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Marín-Valls R, Hernández K, Bolte M, Parella T, Joglar J, Bujons J, Clapés P. Biocatalytic Construction of Quaternary Centers by Aldol Addition of 3,3-Disubstituted 2-Oxoacid Derivatives to Aldehydes. J Am Chem Soc 2020; 142:19754-19762. [PMID: 33147013 DOI: 10.1021/jacs.0c09994] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The congested nature of quaternary carbons hinders their preparation, most notably when stereocontrol is required. Here we report a biocatalytic method for the creation of quaternary carbon centers with broad substrate scope, leading to different compound classes bearing this structural feature. The key step comprises the aldol addition of 3,3-disubstituted 2-oxoacids to aldehydes catalyzed by metal dependent 3-methyl-2-oxobutanoate hydroxymethyltransferase from E. coli (KPHMT) and variants thereof. The 3,3,3-trisubstituted 2-oxoacids thus produced were converted into 2-oxolactones and 3-hydroxy acids and directly to ulosonic acid derivatives, all bearing gem-dialkyl, gem-cycloalkyl, and spirocyclic quaternary centers. In addition, some of these reactions use a single enantiomer from racemic nucleophiles to afford stereopure quaternary carbons. The notable substrate tolerance and stereocontrol of these enzymes are indicative of their potential for the synthesis of structurally intricate molecules.
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Shapenova DS, Shiryaev AA, Bolte M, Kukułka M, Szczepanik DW, Hooper J, Babashkina MG, Mahmoudi G, Mitoraj MP, Safin DA. Cover Feature: Resonance Assisted Hydrogen Bonding Phenomenon Unveiled through Both Experiments and Theory: A New Family of Ethyl N‐Salicylideneglycinate Dyes (Chem. Eur. J. 57/2020). Chemistry 2020. [DOI: 10.1002/chem.202002769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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53
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Kaehler T, John A, Jin T, Bolte M, Lerner H, Wagner M. Selective Vicinal Diiodination of Polycyclic Aromatic Hydrocarbons. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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54
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Georg I, Bursch M, Stückrath JB, Alig E, Bolte M, Lerner HW, Grimme S, Wagner M. Building up Strain in One Step: Synthesis of an Edge-Fused Double Silacyclobutene from an Extensively Trichlorosilylated Butadiene Dianion. Angew Chem Int Ed Engl 2020; 59:16181-16187. [PMID: 32484309 PMCID: PMC7540532 DOI: 10.1002/anie.202006463] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/27/2020] [Indexed: 01/10/2023]
Abstract
The exhaustive trichlorosilylation of hexachloro‐1,3‐butadiene was achieved in one step by using a mixture of Si2Cl6 and [nBu4N]Cl (7:2 equiv) as the silylation reagent. The corresponding butadiene dianion salt [nBu4N]2[1] was isolated in 36 % yield after recrystallization. The negative charges of [1]2− are mainly delocalized across its two carbanionic (Cl3Si)2C termini (α‐effect of silicon) such that the central bond possesses largely C=C double‐bond character. Upon treatment with 4 equiv of HCl, [1]2− is converted into neutral 1,2,3,4‐tetrakis(trichlorosilyl)but‐2‐ene, 3. The Cl− acceptor AlCl3, induces a twofold ring‐closure reaction of [1]2− to form a six‐membered bicycle 4 in which two silacyclobutene rings are fused along a shared C=C double bond (84 %). Compound 4, which was structurally characterized by X‐ray crystallography, undergoes partial ring opening to a monocyclic silacyclobutene 2 in the presence of HCl, but is thermally stable up to at least 180 °C.
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55
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Georg I, Bursch M, Stückrath JB, Alig E, Bolte M, Lerner H, Grimme S, Wagner M. Building up Strain in One Step: Synthesis of an Edge‐Fused Double Silacyclobutene from an Extensively Trichlorosilylated Butadiene Dianion. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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56
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Shapenova DS, Shiryaev AA, Bolte M, Kukułka M, Szczepanik DW, Hooper J, Babashkina MG, Mahmoudi G, Mitoraj MP, Safin DA. Resonance Assisted Hydrogen Bonding Phenomenon Unveiled through Both Experiments and Theory: A New Family of Ethyl N-Salicylideneglycinate Dyes. Chemistry 2020; 26:12987-12995. [PMID: 32428288 DOI: 10.1002/chem.202001551] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/07/2020] [Indexed: 11/06/2022]
Abstract
Extensive experimental and theoretical investigations are reported on the nature of resonance-assisted hydrogen bonding phenomenon (RAHB) and its influence on photophysical properties of the newly designed dyes differing in donor-acceptor properties, namely ethyl N-salicylideneglycinate (1), ethyl N-(5-methoxysalicylidene)glycinate (2), ethyl N-(5-bromosalicylidene)glycinate (3) and ethyl N-(5-nitrosalicylidene)glycinate (4). All compounds are thermochromic in the solid state and they contain a typical intramolecular O-H⋅⋅⋅N hydrogen bond formed between the hydroxyl hydrogen atom and the imine nitrogen atom, yielding the enol form in the solid state. It is unveiled, that the magnitude of RAHB effect fine tunes the strength of the O-H⋅⋅⋅N bonding and accordingly the relative populations of the enol, cis-keto and trans-keto forms leading to variation of the photophysical properties of 1-4. It is determined, that the electron-withdrawing NO2 in 4 amplifies the most RAHB effect causing the breaking of the O-H⋅⋅⋅N hydrogen bond and accordingly formation of the dominant cis-keto isomer in both the solid state and EtOH. To this end, the UV/Vis spectra of 1-3 in EtOH revealed the exclusive presence of the enol form, while the prevalent contribution of the cis-keto form was found for 4. Furthermore, only compound 4 is emissive in the solid state in ambient condition due to dual emission arising from the cis-keto* and trans-keto* forms, while 2 was found to be highly emissive in EtOH. It is revealed qualitatively and quantitatively, based on the ETS-NOCV charge and energy decomposition scheme and the EDDB population-based method, that RAHB is strongly a non-local phenomenon based on electrons pumping or sucking through both the π- and σ-channels, which accordingly exerts chemical bonding changes at both the phenyl ring and predominantly a distant O-H⋅⋅⋅N area.
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57
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Werner P, Wächter T, Asyuda A, Wiesner A, Kind M, Bolte M, Weinhardt L, Terfort A, Zharnikov M. Electron Transfer Dynamics and Structural Effects in Benzonitrile Monolayers with Tuned Dipole Moments by Differently Positioned Fluorine Atoms. ACS APPLIED MATERIALS & INTERFACES 2020; 12:39859-39869. [PMID: 32805830 DOI: 10.1021/acsami.0c10513] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To understand the influence of the molecular dipole moment on the electron transfer (ET) dynamics across the molecular framework, two series of differently fluorinated, benzonitrile-based self-assembled monolayers (SAMs) bound to Au(111) by either thiolate or selenolate anchoring groups were investigated. Within each series, the molecular structures were the same with the exception of the positions of two fluorine atoms affecting the dipole moment of the SAM-forming molecules. The SAMs exhibited a homogeneous anchoring to the substrate, nearly upright molecular orientations, and the outer interface comprised of the terminal nitrile groups. The ET dynamics was studied by resonant Auger electron spectroscopy in the framework of the core-hole clock method. Resonance excitation of the nitrile group unequivocally ensured an ET pathway from the tail group to the substrate. As only one of the π* orbitals of this group is hybridized with the π* system of the adjacent phenyl ring, two different ET times could be determined depending on the primary excited orbital being either localized at the nitrile group or delocalized over the entire benzonitrile moiety. The latter pathway turned out to be much more efficient, with the characteristic ET times being a factor 2.5-3 shorter than those for the localized orbital. The dynamic ET properties of the analogous thiolate- and selenolate-based adsorbates were found to be nearly identical. Finally and most importantly, these properties were found to be unaffected by the different patterns of the fluorine substitution used in the present study, thus showing no influence of the molecular dipole moment.
