1
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Kornowicz A, Pietrzak T, Korona K, Terlecki M, Justyniak I, Kubas A, Lewiński J. Fresh Impetus in the Chemistry of Calcium Peroxides. J Am Chem Soc 2024; 146:18938-18947. [PMID: 38847558 PMCID: PMC11258691 DOI: 10.1021/jacs.4c00906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 07/18/2024]
Abstract
Redox-inactive metal ions are essential in modulating the reactivity of various oxygen-containing metal complexes and metalloenzymes, including photosystem II (PSII). The heart of this unique membrane-protein complex comprises the Mn4CaO5 cluster, in which the Ca2+ ion acts as a critical cofactor in the splitting of water in PSII. However, there is still a lack of studies involving Ca-based reactive oxygen species (ROS) systems, and the exact nature of the interaction between the Ca2+ center and ROS in PSII still generates intense debate. Here, harnessing a novel Ca-TEMPO complex supported by the β-diketiminate ligand to control the activation of O2, we report the isolation and structural characterization of hitherto elusive Ca peroxides, a homometallic Ca hydroperoxide and a heterometallic Ca/K peroxide. Our studies indicate that the presence of K+ cations is a key factor controlling the outcome of the oxygenation reaction of the model Ca-TEMPO complex. Combining experimental observations with computational investigations, we also propose a mechanistic rationalization for the reaction outcomes. The designed approach demonstrates metal-TEMPO complexes as a versatile platform for O2 activation and advances the understanding of Ca/ROS systems.
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Affiliation(s)
- Arkadiusz Kornowicz
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Tomasz Pietrzak
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Krzesimir Korona
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Michał Terlecki
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Iwona Justyniak
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Adam Kubas
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Janusz Lewiński
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
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2
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Terlecki M, Justyniak I, Leszczyński MK, Bernatowicz P, Lewiński J. Factors controlling the structure of alkylzinc amidinates: on the role of N-substituents. Dalton Trans 2023; 52:2712-2721. [PMID: 36748844 DOI: 10.1039/d2dt03722j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Despite various applications of alkylzinc complexes supported by N,N-bidentate ligands in chemistry and materials science, the corresponding organozinc amidinates still represent an insufficiently explored area. To gain a more in-depth understanding of factors controlling the structure and stability of alkylzinc amidinates, we selected benzamidinate and N,N'-diphenylformamidinate ligands as model N,N'-unsubstituted and N,N'-diaryl substituted ligands, respectively, to systematically modify the secondary coordination sphere of the Zn center. A series of new alkylzinc amidinates has been synthesized and their molecular structures identified in both the solid state (single-crystal X-ray crystallography) and solution (NMR and FTIR spectroscopy). The results indicate that [RZnL]x-type amidinate moieties are essentially unstable and tend to undergo Schlenk equilibria-mediated ligand scrambling leading to more thermodynamically stable non-stoichiometric [R2Zn3L4]- and [R3Zn4L5]-type complexes. This process is significantly influenced by the secondary coordination sphere noncovalent interactions as well as the steric hindrance provided by both zinc-bounded alkyl groups and the N-substituents.
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Affiliation(s)
- Michał Terlecki
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Michał K Leszczyński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. .,Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Piotr Bernatowicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Janusz Lewiński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. .,Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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3
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Parr JM, Phanopoulos A, Vickneswaran A, Crimmin MR. Understanding the role of ring strain in β-alkyl migration at Mg and Zn centres. Chem Sci 2023; 14:1590-1597. [PMID: 36794202 PMCID: PMC9906642 DOI: 10.1039/d2sc06288g] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/07/2023] [Indexed: 01/11/2023] Open
Abstract
The activation of C-C σ-bonds within strained three- and four-membered hydrocarbons at electrophilic Mg and Zn centres is reported. This was achieved in a two-step process involving (i) hydrometallation of a methylidene cycloalkane followed by (ii) intramolecular C-C bond activation. While hydrometallation of methylidene cyclopropane, cyclobutane, cyclopentane and cyclohexane occurs for both Mg and Zn reagents, the C-C bond activation step is sensitive to ring size. For Mg, both cyclopropane and cyclobutane rings participate in C-C bond activation. For Zn, only the smallest cyclopropane ring reacts. These findings were used to expand the scope of catalytic hydrosilylation of C-C σ-bonds to include cyclobutane rings. The mechanism of C-C σ-bond activation was investigated through kinetic analysis (Eyring), spectroscopic observation of intermediates, and a comprehensive series of DFT calculations, including activation strain analysis. Based on our current understanding, C-C bond activation is proposed to occur by a β-alkyl migration step. β-Alkyl migration is more facile for more strained rings and occurs with lower barriers for Mg compared to Zn. Relief of ring strain is a key factor in determining the thermodynamics of C-C bond activation, but not in stabilising the transition state for β-alkyl migration. Rather, we ascribe the differences in reactivity to the stabilising interaction between the metal centre and the hydrocarbon ring-system, with the smaller rings and more electropositive metal (Mg) leading to a smaller destabilisation interaction energy as the transition state is approached. Our findings represent the first example of C-C bond activation at Zn and provide detailed new insight into the factors at play in β-alkyl migration at main group centres.
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Affiliation(s)
- Joseph M. Parr
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London82 Wood Lane, White City, Shepherds BushLondonW12 0BZUK
| | - Andreas Phanopoulos
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London 82 Wood Lane, White City, Shepherds Bush London W12 0BZ UK
| | - Aaranjah Vickneswaran
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London 82 Wood Lane, White City, Shepherds Bush London W12 0BZ UK
| | - Mark R. Crimmin
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London82 Wood Lane, White City, Shepherds BushLondonW12 0BZUK
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4
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Korona K, Kornowicz A, Justyniak I, Terlecki M, Błachowski A, Lewiński J. Non-redox reactivity of V( ii) and Fe( ii) formamidinates towards CO 2 resulting in the formation of novel M( ii) carbamates. Dalton Trans 2022; 51:16557-16564. [DOI: 10.1039/d2dt02274e] [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
Multiple CO2 insertions into the M–N bonds of V(ii) and Fe(ii) bis(formamidinates) led to the isolation of three novel carbamates. The CO2 insertion effectivity depended on the solvent used and the metal centre's coordination sphere geometry.
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Affiliation(s)
- Krzesimir Korona
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Arkadiusz Kornowicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Michał Terlecki
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Artur Błachowski
- AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection, al. Mickiewicza 30, 30-059 Kraków, Poland
| | - Janusz Lewiński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warszawa, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
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5
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Tulewicz A, Szejko V, Justyniak I, Wolska M, Lewinski J. Exploring the reactivity of homoleptic organozincs towards SO 2: Synthesis and structure of a homologous series of organozinc sulfinates. Dalton Trans 2022; 51:7241-7247. [DOI: 10.1039/d2dt00577h] [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
Studies on the reactivity of zinc alkyl compounds towards SO2 are relatively less explored than either the oxygenation or hydrolysis reactions. We report on environmentally friendly and efficient syntheses of...
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6
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Budny-Godlewski K, Leszczyński MK, Tulewicz A, Justyniak I, Pinkowicz D, Sieklucka B, Kruczała K, Sojka Z, Lewiński J. A Case Study on the Desired Selectivity in Solid-State Mechano- and Slow-Chemistry, Melt, and Solution Methodologies. CHEMSUSCHEM 2021; 14:3887-3894. [PMID: 34289248 DOI: 10.1002/cssc.202101269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Solution-based syntheses are omnipresent in chemistry but are often associated with obvious disadvantages, and the search for new mild and green synthetic methods continues to be a hot topic. Here, comparative studies in four different reaction media were conducted, that is, the solid-state mechano- and slow-chemistry synthesis, melted phase, and solution protocols, and the impact of the employed solvent-free solid-state versus liquid-phase synthetic approaches was highlighted on a pool of products. A moderately exothermic model reaction system was chosen based on bis(pentafluorophenyl)zinc, (C6 F5 )2 Zn, and 2,2,6,6-tetramethylpiperidinyl oxide (TEMPO) as a stable nitroxyl radical, anticipating that these reagents may offer a unique landscape for addressing kinetic and thermodynamic aspects of wet and solvent-free solid-state processes. In a toluene solution two distinct paramagnetic Lewis acid-base adducts (C6 F5 )2 Zn(η1 -TEMPO) (1) and (C6 F5 )2 Zn(η1 -TEMPO)2 (2) equilibrated, but only 2 was affordable by crystallization. In turn, crystallization from the melt was the only method yielding single crystals of 1. Moreover, the solid-state approaches were stoichiometry sensitive and allowed for the selective synthesis of both adducts by simple stoichiometric control over the substrates. Density functional theory (DFT) calculations were carried out to examine selected structural and thermodynamic features of the adducts 1 and 2. Compound 2 is a unique non-redox active metal complex supported by two nitroxide radicals, and the magnetic studies revealed weak-to-moderate intramolecular antiferromagnetic interactions between the two coordinated TEMPO molecules.
