نتایج جستجو برای: phase transfer catalysis
تعداد نتایج: 893887 فیلتر نتایج به سال:
trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...
run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...
In the present research, the selective oxidation of lauryl alcohol to lauraldehyde was studied under liquid-liquid phase transfer conditions using potassium chromate (K2CrO4) as an oxidizing agent and tetrabutyl ammonium bromide (TBAB) as the phase transfer catalyst. Chromium (VI) reagents are used in these oxidations since the alcohols are selectively oxidized <e...
In this paper, we report the reaction of isoamyl alcohol and 1-chloro-4-nitrobenzene was carried out in a batch reactor under aqueous-organic biphasic conditions using the techniques like phase transfer catalysis and ultrasound irradiation. Tetrabutylammonium bromide (TBAB) was employed as the phase transfer catalyst. The reaction is greatly enhanced by adding a small quantity of phase-transfer...
Phase Transfer Catalysis (PTC) is a powerful tool to perform reactions in practical fashion, both laboratory and industrial scale. Significant cost savings major process improvements can be achieved performed under PTC conditions. In the last few years remarkable results stereoselective were using chiral, non-racemic quaternary ammonium salts. Moreover, use of bulky, chiral phosphate anions pai...
2-Dimethyl-2H-Chromenes, Coumarin Derivatives, Phase-Transfer Catalysis 2,2-Dimethyl-5H-pyrano(3,2-c)-l-benzopyrano-5-one(2) and 4H-2,3-dihydro-3-methyl-2methylene-furan-l-benzopyran-4-one (3), two new coumarin derivatives were synthesised from 4-hydroxycoumarin by treating with 3-chloro-3-methylbut-l-yne and 3-chlorobut-l-yne respectively, both reactions progressing via the phase-transfer cata...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید