1
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Lourenço DL, Fernandes AC. Reduction of sulfoxides catalyzed by the commercially available manganese complex MnBr(CO) 5. Org Biomol Chem 2024; 22:3746-3751. [PMID: 38652042 DOI: 10.1039/d4ob00204k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
A new methodology for the reduction of a wide variety of aliphatic and aromatic sulfoxides catalyzed by the air-stable, cheap and commercially available manganese catalyst MnBr(CO)5 with excellent yields is reported in this work. The catalytic system MnBr(CO)5/PhSiH3 is highly chemoselective, allowing the effective reduction of the SO bond in the presence of different functional groups.
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Affiliation(s)
- Daniel L Lourenço
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Ana C Fernandes
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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2
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Pawar RB, Karmur MH, Punji B. Ligand-free MnBr 2-Catalyzed Chemo- and Stereoselective Hydroboration of Terminal Alkynes. Chem Asian J 2024; 19:e202400158. [PMID: 38512720 DOI: 10.1002/asia.202400158] [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: 02/14/2024] [Revised: 03/19/2024] [Accepted: 03/21/2024] [Indexed: 03/23/2024]
Abstract
Developing simple and benign protocols for synthesizing alkenylboronates is crucial as they are synthetically valuable compounds in various organic transformations. In this work, we report a straightforward ligand-free protocol for synthesizing alkenylboronates via atom-economical hydroboration of alkynes with HBpin catalyzed by a manganese salt. The reaction shows a high level of chemo and regioselectivity for the terminal alkynes and exclusively produces E-selective alkenylboronates. The hydroboration scope is vast, with the resilience of a range of synthetically beneficial functionalities, such as halides, ether, alkenyl, silyl and thiophenyl groups. This reaction proceeds through the involvement of a metal-hydride intermediate. The developed alkenylboronate can be smoothly converted to useful C-C, C-N and C-I bond-forming reactions.
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Affiliation(s)
- Rameshwar B Pawar
- Organometallic Synthesis and Catalysis Lab, Organic Chemistry Division, CSIR - National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411 008, India Ph
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
| | - Mital H Karmur
- Organometallic Synthesis and Catalysis Lab, Organic Chemistry Division, CSIR - National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411 008, India Ph
| | - Benudhar Punji
- Organometallic Synthesis and Catalysis Lab, Organic Chemistry Division, CSIR - National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411 008, India Ph
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
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3
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Nad P, Mukherjee A. A Lewis Acid-Base Pair Catalyzed Dearomative Transformation of Unprotected Indoles via B-H Bond Activation. Chem Asian J 2023; 18:e202300714. [PMID: 37811913 DOI: 10.1002/asia.202300714] [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: 08/14/2023] [Revised: 09/29/2023] [Accepted: 10/09/2023] [Indexed: 10/10/2023]
Abstract
A sustainable and metal-free protocol has been described for the reduction of unprotected indoles. The catalytic system consists of B(C6 F5 )3 and THF as a Lewis acid-base pair that can activate the B-H bond of pincolborane (HBpin). The catalytic system encompasses a broad substrate scope. Control experiments were conducted to understand the possible catalytic intermediates involved during the present protocol.
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Affiliation(s)
- Pinaki Nad
- Department of Chemistry, Indian Institute of Technology Bhilai GEC Campus, Sejbahar, Raipur, 492015, Chhattisgarh (India
| | - Arup Mukherjee
- Department of Chemistry, Indian Institute of Technology Bhilai GEC Campus, Sejbahar, Raipur, 492015, Chhattisgarh (India
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4
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Almutairi N, Vijjamarri S, Du G. Manganese Salan Complexes as Catalysts for Hydrosilylation of Aldehydes and Ketones. Catalysts 2023. [DOI: 10.3390/catal13040665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
Manganese has attracted significant recent attention due to its abundance, low toxicity, and versatility in catalysis. In the present study, a series of manganese (III) complexes supported by salan ligands have been synthesized and characterized, and their activity as catalysts in the hydrosilylation of carbonyl compounds was examined. While manganese (III) chloride complexes exhibited minimal catalytic efficacy without activation of silver perchlorate, manganese (III) azide complexes showed good activity in the hydrosilylation of carbonyl compounds. Under optimized reaction conditions, several types of aldehydes and ketones could be reduced with good yields and tolerance to a variety of functional groups. The possible mechanisms of silane activation and hydrosilylation were discussed in light of relevant experimental observations.
