), and benzophenone (Ph2CO). These crystallographically characterized compounds could be regarded as model intermediates en route to reducing the N═C, P═O, and C═O bonds of unsaturated substrates. Heteroleptic NacNacMg(TMP) intriguingly functions as a TMP nucleophile both with t-BuNCO and t-BuNCS, producing a urea or thiourea derivative respectively attached to Mg, though the NacNac ligand in the former reaction also engages noninnocently with a second t-BuNCO molecule via insertion at the reactive NacNac backbone γ-carbon site.
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Affiliation(s)
- Richard M Gauld
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Jennifer R Lynch
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Jim Barker
- Innospec Ltd., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire CH65 4EY, U.K
| | - Jacqueline Reid
- Innospec Ltd., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire CH65 4EY, U.K
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
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25
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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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26
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Huke CD, Kays DL. Hydrofunctionalization reactions of heterocumulenes: Formation of C–X (X = B, N, O, P, S and Si) bonds by homogeneous metal catalysts. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2021. [DOI: 10.1016/bs.adomc.2021.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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28
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Zovko C, Bestgen S, Schoo C, Görner A, Goicoechea JM, Roesky PW. A Phosphine Functionalized β-Diketimine Ligand for the Synthesis of Manifold Metal Complexes. Chemistry 2020; 26:13191-13202. [PMID: 32285968 PMCID: PMC7693294 DOI: 10.1002/chem.202001357] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Indexed: 01/23/2023]
Abstract
A bis(diphenyl)-phosphine functionalized β-diketimine (PNac-H) was synthesized as a flexible ligand for transition metal complexes. The newly designed ligand features symmetrically placed phosphine moieties around a β-diketimine unit, forming a PNNP-type pocket. Due to the hard and soft donor atoms (N vs. P) the ligand can stabilize various coordination polyhedra. A complete series ranging from coordination numbers 2 to 6 was realized. Linear, trigonal planar, square planar, tetrahedral, square pyramidal, and octahedral coordination arrangements containing the PNac-ligand around the metal center were observed by using suitable metal sources. Hereby, PNac-H or its anion PNac- acts as mono-, bi- and tetradendate ligand. Such a broad flexibility is unusual for a rigid tetradentate system. The structural motifs were realized by treatment of PNac-H with a series of late transition metal precursors, for example, silver, gold, nickel, copper, platinum, and rhodium. The new complexes have been fully characterized by single crystal X-ray diffraction, NMR, IR, UV/Vis spectroscopy, mass spectrometry as well as elemental analysis. Additionally, selected complexes were investigated regarding their photophysical properties. Thus, PNac-H proved to be an ideal ligand platform for the selective coordination and stabilization of various metal ions in diverse polyhedra and oxidation states.
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Affiliation(s)
- Christina Zovko
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraβe 1576131KarlsruheGermany
| | - Sebastian Bestgen
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraβe 1576131KarlsruheGermany
- Department of Chemistry, Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Christoph Schoo
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraβe 1576131KarlsruheGermany
| | - Anne Görner
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraβe 1576131KarlsruheGermany
| | - Jose M. Goicoechea
- Department of Chemistry, Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraβe 1576131KarlsruheGermany
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29
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Okokhere-Edeghoghon B, Dehmel M, Hill MS, Kretschmer R, Mahon MF, McMullin CL, Morris LJ, Rajabi NA. Nucleophilic Magnesium Silanide and Silaamidinate Derivatives. Inorg Chem 2020; 59:13679-13689. [DOI: 10.1021/acs.inorgchem.0c02034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Maximilian Dehmel
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Claire L. McMullin
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Louis J. Morris
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Nasir A. Rajabi
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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30
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Bakewell C. Magnesium hydrides bearing sterically demanding amidinate ligands: synthesis, reactivity and catalytic application. Dalton Trans 2020; 49:11354-11360. [PMID: 32766619 DOI: 10.1039/d0dt02523b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The synthesis and characterisation of a series of magnesium complexes bearing sterically demanding amidinate ligands is reported; this includes magneisum amides (1a and 1b), hydrides (3a and 3b) and alkyl complexes (2b). The solid and solution state behaviour of the complexes has been investigated using single crystal X-ray diffraction and NMR spectroscopy, revealing the magnesium hydrides to exist as dimers in the solid state, dispite the sterically demanding ligand systems and showing a degree of monomeric character in solution. The stoichiometric and catalytic activity of the amidinate complexes were investigated, with the complexes found to efficiently mediate both the hydroamination of N,N'-diisopropylcarbodiimide and the Tishchenko reaction. The metal hydrides are highly reactive towards coordinating substrates, showing a significant increase in catalytic rate compared with more ubiquitous β-diketiminate magnesium hydrides.