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Affiliation(s)
- Krzysztof Budny-Godlewski
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Michał K Leszczyński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Adam Tulewicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Dawid Pinkowicz
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Cracow, Poland
| | - Barbara Sieklucka
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Cracow, Poland
| | - Krzysztof Kruczała
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Cracow, Poland
| | - Zbigniew Sojka
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Cracow, Poland
| | - Janusz Lewiński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
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7
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Towards deeper understanding of multifaceted chemistry of magnesium alkylperoxides. Commun Chem 2021; 4:123. [PMID: 36697811 PMCID: PMC9814855 DOI: 10.1038/s42004-021-00560-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/02/2021] [Indexed: 01/28/2023] Open
Abstract
Despite considerable progress in the multifaceted chemistry of non-redox-metal alkylperoxides, the knowledge about magnesium alkylperoxides is in its infancy and only started to gain momentum. Harnessing the well-defined dimeric magnesium tert-butylperoxide [(f5BDI)Mg(μ-η2:η1-OOtBu)]2 incorporating a fluorinated β-diketiminate ligand, herein, we demonstrate its transformation at ambient temperature to a spiro-type, tetranuclear magnesium alkylperoxide [(f5BDI)2Mg4(μ-OOtBu)6]. The latter compound was characterized by single-crystal X-ray diffraction and its molecular structure can formally be considered as a homoleptic magnesium tert-butylperoxide [Mg(µ-OOtBu)2]2 terminated by two monomeric magnesium tert-butylperoxides. The formation of the tetranuclear magnesium alkylperoxide not only contradicts the notion of the high instability of magnesium alkylperoxides, but also highlights that there is much to be clarified with respect to the solution behaviour of these species. Finally, we probed the reactivity of the dimeric alkylperoxide in model oxygen transfer reactions like the commonly invoked metathesis reaction with the parent alkylmagnesium and the catalytic epoxidation of trans-chalcone with tert-butylhydroperoxide as an oxidant. The results showed that the investigated system is among the most active known catalysts for the epoxidation of enones.
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8
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Zelga K, Pietrzak T, Han T, Justyniak I, Chwojnowska E, Sobota P, Lewiński J. Effectiveness of the Oxygenation over Classical Protonolysis Reactions: A Case of Alkylzinc Complexes Incorporating an Aminoalcoholate Ligand. Chemistry 2021; 27:14234-14239. [PMID: 34346529 DOI: 10.1002/chem.202102172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Indexed: 11/06/2022]
Abstract
Alkylzinc aminoalcoholates have emerged as powerful catalysts in organic synthesis and polymerization processes. Despite extensive research, difficulties in the rational design of these catalytic systems and in-depth understanding of their modes of action have hitherto been encountered. Most of the major obstacles stem largely from the relatively limited knowledge of the structure-activity relationship of zinc catalysts. In fact, the key active species are often generated in situ via the protonolysis of the alkylzinc precursors, which precludes their isolation and detailed characterization. Herein, the effectiveness of the oxygenation over the classical protonolysis in the synthesis of zinc alkylperoxides stabilized by an aminoalcoholate ligand is demonstrated. The controlled oxygenation of a tert-butylzinc complex incorporating a pridinolum (prinol) ligand leads to well-defined a dinuclear adduct of a (prinol)ZnOOtBu moiety with the parent tBuZn(prinol) complex and a novel dimer [tBuOOZn(prinol)]2 with terminal alkylperoxide groups. The observed reaction outcomes strongly depend on the reaction conditions. Although sparse examples of heteroleptic adducts of the [RZn(L)]x [ROOZn(L)]y -type are known, the herein reported homoleptic [ROOZn(L)]x aggregate is unprecedented. Strikingly, comparative studies involving reactions between tBuZn(prinol) and tert-butylhydroperoxide or ethanol revealed that the respective seemingly simple zinc alkylperoxides, or zinc alkoxides, respectively, are not accessible via the classical alcoholysis. We believe that these game-changing results concerning multifaceted chemistry of organozinc aminoalcoholates should pave the way for more rational development of various Zn-based catalytic systems.
