A5080487872- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Asymmetric Hydrogenation and Catalysis
- Catalytic C–H Functionalization Methods
- Metal complexes synthesis and properties
- Radical Photochemical Reactions
- Crystallography and molecular interactions
- Asymmetric Synthesis and Catalysis
- Synthesis and Catalytic Reactions
- DNA and Nucleic Acid Chemistry
- Ferrocene Chemistry and Applications
- Sulfur-Based Synthesis Techniques
- Organometallic Complex Synthesis and Catalysis
- Advanced biosensing and bioanalysis techniques
- Cyclopropane Reaction Mechanisms
- Click Chemistry and Applications
- Synthetic Organic Chemistry Methods
- Oxidative Organic Chemistry Reactions
- Cancer Mechanisms and Therapy
- Chemical Synthesis and Analysis
- Surface Chemistry and Catalysis
- RNA and protein synthesis mechanisms
- Axial and Atropisomeric Chirality Synthesis
- Peptidase Inhibition and Analysis
- Melanoma and MAPK Pathways
Philipps University of Marburg
2016-2025
Weatherford College
2019
Xiamen University
2012-2017
State Council of the People's Republic of China
2015-2017
Xiamen University of Technology
2017
University of Pennsylvania
2004-2012
The Wistar Institute
2008-2012
Philadelphia University
2007-2012
Bausch Health (Germany)
2010
California University of Pennsylvania
2010
A guanine radical cation (G+•) was site-selectively generated in double stranded DNA and the charge transfer different oligonucleotide sequences investigated. The method is based on competition between a from G+• through its trapping reaction with H2O. We analyzed hole this to GGG unit one, two, three, four AT base pairs found that rate decreases by about 1 order of magnitude each intervening pair. This strong distance dependence led β-value 0.7 ± 0.1 Å-1. Within time scale assay nearly...
Visible light driven organic chemistry has sparked much excitement over the last several years. This review summarizes recent progress in combining visible activation with asymmetric catalysis, processes that are either mediated by photoinduced electron or energy transfer. The tasks of photoactivation and catalysis typically accomplished dual catalyst systems but reports demonstrate they can also be effectively executed single catalysts. Beyond discovery novel transformations under mild...
ConspectusCatalysts for asymmetric synthesis must be chiral. Metal-based catalysts are typically constructed by assembling chiral ligands around a central metal. In this Account, new class of effective Lewis acid is introduced in which the octahedral metal center constitutes exclusive source chirality. Specifically, here discussed composed configurationally stable, chiral-at-metal Λ-configured (left-handed propeller) or Δ-configured (right-handed iridium(III) rhodium(III) complexes...
Abstract The catalysis of bioorthogonal transformations inside living organisms is a formidable challenge—yet bears great potential for future applications in chemical biology and medicinal chemistry. We herein disclose highly active organometallic ruthenium complexes under biologically relevant conditions cells. catalysts uncage allyl carbamate protected amines with unprecedented high turnover numbers up to 270 cycles the presence water, air, millimolar concentrations thiols. By live‐cell...
This work demonstrates how photoredox-mediated C(sp3)−H activation through radical translocation can be combined with asymmetric catalysis. Upon irradiation visible light, α,β-unsaturated N-acylpyrazoles react N-alkoxyphthalimides in the presence of a rhodium-based chiral Lewis acid catalyst and photosensitizer fac-[Ir(ppy)3] to provide C−C bond-formation product high enantioselectivity (up 97 % ee) and, where applicable, some diastereoselectivity (3.0:1 d.r.). Mechanistically, synthetic...
A reaction design is reported in which a substrate-bound chiral Lewis acid complex absorbs visible light and generates an excited state that directly reacts with cosubstrate highly stereocontrolled fashion. Specifically, rhodium catalyzes visible-light-activated intermolecular [2+2] cycloadditions, providing wide range of cyclobutanes up to >99% ee >20:1 d.r. Noteworthy the ability create vicinal all-carbon-quaternary stereocenters including spiro centers
Abstract Combining single electron transfer between a donor substrate and catalyst‐activated acceptor with stereocontrolled radical–radical recombination enables the visible‐light‐driven catalytic enantio‐ diastereoselective synthesis of 1,2‐amino alcohols from trifluoromethyl ketones tertiary amines. With chiral iridium complex acting as both Lewis acid photoredox catalyst, enantioselectivities up to 99 % ee were achieved. A quantum yield <1 supports proposed cycle in which at least one...
ConspectusAspects of sustainability are playing an increasingly important role for the development new synthetic methods. In this context, combination asymmetric catalysis, which is considered one most economic strategies to generate nonracemic chiral compounds, and visible light as abundant source energy induce or activate chemical reactions has recently gained much attention. Furthermore, photochemistry with catalysis provides opportunity mechanistically unique reaction schemes. However,...