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5
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Ni C, Pang Z, Qiao Y, Guo P, Ma X, Yang Z. Organoaluminum derived from Schiff bases: Synthesis, characterization and catalytic performance in hydroboration. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Zn-Catalyzed Regioselective and Chemoselective Reduction of Aldehydes, Ketones and Imines. Int J Mol Sci 2022; 23:ijms232012679. [PMID: 36293541 PMCID: PMC9604354 DOI: 10.3390/ijms232012679] [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: 09/19/2022] [Revised: 10/10/2022] [Accepted: 10/16/2022] [Indexed: 01/24/2023] Open
Abstract
An operationally convenient Zn-catalyzed synthesis of alcohols by the reduction of aldehydes, ketones, and α,β-unsaturated aldehydes/ketones is reported. It is a rare example of using mild and sustainable HBpin as a reductant for catalytic reduction of carbonyl compounds in the absence of acid or base as hydrolysis reagent. The reaction is upscalable and proceeds in high selectivity without the formation of boronate ester by-products, and tolerates sensitive functionalities, such as iodo, bromo, chloro, fluoro, nitro, trifluoromethyl, aminomethyl, alkynyl, and amide. The Zn(OAc)2/HBpin combination has been also proved to be chemoselective for the C=N reduction of imine analogs.
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7
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Das K, Waiba S, Jana A, Maji B. Manganese-catalyzed hydrogenation, dehydrogenation, and hydroelementation reactions. Chem Soc Rev 2022; 51:4386-4464. [PMID: 35583150 DOI: 10.1039/d2cs00093h] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The emerging field of organometallic catalysis has shifted towards research on Earth-abundant transition metals due to their ready availability, economic advantage, and novel properties. In this case, manganese, the third most abundant transition-metal in the Earth's crust, has emerged as one of the leading competitors. Accordingly, a large number of molecularly-defined Mn-complexes has been synthesized and employed for hydrogenation, dehydrogenation, and hydroelementation reactions. In this regard, catalyst design is based on three pillars, namely, metal-ligand bifunctionality, ligand hemilability, and redox activity. Indeed, the developed catalysts not only differ in the number of chelating atoms they possess but also their working principles, thereby leading to different turnover numbers for product molecules. Hence, the critical assessment of molecularly defined manganese catalysts in terms of chelating atoms, reaction conditions, mechanistic pathway, and product turnover number is significant. Herein, we analyze manganese complexes for their catalytic activity, versatility to allow multiple transformations and their routes to convert substrates to target molecules. This article will also be helpful to get significant insight into ligand design, thereby aiding catalysis design.
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Affiliation(s)
- Kuhali Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
| | - Satyadeep Waiba
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
| | - Akash Jana
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
| | - Biplab Maji
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
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8
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Assembly of a 3D Cobalt(II) Supramolecular Framework and Its Applications in Hydrofunctionalization of Ketones and Aldehydes. CHEMISTRY 2022. [DOI: 10.3390/chemistry4020029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A ditopic nitrogen ligand (E)-N′-(pyridin-4-ylmethylene)isonicotinohydrazide (L) containing both divergent pyridyl coordination sites and a hydrogen-bonding hydrazide–hydrazone moiety was synthesized. The Co(NCS)2-mediated self-assembly of L has resulted in the synthesis of a novel 3-dimensional (3D) supramolecular framework (1) that features both coordination and hydrogen bonding interactions. X-ray structural analysis reveals the formation and coordination mode of 1 in the solid state. The rational utilization of coordination bonds and hydrogen bonding interactions is confirmed and responsible for constructing the 3D materials. Catalytic studies using 1 in the presence of an activator are performed for the hydroboration and hydrosilylation reactions of ketones and aldehydes, and the results are compared with previously reported cobalt-based polymeric catalysts.
