1
|
Riddhi RK, Penas-Hidalgo F, Chen H, Quadrelli EA, Canivet J, Mellot-Draznieks C, Solé-Daura A. Experimental and computational aspects of molecular frustrated Lewis pairs for CO 2 hydrogenation: en route for heterogeneous systems? Chem Soc Rev 2024; 53:9874-9903. [PMID: 39212094 DOI: 10.1039/d3cs00267e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Catalysis plays a crucial role in advancing sustainability. The unique reactivity of frustrated Lewis pairs (FLPs) is driving an ever-growing interest in the transition metal-free transformation of small molecules like CO2 into valuable products. In this area, there is a recent growing incentive to heterogenize molecular FLPs into porous solids, merging the benefits of homogeneous and heterogeneous catalysis - high activity, selectivity, and recyclability. Despite the progress, challenges remain in preventing deactivation, poisoning, and simplifying catalyst-product separation. This review explores the expanding field of FLPs in catalysis, covering existing molecular FLPs for CO2 hydrogenation and recent efforts to design heterogeneous porous systems from both experimental and theoretical perspectives. Section 2 discusses experimental examples of CO2 hydrogenation by molecular FLPs, starting with stoichiometric reactions and advancing to catalytic ones. It then examines attempts to immobilize FLPs in porous matrices, including siliceous solids, metal-organic frameworks (MOFs), covalent organic frameworks, and disordered polymers, highlighting current limitations and challenges. Section 3 then reviews computational studies on the mechanistic details of CO2 hydrogenation, focusing on H2 splitting and hydride/proton transfer steps, summarizing efforts to establish structure-activity relationships. It also covers the computational aspects on grafting FLPs inside MOFs. Finally, Section 4 summarizes the main design principles established so far, while addressing the complexities of translating computational approaches into the experimental realm, particularly in heterogeneous systems. This section underscores the need to strengthen the dialogue between theoretical and experimental approaches in this field.
Collapse
Affiliation(s)
- Riddhi Kumari Riddhi
- IRCELYON, UMR 5256, Université LYON 1, 2 avenue Albert Einstein, 69626 Villeurbanne Cedex, France
| | - Francesc Penas-Hidalgo
- Laboratoire de Chimie des Processus Biologiques, CNRS UMR 8229, Collège de France, PSL Research University, Sorbonne Université, 75231 Paris Cedex 05, France.
| | - Hongmei Chen
- Laboratoire de Chimie des Processus Biologiques, CNRS UMR 8229, Collège de France, PSL Research University, Sorbonne Université, 75231 Paris Cedex 05, France.
| | | | - Jérôme Canivet
- IRCELYON, UMR 5256, Université LYON 1, 2 avenue Albert Einstein, 69626 Villeurbanne Cedex, France
| | - Caroline Mellot-Draznieks
- Laboratoire de Chimie des Processus Biologiques, CNRS UMR 8229, Collège de France, PSL Research University, Sorbonne Université, 75231 Paris Cedex 05, France.
| | - Albert Solé-Daura
- Department de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo 1, Tarragona 43007, Spain
- Institute of Chemical Research of Catalonia (ICIQ-CERCA), The Barcelona Institute of Science and Technology, Avgda. Països Catalans, 16, 43007 Tarragona, Spain.
| |
Collapse
|
2
|
Thorwart T, Greb L. Structural Flexibility is a Decisive Factor in FLP Dihydrogen Cleavage with Tetrahedral Lewis Acids: A Silane Case Study. Chemistry 2024; 30:e202401912. [PMID: 38856095 DOI: 10.1002/chem.202401912] [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: 05/16/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/11/2024]
Abstract
Dihydrogen activation is the paradigmatic reaction of frustrated Lewis pairs (FLPs). While trigonal-planar Lewis acids have been well established in this transformation, tetrahedral Lewis acids are surprisingly limited. Indeed, several cases were computed as thermodynamically and kinetically feasible but exhibit puzzling discrepancies with experimental results. In the present study, a computational investigation of the factors influencing dihydrogen activation are considered by large ensemble sampling of encounter complexes, deformation energies and the activation strain model for a silicon/nitrogen FLP and compared with a boron/phosphorous FLP. The analysis adds the previously missing dimension of Lewis acids' structural flexibility as a factor that influences preexponential terms beyond pure transition state energies. It sheds light on the origin of "overfrustration" (defined herein), indicates structural constraint in Lewis acids as a linchpin for activation of weak donor substrates, and allows drawing a more refined mechanistic picture of this emblematic reactivity.
