0000000001302371
AUTHOR
Stefan Pusch
showing 37 related works from this author
One-Pot Oxidative C–H Activation/Aza-Prins-Type Reaction of Tertiary Alkynylamines: A Counter Ion-Induced Iminium Ion–Alkyne Cyclization
2021
Herein, the design and development of a new one-pot and metal-free oxidative C-H activation/aza-Prins type cyclization of alkynylamines is reported. The scope of this method was demonstrated by the preparation of ten new pyrido[2,1-a]isoquinolines in moderate to high yields (38-92%). Furthermore, a mechanistic proposal for the alkyne aza-Prins cyclization is described based on DFT calculations.
A Light-Induced Vinylogous Nazarov-Type Cyclization
2016
The first examples of a photochemically induced vinylogous Nazarov-type cyclization forming a cycloheptadienone core are described. The reaction can be included in a three-step cascade consisting of a photochemical isoxazole-azirine ring contraction, cobalt(II)-catalyzed ring expansion, and the photochemical cyclization. Furthermore, the first representative of the hitherto unknown 1-azatricyclo[2.2.0.0(2,6)]hexanes has been identified as a side product of the azirine formation.
Absolute Configuration Determination of 2,3-Dihydro-1H,5H-pyrazolo[1,2-a]pyrazoles Using Chiroptical Methods at Different Wavelengths
2016
A correlation between the absolute configuration and chiroptical properties of nonracemic 1,6,7-trisubstituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazoles was studied. A series of 16 novel representatives were prepared by Cu-catalyzed [3 + 2] cycloadditions of racemic (Z)-2-benzylidene-5-oxopyrazolidin-2-ium-1-ides to tert-butyl (S)-(3-oxopent-4-yn-2-yl)carbamate, and their structures were determined by NMR, VCD, ECD, and X-ray diffraction. A clear correlation between the sign of specific rotation and configuration at position C(1) allows for easy determination of the absolute configuration of 1,6,7-trisubstituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazoles by ECD and NMR. While VCD, requirin…
ChemInform Abstract: A Photochemical One-Pot Three-Component Synthesis of Tetrasubstituted Imidazoles.
2015
α-(alkylideneamino)nitriles generated in situ from α-aminonitriles and aldehydes react with acylaziridines formed in situ by photochemical ring transformation of isoxazoles.
Chemical constituents of the root wood of Erythrina sacleuxii and determination of the absolute configuration of suberectin
2020
Phytochemical investigation on the root wood of Erythrina sacleuxii (Leguminosae) led to the isolation of nine secondary metabolites (1-9). Compound 1 was isolated from the genus Erythrina for the first time. The pure compounds were identified on the basis of comprehensive spectroscopic and spectrometric analyses, while their absolute configurations were determined based on chiroptical measurements. Compounds 5 and 6 showed weak antifungal activity against Pyricularia oryzae with MIC values of 20 µg/mL.
 
 Bull. Chem. Soc. Ethiop. 2020, 34(1), 135-140.
 DOI: https://dx.doi.org/10.4314/bcse.v34i1.12
A Photochemical One-Pot Three-Component Synthesis of Tetrasubstituted Imidazoles
2014
Tetrasubstituted imidazoles can be formed in a photochemical one-pot synthesis from aldehydes, α-aminonitriles, and isoxazoles. Condensation of the first two components produces α-(alkylideneamino)nitriles which react under basic conditions with the acylazirines formed in situ by photochemical ring transformation of the isoxazole component. This process includes an unusual cleavage of the C(2)-C(3) bond of the acylazirine. The reaction mechanism was studied by DFT calculations.
Oxidation of Trialkylamines by BrCCl3 : Scope, Applications and Mechanistic Aspects
2017
Synthesis and Unusual NMR-Spectroscopic Behavior of a Strained Bicyclic Ammonium Salt
2018
Visible Light-Induced Sulfonylation/Arylation of Styrenes in a Double Radical Three-Component Photoredox Reaction
2019
Simultaneous sulfonylation/arylation of styrene derivatives is achieved in a photoredox-catalyzed three-component reaction using visible light. A broad variety of difunctionalized products is accessible in mostly excellent yields and high diastereoselectivity. The developed reaction is scalable and suitable for the modification of styrene-functionalized biomolecules. Mechanistic investigations suggest the transformation to be operating through a designed sequence of radical formation and radical combination.
