um chloride (TMSCH2MgCl) with 1,2-dihalogenoethylene in the presence of 1 mol % of Co(II) or Co(III) acetylacetonate in THF or THF–NMP proceeded exclusively in a mono-coupling pathway to provide 3-trimethylsilyl-1-halogeno-1-propene with >99% of E geometry in high yield, which was converted to a variety of γ-substituted allylsilanes by Ni- or Pd-catalyzed coupling with organometalliccompounds.
A new reaction in organosilicon chemistry: the oxidative ring closure of allylsilanes with ceric ammonium nitrate
作者:Stephen R. Wilson、Corinne E. Augelli-Szafran
DOI:10.1016/s0040-4020(01)86650-3
日期:1988.1
Allylsilanes containing heteroatom nucleophiles yield cyclic products when treated with (NH4)2Ce(NO3)6. For example, hydroxy and amido-containing allylsilanes yield the corresponding tetrahydrofuran, tetrahydropyran, and piperidine analogs. These reactions and their application to natural product synthesis will be discussed.
Allylsilanes containing hydroxy or tosylamide groups undergo palladium(II)catalyzed cyclization to afford derivatives of tetrahydrofuran, piperidine, and pyrrolidine. This catalytic reaction proceeds through an (eta3-allyl)palladium intermediate that is generated by allylic displacement of the silyl group of the allylsilane precursors. The internal nucleophilic attack on the (eta3-allyl)palladium intermediates