Search Results - "Freese, Tyll"

Recent advances in neutral and anionic N-heterocyclic carbene – betaine interconversions. Synthesis, characterization, and applications by Schmidt, Andreas, Wiechmann, Sascha, Freese, Tyll

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Cycloadditions of anionic N-heterocyclic carbenes of sydnone imines by Freese, Tyll, Nieger, Martin, Namyslo, Jan C., Schmidt, Andreas

“…[Display omitted] •Deprotonated sydnone imines can be represented as anionic N-heterocyclic carbenes.•Adduct formation to di-isopropylazodicarboxylate (DIAD)…”
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An Iterative Approach to Unsaturated and Partially Saturated [7]Helicenes by Freese, Tyll, Jones, Peter G, Werz, Daniel B

“…We report a simple, iterative strategy for the synthesis of [7]helicenes starting from substituted 1,4-xylene building blocks. In the first step, we take…”
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Functionalization of Sydnones with Donor‐Acceptor Cyclopropanes, Cyclobutanes, and Michael Acceptors by Ahlburg, Nils L., Freese, Tyll, Kolb, Simon, Mummel, Sebastian, Schmidt, Andreas, Werz, Daniel B.

“…We present a Lewis acid catalyzed nucleophilic ring‐opening of donor‐acceptor cyclopropanes and ‐butanes by sydnones, utilizing their respective 1,3‐ and…”
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One-Pot Strategy for Symmetrical and Unsymmetrical BOIMPY Fluorophores by Freese, Tyll, Patalag, Lukas J, Merz, J. Luca, Jones, Peter G, Werz, Daniel B

“…We report the improved direct access to red-emitting BOIMPY fluorophores (λ ≈ 600 nm) via a simple one-pot approach. Our method starts from easily available…”
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Sulfur, mercury, and boron adducts of sydnone imine derived anionic N-heterocyclic carbenes by Freese, Tyll, Namyslo, Jan C, Nieger, Martin, Schmidt, Andreas

“…The sydnone imines (5-benzoylimino)-3-(2-methoxyphenyl)-sydnone imine and molsidomine were deprotonated at C4 to give sydnone imine anions which can be…”
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Anionic N-heterocyclic carbenes derived from sydnone imines such as molsidomine. Trapping reactions with selenium, palladium, and gold by Freese, Tyll, Lücke, Ana-Luiza, Schmidt, Catharina A.S., Polamo, Mika, Nieger, Martin, Namyslo, Jan C., Schmidt, Andreas

“…The sydnone imines Molsidomine and 5-(benzoylimino)-3-(2-methoxyphenyl)-1,2,3-oxadiazolium-2-ide gave anionic N-heterocyclic carbenes on deprotonation at C4…”
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Borane adducts of punicine and of its dehydroxy derivatives (pyridinium-1-yl)-2- and 3-phenolates by Otto, Christian F., Herzberger, Colin, Liu, Ming, Namyslo, Jan C., Nieger, Martin, Freese, Tyll, Lederle, Felix, Hübner, Eike G., Schmidt, Andreas

“…The natural product punicine (Punica granatum) exists in two tautomeric forms, the cross-conjugated mesomeric betaine…”
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The intersection of allenylidenes and mesomeric betaines. 1-Methylpyridinium-2-acetylide and its palladium complexes by Haindl, Susanne, Xu, Jiayi, Freese, Tyll, Hübner, Eike G., Schmidt, Andreas

“…The anion of 2-ethynyl-1-methylpyridinium salts, which polymerized rapidly, can be represented as the mesomeric betaine 1-methylpyridinium-2-acetylide or as…”
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Sonogashira-Hagihara and Buchwald-Hartwig cross-coupling reactions with sydnone and sydnone imine derived catalysts by Lücke, Ana-Luiza, Pruschinski, Lucas, Freese, Tyll, Schmidt, Andreas

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Heterocycle Syntheses with Anionic N‐Heterocyclic Carbenes: Ring Transformations of Sydnone Imine Anions by Freese, Tyll, Lücke, Ana‐Luiza, Namyslo, Jan C., Nieger, Martin, Schmidt, Andreas

“…Sydnone imines were deprotonated at the C4 position to give lithium‐stabilized anions, which proved to be stable for several months in solution. These anions…”
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Anionic N-heterocyclic carbenes by decarboxylation of sydnone-4-carboxylates by Lücke, Ana-Luiza, Wiechmann, Sascha, Freese, Tyll, Nieger, Martin, Földes, Tamás, Pápai, Imre, Gjikaj, Mimoza, Adam, Arnold, Schmidt, Andreas

“…Unstable N-heterocyclic carbenes can be masked and stabilized as pseudo-cross-conjugated hetarenium-carboxylates which decarboxylate on warming. This study…”
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Dipolar Bent and Linear Acetylenes Substituted by Cationic Quinolinium and Anionic Benzoates. Formation of Mesomeric Betaines by Schmidt, Andreas, Batsyts, Sviatoslav, Smeyanov, Alexey, Freese, Tyll, Hübner, Eike G, Nieger, Martin

“…3-Ethynylquinoline was subjected to a Sonogashira–Hagihara reaction with methyl 2-, 3-, and 4-bromobenzoates, respectively, and then N-methylated to give…”
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Sulfur, mercury, and boron adducts of sydnone imine derived anionic N-heterocyclic carbenesElectronic supplementary information (ESI) available: Spectra, details of the X-ray analyses. CCDC 1889199 (27a), 1889200 (28a), 1889201 (29), 1889202 (30a) and 1889203 (31a) contain the supplementary crystallographic data for this paper. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c9ra00294d by Freese, Tyll, Namyslo, Jan C, Nieger, Martin, Schmidt, Andreas

“…The sydnone imines (5-benzoylimino)-3-(2-methoxyphenyl)-sydnone imine and molsidomine were deprotonated at C4 to give sydnone imine anions which can be…”
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Palladium complexes of anionic N-heterocyclic carbenes derived from sydnones in catalysis by Lücke, Ana-Luiza, Wiechmann, Sascha, Freese, Tyll, Guan, Zong, Schmidt, Andreas

“…The anion of -phenylsydnone, which can be generated on treatment of -phenylsydnone with cyanomethyllithium without decomposition, can be represented as…”
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