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Tapmeyer L, Hill S, Bolte M, Hützler WM. Two monosodium salt hydrates of Colour Index Pigment Red 48. Acta Crystallogr C Struct Chem 2020; 76:716-722. [PMID: 32756033 DOI: 10.1107/s2053229620008530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/25/2020] [Indexed: 11/10/2022] Open
Abstract
We report herein the crystal structures of a monohydrate of Colour Index Pigment Red 48 (P.R.48) (systematic name: monosodium 2-{2-[3-carboxy-2-oxo-1,2-dihydronaphthalen-1-ylidene]hydrazin-1-yl}-4-chloro-5-methylbenzenesulfonate monohydrate), Na+·C18H12ClO6S-·H2O, and a dihydrate, Na+·C18H12ClO6S-·2H2O. The two monosodium salt hydrates of P.R.48 were obtained from in-house synthesized P.R.48. Both have monoclinic (P21/c) symmetry at 173 K. The crystal packing of both crystal structures shows a layer arrangement whereby N-H...O and O-H...O hydrogen bonds are formed.
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59
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Elamri I, Radloff M, Hohmann KF, Nimbarte VD, Nasiri HR, Bolte M, Safarian S, Michel H, Schwalbe H. Synthesis and Biological Screening of New Lawson Derivatives as Selective Substrate-Based Inhibitors of Cytochrome bo 3 Ubiquinol Oxidase from Escherichia coli. ChemMedChem 2020; 15:1262-1271. [PMID: 32159929 PMCID: PMC7497249 DOI: 10.1002/cmdc.201900707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/20/2020] [Indexed: 01/13/2023]
Abstract
The respiratory chain of Escherichia coli contains two different types of terminal oxidase that are differentially regulated as a response to changing environmental conditions. These oxidoreductases catalyze the reduction of molecular oxygen to water and contribute to the proton motive force. The cytochrome bo3 oxidase (cyt bo3 ) acts as the primary terminal oxidase under atmospheric oxygen levels, whereas the bd-type oxidase is most abundant under microaerobic conditions. In E. coli, both types of respiratory terminal oxidase (HCO and bd-type) use ubiquinol-8 as electron donor. Here, we assess the inhibitory potential of newly designed and synthesized 3-alkylated Lawson derivatives through L-proline-catalyzed three-component reductive alkylation (TCRA). The inhibitory effects of these Lawson derivatives on the terminal oxidases of E. coli (cyt bo3 and cyt bd-I) were tested potentiometrically. Four compounds were able to reduce the oxidoreductase activity of cyt bo3 by more than 50 % without affecting the cyt bd-I activity. Moreover, two inhibitors for both cyt bo3 and cyt bd-I oxidase could be identified. Based on molecular-docking simulations, we propose binding modes of the new Lawson inhibitors. The molecular fragment benzyl enhances the inhibitory potential and selectivity for cyt bo3 , whereas heterocycles reduce this effect. This work extends the library of 3-alkylated Lawson derivatives as selective inhibitors for respiratory oxidases and provides molecular probes for detailed investigations of the mechanisms of respiratory-chain enzymes of E. coli.
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Elamri I, Radloff M, Hohmann KF, Nimbarte VD, Nasiri HR, Bolte M, Safarian S, Michel H, Schwalbe H. Front Cover: Synthesis and Biological Screening of New Lawson Derivatives as Selective Substrate‐Based Inhibitors of Cytochrome
bo
3
Ubiquinol Oxidase from
Escherichia coli
(ChemMedChem 14/2020). ChemMedChem 2020. [DOI: 10.1002/cmdc.202000481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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61
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Schödel F, Lerner HW, Bolte M. [1,3-Bis(2,6-diisopropylphenyl)-1,3-dihydro-2 H-imidazol-2-ylidene]triiodoborane benzene hemisolvate. IUCRDATA 2020; 5:x200863. [PMID: 36340616 PMCID: PMC9462236 DOI: 10.1107/s2414314620008639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 11/21/2022] Open
Abstract
