نتایج جستجو برای: good yields
تعداد نتایج: 506625 فیلتر نتایج به سال:
Three-component Process for the Synthesis of Some Thiophene Derivatives Using Water as a Green Media
A convenient and efficient three-component reaction to a one-pot synthesis of thiophene derivatives from activated acetylenic compounds and ethyl 2chloroacetoacetate in the presence of tetramethyl thiourea in water lead to the formation of thiophenes in good yields.
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...
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...
The triphenylphosphine-catalyzed formal [3 + 2] cycloaddition of allenoates and trifluoromethylketones was realized to give the corresponding dihydrofurans in good yields with excellent γ-regioselectivities. Hydrogenation of the dihydrofurans gave 2,4,4-trisubstituted tetrahydrofurans in good yields with exclusive cis-selectivities.
sarvey values personality characteristtics of good and bad curtain gairls
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...
thionyl chloride (or oxalyl chloride) has been used as an efficient and cheap acid activator for one-pot synthesis of β-lactams in good to excellent yields by reaction between imines and acids in the presence of triethylamine at room temperature.
michael addition of pyrimidine and purine nucleobases to substituted as well as unsubstituted α,β-unsaturated esters efficiently proceeds in the presence of catalytic amount of zinc oxide in ionic liquid 1-butyl-3-methylimidazolium bromide (zno/[bmim]br) under microwave irradiation to afford carboacyclic nucleosides, as biologically important compounds, in good to excellent yields and in short ...
a simple and efficient method for the synthesis of quinolines and polycyclic quinolines using li+ modified nanoporous na+-montmorillonite is described. this new nanocatalyst proceeds via friedlander annulation under solvent-free conditions. it describes our observations about a trend of catalytic activity of lithium cation in nanoporous na+-montmorillonite. in this study, several types of 1,3-d...
o-xylylenebis (triphenylphosphonium peroxymonosulfate) (1) was easily prepared from an aqueous solution of oxone and o-xylylenebis- (triphenylphosphonium bromide). this compound (1) is a useful and selective reagent for conversion of oximes, semicarbazones and phenylhydrazones to the corresponding carbonyl compounds. the reaction was carried out under solvent-free conditions and in the presence...
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