Methods of Asymmetric Synthesis—Enantioselective Catalytic Hydrogenation

It is proposed that asymmetric syntheses be divided into enantioselective and diastereoselective syntheses. The enantioselective hydrogenations discussed in the present progress report were catalyzed by Raney nickel that had previously been treated with solutions of optically active compounds. Relationships exist between the enantioselectivity of the catalyst and the structure of the chiral compound used to modify it.     

溴酸钾氧化酸性品红催化光度法测定亚硝酸根

研究了在强酸介质中亚硝酸根催化溴钾氧化酸性品红的褪色反应及其动力学条件，建立了高灵敏测定痕量亚硝酸根的新催化光度法。方法灵敏度为３．７×１０＾－１１ｇ／ｃｍ＾２亚硝酸态氮，线性范围为０．０６－０．４２μｇ／１０ｍＬ，用于测定唾液及硝钾中亚硝酸根。     

Selective determination of oxygenates in complex samples with the O-FID analyzer

A gas-chromatographic analyzer allowing the selective detection of individual oxygenates in complex organic mixtures, such as gasolines, is described. The analyzer is based on the oxygen-specific response flame ionization detection (O-FID) method. The system operates with capillary columns and includes a cracking reactor to convert any oxygenate to carbon monoxide and a special FID equipped with a microreactor for the catalytic hydro-genation of CO and detection as methane. Hydrocarbons give no signal. The selectivity of the method is better than 1:10⁷ and the linear range approaches 10⁵. The analysis of modern fuels containing oxygenated additives, to improve octane ratings, may greatly benefit from the proposed analytical method.     

Catalytic enantioselective allylation of aldehydes via a moisture-tolerant chiral BINOL-In(III) complex

A moisture-tolerant chiral indium complex has been developed to effect good enantioselectivities in the addition of allyltributylstannanes to aldehydes. The allylation of a variety of aromatic, α,β-unsaturated and aliphatic aldehydes resulted in both moderate to good yields and high enantioselectivities (up to 86% ee).     

Enantioselektive Cyclopropanierung von 1,1-Diphenylethylen und Diazoessigester mit Kupfer-Katalysatoren

Copper(II) compounds catalyze the reaction of 1,1-diphenylethylene with diazoacetic acid ethylester. The main product is 2,2-diphenylcyclopropane carboxylic acid ethylester. The formation of the carbene dimerization products fumaric and maleic acid diethylester can be suppressed by the continuous addition of diazoacetic acid ester to 1,1-diphenylethylene.37 optically active ligands, partly new, were combined with copper(II)-acetate to givein-situ-catalysts. In five cases isolated copper complexes were used as catalysts. The best optical inductions in the formation of 2,2-diphenylcyclopro-pane carboxylic acid ethylester with up to 65.6% ee were achieved withSchiff base ligands, which derive from salicylaldehyde and amino alcohols, obtained from amino acid esters and phenylGrignard.

Prof. Dr.Karl Schlögl, Universität Wien, mit den besten Wünschen zum 60. Geburtstag gewidmet.     

Kinetics of no decomposition over Cu/ZSM-5 catalyst

The kinetics of catalytic decomposition of NO over Cu/ZSM-5 catalyst has been studied in an integral flow reactor at atmospheric pressure. Kinetic analysis is based on the assumption that the surface reaction represents the rate-determining step. On the basis of theoretical considerations of different interactions between reactants and catalyst, and experimental evidences, three different mechanistic kinetic models were chosen. Also a power-law model was tested. The best agreement has been achieved with the model

催化动力学光度法测定微量钯

在硫酸 ( 1 + 1 )介质中 ,Pd(Ⅱ )催化过氧化氢氧化酸性铬蓝K的褪色反应。研究了反应的最佳条件 ,建立了催化光度法测定痕量钯的新方法。方法的最低检测限为 5 97× 1 0 - 4 μg/mL。线性范围为 5 97× 1 0 - 4 ～ 2 60× 1 0 - 2 μg/mL。该法用于合成样品和含钯催化剂的分析     

催化动力学极谱法测定痕量钼

在稀Ｈ２ＳＯ４介质中，钼（Ⅵ）对硫酸联氨还原乙基橙的反应有强烈的催化作用。建立了催化动力学极谱法测定痕量钼的新体系，方法线性范围为２０－３００ｎｇ／ｍＬ，检出限为３．５４ｎｇ／ｍＬ。方法应用于尿中中钼的测定，结果满意。     

PREPARATION OF CUO/γ-Al2O3 CATALYSTS FOR CATALYTIC COMBUSTION VOCS VIA PLASMA

CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment.     

催化光度法测定痕量铜的新体系研究

报道了在Ｈ２ＳＯ４介质中，溴代十六烷基吡啶和活化剂乙二胺存在下，痕量铜催化抗坏血酸还原ＣａｄｉｏｎＩ（苯基重氮氨基偶氮苯）的褪色反应，测定了反应表现活化能，探讨了反应机理，建立了选择性地测定痕量铜的新方法，线性范围为０～１．４μｇ／２５ｍＬ，方法用于人发及食品中痕量铜的测定，结果满意。