The mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing a compound of H2PtCl6,WO3 and 1ml HCl (0.1 mol). It should be noted that the catalysts’ activity and selectivity have been determined under these conditions : 450-5000C ,and 15-25atm by H2. For converting n-heptane , the molar ratio H2/C7H16 is 5 , and LHSV is 1.5ml/h. It has been proved tha...

Treatment of 1-(5-bromo-2-chloro-6-methylpyrimidin-4-yl)-1-methylhydrazine with dimethylthiocarbamoylchloride gave 7-chloro-N,N,1,5-tetramethyl-1H-pyrimido[4,5-e][1,3,4]thiadiazin-3-amine in basic acetonitrile. The latter compounds were reacted with secondary amines in boiling ethanol to afford the related 7-amino derivatives.

This communication describes the total synthesis of the marine polyether toxin, gambierol. This work couples our iterative C-glycoside/enol ether-olefin metathesis strategy to the subunits with a unique olefin metathesis/carbonyl olefination reaction to bring the subunits together.

Biotransformation of imidacloprid and the appearance of olefin and 5-hydroxyimidacloprid metabolites in the honeybee were studied by HPLC-MS/MS analysis. Honeybees were treated orally with imidacloprid at 20 and 50 microg kg(-1) bee. Imidacloprid was metabolised relatively quickly and thoroughly. Twenty minutes after the beginning of imidacloprid ingestion, the sum of the residues from the thre...

Here, we describe the combination of OleTJE with a light-driven in situ H2O2-generation system for the selective and quantitative conversion of fatty acids into terminal alkenes. The photobiocatalytic system shows clear advantages regarding enzyme activity and yield, resulting in a simple and efficient system for fatty acid decarboxylation.

The mechanism and origins of Z-selectivity in olefin metathesis with chelated Ru catalysts were explored using density functional theory. The olefin approaches from the "side" position of the chelated Ru catalysts, in contrast to reactions with previous unchelated Ru catalysts that favor the bottom-bound pathway. Steric repulsions between the substituents on the olefin and the N-substituent on ...

Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowe...

Ž .y wŽ . Ž .q Ž . Displacement of the anion H C–B C F from the zirconocene contact-ion pair C H Zr CH PPP m-H C – 3 6 5 3 5 5 2 3 3 Ž .yx B C F by a series of phosphines and formation of a bisphosphine complex by uptake of a second phosphine ligand have 6 5 3 been studied by NMR methods in C D solutions. Evidence is presented that associated, outer-sphere ion pairs 6 6 wŽ . Ž .Ž .xq Ž .y C H Z...

The new highly active supported vanadium-magnesium catalyst (VMC) has been studied in α-olefin (1-butene, 1-hexene)/ ethylene copolymerization in the presence of hydrogen. Data on the effect of α-olefin/ethylene ratio in copolymerization on the content of branchings in copolymers, kinetic profile, copolymer yield, molecular weight and molecular weight distribution of copolymers have been obtain...