نتایج جستجو برای: Trifluoromethyl
تعداد نتایج: 2599 فیلتر نتایج به سال:
The synthesis and properties of new monoazo dyes derived from the diazonium salts of paminobenzoic acid, 3-trifluoromethyl aniline , 4-trifluoromethyl aniline are considered .Theprepared compounds were characterized by UV-Visible , FT-IR and H NMR spectroscopictechniques . The effect of varying solvent upon the absorption ability of p-amino benzoic acidcoupled with 4,4 —diethyl aniline , anilin...
the synthesis and properties of new monoazo dyes derived from the diazonium salts of paminobenzoic acid, 3-trifluoromethyl aniline , 4-trifluoromethyl aniline are considered .theprepared compounds were characterized by uv-visible , ft-ir and h nmr spectroscopictechniques . the effect of varying solvent upon the absorption ability of p-amino benzoic acidcoupled with 4,4 —diethyl aniline , anilin...
The first synthesis of a CF3-substituted semisquarate was accomplished via nucleophilic trifluoromethylation using CF3SiMe3 and subsequent rhenium-catalyzed allylic alcohol rearrangement. The short-step skeletal-divergent synthesis of trifluoromethylated functional molecules was successfully achieved using the CF3-substituted semisquarate as the platform.
Organoboranes carrying electron-withdrawing substituents are commonly used as Lewis acidic catalysts or cocatalysts in a variety of organic processes. These Lewis acids also became popular through their application in `frustrated Lewis pairs', i.e. combinations of Lewis acids and bases that are unable to fully neutralize each other due to steric or electronic effects. We have determined the cry...
nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents. this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...
In this investigation a simple synthetic method for the synthesis of trifluoromethyl-1H-benzo[e][1,2,4]triazolo[1,2-a][1,2,4]triazine-1,3(2H)-diones and (trifluoromethyl)benzo [5,6][1,2,4]triazino[1,2-b]phthalazine-8,13-diones has been developed using urazole or phthalazine and aceteimidoyl chloride derivatives at room temperature under ultrasound irradiations. In the comparison to the conventi...
Nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(Trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents. This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. The prepared sulfated titania s...
This communication describes a chiral base-catalyzed asymmetric [1,3]-proton shift of trifluoromethyl ketimines, giving a wide variety of trifluoromethyl aldimines containing various functional groups with up to 94% ee.
A general synthesis of γ-trifluoromethyl α,β-unsaturated γ-butyrolactones is described. The fluoride-catalyzed nucleophilic addition of a trifluoromethyl (CF3) group generated from (trifluoromethyl)trimethylsilane (CF3SiMe3, Ruppert-Prakash reagent) to a masked maleic anhydride 1 (cyclopentadiene-maleic anhydride adduct) provides the corresponding adducts 2 with high stereoselectivity. The γ-tr...
Nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(Trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents. This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. The prepared sulfated titania s...
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