the catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. the process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–cu(...

background diatomite coated by nanoparticles of copper and zinc mixed oxides were used to investigate catalytic oxidation of carbon monoxide. objectives aim of this paper was to investigatediatomite performance as a supporting host to confine the cuo and zno nanoparticles and its catalytic activity for carbon monoxide oxidation. materials and methods the prepared catalysts were characterized by...

sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl]ester (saspspe) is employed as a recyclable catalyst for the silylation of hydroxyl groups. a good range of primary, secondary alcohols and phenolic hydroxyl groups were effectively converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of saspspe at room temperature with short rea...

cis-polybutadiene was functionalized using in–situ generated dmd as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (ptc). the epoxidation process was investigated by 1hnmr spectroscopy. 1hnmr spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. various factors such as reaction temperature, reaction time and the concentr...

A catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(II) id described. The method is based on the catalytic effect of manganese(II) on the oxidation reaction of ferroin by potassium periodate in acidic media. The reaction is monitored spectrophotometrically at 510 nm by a slope method and Mn(II) is determinable in the range of 1-1000ngmL-1</sup...