十一碳烯氧甲基苯并冠醚的合成与团载化及固载化产物的催化硅氢化性能

十一碳烯氧甲基一缩二乙二醇、二缩三乙二醇分别与１，２－β（β－羟乙氧基）苯双对甲苯磺酸酯在氢化钠存在下关环缩合，得到９－十一碳烯氧甲基－２，３－苯并１５－冠－５与９－十一碳烯氧甲基－２，３－苯并１８－冠－６．二者与三乙氧基硅烷反应产物以二氧化硅固载化，得到具有十一烯氧甲基连接基团的二氧化硅固载苯并冠醚．它们可与铂形成配合物．铂配合物对烯烃与三乙氧基硅烷的硅氢加成反应具有极好的催化效能     

Tri(pentaflurophenyl)borane-catalyzed reduction of cyclic imides with hydrosilanes: Synthesis of pyrrolidines

B(C₆F₅)₃-catalyzed hydrosilylation of cyclic imides afforded an efficient synthetic method of pyrrolidines. In the presence of 5?mol% B(C₆F₅)₃, various aromatic, aliphatic and polycyclic imides were smoothly reduced by PhSiH₃ to generate the corresponding pyrrolidines in high yields. The reaction profiles monitored by ¹H NMR spectroscopy disclosed the reduction process of cyclic imides and the effect of difference structure of the hydrosilanes on the hydrosilylation.     

Tri(t-butyl)phosphine-assisted selective hydrosilylation of terminal alkynes

<正>A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.     

Mechanism of ketone hydrosilylation by Cu(I) catalysts: A theoretical study

The plausibility of the catalytic cycle suggested for the hydrosilylation of ketones by Cu(I) hydrides has been investigated by a theoretical DFT study. A model system made up of a CuH(PH₃)₂ catalyst, acetone and SiH₄ gives us the necessary insight into the intrinsic reactivity of the system. This reactivity is confirmed, by introducing the more rigid CuH[C₄H₄(PH₂)₂] catalyst, as well as tetra-coordinated, CuH(PH₃)₃ and CuH(PH₃)[C₄H₄(PH₂)₂] compounds. Computations show the activation of the copper fluoride pre-catalyst, as well as both steps of the catalytic cycle to involve a 4 center metathesis transition state as suggested in literature. These results show the reaction to be favored by the formation of a Van der Waals complex resembling the transition states. The formation of these latter is induced by stabilizing electrostatic interactions between those atoms involved in the bond breaking and bond forming. Both steps of the actual catalytic cycle show a free energy barrier of about 10 kcal/mol with respect to the isolated reactants, hereby confirming the plausibility of the suggested cycle. We have found a substantial overall exothermicity of the catalytic cycle of about 35 kcal/mol.     

Novel Carbosiloxane Dendrimers with End-Grafted Highly Functionalized Building Blocks

This article concentrates on the divergent growth method for the preparation of SiOCH₂CH₂CH₂-based carbosiloxane dendrimers by applying repetitive hydrosilylation-alcoholysis cycles. The silicon atoms thereby act as the branching points producing a tetrahedral four directional core as well as 1→1 and 1→2 branching centres.     

Cationic nitridoruthenium(VI) catalyzed hydrosilylation of ketones and aldehydes

The first example of a ruthenium nitrido compound as hydrosilylation catalyst is described, using phenylsilane as reductant. A variety of ketones and aldehydes are reduced to alcohols with good to high isolated yields. Some mechanistic insight on this new system is provided on the basis of the available experimental findings.     

Hybrid materials derived from divinylbenzene and cyclic siloxane

In this work, hybrid materials were synthesized as self-supported films from divinylbenzene and cyclic siloxane, in different compositions, by hydrosilylation reaction. These films showed good thermal and mechanical properties. Their glass transition temperatures were higher than those of conventional silicone networks, and dependent on divinylbenzene amounts. Films were homogeneous and no pores were observed by field emission electron scanning microscopy. Relationships between surface roughness and composition of the obtained films were discussed. The nanomorphology of the materials was studied by small angle X-ray scattering, showing polydispersed nano-sized heterogeneities. The gas permeability of the hybrid films was investigated, and the results suggested low permeable behaviour to gases, but high ideal selectivities to some pairs of gases, such as H₂/O₂.     

轴不对称支撑的手性N-O酰胺化合物催化亚胺硅氢化反应的过渡态研究

利用Hartree-Fock(HF)算法和密度泛函理论(DFT)探讨了新型轴手性氮氧酰胺类配体催化亚胺C=N双键不对称硅氢化反应的过渡态.研究发现,H在Si原子上,反应经过渡态TS-2,能垒较低,由此得到产物(-)-N-(1-phenylethyl)aniline的e.e.值与实验结果相吻合.同时,本文还尝试采用合理的简化模型计算反应过渡态,其结果与使用全部分子用于过渡态能量计算的结论一致.     

(Dicyclopentadiene) platinum(II) dichloride: An efficient catalyst for the hydrosilylation reaction between alkenes and triethoxysilane

(Dicyclopentadiene) platinum(II) dichloride was found to be an efficient hydrosilylation catalyst (homogeneous) upon a wide variety of functionalized alkenes and alkenes terminated with chemical moieties (diphenyl amino-, N-carbazol- and N-isoindoline-1,3-dione-). It is noteworthy that the hydrosilylation of aminated alkenes with triethoxysilane exhibited the yield of over 70% and the selectivity (γ-isomer/β-isomer) of more than 3/1. Due to steric hindrance lowering Markovnikov probability, the alkenes with big terminal moieties (diphenyl amino-, N-carbazol- and N-isoindoline-1,3-dione-) presented the high ratio of anti-Markovnikov isomers. The strategy of the hydrosilylation of the protected diamino chelating alkene was developed.     

Hydrosilylation of olefins over rhodium complex anchored over thioether-functionalized MCM-41

<正>The hydrosilylation of alkenes with triethoxysilane has been achieved at 120 C in the presence of 0.01 mol%of thioetherfunctionalized MCM-41 anchored rhodium complex,affording the corresponding addition products in 68-91%yields.This supported rhodium complex can be reused several times without noticeable loss of activity.Our system not only solves the basic problems of catalyst separation and recovery,but also avoids the use of phosphine ligands.