ORGN 6 |
| Allenes are very useful unsaturated partners in synthesis. Few years ago we have shown that they were suitable moieties in the cobalt (I) mediated intramolecular cyclotrimerization with two alkynes. More recently we have shown that this reaction allowed a total transfer from axial to centered chirality and were able to apply this reaction to the synthesis of various functionnalyzed non-natural steroids. We have also described the cobalt (I) mediated cycloisomerization of allumene-ynes. Scope and limitation of this reaction will be discussed. Finally we have very recently discovered the platinum (II) catalyzed cycloisomerization of allene-ynes. This reaction is very substrate dependant and lead selectively either to hydrindienes adducts, vinyl allenes or trienes. The mechanism of this reaction will be discussed.
|
|
Allenes in Synthesis
8:00 AM-12:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- C303/304/305, Oral
Division of Organic Chemistry |