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Affiliation(s)
- Clare Bakewell
- University College London, Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
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31
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Pécharman AF, Hill MS, McMullin CL, Mahon MF. [BO 2 ] - as a Synthon for the Generation of Boron-Centered Carbamate and Carboxylate Isosteres. Angew Chem Int Ed Engl 2020; 59:13628-13632. [PMID: 32401402 PMCID: PMC7496551 DOI: 10.1002/anie.202005674] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/09/2020] [Indexed: 12/14/2022]
Abstract
Oxoborane carbamate and carboxylate analogues result from the in situ trapping of [BO2]− produced by elimination of 2,3‐dimethyl‐2‐butene from a pinacolatoboryl anion.
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Affiliation(s)
| | - Michael S Hill
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | | | - Mary F Mahon
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
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32
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Pécharman A, Hill MS, McMullin CL, Mahon MF. [BO
2
]
−
as a Synthon for the Generation of Boron‐Centered Carbamate and Carboxylate Isosteres. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005674] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | | | - Mary F. Mahon
- Department of Chemistry University of Bath Bath BA2 7AY UK
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33
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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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34
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Magre M, Szewczyk M, Rueping M. N-Methylation and Trideuteromethylation of Amines via Magnesium-Catalyzed Reduction of Cyclic and Linear Carbamates. Org Lett 2020; 22:3209-3214. [PMID: 32216366 DOI: 10.1021/acs.orglett.0c00988] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new reduction of carbamates to N-methyl amines is presented. The magnesium-catalyzed reduction reaction allows the conversion of cyclic and linear carbamates, including N-Boc protected amines, into the corresponding N-methyl amines and amino alcohols which are of significant interest due to their presence in many biologically active molecules. Furthermore, the reduction can be extended to the formation of N-trideuteromethyl labeled amines.
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Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Marcin Szewczyk
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.,KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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35
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Huang W, Roisnel T, Dorcet V, Orione C, Kirillov E. Reduction of CO2 by Hydrosilanes in the Presence of Formamidinates of Group 13 and 12 Elements. Organometallics 2020. [DOI: 10.1021/acs.organomet.9b00853] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Weiheng Huang
- Organometallics: Materials and Catalysis laboratories, Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Thierry Roisnel
- Centre de diffraction X, Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Vincent Dorcet
- Centre de diffraction X, Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Clement Orione
- CRMPO, Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Evgueni Kirillov
- Organometallics: Materials and Catalysis laboratories, Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
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36
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Khononov M, Fridman N, Tamm M, Eisen MS. Hydroboration of Aldehydes, Ketones, and Carbodiimides Promoted by Mono(imidazolin‐2‐iminato) Hafnium Complexes. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901750] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Maxim Khononov
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
| | - Matthias Tamm
- Institut fürAnorganische und Analytische Chemie Technische Universität Braunschweig Hagenring 30 38106 Braunschweig Germany
| | - Moris S. Eisen
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
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37
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Cao X, Wang W, Lu K, Yao W, Xue F, Ma M. Magnesium-catalyzed hydroboration of organic carbonates, carbon dioxide and esters. Dalton Trans 2020; 49:2776-2780. [DOI: 10.1039/d0dt00465k] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A magnesium(i) complex was employed as a highly efficient precatalyst for the hydroboration of carbonates and esters under mild conditions.
