A5029253020- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Sulfur-Based Synthesis Techniques
- Catalytic C–H Functionalization Methods
- Crystallography and molecular interactions
- Synthesis and Catalytic Reactions
- Molecular spectroscopy and chirality
- Oxidative Organic Chemistry Reactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- Radical Photochemical Reactions
- Inorganic Chemistry and Materials
- Organoboron and organosilicon chemistry
- Organometallic Compounds Synthesis and Characterization
- Analytical Chemistry and Chromatography
- Organometallic Complex Synthesis and Catalysis
- Coordination Chemistry and Organometallics
- Phytochemistry and Biological Activities
- Bioactive natural compounds
- Synthesis and biological activity
- Psychedelics and Drug Studies
- Nanoparticles: synthesis and applications
- Electron Spin Resonance Studies
- Synthesis and Reactivity of Heterocycles
- Chemical Reactions and Mechanisms
- Vanadium and Halogenation Chemistry
Johannes Gutenberg University Mainz
2014-2023
University of Göttingen
1988-1993
University of Bremen
1991
CeO2-x nanorods are functional mimics of natural haloperoxidases. They catalyze the oxidative bromination phenol red to bromophenol blue and signaling molecules involved in bacterial quorum sensing. Laboratory field tests with paint formulations containing 2 wt% show a reduction biofouling comparable Cu2 O, most typical biocidal pigment.
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 acylazirines situ by ring transformation isoxazole component. This process includes an unusual cleavage C2–C3 bond acylazirine. The reaction mechanism was studied DFT calculations.
Simultaneous sulfonylation/arylation of styrene derivatives is achieved in a photoredox-catalyzed three-component reaction using visible light. A broad variety difunctionalized products accessible mostly excellent yields and high diastereoselectivity. The developed scalable suitable for the modification styrene-functionalized biomolecules. Mechanistic investigations suggest transformation to be operating through designed sequence radical formation combination.
Tetrasubstituted pyrroles can be synthesized in a one-pot procedure from isoxazoles. The process includes the photoinduced situ formation of acylazirines combined with subsequent cobalt(II)-catalyzed ring expansion 1,3-diketones.
The first examples of a photochemically induced vinylogous Nazarov-type cyclization forming cycloheptadienone core are described. reaction can be included in three-step cascade consisting photochemical isoxazole–azirine ring contraction, cobalt(II)-catalyzed expansion, and the cyclization. Furthermore, representative hitherto unknown 1-azatricyclo[2.2.0.02,6]hexanes has been identified as side product azirine formation.
The synthetic cannabinoid MDMB-CHMCZCA was characterized by various spectroscopic techniques including NMR spectroscopy and tandem mass spectrometry. sample found to be of S -configuration VCD comparison the data with DFT calculations, while ECD inconclusive in this case. enantiomeric purity samples from test purchases police seizures assessed a self-developed chiral HPLC method.
Two new dimeric compounds of the alternariol class, (±)-alternarlactones A (1) and B (2), were isolated along with 11 known from fungus Alternaria alternata P1210. Their structures elucidated assistance long-range HSQMBC to address inadequate cross-peaks in HMBC that result highly dense quaternary carbons, as well theoretical calculations. All altenuisol derivatives screened for their antiparasitic activities, which provide a preliminary structure–activity relationship this class against...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, characterization, and molecular structures of supermesitylgallium- supermesitylindium dihalidesStephan Schulz, Stefan Pusch, Ehmke Pohl, Sven Dielkus, Regine Herbst-Irmer, Anton Meller, Herbert W. RoeskyCite this: Inorg. Chem. 1993, 32, 15, 3343–3346Publication Date (Print):July 1, 1993Publication History Published online1 May 2002Published inissue 1 July...
The catalyst‐free photochemical reaction of trialkylamines and BrCCl 3 induced by visible light was investigated. outcome the found to depend strongly on nature amine substrates. N ‐Methyl‐1,2,3,4‐tetrahydroisoquinolines give 3,4‐dihydroisoquinolinium salts, whereas aliphatic produce hydrohalide salts streptocyanines as major products. addition KCN inhibits streptocyanine formation, results in clean formation α‐aminonitriles instead. light‐absorbing species underlying mechanism were studied...
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, cis, or mixed cis/trans configured products. Singlet biradicals zwitterions occur as intermediates. computational...
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. series 16 novel representatives were prepared by Cu-catalyzed [3 + 2] cycloadditions racemic (Z)-2-benzylidene-5-oxopyrazolidin-2-ium-1-ides to tert-butyl (S)-(3-oxopent-4-yn-2-yl)carbamate, their structures determined NMR, VCD, ECD, X-ray diffraction. clear sign specific rotation at position C(1) allows for easy determination...
Synthesis, Structure, and Rearrangement of Chlorobis(2,4,6‐tri‐ tert ‐butylphenyl)gallane The title compound 1 is easily obtained from GaCl 3 2 equvialents supermesityllithium. According to an X‐ray structure analysis one the supermesityl rings shows a large deviation planarity. Heating in vacuo gives mainly two products: isomer which groups bound Ga by its ‐butyl ( ) benzo[ b ]gallolane formed elimination HCl, analyses full NMR H, 13 C) data are provided for , MS characteristic .
Herein, the design and development of a new one-pot metal-free oxidative C–H activation/aza-Prins type cyclization alkynylamines is reported. The scope this method was demonstrated by preparation ten pyrido[2,1-a]isoquinolines in moderate to high yields (38–92%). Furthermore, mechanistic proposal for alkyne aza-Prins described based on DFT calculations.
The determination of the absolute configuration (AC) an organic molecule is still a challenging task for which combination spectroscopic with quantum-mechanical methods has become promising approach. In this study, we investigated accuracy DFT (480 overall combinations 15 functionals, 16 basis sets, and 2 solvation models) to calculate VCD spectra six chiral molecules in order benchmark their capability facilitate AC.
Abstract The 1,4-dithia-2,6-diaza-3,5-diborinanes 1a-d react with elemental sodium formation of the 1,3-diaza-2,4-diboretidines 2a-d. By use more in case 1 d or 3,5-bis(diethylamino)- 2-cyclohexyl-6-trimethylsilyldiborinane, 1,3-thiaza-2,4-diboretidines 3 were formed. 3.5-Dimethyl-2,6-bis(trimethylsilyl)-1,4-dithia-2,6-diaza-3,5-diborinane gives borazine 4, reaction di-t-butyl-sulfurdiimide 2,6-di-t-butyl-3,5-dimethyl-1,4-dithia-2,6-diaza-3,5-diborinane leads by ring contraction to...
Phytochemical investigation on the root wood of Erythrina sacleuxii (Leguminosae) led to isolation nine secondary metabolites (1-9). Compound 1 was isolated from genus for first time. The pure compounds were identified basis comprehensive spectroscopic and spectrometric analyses, while their absolute configurations determined based chiroptical measurements. Compounds 5 6 showed weak antifungal activity against Pyricularia oryzae with MIC values 20 µg/mL.
 
 Bull. Chem. Soc. Ethiop....
The first synthesis of a 2‐azabicyclo[2.2.0]hexenium salt is described. It available from pyridine in four steps. This strained bicyclic ammonium was characterized by 1 H, 13 C, and 2D NMR spectroscopy as well XRD. Due to its unusual spectroscopic characteristics, DFT calculations were performed additionally support the proposed structure. cation shows significant hyperconjugative stabilization.
Abstract Unter Verwendung von halogensubstituierten 4, 5‐Diethyl‐1, 2, 3‐diselena‐ und ‐dithiaborolen als Ausgangsverbindungen wurden Alkoxy‐ Alkyl(Aryl)thio‐substituierte 1, 3‐Dichalkogenaborole dargestellt. NMR ( 1 H, 11 B, 13 C, 77 Se) MS‐Daten werden mitgeteilt diskutiert.
Abstract The preparation of the desired pyrrole derivatives starts from isoxazole substrates in presence a Co catalyst under irradiation.
Abstract The title reaction is incorporated in a three‐step cascade transformation providing novel tetracyclic ring structures containing seven‐membered ring.
Abstract α‐(alkylideneamino)nitriles generated in situ from α‐aminonitriles and aldehydes react with acylaziridines formed by photochemical ring transformation of isoxazoles.