A highly efficient organo-catalytic protocol for the trimethylsilylation of terminal alkynes and N-silylation of indoles employing Ruppert's reagent as a trimethylsilyl source have been developed under solvent and fluoride free conditions.
Oxyhalogenation reactions of a variety of alkynylsilanes were studied using oxone as mild oxidant and KCl, KBr, and KI as halogen sources. In this study, reaction of an alkynylsilane with oxone-KX (X = Cl or Br) produced trichloromethyl/tribromomethyl ketones in high yields. Under similar conditions, however, reactions of alkynylsilanes with oxone-KI were found to give exclusively 1,2,2-triiodovinyl
申请人:Merck Patent Gesellschaft mit beschrankter Haftung
公开号:US05356562A1
公开(公告)日:1994-10-18
Fluoro tolans of the formula I ##STR1## wherein R.sup.1 denotes alkyl with up to 12 carbon atoms wherein one or two non-adjacent CH.sub.2 groups may also be replaced by --O--, --O--CO--, --CO--O-- and/or --CH.dbd.CH--, A is trans-1,4-cyclohexylene or 1,4-phenylene, r is 0 or 1, s is 0 or 1, Q is --CF.sub.2 -- or --OCF.sub.2 -- and -- if Y=F and/or L.sup.1 =L.sup.2 =F - also a single bond, L.sup.1 and L.sup.2 are H or F, and Y is H, F or Cl are suitable as components of liquid crystalline media.
Transition Metal‐Free Catalytic C−H Silylation of Terminal Alkynes with bis(Trimethylsilyl)acetylene Initiated by KHMDS
作者:Krzysztof Kuciński、Grzegorz Hreczycho
DOI:10.1002/cctc.202200794
日期:2022.9.20
Dealkynative Coupling: C−H silylation of several terminalacetylenes has been established by using sustainable and eco-friendly main-group catalysis. As a result, several alkynes, including pharmaceuticals, were selectively silylated under transition metal-free conditions. Mechanistic studies provided strong support for the deprotonation step, which is followed by the formation of pentacoordinated