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Affiliation(s)
- Xu Cao
- College of Science
- Nanjing Forestry University
- Nanjing 210037
- China
| | - Weifan Wang
- College of Science
- Nanjing Forestry University
- Nanjing 210037
- China
| | - Kai Lu
- College of Science
- Nanjing Forestry University
- Nanjing 210037
- China
| | - Weiwei Yao
- College of Pharmacy
- Nanjing University of Chinese Medicine
- Nanjing 210023
- China
| | - Fei Xue
- College of Science
- Nanjing Forestry University
- Nanjing 210037
- China
| | - Mengtao Ma
- College of Science
- Nanjing Forestry University
- Nanjing 210037
- China
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38
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Li Y, Chen H, Qu L, Bai R, Lan Y. Geometry, stability and aromaticity of β-diketiminate-coordinated alkaline-earth compounds. CHINESE CHEM LETT 2019. [DOI: 10.1016/j.cclet.2019.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Gauld RM, McLellan R, Kennedy AR, Barker J, Reid J, Mulvey RE. Backbone Reactivity of Lithium β-Diketiminate (NacNac) Complexes with CO 2 , tBuNCO and iPrNCO. Chemistry 2019; 25:14728-14734. [PMID: 31574177 DOI: 10.1002/chem.201904013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/27/2019] [Indexed: 01/07/2023]
Abstract
Though alkali metal NacNac (β-diketiminate) complexes have been utilised in synthesis as NacNac-transfer agents, studies of them in their own right with small molecules are exceptionally rare. Here, the lithium compound of the common 2,6-diisopropylphenyl-β-methyldiketiminate [NacNac(Dipp, Me)] ligand is investigated with carbon dioxide and isocyanates. In all four cases reaction occurs at the backbone γ-C atom of the NacNac ligand, which redistributes electronically into a diimine. Insertion of CO2 gives an eight-atom carboxylate (Li2 O4 C2 ) ring at the γ-C site in a dimer. Insertion of tBuNCO gives a secondary amide at the γ-C site in a monomer with TMEDA chelating lithium. Double insertion of tBuNCO and (adventitious) oxygen gives a dimer with a (LiO)2 central core involving the latter source. Insertion of less bulky (iPrNCO) gives a dimer with dimerisation through the C=O bonds of the emergent secondary amide function.
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Affiliation(s)
- Richard M Gauld
- 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
| | - Jim Barker
- Innospec Ltd, Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire, CH65 4EY, UK
| | - Jacqueline Reid
- Innospec Ltd, Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire, CH65 4EY, 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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Garcia L, Dinoi C, Mahon MF, Maron L, Hill MS. Magnesium hydride alkene insertion and catalytic hydrosilylation. Chem Sci 2019; 10:8108-8118. [PMID: 31814958 PMCID: PMC6839609 DOI: 10.1039/c9sc02056j] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/20/2019] [Indexed: 11/21/2022] Open
Abstract
The β-diketiminato magnesium hydride, [(BDI)MgH]]2, reacts with alkenes and catalyses their hydrosilylation with PhSiH3.