The generation of synthetic compounds with exclusive target specificity is an extraordinary challenge molecular recognition and demands novel design strategies, in particular for large homologous protein families such as kinases more than 500 members. Simple organic molecules often do not reach the necessary sophistication to fulfill this task. Here, we present six carefully tailored, stable metal-containing which unique defined geometries natural-product-like structural complexity are...
An efficient enantioselective addition of alkyl radicals, oxidatively generated from organotrifluoroborates, to acceptor-substituted alkenes is catalyzed by a bis-cyclometalated rhodium catalyst (4 mol %) under photoredox conditions. The practical method provides yields up 97% with excellent enantioselectivities 99% ee and can be classified as redox neutral, electron-transfer-catalyzed reaction.
A novel method for the catalytic asymmetric dearomatization by visible-light-activated [2+2] photocycloaddition with benzofurans and one example of a benzothiophene is reported, thereby providing chiral tricyclic structures up to four stereocenters including quaternary stereocenters. The are functionalized at 2-position chelating N-acylpyrazole moiety which permits coordination visible-light-activatable chiral-at-rhodium Lewis acid catalyst. Computational molecular modeling revealed origin...
Electron-acceptor-substituted aryl azides and α-diazo carboxylic esters are used as substrates for visible-light-activated asymmetric α-amination α-alkylation, respectively, of 2-acyl imidazoles catalyzed by a chiral-at-metal rhodium-based Lewis acid in combination with photoredox sensitizer. This novel proton- redox-neutral method provides yields up to 99% excellent enantioselectivities >99% ee broad functional group compatibility. Mechanistic investigations suggest that an intermediate...
Merging electrochemistry with asymmetric catalysis promises to provide an environmentally friendly and efficient strategy for the construction of nonracemic chiral molecules. However, in practice, significant challenges arise from instability or incompatibility catalysts under electrochemical conditions at interface electrode solution. Herein, we report a catalytic indirect electrolysis employing combination redox mediator chiral-at-rhodium Lewis acid, which achieves previously elusive...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Novel Copper-Mediated DNA Base PairEric Meggers, Patrick L. Holland, William B. Tolman, Floyd E. Romesberg, and Peter G. SchultzView Author Information Department of Chemistry The Scripps Research Institute 10550 North Torrey Pines Road La Jolla, California 92037 University Minnesota 207 Pleasant Street SE, Minneapolis, MN 55455 Cite this: J. Am. Chem. Soc. 2000, 122, 43, 10714–10715Publication Date (Web):October 13, 2000Publication History...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Simple Glycol Nucleic AcidLilu Zhang, Adam Peritz, and Eric MeggersView Author Information Department of Chemistry, University Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104 Cite this: J. Am. Chem. Soc. 2005, 127, 12, 4174–4175Publication Date (Web):March 4, 2005Publication History Received10 December 2004Published online4 March 2005Published inissue 1...
Easy going: A ruthenium-catalyzed release of amines from their respective allylcarbamates is disclosed and a step towards the design catalysts as tools for cellular biology. The reaction tolerates combination water, air, thiols can be performed inside living mammalian cells. Cp*=pentamethylcyclopentadienyl, cod=1,5-cyclooctadiene. Supporting information this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z601752_s.pdf or author. Please note: publisher not...
Stable and selective DNA base pairing by metal coordination was recently demonstrated with nucleotides containing complementary pyridine-2,6-dicarboxylate (Dipic) pyridine (Py) bases (Meggers, E.; Holland, P. L.; Tolman; W. B.; Romesberg, F. Schultz, G. J. Am. Chem. Soc. 2000, 122, 10714−10715). To understand the structural consequences of introducing this novel pair into we have solved crystal structure a duplex metallo-base pair. The shows that as designed, but in Z-DNA conformation. also...
Hopping between bases of similar redox potentials is the mechanism by which charge transport occurs through DNA. This was shown rate measurements performed with double strands 1-3. explains why hole transfer displays a strong sequence dependence, and postulates that electron in unperturbed DNA should not be dependent on sequence.
Abstract Unlike other tumors, melanomas harbor wild-type (WT) p53 but exhibit impaired p53-dependent apoptosis. The mechanisms for the activation are poorly understood may be linked to high expression of suppressor Mdm2, which is found in &gt;50% melanoma lesions. Here, we describe an organometallic glycogen synthase kinase 3β (GSK3β) inhibitor (DW1/2) as a potent activator and inducer cell death otherwise highly chemoresistant cells. Using RNA interference pharmacologic approaches, show...