A5067475475- Radical Photochemical Reactions
- Catalytic C–H Functionalization Methods
- Chemical Synthesis and Analysis
- Sulfur-Based Synthesis Techniques
- Porphyrin and Phthalocyanine Chemistry
- Fluorine in Organic Chemistry
- Cyclization and Aryne Chemistry
- Carbohydrate Chemistry and Synthesis
- Asymmetric Synthesis and Catalysis
- Synthesis and Properties of Aromatic Compounds
- Chemical Synthesis and Reactions
- Metal complexes synthesis and properties
- Chemical synthesis and alkaloids
- Synthetic Organic Chemistry Methods
- Advanced Photocatalysis Techniques
- Click Chemistry and Applications
- Oxidative Organic Chemistry Reactions
- DNA and Nucleic Acid Chemistry
- Photoreceptor and optogenetics research
- Synthesis and Characterization of Heterocyclic Compounds
- Catalytic Alkyne Reactions
- Asymmetric Hydrogenation and Catalysis
- Crystallization and Solubility Studies
- Catalytic Cross-Coupling Reactions
- Magnetism in coordination complexes
University of Regensburg
2015-2025
Institute of Organic Chemistry
2020
Polish Academy of Sciences
2020
Délégation Paris 5
2016
Centre National de la Recherche Scientifique
2016
Dr Willmar Schwabe (Germany)
2015
Indian Institute of Technology Madras
2011-2013
Ural Branch of the Russian Academy of Sciences
2009
Institute of Organic Synthesis
2009
Rice University
2000
N-Arylated aliphatic and aromatic amines are important substituents in many biologically active compounds. In the last few years, transition-metal-mediated N -aryl bond formation has become a standard procedure for introduction of into systems. While N-arylation simple halides by works with described methods high yield, reactions may require detailed optimization if applied to synthesis complex molecules additional functional groups, such as natural products or drugs. We discuss compare this...
A general, efficient and green method for the synthesis of dihydropyrimidinones is described under mild conditions employing low melting mixtures L-(+)-tartaric acid urea derivatives as a novel reaction medium. The melt plays triple role: solvent, catalyst reactant, furnishing highly functionalized in good to excellent yields.
A highly efficient, cheap, and organic alternative to the commonly used iridium photosensitizer (Ir[dF(CF3)ppy]2(dtbpy))PF6 ([Ir-F]) is presented for visible-light energy transfer catalysis. The dye 2CzPN surpasses [Ir-F] in selectivity while at same time being easily accessible one step. catalyst recyclable and, due its uncharged nature, soluble nonpolar solvents such as toluene. Furthermore, scope of molecular scaffolds that are compatible substrates catalyzed dearomative cycloadditions expanded.
Synthesis of various derivatives 2-(2-thienyl)pyridine via substituted 3-thienyl-1,2,4-triazines is reported. The final step the synthesis a transformation triazine ring to pyridine in an aza-Diels-Alder-type reaction. resulting 5-aryl-2-(2-thienyl)pyridines (HL1-HL4) and 5-aryl-2-(2-thienyl)cyclopenteno[c]pyridines (HL5-HL8) (with aryl = phenyl, 4-methoxyphenyl, 2-naphtyl, 2-thienyl) were used as cyclometallating ligands prepare series eight luminescent platinum complexes type [Pt(L)(acac)]...
Transition metal-catalyzed cross-coupling reactions are essential in modern organic synthesis, facilitating the rapid creation of complex molecular structures. Traditionally, these rely heavily on conventional bases, with only a few exceptions reported. Recently, we developed adaptive dynamic homogeneous catalysis (AD-HoC), method that enables C(sp2)–S cross-couplings without needing traditional ligands, or additives. Given growing demand for protocols compatible acidic conditions...
Lactam rings are essential structural motifs in organic chemistry, widely present natural products and clinically important drugs, such as antibiotics antiepileptics. Existing methods for synthesizing N‐functionalized lactams often require harsh conditions, toxic reagents, or complex catalytic systems. Here, we report a mild efficient photochemical approach generating N‐centered radicals, enabling straightforward N‐heteroarylation of lactams. This versatile method enables the synthesis range...
Benzoate anions coordinate to cerium ions. Excitation of such complexes by light leads homolytic oxygen-cerium bond cleavage through ligand-to-metal charge transfer (LMCT). This process results in the reduction metal ion and oxidation ligand via a single-electron event. The resulting benzoic acid radical can serve as potent hydro-gen atom abstractor, facilitating activation carbon atoms C-H activation. study investigated scope other oxo-anions ligands on cerium(IV) ions that undergo...
We present a sp2–sp3/sp3–sp bond formation reaction through three-component coupling strategy involving terminal alkynes, [1.1.1]propellane, and aryl thianthrenium salts that are prepared from arenes. The employs dual photo/copper catalysis system provides streamlined approach for assembling 1-alkynyl-3-aryl bicyclo[1.1.1]pentane derivatives with broad spectrum of functional group compatibility. Mechanistic studies suggest the generation radicals copper alkynide intermediates was involved.
Visible light-driven proton transfer is crucial in nature and catalysis. Here, we report that protic merocyanine-based photoswitches, under blue or green light irradiation, act as efficient recyclable homogeneous Brønsted...
Persistent transition metal radicals form the foundation for many metallaphotoredox protocols. Their ability to efficiently trap organic and convert them into various coupling products has inspired exploration of selective radical reactions even beyond d‐block. Radical processes involving bismuth hold great potential but innovative strategies are required control reactivity intermediates. Herein we report preassembly as a powerful strategy enforce recombination bismuth(II) an radical. As...
We report pyridine N-oxides as neutral ligands in cerium photocatalysis. By using those ligands, photoactive Ce(IV)-species are generated, that show an extensive bathochromic shift compared to previously employed cerium-based complexes. This allows the effective utilization of green light redox-neutral CH-hydrazination small molecules under very mild photocatalytic conditions.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, Structure, and Coordination Properties of Silicon-Bridged MacrocyclesBurkhard Koenig, Martin Roedel, Peter Bubenitschek, G. Jones, Iris ThondorfCite this: J. Org. Chem. 1995, 60, 23, 7406–7410Publication Date (Print):November 1, 1995Publication History Published online1 May 2002Published inissue 1 November 1995https://doi.org/10.1021/jo00128a010RIGHTS & PERMISSIONSArticle Views405Altmetric-Citations53LEARN ABOUT THESE METRICSArticle...
Background and Purpose Anion‐selective Cys‐loop receptors (GABA glycine receptors) provide the main inhibitory drive in CNS. Both types of receptor operate via chloride‐selective ion channels, though with different kinetics, pharmacological profiles, localization. Disequilibrium their function leads to a variety disorders, which are often treated allosteric modulators. The few available GABA channel blockers effectively suppress currents neurons, but systemic administration is highly toxic....
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBenzannelated [2.2]paracyclophanes: synthesis and electronic propertiesOliver Reiser, Burkhard Koenig, Klaus Meerholz, Juergen Heinze, Thomas Wellauer, Fabian Gerson, Ron Frim, Mordecai Rabinovitz, Armin de MeijereCite this: J. Am. Chem. Soc. 1993, 115, 9, 3511–3518Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1...
Abstract An efficient and general synthesis of hexahydropyrimidopyrimidinediones has been developed employing a low melting L ‐(+)‐tartaric acid‐dimethylurea mixture as reaction medium. The melt acts at the same time solvent, catalyst reactant. Functionalized are obtained in good to excellent yields after simple work‐up.
Self-assembled lipid vesicles with embedded amphiphilic terbium(III) complexes show a strong temperature dependence of their phosphorescence intensity and lifetime in the physiological range.
Within the framework of discovery chemistry, polyfluorination remains a synthetic challenge despite its ability to provide useful characteristics, such as reduction in number hydrogen bond donors and metabolic stability. Coupling reversal this methodology with photocatalysis has been demonstrated allow rapid synthesis previously difficult or impossible targets by starting fluorines everywhere selectively removing functionalizing them. Herein, we demonstrate novel method synthesize...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBinding of Heptanedioic Acid to a Threefold Pyridine Arylamide Receptor. Enhancement the Stability Supramolecular Solution Structures by Multiple Binding SitesBurkhard Koenig, Oliver Moeller, Peter Bubenitschek, and G. JonesCite this: J. Org. Chem. 1995, 60, 13, 4291–4293Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June...
Abstract 5-(α-D-Glucosyloxymethyl)furfural, a versatile building block from renewable resources, was prepared isomaltulose–choline chloride melts by acid catalysis. In this solvent-free process, moderate yields were achieved under mild reaction conditions. GRAPHICAL ABSTRACT Keywords: Deep eutectic solventglucosylated furfuralisomaltulose ACKNOWLEDGMENTS We thank the Suedzucker AG for their kind gift of isomaltulose and pure GMF as reference. This project financially supported Fachagentur...
Functionalisation of partially water-soluble C-H precursors through Fe(III)Cl3 Ligand-to-Metal charge transfer catalysis in aqueous solution is achieved under near UV-light irradiation. The light-driven bond-homolysis the Fe-Cl bond within iron complex results generation highly reactive chlorine radicals, facilitating hydrogen atom abstraction from a furane-derived starting material. Sugars or cinchonidine derivatives promote interaction between metal salt and organic substrates. Lowering...