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Affiliation(s)
- Karolina Zelga
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Tomasz Pietrzak
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Tomasz Han
- Faculty of Chemistry, University of Wrocław Polish Academy of Science, F. Joliot-Curie '4, 50-383, Wrocław, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Science, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Elżbieta Chwojnowska
- Institute of Physical Chemistry, Polish Academy of Science, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Piotr Sobota
- Faculty of Chemistry, University of Wrocław Polish Academy of Science, F. Joliot-Curie '4, 50-383, Wrocław, Poland
| | - Janusz Lewiński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland.,Institute of Physical Chemistry, Polish Academy of Science, Kasprzaka 44/52, 01-224, Warsaw, Poland
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9
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Jaszczewska‐Adamczak JA, Mlynarski J. Asymmetric Epoxidation of Enones Promoted by Dinuclear Magnesium Catalyst. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Jacek Mlynarski
- Institute of Organic Chemistry Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
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10
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Rola-Noworyta A, Pietrzak T, Szejko V, Justyniak I, Lewiński J. Unveiling Complexity of the Oxygenation of Aluminum Alkyls by the Isolation of Unique Alkylperoxide and Oxoalkoxide Compounds. Inorg Chem 2020; 59:13807-13811. [PMID: 32806017 PMCID: PMC7539294 DOI: 10.1021/acs.inorgchem.0c01962] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
While aluminum alkyls are often considered
to be exemplary compounds of main-group organometallics and an in-depth
understanding of their multifaceted chemistry is continually vital,
the controlled oxygenation of organoaluminum complexes still remains
a largely undeveloped area. In the course of our systematic studies
on the relationship between the Lewis acidity of metal centers and
noncovalent interactions in the secondary coordination sphere, we
report the oxygenation of dialkylaluminum complexes incorporating
a pyrrole–ester ligand, as purposefully selected dormant Lewis
acidic octet-compliant model compounds, and the isolation and characterization
of a new, dimeric aluminum tert-butylperoxide and
an unique example of an aluminum oxoethoxide cluster. Our studies
provide a more in-depth look at the diversity and complexity of the
oxygenation chemistry of aluminum alkyls. We report the reactions of dialkylaluminum complexes incorporating
a pyrrole−ester ligand with dioxygen as well as the isolation
of a novel aluminum tert-butylperoxide and an unique
example of aluminum oxoethoxide. Our studies provide a more in-depth
look at the diversity and complexity of the oxygenation chemistry
of aluminum alkyls.
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Affiliation(s)
- Anna Rola-Noworyta
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Tomasz Pietrzak
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Vadim Szejko
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Janusz Lewiński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.,Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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Monleón A, Montesinos-Magraner M, Sanz-Marco A, Blay G, Pedro JR. Three-Component Synthesis of α-Aminoperoxides Using Primary and Secondary Dialkylzinc Reagents with O 2 and α-Amido Sulfones. Org Lett 2020; 22:5380-5384. [PMID: 32585111 DOI: 10.1021/acs.orglett.0c01692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A straightforward strategy for the synthesis of unprecedented α-aminoperoxides bearing primary and secondary alkylperoxide substituents is described. Commercially available dialkylzinc reagents are oxidized with molecular oxygen and the consequent peroxide species react with stable (hetero)aromatic and aliphatic α-amido sulfones in excellent yields (>90%). The now available α-aminoperoxides are of potential interest in medicinal chemistry, specifically for the synthesis of antimalarial compounds. Moreover, modification of the reaction conditions selectively leads to N,O-acetals in good yields.
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Affiliation(s)
- Alicia Monleón
- Department de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain
| | - Marc Montesinos-Magraner
- Department de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain
| | - Amparo Sanz-Marco
- Department de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain
| | - Gonzalo Blay
- Department de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain
| | - José R Pedro
- Department de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain
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12
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Komorski S, Leszczyński MK, Justyniak I, Lewiński J. Structural diversity of ethylzinc derivatives of 3,5-substituted pyrazoles. Dalton Trans 2020; 49:17388-17394. [PMID: 33211038 DOI: 10.1039/d0dt03026k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Equimolar reactions of Et2Zn with 3,5-dimethylpyrazole (H-pzMe2), 3,5-di-iso-propylpyrazole (H-pziPr2), 3,5-di-tert-butylpyrazole (H-pztBu2) and indazole (H-ind) were investigated in toluene or tetrahydrofuran (as a coordinating solvent). A series of diverse ethylzinc pyrazolates and indazolates were identified using advanced NMR spectroscopy and the single crystal X-ray diffraction techniques. The NMR experiments indicate that dimeric moieties of the general formula [EtZn(pz)]2 or [Et2Zn2(pz)2(THF)] are favoured in solution. Nevertheless, these types of complexes are kinetically labile and tend to undergo ligand scrambling reactions according to the Schlenk equilibrium. For example, the alkyl substituents in the pzMe2 and pziPr2 ligands do not appear to be a strong determinant of the dimeric moieties and the composition of the isolated complexes by crystallisation from the parent reaction mixture varies between spiro-type tri- and tetranuclear aggregates, [Et2Zn3(pz)4(THF)x] (x = 0 or 2) and [Et2Zn4(pz)6(THF)2], respectively. The nonstoichiometric formula of these organozinc derivatives is likely related to both the Schlenk-type equilibria and solubility of the respective moieties. In turn, the high steric demands of the 3,5-di-tert-butylpyrazolate ligand promote the dimeric form in solution and the solid state. Interestingly, the ethylzinc indazolate complex also does not undergo a redistribution reaction and yields a dimer.
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Affiliation(s)
- Szymon Komorski
- Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
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13
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Tulewicz A, Wolska-Pietkiewicz M, Jędrzejewska M, Ratajczyk T, Justyniak I, Lewiński J. Towards Extended Zinc Ethylsulfinate Networks by Stepwise Insertion of Sulfur Dioxide into Zn-C Bonds. Chemistry 2019; 25:14072-14080. [PMID: 31379036 DOI: 10.1002/chem.201902733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/31/2019] [Indexed: 11/06/2022]
Abstract
The ability to utilize polluting gases in efficient metal-mediated transformations is one of the most pressing challenges of modern chemistry. Despite numerous studies on the insertion of SO2 into M-C bonds, the chemical reaction of SO2 with organozinc compounds remains little explored. To fill this gap, we report here the systematic study of the reaction of Et2 Zn towards SO2 as well as the influence of Lewis bases on the reaction course. Whereas the equimolar reaction provided a novel example of a structurally characterized organozinc ethylsulfinate compound of general formula [(EtSO2 )ZnEt]n , the utilization of an excess of SO2 led to the formation of the zinc(II) bis(ethylsulfinate) compound [(EtSO2 )2 Zn]n . Moreover, we have discovered that the presence of N-donor Lewis bases represents an efficient tool for the preparation of extended zinc ethylsulfinates, which in turn led to the formation of 1D [(EtSO2 ZnEt)2 (hmta)]n and 2D [((EtSO2 )2 Zn)2 (DABCO)]n ⋅solv (in which solv=THF or toluene, hmta= hexamethylenetetramine, and DABCO=1,4-diazabicyclo[2.2.2]octane) coordination polymers, respectively. The results of DFT calculations on the reactivity of SO2 towards selected Zn-C reactive species as well as the role of an N-donor Lewis base on the stabilization of the transition states complement the discussion.
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Affiliation(s)
- Adam Tulewicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | | | - Maria Jędrzejewska
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Tomasz Ratajczyk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Iwona Justyniak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Janusz Lewiński
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.,Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
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