The dimeric β-diketiminato magnesium hydride, [(BDI)MgH]2, reacts at 80 °C with the terminal alkenes, 1-hexene, 1-octene, 3-phenyl-1-propene and 3,3-dimethyl-butene to provide the respective n-hexyl, n-octyl, 3-phenylpropyl and 3,3-dimethyl-butyl magnesium organometallics. The facility for and the regiodiscrimination of these reactions are profoundly affected by the steric demands of the alkene reagent. Reactions with the phenyl-substituted alkenes, styrene and 1,1-diphenylethene, require a more elevated temperature of 100 °C with styrene providing a mixture of the 2-phenylethyl and 1-phenylethyl products over 7 days. Although the reaction with 1,1-diphenylethene yields the magnesium 1,1-diphenylethyl derivative as the sole reaction product, only 64% conversion was achieved over a 21 day timeframe. Reactions with the α,ω-dienes, 1,5-hexadiene and 1,7-octadiene, provided divergent results. The initial 5-alkenyl magnesium reaction product of the shorter chain diene undergoes 5-exo-trig cyclisation via intramolecular carbomagnesiation to provide a cyclopentylmethyl derivative, which was shown by X-ray diffraction analysis to exist as a three-coordinate monomer. In contrast, 1,7-octadiene provided a mixture of two compounds, a magnesium oct-7-en-1-yl derivative and a dimagnesium-octane-1,4-diide, as a result of single or two-fold activation of the terminal C
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C double bonds. The magnesium hydride was unreactive towards internal alkenes apart from the strained bicycle, norbornene, allowing the characterisation of the resultant three-coordinate magnesium norbornyl derivative by X-ray diffraction analysis. Computational analysis of the reaction between [(BDI)MgH]2 and 1-hexene using density functional theory (DFT) indicated that the initial Mg–H/C
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C insertion process is rate determining and takes place at the intact magnesium hydride dimer. This exothermic reaction (ΔH = –14.1 kcal mol–1) traverses a barrier of 18.9 kcal mol–1 and results in the rupture of the dinuclear structure into magnesium alkyl and hydride species. Although the latter three-coordinate hydride derivative may be prone to redimerisation, it can also provide a further pathway to magnesium alkyl species through its direct reaction with a further equivalent of 1-hexene, which occurs via a lower barrier of 15.1 kcal mol–1. This Mg–H/C
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C insertion reactivity provides the basis for the catalytic hydrosilylation of terminal alkenes with PhSiH3, which proceeds with a preference for the formation of the anti-Markovnikov organosilane product. Further DFT calculations reveal that the catalytic reaction is predicated on a sequence of Mg–H/C
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C insertion and classical Si–H/Mg–C σ-bond metathesis reactions, the latter of which, with a barrier height of 24.9 kcal mol–1, is found to be rate determining.
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Affiliation(s)
- Lucia Garcia
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK .
| | - Chiara Dinoi
- Université de Toulouse et CNRS , INSA , UPS , UMR 5215 , LPCNO , 135 Avenue de Rangueil , F-31077 Toulouse , France
| | - Mary F Mahon
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK .
| | - Laurent Maron
- Université de Toulouse et CNRS , INSA , UPS , UMR 5215 , LPCNO , 135 Avenue de Rangueil , F-31077 Toulouse , France
| | - Michael S Hill
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK .
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41
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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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42
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Affiliation(s)
- Lucia Garcia
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
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43
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Ding Y, Ma X, Liu Y, Liu W, Yang Z, Roesky HW. Alkylaluminum Complexes as Precatalysts in Hydroboration of Nitriles and Carbodiimides. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00421] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Yi Ding
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xiaoli Ma
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Yashuai Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Wenqing Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Zhi Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Herbert W. Roesky
- Institut für Anorganische Chemie, Georg-August-Universität, Göttingen 37077, Germany
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44
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Pécharman AF, Hill MS, McMullon G, McMullin CL, Mahon MF. Snapshots of magnesium-centred diborane heterolysis by an outer sphere S N2 process. Chem Sci 2019; 10:6672-6682. [PMID: 31367321 PMCID: PMC6624991 DOI: 10.1039/c9sc02087j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 05/24/2019] [Indexed: 01/07/2023] Open
Abstract
Reactions of a magnesium diboranate as a source of [Bpin]– anions are initiated by ‘outer sphere’ attack of C
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N bonded substrates.
