نتایج جستجو برای: Silica-supported Catalyst
تعداد نتایج: 268773 فیلتر نتایج به سال:
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...
The application of silica-supported TEMPO as a recyclable catalyst in the Anelli oxidation of alcohols is reported. The catalyst is easily obtained in a one-step reductive amination procedure starting from a commercially available aminopropyl-functionalized silica. Details of the synthesis of the supported catalyst and its analysis by MAS NMR are presented. Various alcohol oxidations according ...
in this research, different alcohols and phenols are subjected to the reaction with hmds in the presence of ionic liquid and silica-supported catalysts. silylation was accomplished under mild reaction conditions at room temperature in short reaction times and good to excellent yields.
Silica sodium carbonate (SSC) has been used as a valuable silica-supported catalyst for the preparation of a range of known and novel pyrano coumarins via the three-component reactions of aryl aldehydes, active methylene compound (malononitrile or ethyl cyanoacetate), and hydroxycoumarin (5,7-dihydroxy-4-substituted coumarins or 4-hydroxycoumarin). The heterogeneous catalyst showed much the sam...
a green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with uhp at room temperature is reported. the reaction is performed in the presence of vanadia catalyst supported on mesocellular silica foam (mcf) with a v content ranging from 2% to 10% as heterogeneous and reusable catalyst. the structural and textural characterization of this catalyst were don...
bis(2-r-ind)zrcl2 (r: h or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. in this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, tiba) cocatalyst was used instead of expensive methyl aluminiumoxane (mao) cocatalyst in the polymerization. the effect of surface ...
a series of fe3o4 supported on mesoporous fdu-12 silica systems were prepared by the hydrothermal conditions. the surface properties of the functionalized catalyst were analyzed by a series of characterization techniques like ftir, xrd, n2 adsorption–desorption and tem. xrd and adsorption–desorption analysis shows that the mesostructure of fdu silica remains intact after fe3o4 modifications, wh...
The protons on a silica or alu mina su rface can be replaced by manganese( III) porphyrin ca tions, Mn(TPP +). Manganesc(III) porphyrin supported on silica and alumina can activate dioxygen in the presence of additional NaBH4 o r [NBu41rBH41 as an electron source and styrene, affording I-phenyl ethanol and acetophenone in a 4:1 ratio. When oxidation was applied in a mixture of benzene/eth...
a novel rice-husk-silica supported n-propyl bipyridinium chloride (rhprbpcl) has been prepared. due to the basicity of rhprbpcl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. the catalyst was characterized by ft-ir, sem and tga analyses. this methodology offers seve...
nano-silica supported boron trifluoride (bf3.sio2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. so, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes in good to excellent yields. the reactions were carried out at room temperature under solven...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید