A Selective Synthesis of (E)-Vinylsilanes by Cationic Rhodium Complex-Catalyzed Hydrosilylation of 1-Alkynes and Tandem Hydrosilylation/Isomerization Reaction of Propargylic Alcohols to .beta.-Silyl Ketones
作者:Ryo Takeuchi、Shuichi Nitta、Dai Watanabe
DOI:10.1021/jo00115a020
日期:1995.5
(E)-Vinylsilanes were obtained with high selectivities by [Rh(COD)(2)]BF4/2PPh(3)-catalyzed hydrosilylation of 1-alkynes with triethylsilane. A wide range of 1-alkynes were used. The hydrosilylation of propargylic alcohols with triethylsilane gave (E)-gamma-silyl allylic alcohols 2h-r, a useful source of a chiral alcohol, with high selectivities in excellent yields. The reaction can be carried out without protecting the alcohol functionality. The resulting (E)-gamma-silyl allylic alcohols could be transformed into beta-silyl ketones. The isomerization was also catalyzed by [Rh(COD)(2)]BF4/2PPh(3). Furthermore, the tandem hydrosilylation-isomerization of secondary propargylic alcohols could be carried out in a one-pot procedure.
(E)-丙二烯二硅烷通过使用[Rh(COD)(2)]BF4/2PPh(3)协同催化的水硅化反应获得了高选择性,适用于多种一元炔烃底物。丙炔醇的水硅化反应产生γ-硅基 allylic 醇2h-R,并提供了一种高效产率的构象选择性高的旋多糖醇。该反应无需保护醇的功能性即可进行。由此产生的(E)-γ-硅基 allylic 醇可以通过转化得到β-硅基酮。此外,该[Rh(COD)(2)]BF4/2PPh(3)催化还可以催化丙炔醇的同分异构化反应。Furthermore, a one-pot tandem hydrosilylation-isomerization of secondary propargylic alcohols can be achieved using this approach.
Catalytic applications of recyclable silica immobilized NHC–ruthenium complexes
作者:Amàlia Monge-Marcet、Roser Pleixats、Xavier Cattoën、Michel Wong Chi Man
DOI:10.1016/j.tet.2012.10.023
日期:2013.1
A monosilylated Hoveyda–Grubbs ruthenium alkylidene has been prepared and grafted through the NHC ligand to a mesostructured silica, in refluxing toluene or at room temperature, giving two new organic–inorganichybrid silica materials M2 and M3, respectively. While M3 exhibited good performances in several metathesis reactions, M2 showed good selectivity in the hydrosilylation of terminal alkynes,
β-(Z) Selectivity Control by Cyclometalated Rhodium(III)–Triazolylidene Homogeneous and Heterogeneous Terminal Alkyne Hydrosilylation Catalysts
作者:Beatriz Sánchez-Page、Julen Munarriz、M. Victoria Jiménez、Jesús J. Pérez-Torrente、Javier Blasco、Gloria Subias、Vincenzo Passarelli、Patricia Álvarez
DOI:10.1021/acscatal.0c03295
日期:2020.11.20
XPS and extended X-ray absorption fine structure (EXAFS) spectroscopy, showing the replacement of the iodido ligand by O-functionalities on the carbon wall. In sharp contrast with the homogeneous catalyst, the heterogeneous hybrid catalyst TRGO-Triaz-Rh(III) is not active at room temperature although it shows an excellent catalytic performance at 60 °C. In addition, the hybrid catalyst TRGO-Triaz-Rh(III)
Highly Selective Dehydrogenative Silylation of Alkenes Catalyzed by Rhenium Complexes
作者:Yanfeng Jiang、Olivier Blacque、Thomas Fox、Christian M. Frech、Heinz Berke
DOI:10.1002/chem.200802019
日期:2009.2.16
chemicals: Rhenium(I) complexes of type [ReBr2(L)(NO)(PR3)2] (L=H2 (1), CH3CN (2), ethylene (3); R=iPr (a), cyclohexyl (b)) proved to be suitable catalyst precursors for the highlyselectivedehydrogenativesilylation of alkenes. Two types of rhenium(I) hydride species, [ReBrH(NO)(PR3)2] (4) and [ReBr(η2‐CH2CHR1)H(NO)(PR3)2] (5), were found in the [ReBr2(L)(NO)(PR3)2]‐catalyzeddehydrogenative silylation
选择化学药品:[ReBr 2(L)(NO)(PR 3)2 ]类型的R(I)配合物(L = H 2(1),CH 3 CN(2),乙烯(3); R = i Pr (a),环己基(b))被证明是用于烯烃的高度选择性脱氢甲硅烷基化的合适催化剂前体。两种类型的铼(I)氢化物种,[ReBrH(NO)(PR 3)2 ](4)和[ReBr(η 2 -CH 2 CHR 1)H(NO)(PR 3)2 ](5),是在[ReBr 2(L)(NO)(PR 3)2 ]催化的烯烃脱氢甲硅烷基化反应中发现的。
Accessing Two-Coordinate Zn<sup>II</sup>
Organocations by NHC Coordination: Synthesis, Structure, and Use as π-Lewis Acids in Alkene, Alkyne, and CO<sub>2</sub>
Hydrosilylation
作者:David Specklin、Frédéric Hild、Christophe Fliedel、Christophe Gourlaouen、Luis F. Veiros、Samuel Dagorne
DOI:10.1002/chem.201704382
日期:2017.11.13
Discrete two‐coordinate ZnII organocations of the type (NHC)Zn−R+ are reported, thanks to NHC stabilization. In preliminary reactivity studies, such entities, which are direct cationic analogues of long‐known ZnR2 species, act as effective and tunable π‐Lewis acid catalysts in alkene, alkyne, and CO2 hydrosilylation.