Collapse
Affiliation(s)
- Thaddäus Thorwart
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| |
Collapse
|
3
|
Pomogaeva AV, Timoshkin AY. Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study. ACS OMEGA 2022; 7:48493-48505. [PMID: 36591180 PMCID: PMC9798527 DOI: 10.1021/acsomega.2c06836] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Structural features and reactivity of frustrated Lewis pairs (FLPs) formed by pyramidal group 13 Lewis acids based on 9-bora and 9-alatriptycene and bulky phosphines P t Bu3, PPh3, and PCy3 are considered at the M06-2X/def2-TZVP level of theory. Classic FLP is formed only in the B(C6Me4)3CH/P t Bu3 system, while both FLP and donor-acceptor (DA) complex are observed in the B(C6F4)3CF/P t Bu3 system. Formation of DA complexes was observed in other systems; the B(C6H4)3CH·P t Bu3 complex features an elongated DA bond and can be considered a "latent" FLP. Transition states and reaction pathways for molecular hydrogen activation have been obtained. Processes of heterolytic hydrogen splitting are energetically more favored in solution compared to the gas phase, while activation energies in the gas phase and in solution are close. The alternative processes of hydrogenation of B-C or Al-C bonds in the source pyramidal Lewis acids in the absence of a Lewis base are exergonic but have larger activation energies than those for heterolytic hydrogen splitting. The tuning of Lewis acidity of 9-boratriptycene by changing the substituents allows one to control its reactivity with respect to hydrogen activation. Interestingly, the most promising system from the practical point of view is the DA complex B(C6H4)3CH·P t Bu3, which is predicted to provide both low activation energy and thermodynamic reversibility of the heterolytic hydrogen splitting process. It appears that such "not so frustrated" or "latent" FLPs are the best candidates for reversible heterolytic hydrogen splitting.
Collapse
|
4
|
|
5
|
Liu J, Wei Z, Yang J, Ge Y, Wei D, Jackstell R, Jiao H, Beller M. Tuning the Selectivity of Palladium Catalysts for Hydroformylation and Semihydrogenation of Alkynes: Experimental and Mechanistic Studies. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03614] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiawang Liu
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Zhihong Wei
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
- Institute of Molecular Science, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Shanxi University, Taiyuan 030006, P. R. China
| | - Ji Yang
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Yao Ge
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Duo Wei
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Ralf Jackstell
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| | - Matthias Beller
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, Rostock 18059, Germany
| |
Collapse
|
6
|
Heshmat M, Ensing B. Optimizing the Energetics of FLP-Type H 2 Activation by Modulating the Electronic and Structural Properties of the Lewis Acids: A DFT Study. J Phys Chem A 2020; 124:6399-6410. [PMID: 32666803 PMCID: PMC8279552 DOI: 10.1021/acs.jpca.0c03108] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The great potential of frustrated Lewis pairs (FLPs) as metal-free catalysts for activation of molecular hydrogen has attracted increasing interest as an alternative to transition-metal catalysts. However, the complexity of FLP systems, involving the simultaneous interaction of three molecules, impedes a detailed understanding of the activation mechanism and the individual roles of the Lewis acid (LA) and Lewis base (LB). In the present work, using density functional theory (DFT) calculations, we examine the reactivity of 75 FLPs for the H2 splitting reaction, including a series of experimentally investigated LAs combined with conventional phosphine-based (tBu3P) and oxygen-based (i.e., ethereal solvent) Lewis bases. We find that the catalytic activity of the FLP is the result of a delicate balance of the LA and LB strengths and their bulkiness. The H2 splitting reaction can be changed from endergonic to exergonic by tuning the electrophilicity of the LA. Also, a more nucleophilic LB results in a more stable ion pair product and a lower barrier for the hydrogen splitting. The bulkiness of the LB leads to an early transition state to reduce steric hindrance and lower the barrier height. The bulkiness of the fragments determines the cavity size in the FLP complex, and a large cavity allows for a larger charge separation in the ion pair configuration. A shorter proton-hydride distance in this product complex correlates with a stronger attraction between the fragments, which forms more reactive ion pairs and facilitates the proton and hydride donations in the subsequent hydrogenation process. These insights may help with rationalizing the experimentally observed reactivities of FLPs and with designing better FLP systems for hydrogenation catalysis and hydrogen storage.
Collapse
Affiliation(s)
- Mojgan Heshmat
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Bernd Ensing
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
7
|
Zhang N, Ma J, Li R, Jiao H. Hydrocracking of Fused Aromatic Hydrocarbons Catalyzed by Al-Substituted HZSM-5—A Case Study of 9,10-Dihydroanthracene. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00946] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Nan Zhang
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jinghong Ma
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Ruifeng Li
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein Strasse 29a, 18059 Rostock, Germany
| |
Collapse
|
8
|
Heshmat M. Alternative Pathway of CO 2 Hydrogenation by Lewis-Pair-Functionalized UiO-66 MOF Revealed by Metadynamics Simulations. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:10951-10960. [PMID: 34122685 PMCID: PMC8192054 DOI: 10.1021/acs.jpcc.0c01088] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/15/2020] [Indexed: 05/12/2023]
Abstract
The reaction between H2 and CO2 catalyzed by an intramolecular frustrated Lewis pair, which is covalently bonded to a UiO-66 metal-organic framework (MOF), is considered in this work. Free energy surfaces (FESs) for this reaction are generated throughout finite-temperature density functional theory (DFT) metadynamics (MD) simulations. The simulated FESs indicate an alternative stepwise pathway for the hydrogenation of CO2. Furthermore, indications of weaker binding of CO2 than H2 to the Lewis pair centers have been observed via metadynamics simulations. These findings were unknown from the results of static-DFT calculations, which proposed a concerted reduction of CO2. The results of the present work may influence the design of new efficient heterogeneous Lewis pair (LP)-functionalized MOFs to catalyze capture and conversion of CO2 to high-value chemicals.
Collapse
Affiliation(s)
- Mojgan Heshmat
- Van’t
Hoff Institute for Molecular Sciences, Universiteit
van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- ,
| |
Collapse
|
9
|
Gallardo-Fuentes S, Ormazábal-Toledo R. Theoretical insights into the activation of N2O by a model Frustrated Lewis Pair. An ab-initio metadynamics study. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.137002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Daru J, Bakó I, Stirling A, Pápai I. Mechanism of Heterolytic Hydrogen Splitting by Frustrated Lewis Pairs: Comparison of Static and Dynamic Models. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01137] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- János Daru
- Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary
| | - Imre Bakó
- Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary
| | - András Stirling
- Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary
| | - Imre Pápai
- Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary
| |
Collapse
|
11
|
Merk A, Großekappenberg H, Schmidtmann M, Luecke M, Lorent C, Driess M, Oestreich M, Klare HFT, Müller T. Einelektronenübertragungsreaktionen in frustrierten und klassischen Silyliumion/Phosphan‐Lewis‐Paaren. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808922] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anastasia Merk
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Henning Großekappenberg
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Marc Schmidtmann
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Marcel‐Philip Luecke
- Institut für ChemieTechnische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Christian Lorent
- Institut für ChemieTechnische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Matthias Driess
- Institut für ChemieTechnische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Martin Oestreich
- Institut für ChemieTechnische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Hendrik F. T. Klare