In the title hemisolvate, the dihedral angles between the central heterocyclic ring and pendant benzene rings are 82.9 (8) and 88.7 (9)° and the complete benzene solvent molecule of crystallization is generated by a crystallographic centre of inversion. In the crystal, one very weak C—H⋯I interaction links the molecules into [001] chains. In the title hemisolvate, C27H36BI3N2.0.5C6H6, the dihedral angles between the central heterocyclic ring and pendant benzene rings are 82.9 (8) and 88.7 (9)° and the complete benzene solvent molecule of crystallization is generated by a crystallographic centre of inversion. In the crystal, one very weak C—H⋯I interaction links the molecules into [001] chains.![]()
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62
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Scholz AS, Massoth JG, Bursch M, Mewes JM, Hetzke T, Wolf B, Bolte M, Lerner HW, Grimme S, Wagner M. BNB-Doped Phenalenyls: Modular Synthesis, Optoelectronic Properties, and One-Electron Reduction. J Am Chem Soc 2020; 142:11072-11083. [PMID: 32464052 DOI: 10.1021/jacs.0c03118] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A highly modular synthesis of BNB- and BOB-doped phenalenyls is presented. Treatment of the 1,8-naphthalenediyl-bridged boronic acid anhydride 1 with LiAlH4/Me3SiCl afforded the corresponding 1,8-naphthalenediyl-supported diborane(6) 2, which served as the starting material for all subsequent transformations. Upon addition of MesMgBr/Me3SiCl, 2 was readily converted to the tetraorganyl diborane(6) 5. The further heteroatoms were finally introduced through the reaction of 2 with (Me3Si)2NR' or 5 with H2NR' or H2O (R' = H, Me, p-Tol). A helically twisted, fully BNB-embedded PAH 11 was prepared by combining 2 with a dibrominated m-terphenylamine, followed by a Grignard-mediated double ring-closure reaction. All compounds devoid of B-H bonds show favorable optoelectronic properties, such as luminescence and reversible reduction behavior. In the case of the BNB-phenalenyl 7 (BMes, NMe), the radical-anion salt K[7•] was generated through chemical reduction with K metal and characterized by EPR spectroscopy. K[7•] is not long-term stable in a THF/c-hexane solution, but abstracts an H atom with formation of the diamagnetic BNB-doped 1H-phenalene K[7H].
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Trageser T, Bolte M, Lerner HW, Wagner M. B-B Bond Nucleophilicity in a Tetraaryl μ-Hydridodiborane(4) Anion. Angew Chem Int Ed Engl 2020; 59:7726-7731. [PMID: 32058652 PMCID: PMC7317828 DOI: 10.1002/anie.202000292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Indexed: 11/15/2022]
Abstract
The tetraaryl μ‐hydridodiborane(4) anion [2H]− possesses nucleophilic B−B and B−H bonds. Treatment of K[2H] with the electrophilic 9‐H‐9‐borafluorene (HBFlu) furnishes the B3 cluster K[3], with a triangular boron core linked through two BHB two‐electron, three‐center bonds and one electron‐precise B−B bond, reminiscent of the prominent [B3H8]− anion. Upon heating or prolonged stirring at room temperature, K[3] rearranges to a slightly more stable isomer K[3 a]. The reaction of M[2H] (M+=Li+, K+) with MeI or Me3SiCl leads to equimolar amounts of 9‐R‐9‐borafluorene and HBFlu (R=Me or Me3Si). Thus, [2H]− behaves as a masked [:BFlu]− nucleophile. The HBFlu by‐product was used in situ to establish a tandem substitution‐hydroboration reaction: a 1:1 mixture of M[2H] and allyl bromide gave the 1,3‐propylene‐linked ditopic 9‐borafluorene 5 as sole product. M[2H] also participates in unprecedented [4+1] cycloadditions with dienes to furnish dialkyl diaryl spiroborates, M[R2BFlu].
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64
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Gilmer J, Budy H, Kaese T, Bolte M, Lerner H, Wagner M. The 9H-9-Borafluorene Dianion: A Surrogate for Elusive Diarylboryl Anion Nucleophiles. Angew Chem Int Ed Engl 2020; 59:5621-5625. [PMID: 31834978 PMCID: PMC7155136 DOI: 10.1002/anie.201914219] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Indexed: 11/13/2022]
Abstract
Double reduction of the THF adduct of 9H-9-borafluorene (1⋅THF) with excess alkali metal affords the dianion salts M2 [1] in essentially quantitative yields (M=Li-K). Even though the added charge is stabilized through π delocalization, [1]2- acts as a formal boron nucleophile toward organoboron (1⋅THF) and tetrel halide electrophiles (MeCl, Et3 SiCl, Me3 SnCl) to form B-B/C/Si/Sn bonds. The substrate dependence of open-shell versus closed-shell pathways has been investigated.
