Refine
Year of publication
Document Type
- Article (132)
- Postprint (17)
- Doctoral Thesis (3)
Is part of the Bibliography
- yes (152)
Keywords
- X-ray structure (7)
- crystal structure (6)
- ionic liquids (5)
- Lactams (4)
- X-ray (4)
- adsorption (4)
- zinc (4)
- Cycloaddition (3)
- Salts (3)
- Structure elucidation (3)
- Trifluoromethanesulfonamide (3)
- configuration (3)
- conformation (3)
- copper(II) (3)
- electron paramagnetic resonance (3)
- ligand (3)
- metal-organic frameworks (3)
- tetrabromidocuprate(II) (3)
- 2-Azaspiro[4.5]deca-1-ones (2)
- Alkylpyridinium salts (2)
- Arenesulfonamides (2)
- Catalysis (2)
- Cis- and trans-form (2)
- Complex (2)
- Configuration (2)
- Conformation (2)
- EPR (2)
- EPR spectroscopy (2)
- Gas (2)
- Ionic Liquid Precursor (2)
- Ionic liquids (2)
- Michael addition (2)
- N ligands (2)
- Nanostructures (2)
- Oxygen heterocycles (2)
- Palladium (2)
- Phase transitions (2)
- Podanthus mitiqui (2)
- Ruthenium (2)
- Solvents (2)
- Synthesis (2)
- Synthetic methods (2)
- Thermochromism (2)
- carbohydrate derivatives (2)
- carbon-dioxide capture (2)
- germacrane sesquiterpene lactone (2)
- ionic conductivity (2)
- ionogels (2)
- mechanical properties (2)
- microstructure (2)
- phase separation (2)
- 1 (1)
- 1,2-Disulfonamides (1)
- 1,2-Dithiosquarate,1,2-Dithiosquaratonickelate (1)
- 1,2-dithiooxalate (1)
- 1,2-dithiosquarate (1)
- 1,2-dithiosquaratometalate (1)
- 1,3-Dienes (1)
- 1,5-Dienes (1)
- 2'-bipyridine (1)
- 2-Dicyanoethene-1 (1)
- 2-Dithiooxalate (1)
- 2-Dithiosquarate (1)
- 2-Hydroxyethylammonium 1-R-indol-3-ylsulfanylacetates (1)
- 2-dithiolate (1)
- 3,6-Diazabicyclo[3.1.0]hexanes (1)
- 3,8-Diazabicyclo[3.2.1]octane (1)
- 4 (1)
- 4'-Bis(tert-butyl)-2 (1)
- 4,4 '-Bis(tert-butyl)-2,2 '-bipyridine (1)
- Acids (1)
- Alkynes (1)
- Allylamides (1)
- Allylic compounds (1)
- Arenes (1)
- Atropisomerism (1)
- Atropselecrivity (1)
- B3LYP/6-311++G** (1)
- Barrier to rotation about C-N bond (1)
- Biaryls (1)
- C-C coupling (1)
- Cadmium (1)
- Carbamoyl tetrazoles (1)
- Carbene ligands (1)
- Charge transfer (1)
- Chelation effect (1)
- Chiral auxiliaries (1)
- Cobalt (1)
- Coordination polymers (1)
- Copper (1)
- Copper(II) (1)
- Crystal and molecular structure (1)
- Crystal structures (1)
- Cyclodienes (1)
- Cyclophanes (1)
- Density functional calculations (1)
- Desymmetrization (1)
- Diastereoselectivity (1)
- Dynamic H-1-NMR (1)
- Electrochemistry (1)
- Extraction (1)
- Fluorescence lifetime (1)
- Fluorescent dyes (1)
- Formate (1)
- Gas-sorption (1)
- Heck reaction (1)
- Heterocycles (1)
- Hydrogenation (1)
- Imidazole (1)
- Immunoactive properties (1)
- Lactones (1)
- Large Stokes-shifts (1)
- Ligand design (1)
- MP2 calculations (1)
- Macrocycles (1)
- Macrocyclic li-gands (1)
- Magnetic properties (1)
- Maytenus disticha (1)
- Metathesis (1)
- Microwave chemistry (1)
- Mitochondrial ROS (1)
- Mixed-valent compounds (1)
- N (1)
- N-ligands (1)
- N-triflyl guanidines (1)
- Nickel (1)
- Nickel oxide (1)
- O ligands (1)
- Photochemistry (1)
- Protic 2-hydroxyethylammonium ionic liquids (1)
- Rearrangement (1)
- Redox chemistry (1)
- Reduction (1)
- Selenium (1)
- Solvothermal synthesis (1)
- Structure (1)
- Supramolecular chemistry (1)
- TG/DTA (1)
- Thioether ligands (1)
- Transition metals (1)
- Wacker reaction (1)
- X-ray diffraction (1)
- Zinc (1)
- activity (1)
- alkynes (1)
- behavior (1)
- beta-dihydroagarofuran-type sesquiterpene (1)
- building-blocks (1)
- cadmium (1)
- calcium carbonate biomineralization (1)
- capacity (1)
- carbohydrate derivatives (1)
- carbon-dioxide (1)
- catalysts (1)
- coordination polymer (1)
- copper(II) halide salts (1)
- crystal structures (1)
- crystals (1)
- cyclization (1)
- cytotoxic (1)
- diazo compounds (1)
- dihydromyricetin (1)
- dihydromyricetin-3-O-beta-glucoside (1)
- echinoderm skeleton (1)
- electrochemistry (1)
- electron-spin resonance (1)
- enzyme catalysis (1)
- exchange (1)
- flexibility (1)
- gases (1)
- green chemistry (1)
- hierarchical structuring (1)
- holmium(III) (1)
- hydrogen storage (1)
- hydrogenation (1)
- imidazole (1)
- imidazolium salts (1)
- ion exchange (1)
- ionic liquid (1)
- ionothermal synthesis (1)
- isomerization (1)
- lanthanides (1)
- liquid-crystal precursors (1)
- luminescence (1)
- magnetic-properties (1)
- mesocrystal (1)
- metal- organic frameworks (1)
- microporous materials (1)
- mixed-matrix membranes (1)
- molecular-structure (1)
- nanoparticles (1)
- nhc (1)
- nickel(II) (1)
- palladium (1)
- paramagnetic-resonance (1)
- phenols (1)
- pi-Stacking (1)
- pi-pi stacking (1)
- precatalysts (1)
- pressure (1)
- rearrangement (1)
- redox-active ligands (1)
- ruthenium (1)
- salts (1)
- selectivity (1)
- separation (1)
- skeletal elements (1)
- solvent (1)
- spirocycles (1)
- square planar (1)
- surface (1)
- tandem reaction (1)
- temperature (1)
- temperature phase (1)
- tetrachlorocuprate(II) salts (1)
- transition-metal-complexes (1)
- water (1)
- zeolitic imidazolate frameworks (1)
The title compounds, 2-azaspiro[4.5]deca-1-one, C₉H₁₅NO, (1a), cis-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1b), and trans-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1c), were synthesized from benzoic acids 2 in only 3 steps in high yields. Crystallization from n-hexane afforded single crystals, suitable for X-ray diffraction. Thus, the configurations, conformations, and interesting crystal packing effects have been determined unequivocally. The bicyclic skeleton consists of a lactam ring, attached by a spiro junction to a cyclohexane ring. The lactam ring adopts an envelope conformation and the cyclohexane ring has a chair conformation. The main difference between compound 1b and compound 1c is the position of the carbonyl group on the 2-pyrrolidine ring with respect to the methyl group on the 8-position of the cyclohexane ring, which is cis (1b) or trans (1c). A remarkable feature of all three compounds is the existence of a mirror plane within the molecule. Given that all compounds crystallize in centrosymmetric space groups, the packing always contains interesting enantiomer-like pairs. Finally, the structures are stabilized by intermolecular N–H···O hydrogen bonds.
The title compounds, 2-azaspiro[4.5]deca-1-one, C₉H₁₅NO, (1a), cis-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1b), and trans-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1c), were synthesized from benzoic acids 2 in only 3 steps in high yields. Crystallization from n-hexane afforded single crystals, suitable for X-ray diffraction. Thus, the configurations, conformations, and interesting crystal packing effects have been determined unequivocally. The bicyclic skeleton consists of a lactam ring, attached by a spiro junction to a cyclohexane ring. The lactam ring adopts an envelope conformation and the cyclohexane ring has a chair conformation. The main difference between compound 1b and compound 1c is the position of the carbonyl group on the 2-pyrrolidine ring with respect to the methyl group on the 8-position of the cyclohexane ring, which is cis (1b) or trans (1c). A remarkable feature of all three compounds is the existence of a mirror plane within the molecule. Given that all compounds crystallize in centrosymmetric space groups, the packing always contains interesting enantiomer-like pairs. Finally, the structures are stabilized by intermolecular N–H···O hydrogen bonds.
