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91.
An efficient procedure for catalyst solubility, recycling and easy product isolation in oxidation of thiols to disulfides with molecular oxygen catalyzed by cobalt(II) phthalocyanines dissolved in ionic liquid at room temperature is reported. 相似文献
92.
Moderate yields of benzaldehyde, benzyl alcohol and benzylamine are obtained by the biomimetic oxidation of N-nitrosodibenzylamine
with molecular oxygen catalysed by water soluble anionic manganese(III) 5,10,15,20-tetraphenylporphyrin acetate/sodium dithionite/methylene
blue in aerosol-OT (AOT) reverse micelles, under phase transfer conditions with AOT concentration higher than 10−3M. The formation of α-hydroxy-N-nitrosodibenzylamine and its decomposition products, benzaldehyde and benzyl alcohol in reverse
micellar systems are governed by the ratio of water and AOT, pH and other changes in the microenvirpnment. 相似文献
93.
This paper theoretically explores the application of electric field flow fractionation (EFFF) for the size-based separation of DNA strands in a microchannel. An axial electric field cannot separate DNA strands in solution because the electrical mobility of the strands is independent of the length. However, lateral electric fields coupled with an axial Poiseuille flow can separate the DNA strands of different sizes. By using regular perturbation analysis, we obtain the effective diffusivity and the mean velocity of the DNA molecules that are undergoing a pressure driven Poiseuille flow in a 2D channel in presence of a lateral electric field. The mean velocities and the dispersion coefficients are then utilized to determine the scaling for length of the channel and the time required for separation of DNA molecules in different parameter regimes. The results show that EFFF can separate DNA strands in the range of 10 kbp that differ in size by about 2.5 kbp in about half an hour in a 1 cm long channel. While DNA strands can be separated by EFFF, the performance of devices based on EFFF seems to be at best comparable to other techniques such as entropic trapping. 相似文献
94.
Chauhan SM Sahoo B Mohapatra PP Kalra B Gulati A 《Chemical & pharmaceutical bulletin》2001,49(9):1232-1233
The oxidation of 8-methoxypsoralen (2) with hydrogen peroxide and potassium superoxide catalyzed by 5,10,15,20-(2,4,6-trimethylphenyl)porphyrinatoiron(III) chlorides [Me12TPPFe(III)Cl] (1a) and 5,10,15,20-(2,6-dichlorophenyl)porphyrinatoiron(III) chlorides [Cl8TPPFe(III)Cl] (1b) in dichloromethane gives 6-formyl-7-hydroxy-8-methoxycoumarin (3) in moderate yields, whereas the oxidation of (2) with H2O2 catalyzed by 5,10,15,20-(2,6-dichlorophenyl)-beta-octahaloporphyrinatoiron(III) chlorides [Cl8betaX8TPPFe(III)Cl] (X=Cl, Br) (1c, 1d) gives specifically 5,8-dioxopsoralen (4) in moderate yields. 相似文献
95.
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97.
Recent progress in asymmetric organocatalysis has led to the development of several asymmetric transformations that employ various substrates. Among these substrates, maleimides have emerged as excellent Michael acceptors, dienophiles, and dipolarophiles. In this Focus Review we highlight the advances in the asymmetric synthesis of succinimide derivatives through asymmetric organocatalytic addition reactions of maleimides. 相似文献
98.
99.
Goga Geetesh Chauhan Bhupendra Singh Mahla Sunil Kumar Dhir Amit Cho Haeng Muk 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2831-2831
Journal of Thermal Analysis and Calorimetry - In the original publication of the article, Figs. 6 and 7 were published incorrectly without test fuel D80/nb20+BG (0.5 kg/h). 相似文献
100.
N-alkyiation of primary amines has been carried out with alkylbromide using commercial Me2SO and K2CO3 as a base. This process offers a method of selection for obtaining either mono or dialkyl amines. 相似文献