- Institut für ChemieTechnische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Thomas Müller
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| |
Collapse
|
12
|
Merk A, Großekappenberg H, Schmidtmann M, Luecke MP, Lorent C, Driess M, Oestreich M, Klare HFT, Müller T. Single-Electron Transfer Reactions in Frustrated and Conventional Silylium Ion/Phosphane Lewis Pairs. Angew Chem Int Ed Engl 2018; 57:15267-15271. [PMID: 30178534 DOI: 10.1002/anie.201808922] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 08/31/2018] [Indexed: 01/08/2023]
Abstract
Silylium ions undergo a single-electron reduction with phosphanes, leading to transient silyl radicals and the corresponding stable phosphoniumyl radical cations. As supported by DFT calculations, phosphanes with electron-rich 2,6-disubstituted aryl groups are sufficiently strong reductants to facilitate this single-electron transfer (SET). Frustration as found in kinetically stabilized triarylsilylium ion/phosphane Lewis pairs is not essential, and silylphosphonium ions, which are generated by conventional Lewis adduct formation of solvent-stabilized trialkylsilylium ions and phosphanes, engage in the same radical mechanism. The trityl cation, a Lewis acid with a higher electron affinity, even oxidizes trialkylphosphanes, such as tBu3 P, which does not react with either B(C6 F5 )3 or silylium ions.
Collapse
Affiliation(s)
- Anastasia Merk
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129, Oldenburg, Germany
| | - Henning Großekappenberg
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129, Oldenburg, Germany
| | - Marc Schmidtmann
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129, Oldenburg, Germany
| | - Marcel-Philip Luecke
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Christian Lorent
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Matthias Driess
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129, Oldenburg, Germany
| |
Collapse
|
13
|
Pu M, Heshmat M, Privalov T. Liberation of H 2 from (o-C 6H 4Me) 3P-H (+) + (-)H-B(p-C 6F 4H) 3 ion-pair: A transition-state in the minimum energy path versus the transient species in Born-Oppenheimer molecular dynamics. J Chem Phys 2018; 147:014303. [PMID: 28688388 DOI: 10.1063/1.4989672] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Using Born-Oppenheimer molecular dynamics (BOMD) with density functional theory, transition-state (TS) calculations, and the quantitative energy decomposition analysis (EDA), we examined the mechanism of H2-liberation from LB-H(+) + (-)H-LA ion-pair, 1, in which the Lewis base (LB) is (o-C6H4Me)3P and the Lewis acid (LA) is B(p-C6F4H)3. BOMD simulations indicate that the path of H2 liberation from the ion-pair 1 goes via the short-lived transient species, LB⋯H2⋯LA, which are structurally reminiscent of the TS-structure in the minimum-energy-path describing the reversible reaction between H2 and (o-C6H4Me)3P/B(p-C6F4H)3 frustrated Lewis pair (FLP). With electronic structure calculations performed on graphics processing units, our BOMD data-set covers more than 1 ns of evolution of the ion-pair 1 at temperature T ≈ 400 K. BOMD simulations produced H2-recombination events with various durations of H2 remaining fully recombined as a molecule within a LB/LA attractive "pocket"-from very short vibrational-time scale to time scales in the range of a few hundred femtoseconds. With the help of perturbational approach to trajectory-propagation over a saddle-area, we directly examined dynamics of H2-liberation. Using EDA, we elucidated interactions between the cationic and anionic fragments in the ion-pair 1 and between the molecular fragments in the TS-structure. We have also considered a model that qualitatively takes into account the potential energy characteristics of H-H recombination and H2-release plus inertia of molecular motion of the (o-C6H4Me)3P/B(p-C6F4H)3 FLP.
Collapse
Affiliation(s)
- Maoping Pu
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Mojgan Heshmat
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Timofei Privalov
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
14
|
Noroozi-Shad N, Gholizadeh M, Izadyar M, Eshghi H. Theoretical Evaluation of the Efficiency of Novel Frustrated Lewis Pairs in the cis-Hydrogenation Reaction of Dimethylacetylene. PROGRESS IN REACTION KINETICS AND MECHANISM 2017. [DOI: 10.3184/146867817x14954764850469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Frustrated Lewis pairs (FLPs) are the combination of Lewis acid and base motifs where steric hindrance prevents strong adduct formation. Accordingly, the ability of FLPs in small molecule activation and their capability in hydrogen cleavage led to their use in the hydrogenation of a wide range of unsaturated substrates. Here, we investigated theoretically the ability of three intramolecular phosphorus/boron FLPs as bifunctional catalysts in the metal-free hydrogenation of dimethylacetylene to cis-alkene. The mechanism of this hydrogenation reaction, based on the boron acceptor [including –OR substituents (B(OR)2), where R is an aliphatic or aromatic branch] and phosphorus donor, has been explored. Based on the results obtained, it was confirmed that the H2 splitting reaction and the formation of the phosphonium–borohydride motifs for these FLPs are endothermic. It has been shown that these FLPs have a moderate ability in H–H bond splitting. Also, the capability of the boron atom in FLPs on the hydrogenation reaction was investigated. The reduction steps of the mechanism showed an exothermic nature. This result revealed that the presence of the boron as a Lewis acid, with a very limited Lewis acidity, improves the catalytic hydrogenation reaction significantly. Finally, it was confirmed that the proposed FLPs in the cis-hydrogenation of alkynes will be effective.
Collapse
Affiliation(s)
- Nazanin Noroozi-Shad
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mostafa Gholizadeh
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mohammad Izadyar
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hossein Eshghi
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| |
Collapse
|
15
|
Liu L(L, Cao LL, Shao Y, Ménard G, Stephan DW. A Radical Mechanism for Frustrated Lewis Pair Reactivity. Chem 2017. [DOI: 10.1016/j.chempr.2017.05.022] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
16
|
Oestreich M, Hermeke J, Mohr J. A unified survey of Si-H and H-H bond activation catalysed by electron-deficient boranes. Chem Soc Rev 2015; 44:2202-20. [PMID: 25679769 DOI: 10.1039/c4cs00451e] [Citation(s) in RCA: 392] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The bond activation chemistry of B(C6F5)3 and related electron-deficient boranes is currently experiencing a renaissance due to the fascinating development of frustrated Lewis pairs (FLPs). B(C6F5)3's ability to catalytically activate Si-H bonds through η(1) coordination opened the door to several unique reduction processes. The ground-breaking finding that the same family of fully or partially fluorinated boron Lewis acids allows for the related H-H bond activation, either alone or as a component of an FLP, brought considerable momentum into the area of transition-metal-free hydrogenation and, likewise, hydrosilylation. This review comprehensively summarises synthetic methods involving borane-catalysed Si-H and H-H bond activation. Systems corresponding to an FLP-type situation are not covered. Aside from the broad manifold of C=X bond reductions and C=X/C-X defunctionalisations, dehydrogenative (oxidative) Si-H couplings are also included.
Collapse
Affiliation(s)
- Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, D-10623 Berlin, Germany.
| | | | | |
Collapse
|
17
|
Pu M, Privalov T. Chemistry of Intermolecular Frustrated Lewis Pairs in Motion: Emerging Perspectives and Prospects. Isr J Chem 2015. [DOI: 10.1002/ijch.201400159] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Chernichenko K, Kótai B, Pápai I, Zhivonitko V, Nieger M, Leskelä M, Repo T. Intramolecular Frustrated Lewis Pair with the Smallest Boryl Site: Reversible H2Addition and Kinetic Analysis. Angew Chem Int Ed Engl 2014; 54:1749-53. [DOI: 10.1002/anie.201410141] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Indexed: 12/12/2022]
|
19
|
Chernichenko K, Kótai B, Pápai I, Zhivonitko V, Nieger M, Leskelä M, Repo T. Intramolecular Frustrated Lewis Pair with the Smallest Boryl Site: Reversible H2Addition and Kinetic Analysis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201410141] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|