Thiophenol-Mediated Hydrogen Atom Abstraction: An Efficient Tin-Free Procedure for the Preparation of Cyclopentane Derivatives
作者:Florent Beaufils、Fabrice Dénès、Philippe Renaud
DOI:10.1021/ol049162g
日期:2004.7.1
[reaction: see text] An efficient procedure for running a cascade reaction involving 1,5-abstraction of a hydrogenatom followed by a radical cyclization is reported. Alkenyl radicals are generated from easily available terminal alkynes and thiophenol. This procedure eliminates the need of using the toxic tributyltin hydride and gives a greater amount of radical translocation products.
method for cyclization of alkynes is described. The reaction cascade involves the intermolecular addition of a phenylthiyl radical to a terminal triple bond generating an alkenylradical, followed by a 1,5-hydrogen atom transfer and a 5-exo-trig radicalcyclization. This very efficient tin-free procedure allows one to prepare highly functionalized cyclopentane derivatives as well as fused bicyclic and