The pH dependence of the steady state kinetic parameters K,(app) and $,t of the a-, acetylated 6-, and ar-chymotrypsincatalyzed hydrolysis of the specific amide substrate N-acetylr.-tryptophanamide, has been investigated in the neutral and alkaline pH regions. A completely automatic technique for measuring the hydrolysis of amides was used. New results and important aspects of the chymotrypsin-...

selective transformation of 2-propargylthio-6-methyl-pyrimidin-4(1h)on e (2) to 3,5-dimethyl-7h-thiazolo [3,2-a] pyrimidin-7-one (3) is performed under the conditionof base catalysis . for elucidation of structure, palladium catalyzed cyclization reaction of (2) was carried out and the structures of the products were assigned (5) and (6). these compounds underwent isomerization to (3) and (4) r...

nano sio2/hyperbranched polyglycerol (hpg)/so3h catalyst was readily prepared for first time from inexpensive starting materials in aqueous media which catalyzed the synthesis of benzoic acid. ftir spectra, x-ray diffraction (xrd) and transmission electron micrographs (tem) was employed to characterize the properties of the synthesized nano sio2/hpg/so3h. high catalytic activity and ease of rec...

Transition metal-catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose cobalt-catalyzed vinylaziridines giving rise to both linear and branched enynes. The optimization reaction conditions allowed determine key parameters cobalt-based catalytic system. scope investigation showed that is mainly l...

3,4-Dihydropyrimidinones and their derivatives are synthesized via Biginelli routes involving an aromatic aldehydes, ethylacetoacetates and urea in one-pot procedure by using CdS nanoparticles as efficient heterogeneous catalyst in solvent-free conditions. Compared with classical Biginelli reaction reported in 1893, this new method provides much improved modification in terms of simplicity. The...

3,4-dihydropyrimidinones and their derivatives are synthesized via biginelli routes involving an aromatic aldehydes, ethylacetoacetates and urea in one-pot procedure by using cds nanoparticles as efficient heterogeneous catalyst in solvent-free conditions. compared with classical biginelli reaction reported in 1893, this new method provides much improved modification in terms of simplicity. the...

Introduction The possibility of using vegetable oils as fuel has been documented in the beginning of diesel engines. Biodiesel produced from waste oil by trans-esterification process can be used as a substitute for diesel in internal combustion engines [1]. Biodiesel can be produced by the transesterifcation of vegetable oils [2] such as soyabean oil, rapeseed oil, sunflower oil etc. [3]. Trans...

Alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80 °C. Our results showed that Biginelli reaction not only is pH dependent, but the cation of catalyst plays an importan...

In this review, we summarize our recent development of palladium(0)-catalyzed cross-coupling reactions of perfluoro organic compounds with organometallic reagents. The oxidative addition of a C–F bond of tetrafluoroethylene (TFE) to palladium(0) was promoted by the addition of lithium iodide, affording a trifluorovinyl palladium(II) iodide. Based on this finding, the first palladium-catalyzed c...

The C-C bond formation is an important reaction in organic synthesis to obtain value-added intermediates. Therefore, in this paper an attempt has been made to accelerate the Henry reaction (C-C bond formation) between aryl aldehydes and nitromethane using less expensive whole cell biocatalyst, baker’s yeast (BY). The scope of the methodology was also tested for the heteryl aldehyde i.e. 2-chlor...