1
|
Krieft J, Neumann B, Stammler HG, Mitzel NW. Oxidation-dependent Lewis acidity in chalcogen adducts of Sb/P frustrated Lewis pairs. Dalton Trans 2024; 53:11762-11768. [PMID: 38938114 DOI: 10.1039/d4dt01591f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
The reactions of the frustrated Lewis pair (F5C2)2SbCH2P(tBu)2 with oxygen, sulphur, selenium and tellurium led to the mono-oxidation products (F5C2)2SbCH2P(E)(tBu)2 (E = O, S, Se, Te). Further oxidation of these chalcogen adducts with tetrachloro-ortho-benzoquinone (o-chloranil) gave (F5C2)2Sb(CH2)(μ-E)P(tBu)2·CatCl (CatCl = o-O2C6Cl4) with a central four-membered ring heterocycle for E = O, S, and Se. For E = Te the elimination of elemental tellurium led to an oxidation product with two equivalents of o-chloranil, (F5C2)2SbCH2P(tBu)2·2CatCl, which is also accessible by reaction of (F5C2)2SbCH2P(tBu)2 with o-chloranil. The synthesised compounds were characterised by NMR spectroscopy and X-ray structure analyses, and the structural properties were analysed in the light of the altered Lewis acidity due to the oxidation of the antimony atoms.
Collapse
Affiliation(s)
- Jonas Krieft
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Beate Neumann
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Hans-Georg Stammler
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| | - Norbert W Mitzel
- Chair of Inorganic and Structural Chemistry, Center for Molecular Materials CM2, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
| |
Collapse
|
2
|
Krämer F. Aluminum in Frustrated Lewis Pair Chemistry. Angew Chem Int Ed Engl 2024:e202405207. [PMID: 38826040 DOI: 10.1002/anie.202405207] [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: 03/16/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 06/04/2024]
Abstract
This review article describes the development of the use of aluminum compounds in the chemistry of frustrated Lewis pairs (FLPs) over the last 14 years. It also discusses the synthesis, reactivity and catalytic applications of intermolecular, intramolecular and so-called hidden FLPs with phosphorus, nitrogen and carbon Lewis bases. The intrinsically higher acidity of aluminum compounds compared to their boron analogs opens up different reaction pathways. The results are presented in a more or less chronological order. It is shown that Al FLPs react with a variety of polar and non-polar substrates and form both stable adducts and reversibly activate bonds. Consequently, some catalytic applications of the title compounds were presented such as dimerization of alkynes, hydrogenation of tert-butyl ethylene and imines, C-F bond activation, reduction of CO2, dehydrogenation of amine borane and transfer of ammonia. In addition, various Al FLPs were used as initiators in polymerization reactions.
Collapse
Affiliation(s)
- Felix Krämer
- C1 Green Chemicals AG, Am Studio 2a, 12489, Berlin, Germany
| |
Collapse
|
3
|
Mondal H, Chattaraj PK. CO 2 reduction using aluminum hydride: Generation of in-situ frustrated Lewis pairs and small molecule activation therein. J Comput Chem 2024; 45:1098-1111. [PMID: 38261518 DOI: 10.1002/jcc.27285] [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: 11/02/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 01/25/2024]
Abstract
CO2 reduction is appealing for the long-term production of high-value fuels and chemicals. Herein, using density functional theory (DFT) based calculations, we study the CO2 reduction pathway to formic acid using aluminum hydride and phosphine derivatives. Our primary focus is on aluminum hydride derivatives, aimed at improving the efficiency of the CO2 reduction process. Substituents with σ-donating properties at the aluminum center are discovered to lower the activation barriers. We demonstrate how di-tert-butylphosphine oxide (LB-O)/di-tert-butylphosphine sulfide (LB-S)/di-tert-butylphosphanimine (LB-N) work together with aluminum hydride to facilitate CO2 reduction process and generate in-situ frustrated Lewis pairs (FLPs), such as FLP-O, FLP-S, and FLP-N. The activation strain model (ASM) analysis reveals the significance of strain energy in determining activation barriers. EDA-NOCV and PIO analyses elucidate the orbital interactions at the corresponding transition states. Furthermore, the study delves into the activation of various small molecules, such as dihydrogen, acetylene, ethylene, carbon dioxide, nitrous oxide, and acetonitrile, using those in-situ generated FLPs. The study highlights the low activation barriers and emphasizes the potential for small molecule activation in this context.
