B(C 6 F 5 ) 3 catalyzed hydrosilation of enones and silyl enol ethers
作者:James M Blackwell、Darryl J Morrison、Warren E Piers
DOI:10.1016/s0040-4020(02)00974-2
日期:2002.10
β-carbon, 1,4 addition of silane is very clean; in other instances, 1,2 hydrosilation is competitive. The reaction is facile with five commercially available silane reagents. For two examples, a novel hydrosilation of the resulting silylenol ethers was also observed. The net trans stereochemistry of H–Si addition to the silylenol ether CC bond was established and points to a stepwise mechanism for this
描述了由B(C 6 F 5)3(1-2%)催化的各种简单的α,β-不饱和烯酮的1,4氢化硅烷化。对于在β-碳附近没有空间位阻的底物,添加1,4硅烷是非常干净的。在其他情况下,1,2硅氢化反应具有竞争力。该反应易于使用五种可商购的硅烷试剂进行。对于两个实施例,还观察到了所得的甲硅烷基醚的新型硅氢化。建立了甲硅烷基醚CC键中H-Si的净反式立体化学,并指出了该反应的逐步机理。甲硅烷基碳离子中间体与[HB(C 6 F5)3 ] -来自4,4-二甲基-2-环己烯-1-酮和PhMe 2 SiH的甲硅烷基醚的硅氢化反应中的抗衡阴离子。
Dirhodium(II) Tetrakis(perfluorobutyrate)-Catalyzed 1,4-Hydrosilylation of .ALPHA.,.BETA.-Unsaturated Carbonyl Compounds
The use of dirhodium(II) catalysts in the 1,4-hydrosilylation of alpha,beta-unsaturated ketones and aldehydes was explored. Dirhodium(II) tetrakis(perfluorobutyrate), Rh2(pfb)4, proved to be the catalyst of choice for this process, providing the corresponding silyl enol ethers in high yields.
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.
The synergistic effect of nanoporous AuPd alloy catalysts on highly chemoselective 1,4-hydrosilylation of conjugated cyclic enones
The nanoporous AuPd (AuPdNPore) alloy catalyst showed superior chemoselectivity and high catalytic activity for the direct 1,4-hydrosilylation of the conjugated cyclic enones with hydrosilane in comparison with the monometallic nanoporous Au and Pd catalysts. The enhanced catalytic properties of AuPdNPore arise mainly from the nanoporous structure and the synergistic effect of the AuPd alloy.