A New, Simple, and Selective Palladium-Catalyzed Cleavage of Triethylsilyl Ethers
摘要:
[GRAPHICS]A simple procedure for the cleavage of triethylsilyl (TES) ethers in the presence of 10 wt % Pd/C in methanol or 95% ethanol is reported. This method allows selective removal of alkyl TES ethers in the presence of aromatic TES ethers or tert-butyldimethylsilyl (TBS) protecting groups.
Vilsmeier-Haack Reagents. Novel Electrophiles for the One-Step Formylation of<i>O</i>-Silylated Ethers to<i>O</i>-Formates
作者:Jean-Paul Lellouche、Vadim Kotlyar
DOI:10.1055/s-2004-815435
日期:——
Various O-silylated substrates were effectively converted in one-step to their corresponding O-formates using electrophilic racemic and homochiral Vilsmeier-Haack reagents. Reactivity trends of these transformations were examined that, specifically, emphasized their synthetic potential.
hydrosilanes and alcohols was shown to provide silyl ethers in good and reproducible yields. The synthetic methodology is effective for a wide range of simple and bulky silanes and secondary alcohols, while keeping various other functionalgroups intact. The procedure also exhibits high selectivity for the silylation of primary versus secondary alcohols in 1,2‐diols, and allows the successive silylation of alkynols
Copper(I) complexes featuring N-heterocyclic carbenes (NHCs) in which the nitrogen atoms are substituted by a 9-ethyl-9-fluorenyl group (EF) have been synthesised and tested in the hydrosylilation of functionalized and/or sterically demanding ketones and aldehydes. These reactions, carried out with triethylsilane as hydride source, were best achieved with the imidazolylidene copper complex 2d in which
Alcohols, phenols and carboxylic acids are silylated with very good yields in the presence of silyl methallylsulfinates under non-basic conditions and with the formation of volatile co-products.