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Yan B, Ma X, Pang Z, Yang Z. Chemoselective Luche-type reduction of α,β-unsaturated ketones by aluminium hydride catalysis. Dalton Trans 2024; 53:4127-4131. [PMID: 38315772 DOI: 10.1039/d3dt03987k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
A novel, simple, eco-friendly, non-toxic aluminium catalyst was synthesised for the chemoselective reduction of α,β-unsaturated ketones. A wide range of ketones were achieved with excellent yields, mild conditions, and low catalyst loading. Furthermore, this unprecedented method allowed for the stereoselective reduction of natural ketones.
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Affiliation(s)
- Ben Yan
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, P. R. China.
| | - Xiaoli Ma
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, P. R. China.
| | - Ziyuan Pang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, P. R. China.
| | - Zhi Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, P. R. China.
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2
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Patro AG, Sahoo RK, Nembenna S. Zinc hydride catalyzed hydroboration of esters. Dalton Trans 2024; 53:3621-3628. [PMID: 38289250 DOI: 10.1039/d3dt04084d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The conjugated bis-guanidinate (CBG)-supported zinc hydride {LZnH}2; L = {(ArHN)(ArN)-CN-C(NAr)(NHAr); Ar = 2,6-Et2-C6H3} (I) is utilized as a catalyst for the hydroboration of esters with pinacolborane (HBpin) under mild reaction conditions. Various aryl and alkyl substrates containing electron-donating, withdrawing, and cyclic groups of esters are effectively converted into alkoxy boronate esters as products upon hydroboration. Furthermore, stoichiometric experiments have been performed to understand the plausible reaction mechanism for the hydroboration of esters. Additionally, complex (I) was used for the hydroboration of carbonate, carboxylic acid, and anhydride substrates to showcase the broad substrate scope.
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Affiliation(s)
- A Ganesh Patro
- 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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Han HJ, Park SY, Jeon SE, Kwak JS, Lee JH, Jaladi AK, Hwang H, An DK. Grignard Reagent-Catalyzed Hydroboration of Esters, Nitriles, and Imines. Molecules 2023; 28:7090. [PMID: 37894569 PMCID: PMC10609653 DOI: 10.3390/molecules28207090] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
The reduction in esters, nitriles, and imines requires harsh conditions (highly reactive reagents, high temperatures, and pressures) or complex metal-ligand catalytic systems. Catalysts comprising earth-abundant and less toxic elements are desirable from the perspective of green chemistry. In this study, we developed a green hydroboration protocol for the reduction in esters, nitriles, and imines at room temperature (25 °C) using pinacolborane as the reducing agent and a commercially available Grignard reagent as the catalyst. Screening of various alkyl magnesium halides revealed MeMgCl as the optimal catalyst for the reduction. The hydroboration and subsequent hydrolysis of various esters yielded corresponding alcohols over a short reaction time (~0.5 h). The hydroboration of nitriles and imines produced various primary and secondary amines in excellent yields. Chemoselective reduction and density functional theory calculations are also performed. The proposed green hydroboration protocol eliminates the requirements for complex ligand systems and elevated temperatures, providing an effective method for the reduction in esters, nitriles, and imines at room temperature.
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Affiliation(s)
| | | | | | | | | | | | | | - Duk Keun An
- Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Republic of Korea; (H.J.H.); (S.Y.P.); (S.E.J.); (J.S.K.); (J.H.L.); (A.K.J.); (H.H.)
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Kumar GS, Kumar R, Sau A, Chandrasekhar V, Panda TK. Zinc Catalyzed Hydroboration of Esters and Nitriles with Pinacolborane. J Org Chem 2023; 88:12613-12622. [PMID: 37615400 DOI: 10.1021/acs.joc.3c01306] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
We developed a bench-stable iminopyridine-ligated zinc complex for the effective catalytic hydroboration of esters and nitriles under solvent-free conditions. Various esters and nitriles bearing different functionalities were selectively reduced to form corresponding alcohols and amines in good yields. Detailed Hammett plots are provided to explain the electronic effects on the phenyl ring.
