描述了高效的铟(III)催化的各种羧酸与1,1,3,3-四甲基二硅氧烷(TMDS)和溴或碘源的还原溴化或碘化。该官能团互变对几种官能团具有高耐受性,例如卤素,羟基,硝基,烯烃部分和硫化物部分。该铟催化体系也适用于醛化,酰氯和酯的还原碘化。此外,该还原体系可通过添加亲核试剂用于一锅法合成卤代烷和胺衍生物。通过1 H和13 C NMR监测实验的时间过程以及相应的逐步反应,可以深入了解反应机理。
描述了高效的铟(III)催化的各种羧酸与1,1,3,3-四甲基二硅氧烷(TMDS)和溴或碘源的还原溴化或碘化。该官能团互变对几种官能团具有高耐受性,例如卤素,羟基,硝基,烯烃部分和硫化物部分。该铟催化体系也适用于醛化,酰氯和酯的还原碘化。此外,该还原体系可通过添加亲核试剂用于一锅法合成卤代烷和胺衍生物。通过1 H和13 C NMR监测实验的时间过程以及相应的逐步反应,可以深入了解反应机理。
IrIII metallacycle rapidly and selectively catalyses the reduction of various esters, carboxylic acids, ketones, and aldehydes. The reactions proceed in high yields at room temperature by hydrosilylation followed by desilylation. Depending on the substrate, esters are reduced to alcohols or ethers and carboxylic acids to alcohols or aldehydes.
specific chemoselectivity for hydrogenation that has never been achieved by other palladium‐catalyzed methods. Either aliphatic or aromatic N‐Cbz groups could be deprotected to the corresponding free‐amines, while the hydrogenolysis of benzyl esters and ethers did not proceed. Furthermore, aryl chlorides and epoxides were tolerant under the Pd/ceramic‐catalyzed hydrogenation conditions. 5 % Pd/ceramic
Action des trialkylsilanes sur les aldehydes aliphatiques
作者:Rolland Bourhis、Emile Frainnet
DOI:10.1016/s0022-328x(00)89613-8
日期:1975.2
Two competing reactions ensue when trialkylsilanes HSiR′3 are treated with aliphatic aldehydes RCHO in the absence of a solvent and using a nickel catalyst (obtained by the treatment of anhydrous NiCl2 with a trialkylsilane); one gives an alcoxysilane RCH2OSiR′3, the other an ether oxide (RCH2)2O and a siloxane (R′3Si)2O. By variation of the reaction conditions, either reaction can be made exclusive
One-Step Conversion of Formate Esters to O-Silyl Ethers by Means of Samarium Diiodide in the Presence of Chlorosilane Reagents
作者:Toshio Honda、Fumihiro Ishikawa
DOI:10.1080/00397919908085960
日期:1999.10
Abstract One-step conversion of various types of formate esters into the corresponding O-silyl ethers under neutral reaction conditions was established by employing samarium diiodide in the presence of chlorosilane reagents.
Cationic Dirhodium Complexes Bridged by 2-Phosphinopyridines Having an Exquisitely Positioned Axial Shielding Group: A Molecular Design for Enhancing the Catalytic Activity of the Dirhodium Core
create highly electrophilic dirhodium catalysts. The electrophilicity of lantern-type dirhodium complexes is generally decreased by the coordination of a ligand to the axial site, which often causes a reduction in the catalytic activity. We designed and synthesized a series of cationic dirhodium complexesbridged by 2-diarylphosphinopyridines having a bulky 2,4,6-triisopropylphenyl (Tip) group that can