A5026290431- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Catalytic C–H Functionalization Methods
- Asymmetric Synthesis and Catalysis
- Chemical synthesis and alkaloids
- Synthetic Organic Chemistry Methods
- Oxidative Organic Chemistry Reactions
- Axial and Atropisomeric Chirality Synthesis
- Crystallography and molecular interactions
- Marine Sponges and Natural Products
- Inorganic and Organometallic Chemistry
- Asymmetric Hydrogenation and Catalysis
- Organometallic Complex Synthesis and Catalysis
- Catalytic Cross-Coupling Reactions
- Radical Photochemical Reactions
- Bioactive Compounds and Antitumor Agents
- Chemical Synthesis and Analysis
- Advanced Synthetic Organic Chemistry
- Cancer therapeutics and mechanisms
- Traditional and Medicinal Uses of Annonaceae
- Chemical Synthesis and Reactions
- Genetics, Aging, and Longevity in Model Organisms
- Sulfur-Based Synthesis Techniques
- Alkaloids: synthesis and pharmacology
- Analytical Chemistry and Chromatography
TU Dresden
2015-2024
Centro de Investigación Biomédica en Red
2019
Centre for Biomedical Network Research on Rare Diseases
2019
Instituto de Investigación Sanitaria La Fe
2019
Generalitat Valenciana
2019
University of Duisburg-Essen
1990-2010
Max Planck Institute of Molecular Cell Biology and Genetics
2008-2010
Evanston Hospital
2008
University of Zurich
2008
Max Planck Institute of Experimental Medicine
2008
beta-Secretase plays a critical role in beta-amyloid formation and thus provides therapeutic target for Alzheimer's disease. Inhibitor design has usually focused on active-site binding, neglecting the subcellular localization of active enzyme. We have addressed this issue by synthesizing membrane-anchored version beta-secretase transition-state inhibitor linking it to sterol moiety. Thus, we targeted found endosomes also reduced dimensionality inhibitor, increasing its local membrane...
A sequential exchange of one carbonyl ligand by a hydrido with NaOH, and then an iodo iodopentane finally treatment acid transforms tricarbonyl(η4-cyclopentadienone)iron complexes into dicarbonyl(η5-hydroxycyclopentadienyl)iodoiron complexes. These demetalate high selectivity to the corresponding free ligands on contact air in daylight. Under basic reaction conditions at stage complex anionic dicarbonyl(η4-cyclopentadienone)iodoiron is generated, which dimeric solid state has almost...
Abstract Highly convergent syntheses of substituted carbazoles are most conveniently achieved using organometallic chemistry. Construction the carbazole framework via iron-mediated route proceeds by a sequence C–C and C–N bond formation. In highly efficient palladium-catalyzed is formed first followed generation bond. This article highlights some recent developments applications to total synthesis biologically active alkaloids.
Using organometallic chemistry several novel methods for the efficient construction of pyrroles, indoles, and carbazoles have been developed. The key reactions are transition metal-mediated or -catalyzed oxidative cyclizations cycloadditions. In present article we summarize some recent applications these to short convergent total syntheses naturally occurring biologically active alkaloids including fused indolizidines, yohimbanes, Amaryllidaceae alkaloids, carbazoles. Keywords: cyclizations,...
Abstract We have developed a highly efficient route to 2‐hydroxy‐3‐methylcarbazole ( 1 ) via palladium‐catalyzed construction of the carbazole skeleton. Using as relay compound, different methods for annulations pyran rings by reaction with terpenoid building blocks been tested. The Lewis acid promoted prenal 21 opened up an girinimbine 3 and corresponding citral 25 afforded mahanimbine 5 ). Oxidation compounds provided murrayacine 4 murrayacinine 6 Following biogenetic proposal, has...
Why take things one step at a time? Aryl–pyran-linked biscarbazole alkaloids of the murrafoline group (see crystal structure A; dark gray: C, red: O, blue: N) were accessed readily by novel domino reaction sequence involving Sonogashira coupling, Claisen rearrangement, and electrocyclization. The one-pot procedure enables straightforward synthesis these structurally challenging in only few steps.
Abstract Inherited cardiomyopathies are common cardiac diseases worldwide, leading in the late stage to heart failure and death. The most promising treatments against these small molecules directly modulating force produced by β-cardiac myosin, molecular motor driving contraction. Omecamtiv mecarbil Mavacamten two such that completed phase 3 clinical trials, inhibitor is now approved FDA. In contrast Mavacamten, acts as an activator of contractility. Here, we reveal X-ray crystallography...
Upon starvation or overcrowding, Caenorhabditis elegans interrupts its reproductive cycle and forms a specialised larva called dauer (enduring). This process is regulated by TGF-β insulin-signalling pathways connected with the control of life span through insulin pathway components DAF-2 DAF-16. We found that replacing cholesterol methylated metabolite lophenol induced worms to form larvae in presence food low population density. Our data indicate sterols do not actively induce formation but...
Not the amine‐ N ‐Boc derivatives, but isocyanates form in reaction of alkyl‐ or arylamines with di‐ tert ‐butyl dicarbonate ((Boc) 2 O) presence a catalytic amount 4‐dimethylaminopyridine (DMAP) according to Equation (a). The procedure provides simple laboratory method generating sterically hindered alkyl and aryl without use phosgene. equation image
The reaction of pentacarbonyliron with trimethylsilylsubstituted alkynes regioselectively provides tricarbonyl(η4-2,5-bistrimethylsilylcyclopentadienone)iron complexes.
The reaction of tricarbonyliron-Complexed cyclohexadienylium cations with arylamines allows regio- and stereoselective formation carbon-carbon carbon-nitrogen bonds, gives easy access to nitrogen heterocyclic ring systems. Electrophilic aromatic substitution subsequent oxidative cyclization provides a convergent route biologically active carbazole alkaloids. Cyclization by nucleophilic leaving group in the side chain cyclohexadiene opens up versatile synthesis 3-aza-...
The isolation and biological activity of carbazole alkaloids is summarized. Recent developments novel methodologies for the synthesis are described. focus on syntheses using oxidative coupling arylamines with either arenes, cyclohexadienes, or cyclohexene mediated catalyzed by palladium, iron, molybdenum. implementation these annulations in total provides highly convergent routes to biologically active alkaloids. Advantages, scope, limitations different synthetic methods discussed. Keywords:...
Using a convergent palladium-catalyzed construction of the carbazole framework as key step we have achieved short synthesis 7-oxygenated alkaloids clauszoline-K, 3-formyl-7-hydroxycarbazole, clausine C (clauszoline-L), M, N and anti-HIV active siamenol.
A series of carbazole derivatives was tested for inhibition Mycobacterium tuberculosis growth and a mammalian cell line. Among several compounds with anti-TB activity, carbazoles B showed MIC values 4.0 μg mL−1 (8 μM) 2.2 (9 respectively, against M. were relatively nontoxic the
PdII caught in the act: The diaryl intermediate of a PdII-catalyzed oxidative biaryl bond formation proceeding via double CH activation has been isolated and fully characterized, including an X-ray crystal structure analysis (see figure). Stabilization due to chelation by adjacent pivaloyloxy acetyl groups allowed isolation this long-sought crucial intermediate. On gentle warming, complex is transformed into carbazole product, catalytically active species regenerated oxidation with CuII....