Stereoselective synthesis of either (E)- or (Z)-silyl enol ether from the same acyclic α,β-unsaturated ketone using cationic rhodium complex-catalyzed 1,4-hydrosilylation
The stereoselective synthesis of either (E)- or (Z)-silyl enolether from the same acyclic α,β-unsaturated ketone is reported. Highly (Z)-selective conditions were the use of [Rh(cod)2]BF4/DPPE at roomtemperature with no solvent, whereas (E)-selective conditions were the use of [Rh(cod)2]BF4/P(1-Nap)3 (1-Nap = 1-naphthyl) under refluxing dichloromethane.
Graphene-enhanced platinum-catalysed hydrosilylation of amides and chalcones: a sustainable strategy allocated with in situ heterogenization and multitask application of H<sub>2</sub>PtCl<sub>6</sub>
simple hydrosilylation-type reduction could be further used in the 1,4-hydrosilylation of chalcones. The rationally designed and in situ formed Pt@G@Si nanocatalyst is demonstrated to be highly effective in the 1,4-hydrosilylation of α,β-unsaturated enones, allowing for the facile synthesis of a variety of otherwise inaccessible substituted silyl enolates. In addition, with the aid of platinum catalyst
我们描述了在不同的有机转化中综合利用铂催化剂的新可持续战略,其中由简单的氢化硅烷化型还原制备的有机硅/石墨烯负载的铂催化剂可以进一步用于查耳酮的1,4-氢化硅烷化中。事实证明,合理设计和原位形成的Pt @ G @ Si纳米催化剂在α,β-不饱和烯酮的1,4-氢化硅烷化中非常有效,从而可以轻松合成各种本来无法获得的取代的甲硅烷基烯醇酸酯。另外,在这项工作中,还报道了借助铂催化剂残留物和TBAF,将一锅下游迈克尔取代的烯丙基甲硅烷基化物添加到丙烯酸烷基酯中。
Rhodium-Catalyzed, Efficient Deutero- and Tritiosilylation of Carbonyl Compounds from Hydrosilanes and Deuterium or Tritium
作者:Miguel Rubio、Jesús Campos、Ernesto Carmona
DOI:10.1021/ol202117t
日期:2011.10.7
A cationic rhodium compound which is an active catalyst for both the hydrogen isotope exchange in hydrosilanes and the hydrosilylation of carbonyl compounds permits, in a one-flask, two-step procedure, efficient deutero- and tritiosilylations using SiEt3H under D-2 (0.5 bar) or T-2, at low catalyst loadings (0.1-0.5 mol%).
Controlled Hydrosilylation of Carbonyls and Imines Catalyzed by a Cationic Aluminum Alkyl Complex
作者:Jürgen Koller、Robert G. Bergman
DOI:10.1021/om2008277
日期:2012.4.9
The synthesis, characterization, and unprecedented catalytic activity of cationic aluminum alkyl complexes toward hydrosilylation are described. X-ray crystallographic analysis of Tp*AlMe2 (1) and [Tp*AlMe][I-3] (3) revealed the preference of Al for a tetrahedral coordination environment and the versatility of the Tp* ligand in stabilizing Al in bi- and tridentate coordination modes. [Tp*AlMe][MeB(C6F5)(3)] (2) is highly active toward the hydrosilylation of a wide variety of carbonyls and imines, thus providing an inexpensive and versatile alternative to late transition metal catalysts.
Supported Palladium–Gold Alloy Catalysts for Efficient and Selective Hydrosilylation under Mild Conditions with Isolated Single Palladium Atoms in Alloy Nanoparticles as the Main Active Site
Supported Pd–Au alloy catalysts were developed for the highly efficient and selective hydrosilylation of α,β-unsaturated ketones and alkynes. The Pd/Au atomic ratio of the Pd–Au alloy and the supporting material affected the catalytic activity, and supported Pd–Au alloy nanoparticles with a low Pd/Au atomic ratio functioned as highly active heterogeneouscatalystsundermildreactionconditions. Structural