نتایج جستجو برای: spirooxindole chromene derivatives
تعداد نتایج: 105566 فیلتر نتایج به سال:
Herein, we report our preliminary results concerning the first promising asymmetric synthesis of highly functionalized 2-oxospiro-[indole-3,4'-(1',4'-dihydropyridine)] via the reaction of an enamine with isatylidene malononitrile derivatives in the presence of a chiral base organocatalyst. The moderate, but promising, enantioselectivity observed (30%-58% ee (enantiomeric excess)) opens the door...
The cesium carbonate-mediated reaction of 2-bromoallyl sulfones and ortho-hydroxychalcones furnished 3-arylsulfonyl-4H-chromene derivatives in 58-67% yield (18 examples). 2-Bromoallyl sulfones functioned as synthetic surrogates for allenyl sulfones in the reaction.
The reaction of dimethyl acetylenedicarboxylate with OH-acid such as 2-naphthol in the presence of trimethyl or triphenyl phosphite under solvent-free conditions produce oxaphosphaphenanthrene derivatives in good yields. Also, the reaction of dimethyl acetylenedicarboxylate and trimethyl phosphite in the presence of 1-naphthol leads to succinate derivatives in excellent yields. Using triethyl p...
Efficient kinetic resolution of racemic 3-nitro-2H-chromenes by bifunctional thiourea afforded optically active (R)-3-nitro-2H-chromene derivatives with moderate to good enantioselectivities, which simultaneously gave the multifunctional 3,4-diphenyl-3a-nitrobenzopyrano-[3,4-c]-pyrrolidine-1,1-dicarboxylate derivatives with four vicinal chiral carbon centers.
Dynamic kinetic asymmetric transformation (DYKAT) reactions of racemic diastereomer mixtures that afford the products as essentially single diastereomers with high enantioselectivities are described. We demonstrated DYKAT in diastereo- and enantioselective synthesis spirooxindoles bearing furan-fused rings. The starting materials DYKAT, dihydrobenzofuranone derivatives, were synthesized mixture...
One of the important Multi-component reaction (MCRs) is the synthesis of dihydropyrano chromene derivatives by one-pot reaction. In this research, an inexpensive and effective one pot three component procedure with good yields for the synthesis of dihydro pyrano chromenes is reported. In this method, the synthesis of pyrano chromene derivatives was followed by using 4-hydroxycoumarin, malononit...
an efficient and green method for the synthesis of pyrano[3,2-c]chromene or pyrano[4,3-b]pyrone derivatives is described by using a three-component condensation process of malononitrile, aldehyde, and 4-hydroxycoumarine or 4-hydroxypyrone in [bmim]bf4-licl as an ionic liquid.
1-Methyl-1H-imidazol-3-ium 2,3,4,5,6-pentafluorophenolate [mim]C6F5O as a novel nano ionic liquid was designed, synthesized and characterized by using various techniques such as Fourier transform spectroscopy infrared (FT-IR), nuclear magnetic resonance (NMR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ener...
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