A5011418889- Radical Photochemical Reactions
- Catalytic C–H Functionalization Methods
- Asymmetric Hydrogenation and Catalysis
- Cyclopropane Reaction Mechanisms
- Chemical Reactions and Isotopes
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Ammonia Synthesis and Nitrogen Reduction
- Sulfur-Based Synthesis Techniques
- CO2 Reduction Techniques and Catalysts
- Catalytic Alkyne Reactions
- Organometallic Compounds Synthesis and Characterization
- Organoselenium and organotellurium chemistry
- Organometallic Complex Synthesis and Catalysis
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Photonic and Optical Devices
- Advanced Photocatalysis Techniques
- Corporate Taxation and Avoidance
- Enzyme Catalysis and Immobilization
- Fluorine in Organic Chemistry
- Oxidative Organic Chemistry Reactions
- Molecular Sensors and Ion Detection
- Plant biochemistry and biosynthesis
- Photorefractive and Nonlinear Optics
University of Freiburg
2023-2025
Technische Universität Braunschweig
2020-2022
Scripps (United States)
2022
Scripps Institution of Oceanography
2022
Torrey Pines Institute For Molecular Studies
2022
University of Bayreuth
2020
A useful protocol for achieving decarboxylative cross-coupling (DCC) of redox-active esters (RAE, isolated or generated in situ) and halo(hetero)arenes is reported. This pragmatically focused study employs a unique Ag-Ni electrocatalytic platform to overcome numerous limitations that have plagued this strategically powerful transformation. In its optimized form, coupling partners can be combined surprisingly simple way: open the air, using technical-grade solvents, an inexpensive ligand Ni...
Abstract Chalcogen bonding is important in numerous aspects of chemistry, both the solid state and solution. Surveying literature, it becomes clear that during its rebranding from chalcogen–chalcogen interactions, some parts community have somewhat neglected to recall discovery initial studies referring previous guise. In this Viewpoint, we trace path research into phenomenon, discovery, through renaming, varied interesting chemistry has led so far, ranging crystal engineering supramolecular...
We describe the first electrochemical activation of D-A cyclopropanes and cyclobutanes leading after C(sp
We describe an operationally simple and user-friendly protocol that allows the site-selective hydrogenation deuteration of di-, tri- tetrasubstituted benzylic olefins by electroreduction while other groups prone to are present. The radical anionic intermediates react with most inexpensive hydrogen/deuterium source H2 O/D2 O. Our method overcomes many limitations arise from previously reported electroreductive hydrogenations. applicability this reaction is demonstrated a broad substrate scope...
We describe a general electrochemical method to functionalize donor–acceptor (D–A) cyclopropanes and -butanes with arenes utilizing Friedel–Crafts-type reactivity. The catalyst-free strategy relies on the direct anodic oxidation of strained carbocycles, which leads after C(sp3)–C(sp3) cleavage radical cations that act as electrophiles for arylation reaction. Broad reaction scopes in regard cyclopropanes, cyclobutanes, aromatic partners are presented. Additionally, plausible electrolysis...
The Fujiwara–Moritani reaction using electric current is a powerful tool for the olefination of arenes by Pd-catalysed C–H activation.
Abstract Deuterated and tritiated analogs of drugs are valuable compounds for pharmaceutical medicinal chemistry. In this work, we present a novel hydrogen isotope exchange reaction using non‐directed homogeneous Pd‐catalysis. Aromatic C−H activation is achieved by commercially available pyridine ligand. Using the most convenient cheapest deuterium source, D 2 O, as only solvent 39 pharmaceuticals were labelled with clean profiles high uptakes. Additionally, describe first application...
Herein we report (3+2) cycloaddition reactions of halogenated donor‐acceptor cyclopropanes (HDACs) as surrogates for cyclopropenes. Upon reaction with a variety 2π‐components, followed by elimination generates the unsaturated five‐membered ring products. A series HDACs were shown to be effective in thioketones. Five further used showcase broad applicability these cyclopropene surrogates. Kinetic studies allowed proposal plausible mechanism this reaction.
Herein we report (3+2) cycloaddition reactions of halogenated donor‐acceptor cyclopropanes (HDACs) as surrogates for cyclopropenes. Upon reaction with a variety 2π‐components, followed by elimination generates the unsaturated five‐membered ring products. A series HDACs were shown to be effective in thioketones. Five further used showcase broad applicability these cyclopropene surrogates. Kinetic studies allowed proposal plausible mechanism this reaction.
Abstract Chalcogen Bonding spielt in verschiedenen Bereichen der Chemie sowohl im Festkörper als auch Lösung eine entscheidende Rolle. Bei genauer Literaturrecherche wird allerdings deutlich, dass – nachdem sich Begriff von “Chalkogen‐Chalkogen‐Wechselwirkungen” zum prägnanteren “Chalcogen Bonding” verkürzt hatte ein Teil wissenschaftlichen Gemeinschaft an die Herkunft dieses Phänomens nicht mehr erinnert und seiner ursprünglichen Form referenziert. In diesem Viewpoint verfolgen wir...
Abstract We describe the first electrochemical activation of D–A cyclopropanes and cyclobutanes leading after C(sp 3 )−C(sp ) cleavage to formation highly reactive radical cations. This concept is utilized formally insert molecular oxygen direct or DDQ‐assisted anodic oxidation strained carbocycles, delivering β‐ γ‐hydroxy ketones 1,2‐dioxanes electrocatalytically. Furthermore, insights into mechanism oxidative process, obtained experimentally by additional quantum‐chemical calculations are...
