Starting from diallylethers, -silanes, or -amines various di- or triamines with potential biological activity are obtainable in one step by RhI-catalysed hydroaminomethylation of the alkene moieties in the presence of synthesis gas.
All-Carbon-Substituted Vinylsilane Stable to TBAF: Synthesis of Allyldimethylvinylsilane and Its Pd-Catalyzed Cross-Coupling under Mild Conditions
作者:Lianhai Li、Neenah Navasero
DOI:10.1021/ol061288l
日期:2006.8.1
Allyldimethylvinylsilanes 3 are easily synthesized by the reaction of silylallylmetals, generated from 1 by n-BuLi/t-BuOK, with carbonyl compounds in the absence or presence of metal halides. They can tolerate 2 equiv of TBAF in THF at room temperature for at least 6 h but can be easily activated in the presence of a palladium catalyst and TBAF to perform the cross-coupling reaction with aryl iodides at room temperature.
Catalytic Synthesis of Linear Oligosiloxanes and Germasiloxanes Mediated by Scandium Trifluoromethanesulfonate
Sc(OTf)(3)-catalyzed coupling reaction of silanediols with 2-methylallylsilanes and germanes leading to SiO-Si or SiO-Ge bond formation with the evolution of isobutylene is described. Diisopropyl-substituted silanediols of the general formula HO(i-Pr)(2)Si[OSi(i-Pr)(2)](n)OH (n = 0,1) have been successfully functionalized by using 2-methylallylsilanes or 2-methylallylgermanes in the presence of scandium trifluoromethanesulfonate to yield new linear tri- and tetrasiloxanes or germasiloxanes under mild conditions. The reaction can be readily extended to the synthesis of high molecular weight polysiloxanes by using di(methylallyl)silane as a metalating agent. Unsaturated oligosiloxane products have been used as substrates for further functionalization via catalytic silylative coupling and hydrosilylation reactions:
Studies in Organosilicon Chemistry. XXXV. Preparation of Certain Olefinic and Alkylsilanes