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9
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Zhang L, Zhao Y, Liu C, Pu M, Lei M, Cao Z. Hydroboration of CO 2 to Methyl Boronate Catalyzed by a Manganese Pincer Complex: Insights into the Reaction Mechanism and Ligand Effect. Inorg Chem 2022; 61:5616-5625. [PMID: 35357141 DOI: 10.1021/acs.inorgchem.2c00285] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The conversion of carbon dioxide to fuels, polymers, and chemicals is an attractive strategy for the synthesis of high-value-added products and energy-storage materials. Herein, the density functional theory method was employed to investigate the reaction mechanism of CO2 hydroboration catalyzed by manganese pincer complex, [Mn(Ph2PCH2SiMe2)2NH(CO)2Br]. The carbonyl association and carbonyl dissociation mechanisms were investigated, and the calculated results showed that the carbonyl association mechanism is more favorable with an energetic span of 27.0 kcal/mol. Meanwhile, the solvent effect of the reaction was explored, indicating that the solvents could reduce the catalytic activity of the catalyst, which was consistent with the experimental results. In addition, the X ligand effect (X = CO, Br, H, PH3) on the catalytic activity of the manganese complex was explored, indicating that the anionic complexes [MnI - Br]- and [MnI - H]- have higher catalytic activity. This may not only shed light on the fixation and conversion of CO2 catalyzed by earth-abundant transition-metal complexes but also provide theoretical insights to design new transition-metal catalysts.
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Affiliation(s)
- Lin Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, China
| | - Yaqi Zhao
- State Key Laboratory of Chemical Resource Engineering, Institute of Computational Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Chong Liu
- State Key Laboratory of Chemical Resource Engineering, Institute of Computational Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Min Pu
- State Key Laboratory of Chemical Resource Engineering, Institute of Computational Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Ming Lei
- State Key Laboratory of Chemical Resource Engineering, Institute of Computational Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zexing Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 360015, China
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10
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Wang S, Qiu L, Li C, Zheng Y, Pan L. Highly porous CuO/MnO2 catalyst prepared by gas release-assisted technology and its enhancement of formaldehyde removal efficiency. RESEARCH ON CHEMICAL INTERMEDIATES 2022. [DOI: 10.1007/s11164-022-04696-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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11
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Jia Z, Li L, Zhang X, Yang K, Li H, Xie Y, Schaefer HF. Acceleration Effect of Bases on Mn Pincer Complex-Catalyzed CO 2 Hydroboration. Inorg Chem 2022; 61:3970-3980. [PMID: 35212516 DOI: 10.1021/acs.inorgchem.1c03614] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Herein, we report a comprehensive study of CO2 hydroboration catalyzed by Mn pincer complexes. The traditional metal-ligand cooperation (MLC) mechanism based on the H-Mn-N-Bpin pincer complex is not viable due to the competing abstraction of the Bpin group from the H-Mn-N-Bpin complex by NaOtBu. Instead, we propose an ionic mechanism based on the H-Mn-N-Na species with a low energy span (22.5 kcal/mol) and unveil the acceleration effect of bases. The X groups in the H-Mn-N-X catalyst models are further modulated, and the steric hindrance and H→B donor-acceptor interactions of the X group increase the energy barrier of the hydride transfer. The hydrogen bond and electrostatic interactions of the X group can accelerate the hydride transfer to HCOOBpin and HCHO molecules except for the nonpolar CO2 molecule. Based on these discoveries, we designed a pyridine-based Mn pincer catalyst system, which could achieve CO2 hydroboration in low-temperature and base-free conditions through a metal-ligand cooperation mechanism.
