Preparation of rhodium–phyllosilicate catalysts without leaching in liquid-phase 1-hexene hydrogenation

Rhodium catalysts have been prepared on palygorskite and montmorillonite (clay) supports by reduction with hydrogen (1 atmosphere) at room temperature of a cationic organometallic rhodium compound anchored to the support. The activity of these catalysts for the hydrogenation of liquid-phase 1-hexene remains constant with increase of prehydrogenation time and with re-use for several runs. No rhodium leaching is observed.     

One Alkenylphenol and Steroids from the Aquatic Plant Monochoria Vaginalis

Two new compounds have been isolated from the whole plant of Monochoria vaginalis and characterized as: (10Z)‐1‐(2,6‐dihydroxyphenyl)octadec‐10‐en‐1‐one ( 1 ) (20R, 24R)‐campest‐5‐ene‐3β, 4β‐diol ( 2 ) together with nine known ones. The structures of these compounds were elucidated on the basis of spectral data and chemical evidence.     

Mechanism of catalytic asymmetric hydrogenation of 2-formyl-1-methylene-1,2,3,4-tetrahydroisoquinoline using Ru(CH3COO)2[(S)-binap]

The mechanism of the asymmetric hydrogenation of 2-acyl-1-alkylidene-1,2,3,4-tetrahydroisoquinolines, the first reported reaction with the Noyori-Takaya Ru(CH₃COO)₂(binap) complex, has been investigated by means of deuterium labeling, kinetics, and NMR analysis. A series of experiments has revealed that (1) a monohydride-unsaturated mechanism operates involving the initial formation of RuH followed by reaction with the enamide substrate, (2) the hydride transfer from RuH to the olefinic double bond is endothermic and reversible, and (3) the rate is determined in the hydrogenolysis step. This view is consistent with that of proposed for the BINAP-Ru catalyzed Kagan reaction.     

Activity of TiO2 deposited by the CVD method on ammoxidized surface of a carbonaceous material in hydrogenation of styrene

Hydrogenation of styrene has been applied as a test reaction to study the catalytic activity of TiO₂ deposited by the CVD (chemical vapour deposition) method on the surface of a carbonaceous material enriched in nitrogen (C_N).     

负载型双金属簇催化剂的多相一氧化碳加氢反应性能

负载型双金属簇催化剂的多相一氧化碳加氢反应性能索全伶，李晔（内蒙古工业大学化学工程系，呼和浩特０１００６２）殷元骐，金道森（中国科学院兰州化学物理研究所，兰州７３００００）关键词一氧化碳加氢，多相催化，双金属簇催化剂，钾效应。１．引言异核金属羰基簇作...     

苯部分加氢制环己烯的非晶态Ru-M-B/ZrO2催化剂的表征

采用化学还原法，制备了高活性，高选择性非晶态RU-M-B/ZRO2催化剂，并将其用于催化苯部分加氢制环己烯，在140℃、5.0Mpa氢压下，苯转化40%时，环己烯选择性达到85%左右。环己烯最高收率达到52.1%，用XRD、SEM、BET比表面积测定等手段对摧化剂进行表征，XRD和SEM测试表明，RU-U-B/ZRO2属于非晶态，活性组分高度分散，XRD结果证实，在加氢过程中，非晶分解，RU晶化；温度愈高，RU晶化愈快，催化剂的活性、选择性与RU微晶的粒径有关，RU微晶粒径应控制在5nm左右，BET比表面积测定表明，ZRO2的负载提高了催化剂的比表面积，从而有利于活性组分的高度分散，并可阻止RU微晶的长大，讨论了B和ZRO2对提高选择性的作用。     

非晶态合金催化剂用于二甲基紫脲酸加氢反应

二甲基紫脲酸加氢反应;nicob/白炭黑催化剂;非晶态合金催化剂     

不对称氢化反应

本文总结了各种手性膦配体以及它们的铑络合物在不对称氢化中的应用,并讨论了不对称氢化的机理和影响不对称诱导的各种因素。     

MODIFICATION OF TRANSITION METAL CATIONS TO POLYMER-STABILIZED PLATINUM COLLOIDAL CLUSTERS IN ENANTIOSELECTIVE HYDROGENATION OF METHYL PYRUVATE

Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate. Compared to the enantiomeric excess (e.e.) value (71.4%) obtained without the presence of metal cations, obvious e.e. enhancement (up to 82.5%) was resulted from the addition of Zn^2 but with a certain decrease in activity. The reaction parameters in the presence of Zn^2 were also studied. It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.