Mechanism and cis/trans Selectivity of Vinylogous Nazarov-type [6π] Photocyclizations
2017
Vinylogous Nazarov-type cyclizations yield seven-membered rings from butadienyl vinyl ketones via a photochemical [6π] photocyclization followed by subsequent isomerization steps. The mechanism of this recently developed method was investigated using unrestricted DFT, SF-TDDFT, and CASSCF/NEVPT2 calculations, suggesting three different pathways that lead either to pure trans, pure cis, or mixed cis/trans configured products. Singlet biradicals or zwitterions occur as intermediates. The computational results are supported by deuterium-labeling experiments.
Quantitative Imaging of D-2-Hydroxyglutarate in Selected Histological Tissue Areas by a Novel Bioluminescence Technique
2016
Abstract Patients with malignant gliomas have a poor prognosis with average survival of less than one year. Whereas in other tumor entities the characteristics of tumor metabolism are successfully used for therapeutic approaches, such developments are very rare in brain tumors, notably in gliomas. One metabolic feature characteristic of gliomas, in particular diffuse astrocytomas and oligodendroglial tumors, is the variable content of D-2-hydroxyglutarate (D2HG), a metabolite, which was discovered first in this tumor entity. D2HG is generated in large amounts due to various “gain-of–function” mutations in the isocitrate dehydrogenases IDH-1 and IDH-2. Meanwhile, D2HG has been detected in se…
ChemInform Abstract: A Light-Induced Vinylogous Nazarov-Type Cyclization.
2016
The title reaction is incorporated in a three-step cascade transformation providing novel tetracyclic ring structures containing a seven-membered ring.
A Photoinduced Cobalt-Catalyzed Synthesis of Pyrroles through in Situ-Generated Acylazirines
2016
Tetrasubstituted pyrroles can be synthesized in a one-pot procedure from isoxazoles. The process includes the photoinduced in situ formation of acylazirines combined with a subsequent cobalt(II)-catalyzed ring expansion with 1,3-diketones.
Polyethylene bio-degradation by caterpillars?
2017
In their recent paper on the degradation of polyethylene by caterpillars of the wax moth Galleria melonella, Bombelli et al.[1] report various experiments, including microscopic and spectroscopic data which the authors believe support the chemical digestion of the polymers by these insects. While the biodegradation of mostly inert artificial polymers is definitely a very interesting research field, we must respectfully disagree with the methodology and conclusions from this paper.
ChemInform Abstract: A Photoinduced Cobalt-Catalyzed Synthesis of Pyrroles Through in situ-Generated Acylazirines.
2016
Tetrasubstituted pyrroles can be synthesized in a one-pot procedure from isoxazoles. The process includes the photoinduced in situ formation of acylazirines combined with a subsequent cobalt(II)-catalyzed ring expansion with 1,3-diketones.
Characterization of the synthetic cannabinoid MDMB-CHMCZCA
2016
The synthetic cannabinoid MDMB-CHMCZCA was characterized by various spectroscopic techniques including NMR spectroscopy and tandem mass spectrometry. The synthetic sample was found to be of S-configuration by VCD spectroscopy and comparison of the data with DFT calculations, while ECD spectroscopy was found to be inconclusive in this case. The enantiomeric purity of samples from test purchases and police seizures was assessed by a self-developed chiral HPLC method.
T-cell Receptor Therapy Targeting Mutant Capicua Transcriptional Repressor in Experimental Gliomas
2021
Abstract Purpose: Gliomas are intrinsic brain tumors with a high degree of constitutive and acquired resistance to standard therapeutic modalities such as radiotherapy and alkylating chemotherapy. Glioma subtypes are recognized by characteristic mutations. Some of these characteristic mutations have shown to generate immunogenic neoepitopes suitable for targeted immunotherapy. Experimental Design: Using peptide-based ELISpot assays, we screened for potential recurrent glioma neoepitopes in MHC-humanized mice. Following vaccination, droplet-based single-cell T-cell receptor (TCR) sequencing from established T-cell lines was applied for neoepitope-specific TCR discovery. Efficacy of intravent…
Cover Feature: Visible Light‐Induced Sulfonylation/Arylation of Styrenes in a Double Radical Three‐Component Photoredox Reaction (Chem. Eur. J. 38/20…
2019
(±)-alternarlactones A and B, two antiparasitic alternariol-like dimers from the fungus alternaria alternata P1210 isolated from the halophyte salico…
2019
Two new dimeric compounds of the alternariol class, (±)-alternarlactones A (1) and B (2), were isolated along with 11 known compounds from the fungus Alternaria alternata P1210. Their structures were elucidated with the assistance of long-range HSQMBC to address inadequate cross-peaks in HMBC that result from the highly dense quaternary carbons, as well as theoretical calculations. All isolated altenuisol derivatives were screened for their antiparasitic activities, which provide a preliminary structure-activity relationship of this class of compounds against neglected tropical diseases.