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Trageser T, Bolte M, Lerner H, Wagner M. B−B Bond Nucleophilicity in a Tetraaryl μ‐Hydridodiborane(4) Anion. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000292] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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66
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Schödel F, Bolte M, Wagner M, Lerner H. NHC Supersilyl Silver Complex [Ag(IPr)Si
t
Bu
3
] as a Promising Agent for Substitution Reactions. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.201900304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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67
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Tillmann J, Lerner HW, Bolte M. A new pseudopolymorph of perchlorinated neo-penta-silane: the benzene monosolvate Si(SiCl 3) 4·C 6H 6. ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS 2020; 76:261-263. [PMID: 32071758 PMCID: PMC7001847 DOI: 10.1107/s2056989020000900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/23/2020] [Indexed: 11/21/2022]
Abstract
A new pseudopolymorph of dodecachloropentasilane, namely a benzene monosolvate, Si5Cl12.C6H6, is described. There are two half molecules of each kind in the asymmetric unit. Both Si5Cl12 molecules are completed by crystallographic twofold symmetry. One of the benzene molecules is located on a twofold rotation axis with two C—H groups located on this rotation axis. The second benzene molecule has all atoms on a general position: it is disordered over two equally occupied orientations. No directions interactions beyond normal van der Waals’ contacts occur in the crystal. A new pseudopolymorph of dodecachloropentasilane, namely a benzene monosolvate, Si5Cl12·C6H6, is described. There are two half molecules of each kind in the asymmetric unit. Both Si5Cl12 molecules are completed by crystallographic twofold symmetry. One of the benzene molecules is located on a twofold rotation axis with two C—H groups located on this rotation axis. The second benzene molecule has all atoms on a general position: it is disordered over two equally occupied orientations. No directional interactions beyond normal van der Waals contacts occur in the crystal.
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Gilmer J, Budy H, Kaese T, Bolte M, Lerner H, Wagner M. The 9
H
‐9‐Borafluorene Dianion: A Surrogate for Elusive Diarylboryl Anion Nucleophiles. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914219] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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69
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Esteve F, Altava B, Bolte M, Burguete MI, García-Verdugo E, Luis SV. Highly Selective Anion Template Effect in the Synthesis of Constrained Pseudopeptidic Macrocyclic Cyclophanes. J Org Chem 2020; 85:1138-1145. [PMID: 31858803 DOI: 10.1021/acs.joc.9b03048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we report the synthesis of a novel family of constrained pseudopeptidic macrocyclic compounds containing the hexahydropyrrolo[3,4-f]isoindolocyclophane scaffold and involving four coupled substitution reactions in the macrocyclization process. Although the increase in the number of steps involved in the macrocyclization could lead to a larger number of possible side products, the optimization of the methodology and the study of the driving forces have made it possible to obtain the desired macrocycles in excellent yields. A thorough computational study has been carried out to understand the macrocyclization process, and the results obtained nicely agree with experimental data. Moreover, the bromide anion had a clear catalytic template effect in the macrocyclization reaction, and surprisingly, the chloride anion had a negative template effect in opposition to the results obtained for analogous macrocycles. The parameters responsible for the specific kinetic template effect observed have been studied in detail.
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Shabir G, Saeed A, Qasim M, Bolte M, Hökelek T, Erben MF. On the planarity of the cyclobutane ring in the crystal of dimethyl 2,4-bis(3,4-dimethoxyphenyl)cyclobutane-1,3-dicarboxylate: a natural bond orbital and Hirshfeld surface analysis study. NEW J CHEM 2020. [DOI: 10.1039/d0nj02739a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The α-form of this 1,3-di-(substituted)-2,4-bis-(substituted)-cyclobutane derivative displays a planar ring in the gas phase and solution. The intermolecular interactions in the crystal have been determined.