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Affiliation(s)
- Zixing Jia
- College of Pharmacy, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Hebei University, Baoding 071002, Hebei, P. R. China
| | - Longfei Li
- College of Pharmacy, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Hebei University, Baoding 071002, Hebei, P. R. China
| | - Xuewen Zhang
- College of Pharmacy, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Hebei University, Baoding 071002, Hebei, P. R. China
| | - Kan Yang
- College of Pharmacy, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Hebei University, Baoding 071002, Hebei, P. R. China
| | - Huidong Li
- Research Center for Advanced Computation, School of Science, Xihua University, Chengdu 610039, P. R. China
| | - Yaoming Xie
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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12
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Abstract
AbstractRecent developments in manganese-catalyzed reducing transformations—hydrosilylation, hydroboration, hydrogenation, and transfer hydrogenation—are reviewed herein. Over the past half a decade (i.e., 2016 to the present), more than 115 research publications have been reported in these fields. Novel organometallic compounds and new reduction transformations have been discovered and further developed. Significant challenges that had historically acted as barriers for the use of manganese catalysts in reduction reactions are slowly being broken down. This review will hopefully assist in developing this research area, by presenting a clear and concise overview of the catalyst structures and substrate transformations published so far.1 Introduction2 Hydrosilylation3 Hydroboration4 Hydrogenation5 Transfer Hydrogenation6 Conclusion and Perspective
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Affiliation(s)
- Christophe Werlé
- Max Planck Institute for Chemical Energy Conversion
- Ruhr University Bochum
| | - Peter Schlichter
- Max Planck Institute for Chemical Energy Conversion
- Institut für Technische und Makromolekulare Chemie (ITMC), RWTH Aachen University
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13
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Geier SJ, Vogels CM, Melanson JA, Westcott SA. The transition metal-catalysed hydroboration reaction. Chem Soc Rev 2022; 51:8877-8922. [DOI: 10.1039/d2cs00344a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review covers the development of the transition metal-catalysed hydroboration reaction, from its beginnings in the 1980s to more recent developments including earth-abundant catalysts and an ever-expanding array of substrates.
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Affiliation(s)
- Stephen J. Geier
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Christopher M. Vogels
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Jennifer A. Melanson
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Stephen A. Westcott
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
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Aversa-Fleener CR, Chang DK, Liberman-Martin AL. Carbodiphosphorane-Catalyzed Hydroboration of Ketones and Imines. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Cara R. Aversa-Fleener
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, California 92866, United States
| | - Daniel K. Chang
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, California 92866, United States
| | - Allegra L. Liberman-Martin
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, California 92866, United States
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15
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Weber S, Zobernig D, Stöger B, Veiros LF, Kirchner K. Hydroboration of Terminal Alkenes and trans-1,2-Diboration of Terminal Alkynes Catalyzed by a Manganese(I) Alkyl Complex. Angew Chem Int Ed Engl 2021; 60:24488-24492. [PMID: 34435424 PMCID: PMC8596825 DOI: 10.1002/anie.202110736] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Indexed: 11/21/2022]
Abstract
A MnI‐catalyzed hydroboration of terminal alkenes and a 1,2‐diboration of terminal alkynes with pinacolborane (HBPin) is described. For alkenes, anti‐Markovnikov hydroboration takes place; for alkynes the reaction proceeds with excellent trans‐1,2‐selectivity. The most active pre‐catalyst is bench‐stable alkyl bisphosphine MnI complex fac‐[Mn(dippe)(CO)3(CH2CH2CH3)]. The catalytic process is initiated by migratory insertion of a CO ligand into the Mn–alkyl bond to yield an acyl intermediate, which undergoes B−H bond cleavage of HBPin (for alkenes) and rapid C−H bond cleavage (for alkynes), forming the active MnI boryl and acetylide catalysts [Mn(dippe)(CO)2(BPin)] and [Mn(dippe)(CO)2(C≡CR)], respectively. A broad variety of aromatic and aliphatic alkenes and alkynes was efficiently and selectively borylated. Mechanistic insights are provided based on experimental data and DFT calculations revealing that an acceptorless reaction is operating involving dihydrogen release.
