A5035288212- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Synthesis and Reactions of Organic Compounds
- Synthesis and Biological Evaluation
- Chemical Synthesis and Analysis
- Organic Chemistry Cycloaddition Reactions
- Click Chemistry and Applications
- Synthesis and Characterization of Heterocyclic Compounds
- Cyclopropane Reaction Mechanisms
- Synthesis and Reactivity of Heterocycles
- Fluorine in Organic Chemistry
- Multicomponent Synthesis of Heterocycles
- Synthesis and Catalytic Reactions
- Chemical Reaction Mechanisms
- Asymmetric Synthesis and Catalysis
- Microwave-Assisted Synthesis and Applications
- Synthesis and biological activity
- Crystallography and molecular interactions
- Synthesis of Organic Compounds
- Oxidative Organic Chemistry Reactions
- Berberine and alkaloids research
- Synthesis of heterocyclic compounds
- Inorganic and Organometallic Chemistry
- Chemical Synthesis and Reactions
- Catalytic Alkyne Reactions
Masaryk University
2009-2024
University of Pardubice
2007
Jan Evangelista Purkyně University in Ústí nad Labem
1968-1989
Leipzig University
1989
This review deals with the fully aromatic quaternary benzo[ c ]phenanthridine alkaloids in several aspects. Firstly nomenclature principles for numbering fused heterocycles are given. Then richest botanical sources of ]phenanthridines mentioned as well isolation, separation and determination methods presented. The emphasis this survey is focused on chemical reactivity. main pharmacological effects discussed.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of Chelerythrine BaseJiří Dostál, Eva Táborská, Jiří Slavík, Milan Potáček, and Edmond de HoffmannCite this: J. Nat. Prod. 1995, 58, 5, 723–729Publication Date (Print):May 1, 1995Publication History Published online1 July 2004Published inissue 1 May 1995https://pubs.acs.org/doi/10.1021/np50119a010https://doi.org/10.1021/np50119a010research-articleACS PublicationsRequest reuse permissionsArticle Views301Altmetric-Citations34LEARN ABOUT...
Abstract The thermally initiated intramolecular criss‐cross cycloaddition of 3‐substituted homoallenylaldazines 5 has been explored. Their cyclization led to interesting new fused heterocyclic systems 6 consisting four five‐membered rings with two nitrogen heteroatoms. azines were prepared by the reaction homoallenyl aldehydes 4 hydrazine. synthesized Claisen rearrangement N , ‐disubstituted 4‐[(2‐methylprop‐1‐en‐1‐yl)oxy]but‐2‐yn‐1‐amines 3a – f Mannich 2‐methylprop‐1‐en‐1‐yl prop‐2‐yn‐1‐yl...
New compounds with the ethyl hexahydro-1H-pyrrolo[3,2-c]quinoline-2-carboxylate skeleton were prepared by microwave-assisted intramolecular 1,3-dipolar cycloaddition reactions. The reactions carried out under solvent-free conditions and compared same reaction in presence of a solvent catalyst. Steric effects on selectivity noted evaluated.
The preparation of new non-symmetrical allenyl azines 5 with aliphatic and alicyclic substituents their reactions are described.When aldazines were refluxed in xylene formation bicyclic products 7 was observed.Compounds appeared as derivatives isowithasomnine.Combined intra-intermolecular criss-cross cycloadditions afforded heterocyclic 8 9 containing three fused five-membered rings.Structures all compounds elucidated by 1 H 13 C NMR, IR MS measurements some cases X-ray structure analysis.
Abstract Thermally initiated cycloaddition reactions of nonsymmetrical allenyl azines 1 with alkynes or other dipolarophiles usually lead to compounds three fused, five‐membered heterocyclic rings. With pronounced “push–pull” systems, however, the reaction ends formation substituted pyrrolidino[1,2‐ b ]pyrazoles 4 and, in case trifluoromethyl substitution, ring opening leads isolation 9 . Reaction mechanisms for these transformations are proposed. The molecular structures new heterocycles...
C-H activation of position 3 a substituted pyrazole ring catalyzed by palladium(II) was straightforward and convenient for arylated or heteroarylated 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoles. Moreover, we introduced simple protection the nitrogen in pyridin-2-yl directing group, which otherwise does not allow cross-coupling reaction, transformation to N-oxide. Selected final products were reasonably selective ALK5 kinase inhibitors.
The formation of sanguinarine pseudobase (6-hydroxydihydrosanguinarine) was studied by 1D and 2D NMR spectroscopy. unequivocal evidence a hemiaminal OH group unambiguous 1H, 13C 15N assignments this compound are discussed. © 1998 John Wiley & Sons, Ltd.
Abstract We report the microwave‐assisted solvent‐free synthesis of hexahydrochromeno[4,3‐ b ]pyrroles. Intramolecular 1,3‐dipolar cycloadditions proceed under these conditions within 15 min in 80% yields. Moreover, we have observed pronounced steric requirements alkyl substituents toward cycloadditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The reactivity of alicyclic ketazines in criss-cross cycloadditions was investigated. They react with potassium cyanate and ammonium thiocyanate the presence acetic acid to form spirocyclic perhydro[1,2,4]triazolo[1,2-alpha][1,2,4]triazole-1,5-diones perhydro[1,2,4]triazolo[1,2-alpha][1,2,4]triazole-1,5-dithiones, respectively, relatively high yields.
Herein, we report a molecular framework design differing significantly from the traditional topology of proton sponges. We developed synthetic approach to preparation caged secondary amines by acid-catalyzed rearrangement fused tetracyclic heterocycles synthesized intramolecular criss-cross cycloaddition. Alkylation led air nonsensitive diazatetracyclo[4.4.0.13,10.15,8]dodecanes (DTDs) with rare alicyclic scaffolding in high overall yields. Their pKBH+ values were determined transprotonation...
The structure of sanguinarine free base was examined. is either bis[6-(5,6-dihydrosanguinarinyl)] ether (3) or bis[6-(5,6-dihydrosanguinarinyl)]amine (4) depending on whether Na2CO3 NH3, respectively, used as an alkalizing agent. Oxysanguinarine (5) identified a side product formed by disproportionation the pseudobase intermediate 2a.
Berberine azide, berberine thiocyanate, and 8-cyano-8H-berberine were prepared from chloride, a quaternary protoberberine alkaloid. The molecular crystal structures of all compounds are reported discussed.