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Rivera A, Rojas JJ, Sadat-Bernal J, Ríos-Motta J, Bolte M. Mechanochemical synthesis and X-ray structural characterization of three 3-nitrophenol cocrystals with three aminal cage azaadamantanes: the role of the stereoelectronic effect on intermolecular hydrogen-bonding patterns. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2019; 75:1635-1643. [PMID: 31802753 DOI: 10.1107/s205322961901516x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/11/2019] [Indexed: 11/11/2022]
Abstract
The structures of the cocrystalline adducts of 3-nitrophenol (3-NP) with 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane [HMTA, (1)] as the 2:1:1 hydrate, 2C6H5NO3·C6H12N4·H2O, (1a), with 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecane [TATU (2)] as the 2:1 cocrystal, 2C6H5NO3·C7H14N4, (2a), and with 1,3,6,8-tetraazatricyclo[4.4.1.13,8]dodecane [TATD, (3)] as the 2:1 cocrystal, 2C6H5NO3·C8H16N4, (3a), are reported. In the binary crystals (2a) and (3a), the 3-nitrophenol molecules are linked via O-H...N hydrogen bonds into aminal cage azaadamantanes. In (1a), the structure is stabilized by O-H...N and O-H...O hydrogen bonds, and generates ternary cocrystals. There are C-H...O hydrogen bonds present in all three cocrystals, and in (1a), there are also C-H...O and C-H...π interactions present. The presence of an ethylene bridge in the structures of (2) and (3) defines the formation of a hydrogen-bonded motif in the supramolecular architectures of (2a) and (3a). The differences in the C-N bond lengths of the aminal cage structures, as a result of hyperconjugative interactions and electron delocalization, were analysed. These three cocrystals were obtained by the solvent-free assisted grinding method. Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation from a mixture of hexanes.
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Paul I, Ghosh A, Bolte M, Schmittel M. Remote Control of the Synthesis of a [2]Rotaxane and its Shuttling via Metal-Ion Translocation. ChemistryOpen 2019; 8:1355-1360. [PMID: 31763127 PMCID: PMC6863578 DOI: 10.1002/open.201900293] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/30/2019] [Indexed: 12/25/2022] Open
Abstract
Remote control in an eight-component network commanded both the synthesis and shuttling of a [2]rotaxane via metal-ion translocation, the latter being easily monitored by distinct colorimetric and fluorimetric signals. Addition of zinc(II) ions to the red colored copper-ion relay station rapidly liberated copper(I) ions and afforded the corresponding zinc complex that was visualized by a bright sky blue fluorescence at 460 nm. In a mixture of all eight components of the network, the liberated copper(I) ions were translocated to a macrocycle that catalyzed formation of a rotaxane by a double-click reaction of acetylenic and diazide compounds. The shuttling frequency in the copper-loaded [2]rotaxane was determined to k 298=30 kHz (ΔH ≠=62.3±0.6 kJ mol-1, ΔS ≠=50.1±5.1 J mol-1 K-1, ΔG ≠ 298=47.4 kJ mol-1). Removal of zinc(II) ions from the mixture reversed the system back generating the metal-free rotaxane. Further alternate addition and removal of Zn2+ reversibly controlled the shuttling mode of the rotaxane in this eight-component network where the ion translocation status was monitored by the naked eye.
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73
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Kliemt K, Peters M, Feldmann F, Kraiker A, Tran D, Rongstock S, Hellwig J, Witt S, Bolte M, Krellner C. Crystal Growth of Materials with the ThCr
2
Si
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Structure Type. CRYSTAL RESEARCH AND TECHNOLOGY 2019. [DOI: 10.1002/crat.201900116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Saeed A, Shehzadi SA, Bolte M, Franca CA, Erben MF. Interplay between Conformation and Crystal Packing in Aryl Propargyl Ethers: Structural and Spectroscopic Properties of 2‐(prop‐2‐yn‐1‐yloxy)acene Derivatives. ChemistrySelect 2019. [DOI: 10.1002/slct.201902506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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75
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Kramer P, Grimmer J, Bolte M, Manolikakes G. An Enamide-Based Domino Reaction for a Highly Stereoselective Synthesis of Tetrahydropyrans. Angew Chem Int Ed Engl 2019; 58:13056-13059. [PMID: 31298800 PMCID: PMC6772187 DOI: 10.1002/anie.201907565] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Indexed: 12/23/2022]
Abstract
A novel method for the highly stereoselective synthesis of tetrahydropyrans is reported. This domino reaction is based on a twofold addition of enamides to aldehydes followed by a subsequent cyclization and furnishes fully substituted tetrahydropyrans in high yields. Three new σ‐bonds and five continuous stereogenic centers are formed in this one‐pot process with a remarkable degree of diastereoselectivity. In most cases, the formation of only one out of 16 possible diastereomers is observed. Two different stereoisomers can be accessed in a controlled fashion starting either from an E‐ or a Z‐configured enamide.
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