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1.
本文报道了首例硒杂冠醚铂配合物-10-硒杂苯并-15-冠-5铂配合物的合成,并研究了它对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性.实验结果表明:它是此类反应的一个高效催化剂.  相似文献   

2.
徐汉生  李卫平  卢雪然  刘秀芳 《化学学报》1993,51(12):1170-1173
本文报道了首例碲杂冠醚铂配合物:10-碲杂苯并-15-冠-5铂配合物的合成, 并研究了它对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性.实验结果表明:其催化活性不如相应的硒杂冠醚铂配合物,但对某些烯烃,如苯基烯丙醚, 仍有较高的催化活性  相似文献   

3.
本文通过双(2-羟基乙基)碲醚与二醇的二对甲苯磺酸酯缩合, 首次合成了一类新型的冠醚-碲杂冠醚及其中一个碲杂冠醚与二氯化铂的配合物,并对碲杂冠醚的合成方法.结构特征以及配位性能等进行了讨论.  相似文献   

4.
蔡明中  赵红  黄义争 《有机化学》2003,23(6):555-558
4-氧杂-6,7-二氯庚基三甲氧基硅烷依次与气相法二氧化硅、甲硒基钠、氯化 钯作用,然后用水合肼还原,合成了二氧化硅负载的聚-4-氧杂,6,7-二甲硒基庚 基硅氧烷钯(O)配合物.该配合物是苯乙烯及丙烯酸的Heck芳基化反应的有效催化 剂,为立体选择性地合成各种取代的反式-1,2-二苯乙烯及反式肉桂酸提供了简便 且实用的新方法  相似文献   

5.
本文通过超声反应,将氮杂15-冠-5-苯乙炔引入聚苯乙烯负载多吡啶铂(Ⅱ)配合物.研究发现聚苯乙烯负载氮杂15-冠-5-苯乙炔基多吡啶铂(Ⅱ)配合物完全保持了单体多吡啶铂(Ⅱ)配合物的性质,并能够通过发光光谱的显著增强选择性地检测Mg2+离子.通过加入极性溶剂沉淀析出聚苯乙烯负载多吡啶铂(Ⅱ)配合物,从而达到分离的目的.  相似文献   

6.
本文通过双(2-羟基乙基)硫醚与1,2-双(2'-对甲苯磺酰氧基乙氧基)苯缩合闭环,得到10-硫杂苯并-15冠-5,后者再与氯亚铂酸钾反应得到标配合物;同时研究了该配合物对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性,并与硒,碲的类似配合物进行了比较,结果表明,此配合物是烯烃硅氢化反应的高效催化剂。  相似文献   

7.
合成了7,11-二硒杂苯并-13-冠-4及其铂配合物,并从底物的性质,反应温度、催化剂用量以及化学气氛四个方面考察了该配合物对烯烃与三乙氧基硅氢加成反应的催化特性,与单硒杂冠醚配合物相比,该配合物对某些烯烃的催化活性较高,但催化反应需要的温度也较高。  相似文献   

8.
合成了7,11-二硒杂苯并-13-冠-4及其铂配合物,并从底物的性质、反应温度、催化剂用量以及化学气氛四个方面考察了该配合物对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性。与单硒杂冠醚配合物相比,该配合物对某些烯烃的催化活性较高,但催化反应需要的温度也较高.  相似文献   

9.
6-(ω'-十一碳烯氧甲基)-1-硫杂-4,7,1O,13-四氧杂环十五烷与三乙氧基硅烷进行硅氢加成,产物依次以气相法二氧化硅固载、氯亚铂酸钾或三氯化铑络合,合成了相应的二氧化硅-聚硅氧烷负载硫杂-15-冠-5-铂、铑配合物,并研究了它们在烯烃与三乙氧基硅烷的硅氢加成反应中的催化性能.结果表明,二者均为硅氢加成反应的高效催化剂.  相似文献   

10.
陈家碧  FISCHER  ERNST O. 《化学学报》1985,43(2):188-191
锰和铼的阳离子卡宾配合物分别与1-萘硒基锂, LiSeC10H7-1 反应, 生成锰和铼的萘硒基基卡宾配合物(4)及铼的烷基卡宾配合物这些新卡宾配合物均经元素素分析, IR,1HNMR 和MS 鉴定.  相似文献   

