نتایج جستجو برای: imidazoles multicomponent nmr
تعداد نتایج: 72088 فیلتر نتایج به سال:
A general approach for the synthesis of bis(imidazolium) dichloride salts from imidazoles and dichloroalkanes is reported. Typical limitations this reaction formation methylene-bridge...
aza heterocyclic compounds are major interest for organic chemists because of their mainly pharmacological activities and clinical applications such as antianxiety, antitumor, anticonvulsant, cardiotonic and vasorelaxant. this contribution describes an electrochemical approach for the preparation of nanosized particles of phthalazine in high yields and very short reaction time. the method is ba...
Particle and domain sizes strongly influence the properties of materials. Here we present an NMR approach based on paramagnetic relaxation enhancement (PRE) relayed by spin diffusion (SD), which allows us to determine lengths in the nm-μm range. We demonstrate the method on multicomponent organic polymer mixtures by selectively doping one component with a paramagnetic center in order to measure...
A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a ...
Copper nanoparticles on activated carbon have been found to effectively catalyze the multicomponent synthesis of β-hydroxy-1,2,3-triazoles from a variety of epoxides and alkynes in water. The catalyst is easy to prepare, reusable at a low copper loading (0.5 mol %), and exhibits higher catalytic activity than some commercially available copper sources. The regio- and stereochemistry of the reac...
Aza heterocyclic compounds are major interest for organic chemists because of their mainly pharmacological activities and clinical applications such as antianxiety, antitumor, anticonvulsant, cardiotonic and vasorelaxant. This contribution describes an electrochemical approach for the preparation of nanosized particles of phthalazine in high yields and very short reaction time. The method is ba...
A one-pot multicomponent reaction of aryl aldehydes, 2-amino benzimidazole and ethyl 2-mercaptoacetate is described as an efficient and environmentally method for the synthesis of some novel ethyl 2-((1H-benzo[d]imidazol-2-ylamino)(Aryl)methylthio) acetates in the presence of nano-Copper Y Zeolite (NCZ) as a catalyst in ethanol at room temperature. After optimizing of r...
A new way to analyze supramolecular dendritic architectures is reported by making use of (13)C NMR and (31)P NMR. Two ethylene glycol guest molecules have been synthesized containing a (13)C labeled carboxylic acid headgroup (2) and a phosphonic acid headgroup (3). The binding of these guests to urea-adamantyl modified poly(propylene imine) dendrimers has been investigated with (13)C NMR and (3...
Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks
Two pairs of divalent and tetravalent porphyrin building blocks carrying the complementary supramolecular crown ether/secondary ammonium ion binding motif have been synthesized and their derived pseudorotaxanes have been studied by a combination of NMR spectroscopy in solution and ESI mass spectrometry in the gas phase. By simple mixing of the components the formation of discrete dimeric and tr...
A palladium-catalyzed regiodivergent C1 insertion multicomponent reaction involving aryne, CO, and 2-iodoaniline is established to construct the scaffolds of phenanthridinone and acridone alkaloids. Regioselective control is achieved under the guidance of selective ligands. The phenanthridinones are solely obtained under ligand-free condition. In comparison, application of the electron-abundant...
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