Haloperoxidase Mimicry by CeO2−xNanorods Combats Biofouling
2016
CeO2-x nanorods are functional mimics of natural haloperoxidases. They catalyze the oxidative bromination of phenol red to bromophenol blue and of natural signaling molecules involved in bacterial quorum sensing. Laboratory and field tests with paint formulations containing 2 wt% of CeO2-x nanorods show a reduction in biofouling comparable to Cu2 O, the most typical biocidal pigment.
Front Cover: Synthesis and Unusual NMR-Spectroscopic Behavior of a Strained Bicyclic Ammonium Salt (Eur. J. Org. Chem. 10/2018)
2018
CCDC 1049822: Experimental Crystal Structure Determination
2015
Related Article: Stefan Pusch and Till Opatz|2014|Org.Lett.|16|5430|doi:10.1021/ol502667h
CCDC 1891336: Experimental Crystal Structure Determination
2019
Related Article: Benjamin Lipp, Lisa Marie Kammer, Murat Kücükdisli, Adriana Luque, Jonas Kühlborn, Stefan Pusch, Gita Matulevičiūtė, Dieter Schollmeyer, Algirdas Šačkus, Till Opatz|2019|Chem.-Eur.J.|25|8965|doi:10.1002/chem.201901175
CCDC 1497003: Experimental Crystal Structure Determination
2016
Related Article: Eva Pušavec Kirar, Uroš Grošelj, Amalija Golobič, Franc Požgan, Stefan Pusch, Carina Weber, Lars Andernach, Bogdan Štefane, Till Opatz, Jurij Svete|2016|J.Org.Chem.|81|11802|doi:10.1021/acs.joc.6b02270
CCDC 1483914: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Danuta Kowalczyk, and Till Opatz|2016|J.Org.Chem.|81|4170|doi:10.1021/acs.joc.6b00511
CCDC 1484250: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449
CCDC 1049823: Experimental Crystal Structure Determination
2015
Related Article: Stefan Pusch and Till Opatz|2014|Org.Lett.|16|5430|doi:10.1021/ol502667h
CCDC 1483913: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Danuta Kowalczyk, and Till Opatz|2016|J.Org.Chem.|81|4170|doi:10.1021/acs.joc.6b00511
CCDC 1497004: Experimental Crystal Structure Determination
2016
Related Article: Eva Pušavec Kirar, Uroš Grošelj, Amalija Golobič, Franc Požgan, Stefan Pusch, Carina Weber, Lars Andernach, Bogdan Štefane, Till Opatz, Jurij Svete|2016|J.Org.Chem.|81|11802|doi:10.1021/acs.joc.6b02270
CCDC 1484249: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449
CCDC 1484253: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449
CCDC 1497005: Experimental Crystal Structure Determination
2016
Related Article: Eva Pušavec Kirar, Uroš Grošelj, Amalija Golobič, Franc Požgan, Stefan Pusch, Carina Weber, Lars Andernach, Bogdan Štefane, Till Opatz, Jurij Svete|2016|J.Org.Chem.|81|11802|doi:10.1021/acs.joc.6b02270
CCDC 1585828: Experimental Crystal Structure Determination
2018
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2018|Eur.J.Org.Chem.|2018|1204|doi:10.1002/ejoc.201701594
CCDC 1484252: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449
CCDC 1484251: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449
CCDC 1521512: Experimental Crystal Structure Determination
2017
Related Article: Carina Weber, Stefan Pusch, Dieter Schollmeyer, Sascha Münster-Müller, Michael Pütz, Till Opatz|2016|Beilstein J.Org.Chem.|12|2808|doi:10.3762/bjoc.12.279
CCDC 1484248: Experimental Crystal Structure Determination
2016
Related Article: Stefan Pusch, Dieter Schollmeyer, Till Opatz|2016|Org.Lett.|18|3043|doi:10.1021/acs.orglett.6b01449