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Affiliation(s)
- Stefan Weber
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-AC, A-1060, Wien, Austria
| | - Daniel Zobernig
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-AC, A-1060, Wien, Austria
| | - Berthold Stöger
- X-Ray Center, Vienna University of Technology, Getreidemarkt 9, A-1060, Wien, Austria
| | - Luis F Veiros
- Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av Rovisco Pais, 1049-001, Lisboa, Portugal
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-AC, A-1060, Wien, Austria
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16
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Weber S, Zobernig D, Stöger B, Veiros LF, Kirchner K. Hydroboration of Terminal Alkenes and trans-1,2-Diboration of Terminal Alkynes Catalyzed by a Manganese(I) Alkyl Complex. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 133:24693-24697. [PMID: 38505543 PMCID: PMC10947181 DOI: 10.1002/ange.202110736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Indexed: 12/21/2022]
Abstract
A MnI-catalyzed hydroboration of terminal alkenes and a 1,2-diboration of terminal alkynes with pinacolborane (HBPin) is described. For alkenes, anti-Markovnikov hydroboration takes place; for alkynes the reaction proceeds with excellent trans-1,2-selectivity. The most active pre-catalyst is bench-stable alkyl bisphosphine MnI complex fac-[Mn(dippe)(CO)3(CH2CH2CH3)]. The catalytic process is initiated by migratory insertion of a CO ligand into the Mn-alkyl bond to yield an acyl intermediate, which undergoes B-H bond cleavage of HBPin (for alkenes) and rapid C-H bond cleavage (for alkynes), forming the active MnI boryl and acetylide catalysts [Mn(dippe)(CO)2(BPin)] and [Mn(dippe)(CO)2(C≡CR)], respectively. A broad variety of aromatic and aliphatic alkenes and alkynes was efficiently and selectively borylated. Mechanistic insights are provided based on experimental data and DFT calculations revealing that an acceptorless reaction is operating involving dihydrogen release.
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Affiliation(s)
- Stefan Weber
- Institute of Applied Synthetic ChemistryVienna University of TechnologyGetreidemarkt 9/163-ACA-1060WienAustria
| | - Daniel Zobernig
- Institute of Applied Synthetic ChemistryVienna University of TechnologyGetreidemarkt 9/163-ACA-1060WienAustria
| | - Berthold Stöger
- X-Ray CenterVienna University of TechnologyGetreidemarkt 9A-1060WienAustria
| | - Luis F. Veiros
- Centro de Química Estrutural and Departamento de Engenharia QuímicaInstituto Superior TécnicoUniversidade de LisboaAv Rovisco Pais1049-001LisboaPortugal
| | - Karl Kirchner
- Institute of Applied Synthetic ChemistryVienna University of TechnologyGetreidemarkt 9/163-ACA-1060WienAustria
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17
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Wan X, Li M, Liao RZ. Ligand-assisted Hydride Transfer: A Pivotal Step for CO 2 Hydroboration Catalyzed by a Mononuclear Mn(I) PNP Complex. Chem Asian J 2021; 16:2529-2537. [PMID: 34278731 DOI: 10.1002/asia.202100582] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/14/2021] [Indexed: 11/09/2022]
Abstract
A mononuclear Mn(I) pincer complex [Mn(Ph2 PCH2 SiMe2 )2 NH(CO)2 Br] was disclosed to catalyze the pinacolborane (HBpin)-based CO2 hydroboration reaction. Density functional calculations were conducted to reveal the reaction mechanism. The calculations showed that the reaction mechanism could be divided into four stages: (1) the addition of HBpin to the unsaturated catalyst C1; (2) the reduction of CO2 to HCOOBpin; (3) the reduction of HCOOBpin to HCHO; (4) the reduction of HCHO to CH3 OBpin. The activation of HBpin is the ligand-assisted addition of HBpin to the unsaturated Mn(I)-N complex C1 generated by the elimination of HBr from the Mn(I) pincer catalyst. The sequential substrate reductions share a common mechanism, and every hydroboration commences with the nucleophilic attack of the Mn(I)-H to the electron-deficient carbon centers. The hydride transfer from Mn(I) to HCOOBpin was found to be the rate-limiting step for the whole catalytic reaction, with a total barrier of 27.0 kcal/mol, which fits well with the experimental observations at 90 °C. The reactivity trend of CO2 , HCOOBpin, HCHO, and CH3 OBpin was analyzed through both thermodynamic and kinetic analysis, in the following order, namely HCHO>CO2 >HCOOBpin≫CH3 OBpin. Importantly, the very high barrier for the reduction of CH3 OBpin to form CH4 reconciles with the fact that methane was not observed in this catalytic reaction.
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Affiliation(s)
- Xiang Wan
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Man Li
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
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18
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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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19
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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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Roa DA, Garcia JJ. Mild reduction with silanes and reductive amination of levulinic acid using a simple manganese catalyst. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120167] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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