Collapse
Affiliation(s)
- Himangshu Mondal
- Department of Chemistry, Indian Institute of Technology, Kharagpur, India
| | | |
Collapse
|
4
|
Kou X. Mechanistic Insight Into the Reactivity of Frustrated Lewis Pairs: Liquid-State NMR Studies. Crit Rev Anal Chem 2024:1-12. [PMID: 38446616 DOI: 10.1080/10408347.2024.2324299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Frustrated Lewis pairs (FLPs) have been widely investigated as promising catalysts due to their metal-free feature and ability to activate small molecules. Over the last few years, the structure, dynamics and interactions between the Lewis centers and their effects on the reactivity with different substrates have been studied. Nuclear magnetic resonance (NMR) is a powerful tool in studying the reaction intermediates, kinetics and mechanism of frustrated Lewis pairs (FLPs). Various NMR experiments have been applied to precisely determine the association or cooperativity of FLPs and one or two-dimensional spectra were obtained. Herein, insights coming from NMR spectroscopy for FLPs are presented, the structure and reactivity of FLPs in solution are described, and their effects on the kinetics and mechanism of different substrates are also illustrated in this review.
Collapse
Affiliation(s)
- Xinhui Kou
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department, Analyses and Testing Center, Qingdao University of Science and Technology, Qingdao, China
| |
Collapse
|
5
|
Bisht SK, Sharma D, Kannan R, Rajeshkumar T, Maron L, Venugopal A. Quest for Active Species in Al/B-Catalyzed CO 2 Hydrosilylation. Inorg Chem 2023; 62:18543-18552. [PMID: 37906233 DOI: 10.1021/acs.inorgchem.3c02771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
We demonstrate the catalytic role of aluminum and boron centers in aluminum borohydride [(2-Me2CH2C6H4)(C6H5)Al(μ-H)2B(C6H5)2] (6) during carbon dioxide (CO2) hydrosilylation. Preliminary investigations into CO2 reduction using [(2-Me2NCH2C6H4)(H)Al(μ-H)]2 (1) and [Ph3C][B(3,5-C6H3Cl2)4] (2) in the presence of Et3SiH and PhSiH3 resulted in CH2(OSiR3)2 and CH3OSiR3, which serve as formaldehyde and methanol surrogates, respectively. In pursuit of identifying the active catalytic species, three compounds, B(3,5-C6H3Cl2)3 (3), [(2-Me2NCH2C6H4)(3,5-C6H3Cl2)Al(μ-H)2B(3,5-C6H3Cl2)2] (4), and [(2-Me2NCH2C6H4)2Al(THF)][B(3,5-C6H3Cl2)4] (5), were isolated. Among compounds 2-5, the highest catalytic conversion was achieved by 4. Further, 4 and 6 were prepared in a straightforward method by treating 1 with 3 and BPh3, respectively. 6 was found to be in equilibrium with 1 and BPh3, thus making the catalytic process of 6 more efficient than that of 4. Computational investigations inferred that CO2 reduction occurs across the Al-H bond, while Si-H activation occurs through a concerted mechanism involving an in situ generated aluminum formate species and BPh3.