11.
In this study, a novel Rh–iodide complex was synthesized through a surface reaction between an immobilized Rh cyclooctadiene complex and alkylammonium iodide (N+I) on SiO2. In the presence of ammonium cations, the SiO2-supported Rh–iodide complex could be effectively used for the one-pot synthesis of various silylcarbonate derivatives starting from epoxy olefins, hydrosilanes, and CO2. The maximum turnover numbers (TONs) for the hydrosilylation reaction and the CO2 cycloaddition were 7600 (Rh) and 130 (N+I), respectively. The catalyst exhibited much higher performance for hydrosilylation than solely the Rh complex on SiO2. The mechanism of the Rh-catalyzed hydrosilylation reaction and the local structure of Rh, which is affected by the co-immobilized N+I, were investigated by using Rh and I K-edge XAFS and XPS. Analysis of the XAFS profiles indicated the presence of a Rh−I bond. The Rh unit was in its electron-rich state. Curve-fitting analysis of the Rh K-edge EXAFS profiles suggests dissociation of the cycloocta-1,5-diene (COD) ligand from the Rh center. Results from spectroscopic and kinetic analyses revealed that the high activity of the catalyst (during hydrosilylation) could be attributed to a decrease in steric hindrance and the electron-rich state of the Rh. The decrease in the steric hindrance could be attributed to the absence of COD, and the electron-rich state promoted the oxidative addition of Si−H. To the best of our knowledge, this is the first example of a one-pot silylcarbonate synthesis as well as a determination of a novel surface Rh–iodide complex and its catalysis.  相似文献   

12.
Rh(I) NHC and Rh(III) Cp* NHC complexes (Cp*=pentamethylcyclopentadienyl, NHC=N-heterocyclic carbene=pyrid-2-ylimidazol-2-ylidene (Py−Im), thiophen-2-ylimidazol-2-ylidene) are presented. Selected catalysts were selectively immobilized inside the mesopores of SBA-15 with average pore diameters of 5.0 and 6.2 nm. Together with their homogenous progenitors, the immobilized catalysts were used in the hydrosilylation of terminal alkynes. For aromatic alkynes, both the neutral and cationic Rh(I) complexes showed excellent reactivity with exclusive formation of the β(E)-isomer. For aliphatic alkynes, however, selectivity of the Rh(I) complexes was low. By contrast, the neutral and cationic Rh(III) Cp* NHC complexes proved to be highly regio- and stereoselective catalysts, allowing for the formation of the thermodynamically less stable β-(Z)-vinylsilane isomers at room temperature. Notably, the SBA-15 immobilized Rh(I) catalysts, in which the pore walls provide an additional confinement, showed excellent β-(Z)-selectivity in the hydrosilylation of aliphatic alkynes, too. Also, in the case of 4-aminophenylacetylene, selective formation of the β(Z)-isomer was observed with a neutral SBA-15 supported Rh(III) Cp* NHC complex but not with its homogenous counterpart. These are the first examples of high β(Z)-selectivity in the hydrosilylation of alkynes by confinement generated upon immobilization inside mesoporous silica.  相似文献   

13.
The catalytic activity of tris(pentanedionato)rhodium(III), (or rhodium(III) acetylacetonate) (I) has been investigated for the hydrosilylation of a variety of organic substrates: alkenes, terminal or internal acetylenes, conjugated dienes, or α,β-unsaturated carbonyls or nitriles. With PhCHCH2 or PhCH2CHCH2, ω-substitution was unexpectedly observed, as well as addition. Compound I is an active hydrosilylation catalyst in the absence of any added reducing agent, as is tetrakis(μ-acetato)dirhodium(II) (II) which does not, however, show any unusual catalytic activity due to the two metal atom cluster. Possible mechanisms are suggested.  相似文献   

14.
杨慕杰  张富尧  赵健  沈之荃 《化学学报》1990,48(10):1036-1042
本文首次应用六种过渡金属(V、Cr、Mn、Fe、Co、Ni)环烷酸盐-三异丁基铝配合催化体系, 在室温下, 于加氢汽油-甲苯混合溶剂中, 使苯乙炔直接聚合成膜。研究了成膜聚合反应特征, 动力学行为及溶剂的影响。比较了不同催化体系的活性(Fe>Cr>Co>Mn>V>Ni)。表征了所制备的聚苯乙炔膜。聚苯乙炔膜可为黄、橙、红或褐色, 具有高顺式、高分子量、高稳定性及较好结晶性和半导体特性(电阻率为10^9Ω·cm)。  相似文献   

15.
《Tetrahedron: Asymmetry》2000,11(16):3419-3426
Copper(I) and rhodium(I) complexes prepared in situ from [Cu(OTf)(C6H6)0.5] and [Rh(cod)Cl]2 with a range of chiral 2,2′-bipyridines, 5,6-dihydro-1,10-phenanthrolines, 1,10-phenanthrolines and 2,2′:6′,2′′-terpyridines were assessed as chiral catalysts for the enantioselective cyclopropanation of styrene with diazoacetates and for the hydrosilylation of acetophenone with diphenylsilane. Enantioselectivities up to 68% in the cyclopropanation and up to 32% in the hydrosilylation were obtained.  相似文献   

16.
The complex [Rh(I(t)Bu)(2)HCl] has been shown to be an active catalyst in the hydrosilylation of carbonyl and imine complexes. This reactivity, combined with the previously reported H/D exchange catalyzed by these complexes allows for a one pot, two step reaction using a single catalyst for both H/D exchange and hydrosilylation. Using triethylsilane, [Rh(I(t)Bu)(2)Cl] catalyst, and D(2) gas, deuterated silyl-ethers can be synthesized in an atom-economical, solvent-free reaction.  相似文献   

17.
水合稀土二氯醋酸盐的合成及热分解研究   总被引:1,自引:0,他引:1  
熊为淼  吴淑荣  孟艳 《化学学报》1987,45(5):426-431
合成了La,Ce,Nd,Sm,Eu,Gd二氯醋酸盐,经化学分析,热重法和五氧化二磷真空千燥脱水法确定组成为Ln(CHCl2COO)3.nH2O(n=2,Ln=La,Ce,Nd;n=1.5,Ln=Sm;n=1.25,Ln=Eu;n=1,Ln=Gd),它们均属新水合物.用DTA-TG-DTG并用技术并辅以化学分析和红外光谱技术研究了其热分解机理,实验证明,由室温至600℃范围内,它们均发生三步主要反应:水合盐脱水变为无水盐;无水盐分解为中间产物,Ln2(OH)Cl5.3H2O[Eu盐分解为Eu2(OH)Cl5.2H2O];中间产物进一步分解为LnOCl[Ce盐为CeO2].并观察到无水盐和氯氧化物形成温度皆与原子序数呈现镧系"双一双效应".  相似文献   

18.
刘秋田  黄梁仁  杨瑜  卢嘉锡 《化学学报》1988,46(11):1075-1080
在二甲胺基二硫代甲酸钠、氯化亚铁及四硫代钼酸铵的自兜反应体系中, 以分步结晶法分离出MeFe3S4(Me2NCS2)5.CH2Cl2及MoFe3S1(Me2NCS2)6.2CH3CN等单立方烷簇合物, 并测定了后者的结构. 它的分子含两个Me2NCS2并具有最高核心氧化态[MoFe3S4]^6^+. 本文报道该化合物的结构特点, 指出在自兜反应体系中, 可能存在几种不同氧化态的单立方烷原子簇化合物.  相似文献   

19.

The hydrosilylation of a range of para-substituted acetophenones XC6H4COCH3 (X = H, Me, MeO, F, Cl, NO2) with 1,1,3,3-tetramethyl disiloxane mediated by complexes of rhodium (I) and platinum (II) was investigated. The complexes of platinum (II) are less effective than complexes of rhodium (I), but display greater selectivity. Six 1-(1′-arylethoxy)-1,1,3,3-tetramethyl disiloxanes have been synthesized by hydrosilylation using several coupling catalysts.  相似文献   

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