1,1′-双(苄硫基)二茂铁铂、铑配合物对烯烃硅氢加成反应的催化性能

二茂铁衍生物的金属配合物对于氢化、偶联及不对称合成的催化作用已有报道,但用于烯烃硅氢加成还只有关于手征性二茂铁膦钯配合物和聚合物负载二茂铁膦钯、膦铂配合物的研究。Macosko等曾用顺式二氯化双乙硫醚铂配合物催化聚异丁烯末端双键进行硅氢加成,我们也发现聚-4-氧杂-6,7-双甲硫基庚基硅氧烷铂配合物对于烯烃的硅氢加成反应具有良好的催化活性。因此,预期1,1′-双烷硫基二茂铁铂、铑配合物也应是烯烃硅氢加成的有效催化剂。     

二氧化硅-聚硅氧烷负载硫杂-15-冠-5铂、铑配合物的合成及其催化硅氧化性能

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.     

聚-4-氧杂-6,7-双二苯膦基庚基硅氧烷铂配合物的合成及其在烯烃硅氢化反应中的催化性能

高分子负载膦铂配合物是一类很好的烯烃硅氢加成催化剂,但迄今未见有关螯合型双膦铂配位负载催化剂的报道。1983年,Micholska报道了胺膦双齿配体铑配合物的合成与催化性能。最近,我们合成了气相法二氧化硅负载的聚-4-氧杂-6,7-双二苯膦庚基硅氧烷     

二氧化硅—聚硅氧烷负载硫杂—15—冠—5,铂,铑配合物的合成…

６－（ω′－十一碳烯氧甲基）－１－硫杂－４，７，１０，１３－四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。     

1,1′-双(乙硫基)二茂铁铂、铑配合物的合成及其对烯烃硅氢加成反应的催化性能

研究了1,1'-双(乙硫基)二茂铁铂、铑配合物在烯烃与三烷氧基硅烷的硅氢加成反应中的催化性能。结果表明,该催化剂在70～120℃时具有良好的活性。提出并讨论了铂、铑催化烯烃硅氢化反应的可能机理。     

C~6~0乙醇胺铂配合物的合成及其催化硅氢化性能

C~6~0与乙醇胺反应,然后与亚氯铂酸钾络合,制得了含配位氮原子的富勒烯铂配合物。该配合物能有效地催化烯烃与三乙氧基硅烷的硅氢化反应,并对苯乙烯有独特的催化性能,以近100%的区域选择性得到α-加成产物。还对催化机理进行了初步的探讨。     

聚γ—（β—氰乙硫基）丙基硅氧烷铑配合物的合成与催化硅氢化…

γ－巯丙基三乙氧基硅烷与丙烯腈加成，得到γ－（β－氰乙硫基）丙基三乙氧基硅烷，后者依次与气相法二氧化硅，三氯化铑作用，合成了聚γ－（β－氰乙硫基）丙基硅氧烷铑配合物，研究了其催化烯烃与三乙氧基硅烷硅氢加成反应的特性。     

聚γ-(β-氰乙硫基)两基硅氧烷铑配合物的合成与催化硅氢化性能

γ-巯丙基三乙氧基硅烷与丙烯腈加成，得到γ－（β-氰乙硫基）丙基三乙氧基硅烷，后者依次与气相法二氧化硅、三氯化铑作用，合成了聚γ-（β-氰乙硫基）丙基硅氧烷铑配合物，研究了其催化烯烃与三乙氧基硅烷硅氢加成反应的特性。     

共聚物铑配合物催化甲醇羰基化速控步骤的理论研究

采用以原子重叠及电子离域的分子轨道理论ＡＳＥＤ ＭＯ（含原子对排斥的ＥＨＭＯ法）为基础的结构自动优化法，对共聚物铑配合物催化甲醇羰基化制乙酸反应速率控制步骤 氧化加成进行了理论研究．计算了不同共聚物配体形成的铑催化剂与碘甲烷的氧化加成反应途径，并得到反应活化能，分析了氧化加成反应过程中的电子转移和空间因素对活化能的影响，计算结果与实验结果是相符的，并从理论上解释了２ 乙烯基吡啶形成的共聚物铑配合物催化活性高于４ 乙烯基吡啶形成的共聚物铑配合物催化活性的原因．     