Reactions of the β-diketiminato magnesium diboranate derivative, [(BDI)Mg{pinB(n-Bu)Bpin}] (BDI = HC{(Me)CNDipp}2; Dipp = 2,6-i-Pr2C6H3), with N,N′-dialkyl and N,N′-diaryl carbodiimides provided the corresponding C-borylated magnesium borylamidinates. This reactivity occurs with the displacement of n-BuBpin and with the apparent addition of a nucleophilic {Bpin} anion to the electrophilic unsaturated carbodiimide carbon centres. In contrast, while analogous reactions of [(BDI)Mg{pinB(n-Bu)Bpin}] with N-alkyl or N-aryl aldimines and ketimines also resulted in facile displacement of n-BuBpin, they provided the organomagnesium products of {Bpin} addition to the imine nitrogen atom rather than the more electrophilic trigonal imine carbon. Computational assessment by density functional theory (DFT) indicated that, although the energetic differences are marginal, the organomagnesium products may be considered as the kinetic outcome of these reactions with respect to the generation of alternative amidomagnesium regioisomers. This latter deduction was borne out by the thermally-induced conversion of two such organomagnesium species to their C-borylated amidomagnesium isomers, both of which occur with negligible entropies of activation indicative of purely intramolecular processes. Detailed analysis by DFT of the reaction of [(BDI)Mg{pinB(n-Bu)Bpin}] with PhN
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CHPh indicated that B–N bond formation is initiated by attack of the imine nitrogen at the three-coordinate boron atom of the diboranate anion rather than the more crowded magnesium centre. Consistent with an effectively spontaneous reaction, the resultant cleavage of the B–B bond of the diboranate unit is accomplished via the traversal of two very modest barriers of only 8.3 and 6.7 kcal mol–1. This analysis was also supportive of a subsequent intramolecular B–N to B–C isomerisation process. Of greater general significance, however, the addition of the {Bpin}– anion to the reducible aldimine is best rationalised as a consequence of the electrophilic character of this three-coordinate boron centre rather than any intrinsic nucleophilicity associated with the B–B bond of the [pinBB(n-Bu)pin]– anion.
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Affiliation(s)
| | - Michael S Hill
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Grace McMullon
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Claire L McMullin
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
| | - Mary F Mahon
- Department of Chemistry , University of Bath , Claverton Down , Bath , BA2 7AY , UK . ;
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45
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Ren W, Zhang S, Xu Z, Ma X. Reactivity of a β-diketiminate-supported magnesium alkyl complex toward small molecules. Dalton Trans 2019; 48:3109-3115. [PMID: 30768120 DOI: 10.1039/c9dt00090a] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The reactivity of the magnesium alkyl {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(nBu)}2 (1) toward various small molecules provides access to a variety of magnesium derivatives. For example, the insertion of elemental chalcogens (S8 and Se8) into the Mg-C bond of complex 1 gives the dimeric magnesium thiolate {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(μ-SnBu)}2 (2), magnesium selenolate [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(SenBu)(THF) (3), and magnesium diselenolate [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(Se2nBu)(THF) (4). Meanwhile, compound 4 can be readily obtained by further insertion of one selenium atom into complex 3. Moreover, the reactions of complex 1 with diphenyl dichalcogenides (PhSSPh and PhSeSePh) by σ bond metathesis afford the corresponding magnesium phenyl chalcogenolates [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(EPh)(THF) (E = S 5, Se 6) concomitant with PhEnBu release. Furthermore, the treatment of complex 1 with benzonitrile and phenyl isothiocyanate produces the serendipitous magnesium-1-azaallyl complex [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(N(H)C(Ph)[double bond, length as m-dash]CHC3H7)(DME) (7) and the diimino-thioamidato magnesium compound {κ3-N,N',N''-(ArNCMe)2[N(Ph)CS]CH}Mg[(Ph)NC(nBu)S] (8) (Ar = 2,6-iPr2C6H3). In addition, deprotonation occurs between compound 1 and 1-methylimidazole to generate the imidazolyl complex {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(μ-Im)}2 (9) (Im = 2-N-methylimidazolyl). These results indicated that the butylmagnesium complex 1 possesses high activity toward small molecules and revealed several unusual transformations. All the new compounds were characterized by various spectroscopic methods, and their solid-state structures were further confirmed by single-crystal X-ray diffraction analyses.