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Affiliation(s)
- Gobbilla Sai Kumar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Hyderabad, Telangana 502284, India
| | - Ravi Kumar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Hyderabad, Telangana 502284, India
| | - Abhijit Sau
- Department of Chemistry, Indian Institute of Technology Hyderabad, Hyderabad, Telangana 502284, India
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500107, India
- Department of Chemistry, IIT Kanpur, Kanpur 208016, India
| | - Tarun K Panda
- Department of Chemistry, Indian Institute of Technology Hyderabad, Hyderabad, Telangana 502284, India
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5
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Zhang G, Zeng H, Tang Q, Ates S, Zheng S, Neary MC. Vanadium-catalysed regioselective hydroboration of epoxides for synthesis of secondary alcohols. Dalton Trans 2023; 52:11395-11400. [PMID: 37577840 DOI: 10.1039/d3dt01865b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Regioselective epoxide ring-opening through hydroboration catalysed by a vanadium(III) dialkyl complex supported by a redox-active terpyridine ligand is reported. Secondary alcohols were obtained in high yields via effective Markovnikov hydroboration of terminal epoxides, showcasing a new catalytic application of an earth-abundant vanadium(III) complex.
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Affiliation(s)
- Guoqi Zhang
- Department of Sciences, John Jay College and PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY 10019, USA.
| | - Haisu Zeng
- Department of Sciences, John Jay College and PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY 10019, USA.
- Department of Chemistry, Hunter College, the City University of New York, New York, 10065 NY, USA
| | - Quan Tang
- Department of Sciences, John Jay College and PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY 10019, USA.
| | - Selin Ates
- Department of Sciences, John Jay College and PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY 10019, USA.
| | - Shengping Zheng
- Department of Chemistry, Hunter College, the City University of New York, New York, 10065 NY, USA
| | - Michelle C Neary
- Department of Chemistry, Hunter College, the City University of New York, New York, 10065 NY, USA
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6
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Merschel A, Vishnevskiy YV, Neumann B, Stammler HG, Ghadwal RS. Highly Soluble Cyclic Organoalanes Based on Anionic Dicarbenes. Chemistry 2023; 29:e202301037. [PMID: 37293882 DOI: 10.1002/chem.202301037] [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: 03/31/2023] [Revised: 05/16/2023] [Accepted: 06/09/2023] [Indexed: 06/10/2023]
Abstract
Cyclic organoalane compounds [(ADCAr )AlH2 ]2 (ADCAr = ArC{(DippN)C}2 ; Dipp = 2,6-iPr2 C6 H3 ; Ar = Ph or 4-PhC6 H4 (Bp)) based on anionic dicarbene (ADC) frameworks have been reported as crystalline solids. Treatments of Li(ADCAr ) with LiAlH4 at room temperature afford [(ADCAr )AlH2 ]2 with the concomitant release of LiH. Compounds [(ADCAr )AlH2 ]2 are stable crystalline solids and are freely soluble in common organic solvents. They are annulated tricyclic compounds with an almost planar central C4 Al2 -core embedded between two peripheral 1,3-imidazole (C3 N2 ) rings. At room temperature, [(ADCPh )AlH2 ]2 readily reacts with CO2 to form two- and four-fold hydroalumination products [(ADCPh )AlH(OCHO)]2 and [(ADCPh )Al(OCHO)2 ]2 , respectively. Further hydroalumination reactivity of [(ADCPh )AlH2 ]2 has been shown with isocyanate (RNCO) and isothiocyanate (RNCS) species (R=alkyl or aryl group). All compounds have been characterized by NMR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction.
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Affiliation(s)
- Arne Merschel
- Molecular Inorganic Chemistry and Catalysis, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Yury V Vishnevskiy
- Molecular Inorganic Chemistry and Catalysis, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Beate Neumann
- Molecular Inorganic Chemistry and Catalysis, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Molecular Inorganic Chemistry and Catalysis, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Rajendra S Ghadwal
- Molecular Inorganic Chemistry and Catalysis, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
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