聚γ-[N,N-双(β-乙硫乙基)胺基]丙基硅氧烷铑配合物的合成及其催化硅氢化性能

从二(β-氟乙基)烯丙胺出发,通过乙硫醚化、硅氢加成、气相法二氧化硅固载,再与三氯化铑作用,合成了标题配合物,它们是烯烃与三乙氧基硅烷的硅氢加成反应的有效催化剂,对其催化特性进行了研究。     

Rhodium carbene complexes as hydrosilylation catalysts

The catalytic activity of various rhodium carbene complexes has been investigated. These complexes are active for the hydrosilylation of a wide variety of unsaturated organic molecules such as olefins, acetylenes and dienes. Their activity is comparable to other rhodium(I) complexes previously used as hydrosilylation catalysts. The yield of products is found to vary with catalyst, silane and organic substrate.     

SYNTHESIS AND CATALYTIC BEHAVIOR OF POLYSILOXANESUPPORTED FULLERENE PLATINUM OR RHODIUM COMPLEXES*

Two polysiloxanes with pendant fullerene moieties and their platinum or rhodium complexes havebeen prepared from C_(60) via amination with ω-decenylamine, followed by hydrosilylation with triethoxysilaneand immobilization on fumed silica or by hydrosilylation with methyldichlorosilane and polycondensationwith polydimethylsiloxanol, and then by reacting them with potassium chloroplatinite or rhodium chloride inacetone respectively under argon atmosphere. It was found that the four noble metal complexes are effectivecatalysts for the hydrosilylation of olefins with triethoxysilane. The regioselcctivity of platinum complexesfor styrene increases remarkably by introducing C_(60) moiety. Factors influencing catalytic activity and themechanism have been investigated.     

The Catalytic Isomerization of Terminal Carbon–Carbon Double Bonds in Liquid Crystalline Polyesters at Hydrosilation with 1-(1′-Arylethoxy)-1,1,3,3-Tetramethyl Disiloxanes

In the present article, we report on the synthesis and investigation of the hydrosilylation of liquid crystalline compounds with terminal carbon–carbon double bonds in aliphatic tails mediated by complexes of rhodium (I) and platinum (II). New liquid crystalline compounds based on terephthaloyl-bis-4-oxybenzoate with terminal carbon-carbon double bonds in aliphatic tails were synthesized. The introduction in aliphatic tails of polar and light polarizible fragments lead to a decrease of mesomorphogenic ability-resulting compounds. The hydrosilylation of liquid crystalline compounds with terminal carbon-carbon double bonds in aliphatic tails with 1-(1′-arylethoxy)-1,1,3,3-tetramethyl disiloxanes mediated by complexes of rhodium (I) and platinum (II) was investigated. The main process in these conditions was the isomerization of olefin fragments.     

Design and Synthesis of Isocyanide Ligands for Catalysis: Application to Rh‐Catalyzed Hydrosilylation of Ketones