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Affiliation(s)
- Wenshan Ren
- College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
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46
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Patnaik S, Sadow AD. Interconverting Lanthanum Hydride and Borohydride Catalysts for C=O Reduction and C−O Bond Cleavage. Angew Chem Int Ed Engl 2019; 58:2505-2509. [DOI: 10.1002/anie.201813305] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Smita Patnaik
- Department of Chemistry and US Department of Energy Ames Laboratory Iowa State University 1605 Gilman Hall Ames IA USA
| | - Aaron D. Sadow
- Department of Chemistry and US Department of Energy Ames Laboratory Iowa State University 1605 Gilman Hall Ames IA USA
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47
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Patnaik S, Sadow AD. Interconverting Lanthanum Hydride and Borohydride Catalysts for C=O Reduction and C−O Bond Cleavage. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813305] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Smita Patnaik
- Department of Chemistry and US Department of Energy Ames Laboratory Iowa State University 1605 Gilman Hall Ames IA USA
| | - Aaron D. Sadow
- Department of Chemistry and US Department of Energy Ames Laboratory Iowa State University 1605 Gilman Hall Ames IA USA
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48
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Carden JL, Gierlichs LJ, Wass DF, Browne DL, Melen RL. Unlocking the catalytic potential of tris(3,4,5-trifluorophenyl)borane with microwave irradiation. Chem Commun (Camb) 2019; 55:318-321. [DOI: 10.1039/c8cc09459d] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The catalytic activity of tris(3,4,5-trifluorophenyl)borane has been explored in the 1,2-hydroboration reactions of unsaturated substrates.
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Affiliation(s)
- Jamie L. Carden
- School of Chemistry
- Cardiff University
- Main Building
- Park Place
- Cardiff
| | | | - Duncan F. Wass
- School of Chemistry
- Cardiff University
- Main Building
- Park Place
- Cardiff
| | - Duncan L. Browne
- School of Chemistry
- Cardiff University
- Main Building
- Park Place
- Cardiff
| | - Rebecca L. Melen
- School of Chemistry
- Cardiff University
- Main Building
- Park Place
- Cardiff
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49
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Dyall J, Hill MS, Mahon MF, Teh L, Wilson ASS. Calcium formamidinate derivatives by hydride insertion of carbodiimides. Dalton Trans 2019; 48:4248-4254. [DOI: 10.1039/c8dt05107k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Insertion reactions of N,N′-dialkyl and N,N′-diaryl carbodiimides with a dimeric calcium hydride provide formamidinate derivatives whose structures on the steric demands of the carbodiimide reagent.
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Affiliation(s)
| | | | | | - Luke Teh
- Department of Chemistry
- University of Bath
- Bath
- UK
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50
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Ramos A, Antiñolo A, Carrillo-Hermosilla F, Fernández-Galán R, García-Vivó D. 9-Borabicyclo[3.3.1]nonane: a metal-free catalyst for the hydroboration of carbodiimides. Chem Commun (Camb) 2019; 55:3073-3076. [DOI: 10.1039/c9cc00593e] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A 9-borabicyclo[3.3.1]nonane dimer is used as the first example of metal-free catalysts for the monohydroboration of carbodiimides with pinacol borane.
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Affiliation(s)
- Alberto Ramos
- Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Departamento de Química Inorgánica
- Orgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla-La Mancha
| | - Antonio Antiñolo
- Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Departamento de Química Inorgánica
- Orgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla-La Mancha
| | - Fernando Carrillo-Hermosilla
- Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Departamento de Química Inorgánica
- Orgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla-La Mancha
| | - Rafael Fernández-Galán
- Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Departamento de Química Inorgánica
- Orgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla-La Mancha
| | - Daniel García-Vivó
- Departamento de Química Orgánica e Inorgánica/IUQOEM
- Universidad de Oviedo
- E-33071 Oviedo
- Spain
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