The title compound, erioflorin, C19H24O6 [systematic name: (1aR,3S,4Z,5aR,8aR,9R,10aR)-1a, 2,3,5a, 7,8,8a, 9,10,10a-decahydro-3-hydroxy-4,10a-dimethyl-8-methylidene-7-oxooxireno[5,6] cyclodeca[1,2-b]furan-9-yl methacrylate], is a tricyclic germacrane sesquiterpene lactone, which was isolated from Podanthus mitiqui (L.). The compound crystallizes in the space group P2(1)2(1)2(1), and its molecular structure consists of a methacrylic ester of a ten-membered ring sesquiterpenoid annelated with an epoxide and a butyrolactone. The structure is stabilized by one intramolecular C-H center dot center dot center dot O hydrogen bond. An O-H center dot center dot center dot O hydrogen bond and further C-H center dot center dot center dot O interactions can be observed in the packing.
The title compound, erioflorin, C19H24O6 [systematic name: (1aR,3S,4Z,5aR,8aR,9R,10aR)-1a, 2,3,5a, 7,8,8a, 9,10,10a-decahydro-3-hydroxy-4,10a-dimethyl-8-methylidene-7-oxooxireno[5,6] cyclodeca[1,2-b]furan-9-yl methacrylate], is a tricyclic germacrane sesquiterpene lactone, which was isolated from Podanthus mitiqui (L.). The compound crystallizes in the space group P2(1)2(1)2(1), and its molecular structure consists of a methacrylic ester of a ten-membered ring sesquiterpenoid annelated with an epoxide and a butyrolactone. The structure is stabilized by one intramolecular C-H center dot center dot center dot O hydrogen bond. An O-H center dot center dot center dot O hydrogen bond and further C-H center dot center dot center dot O interactions can be observed in the packing.
The reaction of pharmacological active protic ionic liquid tris-(2-hydroxyethyl)ammonium 4-chlorophenylsulfanylacetate H + N(CH 2 CH 2 OH) 3 ∙ ( - OOCCH 2 SC 6 H 4 Cl-4) (1) with zinc or nickel chloride in a ratio of 2:1 affords stable at room temperature powder-like adducts [H + N(CH 2 CH 2 OH) 3 ] 2 ∙ [M(OOCCH 2 SC 6 H 4 Cl-4) 2 Cl 2 ] 2- , M = Zn (2), Ni (3). By recrystallization from aqueous alcohol compound 2 unexpectedly gives Zn(OOCCH 2 SC 6 H 4 Cl-4) 2 ∙ 2H 2 O (4). Unlike 2, compound 3 gives crystals [N(CH 2 CH 2 OH) 3 ] 2 Ni 2+ · [ - OOCCH 2 SC 6 H 4 Cl-4] 2 (5), which have a structure of metallated ionic liquid. The structure of 5 has been proved by X-ray diffraction analysis. It is the first example of the conversion of a protic ionic liquid into potentially biological active metallated ionic liquid (1 → 3 → 5).
The title compound was prepared by the reaction of 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane with 4-chloro-2-methyl-phenoxyacetic acid in a ratio of 1:2. The structure has been proved by the data of elemental analysis, IR spectroscopy, NMR ( 1 H, 13 C) technique and by X-ray diffraction analysis. Intermolecular hydrogen bonds between the azonium protons and oxygen atoms of the carboxylate groups were found. Immunoactive properties of the title compound have been screened. The compound has the ability to suppress spontaneous and Con A-stimulated cell proliferation in vitro and therefore can be considered as immunodepressant.
Ionogels (IGs) based on poly(methyl methacrylate) (PMMA) and the metal-containing ionic liquids (ILs) bis-1-butyl-3-methlimidazolium tetrachloridocuprate(II), tetrachloride cobaltate(II), and tetrachlorido manganate(II) have been synthesized and their mechanical and electrical properties have been correlated with their microstructure. Unlike many previous examples, the current IGs show a decreasing stability in stress-strain experiments on increasing IL fractions. The conductivities of the current IGs are lower than those observed in similar examples in the literature. Both effects are caused by a two-phase structure with micrometer-sized IL-rich domains homogeneously dispersed an IL-deficient continuous PMMA phase. This study demonstrates that the IL-polymer miscibility and the morphology of the IGs are key parameters to control the (macroscopic) properties of IGs.