Abstract Lithium niobate is a material of special interest for its challenging functional properties, which can suit various applications. However, high quality 200‐mm Li x Nb 1‐x O 3 thin film grown on sapphire substrate have never been reported so far limits these potential This paper reports the efficient optimization LiNbO deposition (001) through chemical beam vapor in combinatorial configuration. With this technique, flow ratio Li/Nb be tuned from ≈0.25 to ≈2.45 single wafer. Various...
Abstract We present a Lewis acid catalyzed nucleophilic ring‐opening of donor‐acceptor cyclopropanes and ‐butanes by sydnones, utilizing their respective 1,3‐ 1,4‐reactivity. The same conditions can be applied for the addition sydnones to Michael acceptors. propose Friedel‐Crafts like mechanism. reaction provides rare, low‐temperature, transition metal‐free, functional group tolerant protocol late‐stage functionalization these mesoionic compounds emerging importance in catalysis...
Biosynthetic pathways of natural products contain many enzymes that contribute to the rapid assembly molecular complexity. Enzymes form complex structural elements with multiple stereocenters, like chiral saturated oxygen heterocycles (CSOH), are particular interest for a synthetic application, as their use promises significantly simplify access these elements. Here, biocatalytic characterization AmbDH3, an enzyme catalyzes intramolecular oxa-Michael addition (IMOMA) is reported. This...
An established concept to create radical intermediates is photoexcitation of a catalyst higher energy intermediate, subsequently leading photoinduced electron transfer (PET) with reaction partner. The known consecutive (con‐PET) leads catalytically active species even in by the uptake two photons. Generally speaking, increased photon more potent reductant. Here, we report multi‐photoinduced catalysis (>2 photons), termed multi‐PET, which enabled one‐electron reductions an organic dye....
Abstract An electrochemical method for the synthesis of 3,3,5,5-tetrasubstituted 1,2-dioxolanes from donor–acceptor cyclopropanes with quaternary donor positions is described. This catalyst-free strategy delivers radical cations after C(sp3)–C(sp3) cleavage by direct anodic oxidation strained carbocycle. A broad scope regard to employed in reaction presented. Additionally, we propose a plausible mechanism reaction.
A useful protocol for achieving decarboxylative cross coupling (DCC) of redox-active esters (RAE, isolated or generated in situ) and halo(hetero)arenes is reported. This pragmatically focused study employs a unique Ag-Ni electrocatalytic platform to overcome numerous limitations that have plagued this strategically powerful transformation. In its optimized form partners can be combined surprisingly simple way: open the air, technical grade solvents, an inexpensive ligand Ni source,...
The recently reported electrochemical, organo mediator enabled deuteration of styrenes, a reaction referred to as “electrochemical deuterium atom transfer”, differs mechanistically from direct electrochemical hydrogenations/deuterations only by mediated, homogeneous SET the substrates. By comparing vs. mediated processes in general and for styrene reduction, we display that Qiu’s work does not change concept this chemistry. Experiments with mediators reduction examples scope show even...
Deuterated and tritiated analogs of drugs are valuable compounds for pharmaceutical medicinal chemistry. In this work, we present a novel hydrogen isotope exchange reaction using non-directed homogeneous Pd catalysis. Aromatic C–H activation is achieved by commercially available pyridine ligand. Using the most convenient cheapest deuterium source, D2O, as only solvent 34 pharmaceuticals were labelled with clean profiles high uptakes. Additionally, describe first application catalysis H/T on...
Abstract The recently reported electrochemical, organo‐mediator enabled deuteration of styrenes, a reaction referred to as “electrochemical deuterium atom transfer”, differs mechanistically from direct electrochemical hydrogenations/deuterations only by mediated, homogeneous SET the substrates. By comparing vs. mediated processes in general and for styrene reduction, we display that Qiu's work does not change concept this chemistry. Experiments with mediators reduction examples scope show...
Abstract Deuterated and tritiated analogs of drugs are valuable compounds for pharmaceutical medicinal chemistry. In this work, we present a novel hydrogen isotope exchange reaction using non‐directed homogeneous Pd‐catalysis. Aromatic C−H activation is achieved by commercially available pyridine ligand. Using the most convenient cheapest deuterium source, D 2 O, as only solvent 39 pharmaceuticals were labelled with clean profiles high uptakes. Additionally, describe first application...
An established concept to create radical intermediates is photoexcitation of a catalyst higher energy intermediate, subsequently leading photoinduced electron transfer (PET) with reaction partner. The known consecutive (con‐PET) leads catalytically active species even in by the uptake two photons. Generally speaking, increased photon more potent reductant. Here, we report multi‐photoinduced catalysis (>2 photons), termed multi‐PET, which enabled one‐electron reductions an organic dye....
Single electron redox processes allow the formation of highly reactive radicals – valuable intermediates that enable unique transformations in organic chemistry (1,2). An established concept to create radical is photoexcitation a catalyst higher energy intermediate, subsequently leading photoinduced transfer (PET) with reaction partner (3–7). The known consecutive (con PET) leads catalytically active species even by uptake two photons (8). This process has already been used widely for...