نتایج جستجو برای: polyhydroquinoline derivatives
تعداد نتایج: 104912 فیلتر نتایج به سال:
Hexa-substituted benzene derivatives show larger two-photon cross sections than the corresponding dipolar counterparts and the largest values of delta(max) = 2000 GM and delta(max)/MW = 2.25 GM g(-1) have been obtained with a compound having C[triple bond]C and C=C bonds in the conjugation bridge.
We have successfully developed a new synthetic approach to modulate the electrostatic potentials of metallocavitands and thus their selective recognition towards substituted benzene derivatives via integrating two metal cations of different electronegativity into a self-assembled system.
By the immobilization of bipyridinium chloride onto mesoporous MCM-41encapsulated Fe3O4 nanoparticles via a simple post-synthesis method, a totally new organic-inorganic hybrid nanocomposite was formulated. The heterogeneous hybrid nanomagnetic composite was characterized by <spa...
abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...
An efficient, recyclable and environmental-friendly synthetic route to polyhdroquinoline derivatives have been developed via multi-component one-pot Hantzsch reaction of various aromatic aldehyde, 2 equivalents of 5,5-dimethyl-1,3-cyclohexanedione (dimedone), ethyl acetoacetate and ammonium acetate using nano magnesium oxide as a catalyst in ethanol under reflux condition. Reaction with 4-chlor...
The condensation of aromatic aldehydes, dimedone, ethylacetoacetate and ammonium acetate promoted by was Phosphorus pentoxide supported on alumina carried out under solvent-free conditions to afford corresponding polyhydroquinolinederivatives. This method provides several advantages including high yields, low reaction times, easy work up and little catalyst loading.
We consider the task of filtering the noise from images and other types of inputs which are assumed to be piecewise continuous and piecewise monotone. We show that nonlinear diffusion of the data, a powerful filtering method, is too restrictive for such a case, leading to piecewise constant functions. We claim that the piecewise monotonicity can be enhanced by nonlinear diffusion of first parti...
Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...
A new formulation of a pose refinement technique using “active” models is described. An error term derived from the detection of image derivatives close to an initial object hypothesis is linearised and solved by least squares. The method is particularly well suited to problems involving external geometrical constraints (such as the ground-plane constraint). We show that the method is able to r...
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