Collapse
Affiliation(s)
- Sheetal Kathayat Bisht
- School of Chemistry, Indian Institute of Science Education and Research (IISER) Thiruvananthapuram, Vithura, Thiruvananthapuram 695551, India
| | - Deepti Sharma
- School of Chemistry, Indian Institute of Science Education and Research (IISER) Thiruvananthapuram, Vithura, Thiruvananthapuram 695551, India
| | - Ramkumar Kannan
- School of Chemistry, Indian Institute of Science Education and Research (IISER) Thiruvananthapuram, Vithura, Thiruvananthapuram 695551, India
| | - Thayalan Rajeshkumar
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées, Toulouse, Cedex 4 31077, France
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées, Toulouse, Cedex 4 31077, France
| | - Ajay Venugopal
- School of Chemistry, Indian Institute of Science Education and Research (IISER) Thiruvananthapuram, Vithura, Thiruvananthapuram 695551, India
| |
Collapse
|
6
|
Pérez-Jiménez M, Corona H, de la Cruz-Martínez F, Campos J. Donor-Acceptor Activation of Carbon Dioxide. Chemistry 2023; 29:e202301428. [PMID: 37494303 DOI: 10.1002/chem.202301428] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 07/28/2023]
Abstract
The activation and functionalization of carbon dioxide entails great interest related to its abundance, low toxicity and associated environmental problems. However, the inertness of CO2 has posed a challenge towards its efficient conversion to added-value products. In this review we discuss one of the strategies that have been widely used to capture and activate carbon dioxide, namely the use of donor-acceptor interactions by partnering a Lewis acidic and a Lewis basic fragment. This type of CO2 activation resembles that found in metalloenzymes, whose outstanding performance in catalytically transforming carbon dioxide encourages further bioinspired research. We have divided this review into three general sections based on the nature of the active sites: metal-free examples (mainly formed by frustrated Lewis pairs), main group-transition metal combinations, and transition metal heterobimetallic complexes. Overall, we discuss one hundred compounds that cooperatively activate carbon dioxide by donor-acceptor interactions, revealing a wide range of structural motifs.
Collapse
Affiliation(s)
- Marina Pérez-Jiménez
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Sevilla and Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 49, 41092, Sevilla, Spain
| | - Helena Corona
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Sevilla and Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 49, 41092, Sevilla, Spain
| | - Felipe de la Cruz-Martínez
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Sevilla and Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 49, 41092, Sevilla, Spain
| | - Jesús Campos
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Sevilla and Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 49, 41092, Sevilla, Spain
| |
Collapse
|
7
|
Wickemeyer L, Fernández I, Neumann B, Stammler HG, Mitzel NW. Selective 3,3-Rearrangement of Azobenzenes upon Complexation by a Frustrated Lewis Pair. Angew Chem Int Ed Engl 2023; 62:e202216943. [PMID: 36645230 DOI: 10.1002/anie.202216943] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/17/2023]
Abstract
The reaction of the oxygen-bridged frustrated Lewis pairs (FLPs) tBu2 P-O-Si(C2 F5 )3 (1) and tBu2 P-O-AlBis2 (2) with azobenzene, promoted by UV irradiation, led to a selective complexation of the cis-isomer. The addition product of 2 is stable, while the adduct of 1 isomerizes in solution in an ortho-benzidine-like [3,3]-rearrangement by cleavage of the N-N bond, saturation of the nitrogen atoms with hydrogen atoms and formation of a new bond between two phenyl ortho-carbon atoms. Similar rearrangements take place with different para-substituted azobenzenes (R=Me, OMe, Cl) and di(2-naphthyl)diazene, while ortho-methylated azo compounds do not form adducts with 1. All adducts were characterized by multinuclear NMR spectroscopy and elemental analyses and the mechanism of the rearrangement was explored by quantum-chemical calculations.
Collapse
Affiliation(s)
- Lucas Wickemeyer
- Lehrstuhl für Anorganische Chemie und Strukturchemie and Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Israel Fernández
- Departamento de Química Orgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria, 28040, Madrid, Spain
| | - Beate Neumann
- Lehrstuhl für Anorganische Chemie und Strukturchemie and Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Lehrstuhl für Anorganische Chemie und Strukturchemie and Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Norbert W Mitzel
- Lehrstuhl für Anorganische Chemie und Strukturchemie and Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| |
Collapse
|
8
|
Wickemeyer L, Hartmann L, Neumann B, Stammler H, Mitzel NW. Differences in the Reactivity of Geminal Si-O-P and Al-O-P Frustrated Lewis Pairs. Chemistry 2023; 29:e202202842. [PMID: 36349870 PMCID: PMC10107522 DOI: 10.1002/chem.202202842] [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: 09/12/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022]
Abstract
The new oxygen-bridged geminal Si/P Frustrated Lewis Pair (FLP) tBu2 P-O-Si(C2 F5 )3 (2) is able to reversibly bind carbon dioxide at ambient temperature. We compared its reactivity towards benzil, but-3-en-2-one, nitriles and phenylacetylene to that of the Al/P FLP tBu2 P-O-AlBis2 (Bis=-CH(SiMe3 )2 ) (1). When reacted with benzil, both, 1 and 2, form the 1,2-addition product, but in the Si/P FLP 2, the second carbonyl function additionally binds to the silicon atom. With but-3-en-2-one 2 forms the 1,2-addition product, while 1 binds in 1,4-position. The reaction with acetonitrile yielded an unexpected etheneimine adduct for both systems, while only 1 reacted with tert-butylnitrile. With benzonitrile and acrylonitrile, 2 showed reversible addition to the C≡N bond and 1 forms a stable adduct with benzonitrile. Solely 1 shows reactivity towards phenylacetylene affording a mixture of the CH deprotonation adduct tBu2 P(H)-O-AlBis2 (CCPh) and the FLP -C≡C 1,2-addition adduct under ring formation. All compounds were characterized by multinuclear NMR spectroscopy, XRD and elemental analysis.
Collapse
Affiliation(s)
- Lucas Wickemeyer
- Lehtuhl für Anorganische Chemie und Strukturchemie andCentrum für Molekulare Materialen CM2Fakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Lukas Hartmann
- Lehtuhl für Anorganische Chemie und Strukturchemie andCentrum für Molekulare Materialen CM2Fakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Beate Neumann
- Lehtuhl für Anorganische Chemie und Strukturchemie andCentrum für Molekulare Materialen CM2Fakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Hans‐Georg Stammler
- Lehtuhl für Anorganische Chemie und Strukturchemie andCentrum für Molekulare Materialen CM2Fakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Norbert W. Mitzel
- Lehtuhl für Anorganische Chemie und Strukturchemie andCentrum für Molekulare Materialen CM2Fakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| |
Collapse
|
9
|
Wickemeyer L, Trapp PC, Aders N, Neumann B, Stammler HG, Mitzel NW. Reactivity of Oxygen-Bridged Geminal Al/P and Si/P Frustrated Lewis Pairs towards Heterocumulenes. Chemistry 2023; 29:e202203685. [PMID: 36734185 DOI: 10.1002/chem.202203685] [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: 11/28/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/04/2023]
Abstract
The two oxygen-bridged geminal frustrated Lewis pairs (FLP) tBu2 P-O-AlBis2 (Bis=CH(SiMe3 )2 ; 1) and tBu2 P-O-Si(C2 F5 )3 (2) were reacted with the heterocumulenes PhNCO, PhOCN, PhNCS, CS2 and PhNSO as well as SO2 . With isocyanate and cyanate, both 1 and 2, form addition products under formation of five-membered rings. With CS2 , isothiocyanate and sulfinylaniline, only 1 forms stable adducts, whereas 2 shows reactivity towards sulfinylaniline, but the product decomposed after a few minutes. The reaction of 1 with SO2 led to partial cleavage of the P-O-Al and Al-C units, as confirmed by X-ray diffraction studies of a complex aggregate. The reaction of 2 with SO2 affords the 1,2-addition product. All adducts were characterized by means of multinuclear NMR spectroscopy, X-ray crystallography and CHN analyses.
Collapse
Affiliation(s)
- Lucas Wickemeyer
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Pia C Trapp
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Niklas Aders
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Beate Neumann
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Hans-Georg Stammler
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Norbert W Mitzel
- Lehrstuhl für Anorganische Chemie und Strukturchemie and, Centrum für Molekulare Materialen CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, 33615, Bielefeld, Germany
| |
Collapse
|