New isocyanide ligands with meta‐terphenyl backbones were synthesized. 2,6‐Bis[3,5‐bis(trimethylsilyl)phenyl]‐4‐methylphenyl isocyanide exhibited the highest rate acceleration in rhodium‐catalyzed hydrosilylation among other isocyanide and phosphine ligands tested in this study. ¹H NMR spectroscopic studies on the coordination behavior of the new ligands to [Rh(cod)₂]BF₄ indicated that 2,6‐bis[3,5‐bis(trimethylsilyl)phenyl]‐4‐methylphenyl isocyanide exclusively forms the biscoordinated rhodium–isocyanide complex, whereas less sterically demanding isocyanide ligands predominantly form tetracoordinated rhodium–isocyanide complexes. FTIR and ¹³C NMR spectroscopic studies on the hydrosilylation reaction mixture with the rhodium–isocyanide catalyst showed that the major catalytic species responsible for the hydrosilylation activity is the Rh complex coordinated with the isocyanide ligand. DFT calculations of model compounds revealed the higher affinity of isocyanides for rhodium relative to phosphines. The combined effect of high ligand affinity for the rhodium atom and the bulkiness of the ligand, which facilitates the formation of a catalytically active, monoisocyanide–rhodium species, is proposed to account for the catalytic efficiency of the rhodium–bulky isocyanide system in hydrosilylation.     

Catalysis of hydrosilylation XIII. Gas-phase hydrosilylation of acetylene by trichlorosilane on functionalised silica supported rhodium and ruthenium phosphine complexes

Gas-phase hydrosilylation of acetylene by tri-chlorosilane catalyzed in a continuous flow apparatus by rhodium and ruthenium phosphine complexes immobilized on the silica via mercapto, phosphine, amine and nitrile ligands has been studied. GLC analysis of the reaction products showed vinyltrichlorosilane to be accompanied by products of double hydrosilylation of acetylene and the redistribution of trichlorosilane followed by the hydrosilylation and hydrogenative hydrosilylation of acetylene with dichlorosilane. A scheme for this complex competitive–consecutive reaction was proposed. The yield and selectivity of vinyltrichlorosilane can be much improved under special reaction conditions, e.g. rate flow of the particular substrates, temperature, given catalyst and others. Kinetic measurements carried out in the range of 115–140°C allowed us to evaluate the activation energy, E_a, for the vinyltrichlorosilane synthesis, which varied between 20.5 and 27.6 kJ mol^?1 for the selected rhodium and ruthenium supported complexes.     

Synthesis and structural studies on the chiral phosphine-NHC rhodium and palladium complexes for their performances in the metal-catalyzed reactions

Diverse chiral rhodium and palladium complexes ligated with phosphine-functionalized N-heterocyclic carbene ligands based on 1,1′-binaphthyl backbone have been synthesized. The structures of these phosphine-NHC rhodium and palladium complexes have been confirmed by X-ray diffraction analysis. The different sizes of the N-substituents from the NHC-P rhodium complexes had an inverse relationship with their ability of chiral induction, which was accounted by the Rh-catalyzed asymmetric hydrosilylation of acetophenone to afford corresponding chiral alcohol with up to 72% ee. The NHC-P palladium complexes connected with different kinds of coordination anions were also applied in the Suzuki and Heck reactions. The acetate-coordinated NHC-P palladium complex exhibited better catalytic activity to give the products in excellent yield under mild conditions.     

Regioselective rhodium-containing catalysts for ring-opening polymerizations and hydrosilylations

Organometallic rhodium complexes are described which are highly efficient initiators for the ring-opening polymerization of expoxides and other heterocyclic compounds. A cocatalyst, consisting of a compound or polymer containing silicon–hydrogen bonds must also be present. These same catalyst–cocatalyst mixtures are also highly active for hydrosilylation reactions. Other complexes bearing phosphine ligands have been discovered, which while active for hydrosilylation, are not catalysts for epoxide polymerizations. Polymer supported rhodium catalysts are also described which permit the synthesis of epoxy-functional silanes in high yields without competing ring-opening polymerization.     

Dendrimer N-heterocyclic carbene complexes with rhodium(I) at the core

Novel dendrimer N-heterocyclic carbene complexes with rhodium(I) located at the core were synthesized, and a positive dendrimer effect was found in the hydrosilylation of ketones catalyzed by them.     

Catalytic Hydrosilylation of Substituted Acetophenones by 1,1,3,3-Tetrametyldisiloxane with Complexes Rhodium (I) and Platinum (II)

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.