Planar bis(1,2-dithiooxalato)nickelate(II), [Ni(dto)]2− reacts in aqueous solutions with lanthanide ions (Ln3+) to form pentanuclear, hetero-bimetallic complexes of the general composition [{Ln(H2O)n}2{Ni(dto)2}3]·xH2O. (n = 4 or 5; x = 9–12). The complex [{Ho(H2O)5}2{Ni(dto)2}3]·10H2O, Ho2Ni3, was synthesized and characterized by single crystal X-ray structure analysis and powder diffraction. The Ho2Ni3 complex crystallizes as monoclinic crystals in the space group P21/c. The channels and cavities, appearing in the crystal packing of the complex molecules, are occupied by a varying amount of non-coordinated water molecules.
In this work, three ligands produced from amino acids were synthesized and used to produce five bis- and PEPPSI-type palladium–NHC complexes using a novel synthesis route from sustainable starting materials. Three of these complexes were used as precatalysts in the aqueous-phase Suzuki–Miyaura coupling of various substrates displaying high activity. TEM and mercury poisoning experiments provide evidence for Pd-nanoparticle formation stabilized in water.
Immunoactive ionic liquids (2-hydroxyethyl) ammonium 1-R-indol-3-ylsulfanyl-acetates HN+R1R2(CH2CH2OH)center dot O-(O)CCH2S-Ind-R-3-1(1-5), were synthesized by the reaction of (2-hydroxyethyl)amines with indol-3-ylsulfanylacetic- or 1-benzylindol-3-ylsulfanylacetic acid. 1: R-1 = R-2 = CH2CH2OH, R-3 = H; 2: R-1 =CH3, R-2=CH2CH2OH, R3 = H; 3: R-1 = R-2 = CH3, R-3 = H; 4: R-1 = R-2 = CH2CH2OH, R-3 = CH2C6H5; 5: R-1 = CH3; R-2 = CH2CH2OH; R-3 = CH2C6H5. The structure of each compound was elucidated by IR, NMR H-1, C-13, and N-15 techniques and their composition was confirmed by elemental analysis. The crystal structure of tris-(2-hydroxyethyl) ammonium indol-3-ylsulfanylacetate was investigated by X-ray diffraction analysis. Immunoactive properties of the title compounds were screened.
1,2-Dithiosquaratonickelates are available by direct synthesis from metal salts with dipotassium-1,2-dithiosquarate and the appropriate counter cations. The synthesis and characterization, including mass spectrometry, of a series 1,2-dithiosquaratonickelates(II), [Ni(dtsq)(2)](2-), with several "onium" cations is reported and the X-ray structures of two diamagnetic complexes, (HexPh(3)P)(2)[Ni(dtsq)(2)] and (BuPh3P)(2)[Ni(dtsq)(2)] with sterically demanding counter ions are presented. The diamagnetic nickel complexes have been doped as host lattices with traces of Cu(II) to measure EPR for additional structural information. The thermal behavior of this series is studied by thermogravimetry and differential thermal analysis (TG/DTA). The thermolysis in air as well as under nitrogen atmosphere of these complexes results in nickel oxide nano-particles in all cases, which are characterized by X-ray powder diffraction.
The acetamide group enables regioselective oxidative ortho-C-H activation reactions, such as Pd-catalyzed acylation. The synthetic utility of these transformations can be significantly enhanced by using the acetamide as a quasi-leaving group in a subsequent conventional Pd-catalyzed coupling or cross-coupling reaction. The concept is illustrated herein for the synthesis of o-alkenyl- and o-arylphenones, which have potential for the synthesis of arylated aromatic heterocycles.
Cadmium(II) based 2D coordination polymer [Cd(L1)(2)(DMF)(2)] (1) (L1 = 4,5-dicyano-2-methylimidazolate, DMF = N,N'-dimethylformamide) and 2D cobalt(II)-imidazolate framework [Co(L3)(4)] (2) (L3 = 4,5-diamide-2-ethoxyimidazolate) were synthesized under solvothermal reaction conditions. The materials were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction measurement (PXRD) and single-crystal X-ray diffraction. Compound 1 has hexacoordinate Cd-II ions and forms a zigzag chain-like coordination polymer structure, whereas compound 2 exhibits a 2D square grid type structure. The thermal stability analysis reveals that 2 showed an exceptional thermal stability up to 360 degrees C. Also, 2 maintained its fully crystalline integrity in boiling water as confirmed by PXRD. The solid state luminescent property of 1 was not observed at room temperature. Compound 2 showed an independent high spin central Co-II atom.
Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones
(2015)
Allyl, dimethylallyl and prenyl ethers derived from o-acyl-phenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs.