A5062164800- Carbohydrate Chemistry and Synthesis
- Synthetic Organic Chemistry Methods
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Sphingolipid Metabolism and Signaling
- Chemical Synthesis and Analysis
- Synthesis and Reactivity of Sulfur-Containing Compounds
- Asymmetric Synthesis and Catalysis
- Synthesis and Characterization of Heterocyclic Compounds
- Synthesis of heterocyclic compounds
- Synthesis and Catalytic Reactions
- Synthesis and biological activity
- Chemical synthesis and alkaloids
- Synthesis and Reactions of Organic Compounds
- Phenothiazines and Benzothiazines Synthesis and Activities
- Marine Sponges and Natural Products
- Berberine and alkaloids research
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Organic Chemistry Cycloaddition Reactions
- Polyamine Metabolism and Applications
- Synthesis and Biological Evaluation
- Fluorine in Organic Chemistry
- Quinazolinone synthesis and applications
- Crystallography and molecular interactions
- Microbial Natural Products and Biosynthesis
University of Pavol Jozef Šafárik
2013-2023
Technical University of Košice
2019-2020
Institute of Chemistry of the Slovak Academy of Sciences
2004
Novartis (Switzerland)
1991-1997
In the thermal rearrangement of allylic trichloroacetimidates 6, no 1, 2-asymmetric induction can be observed. Palladium(II) catalyzed, however, takes place at 25°C and yields diastereoselectively (de ≥ 98%) anti-1,2-diamines 7. The 6 easily prepared starting from α-amino acids.
Among the reactions available to synthetic chemists for construction of new C--C bonds, Claisen rearrangement is one most powerful, elegant, and well-characterized methods. A genuinely variant, Bellus-Claisen came light a quarter century ago: The reaction an allylic ether, thioether, or amine with ketene leads through [3,3] sigmatropic bond reorganization zwitterionic intermediate E unsaturated ester, thioester, amide. When applied cyclic substrates, ring-enlargement by four carbon atoms in...
Optically active α-siloxycarbonates are converted to optically allylsulfides 1. These intermediates allowed react with dichloroketene (generated in situ) leading α,α-dichloro-β-vinyl-γ-siloxy-substituted thioesters 2. The assumed transition state is represented by 3. This ketene-Claissen rearrangement shows complete 1,2-asymmetric induction all of the cases examined. Reductive dechlorination γ-siloxy-substituted provides 3,4-cis-distubstituted γ-lactones. R = Me, iPr, C2H4OTBDMS; TBDMS...
A stereoselective approach has been developed to the new sugar amino acid and potential potent turn mimic 5-O-(tert-butyldimethylsilyl)-3-deoxy-1,2-O- isopropylidene-3-methoxycarbonylamino-α-D-xylofuranose 3-C-carboxylic (12), via [3,3]-sigmatropic rearrangement of allylic thiocyanates (Z)-6 (E)-7, prepared from D-xylose. The synthesis a dipeptide 13 is also described.
Abstract A novel type of ketene‐ Claisen rearrangement in which the precursor is generated situ by reaction optically active allyl thioethers with dichloroketene described. characteristic feature this excellent chemoselectivity favor vs. ethers, i.e. , exclusive chirality transfer allylic sulfur moiety observed 12, 13 and 25‐‐27 . The cyclic, (+)‐( R )‐ 4 (−)‐( S open‐chain 11‐‐13 rearrange to thioesters 28 31‐33 respectively. chirality‐transfer > 99% cyclic cases 96‐‐98 % observed....
The synthesis of photochromic active sphingosine analogues and their antiproliferative activity against seven human cancer cell lines is reported.