794513-75-0Relevant academic research and scientific papers
Ru-catalyzed alkene-alkyne coupling. Total synthesis of amphidinolide P
Trost, Barry M.,Papillon, Julien P. N.,Nussbaumer, Thomas
, p. 17921 - 17937 (2007/10/03)
A coordinatively unsaturated ruthenium complex catalyzed the formation of a carbon-carbon bond between two judiciously chosen alkene and alkyne partners in good yield, and in a chemo- and regioselective fashion, despite the significant degree of unsaturation of the substrates. The resulting 1,4-diene forms the backbone of the cytotoxic marine natural product amphidinolide P. The alkene partner was rapidly assembled from (R)-glycidyl tosylate, which served as a linchpin in a one-flask, sequential three-components coupling process using vinyllithium and a vinyl cyanocuprate. The synthesis of the alkyne partner made use of an unusual anti-selective addition under chelation-control conditions of an allyltin reagent derived from tiglic acid. In addition, a remarkably E-selective E2 process using the azodicarboxylate-triphenylphosphine system is featured. Also featured is the first example of the use of a β-lactone as a thermodynamic spring to effect macrolactonization. The oxetanone ring was thus used as a productive protecting group that increased the overall efficiency of this total synthesis. This work was also an opportunity to further probe the scope of the ruthenium-catalyzed alkene-alkyne coupling, in particular using enynes, and studies using various functionalized substrates are described.
Alkene-alkyne coupling as a linchpin: An efficient and convergent synthesis of amphidinolide P
Trost, Barry M.,Papillon, Julien P. N.
, p. 13618 - 13619 (2007/10/03)
A short and efficient synthesis of the cytotoxic macrolide amphidinolide P is described. A remarkably chemo- and regioselective ruthenium-catalyzed alkene-alkyne coupling allows for a convergent synthesis and demonstrates that both enynes and β-lactones are suitable coupling partners. This work also features a novel strategy for the preparation of macrolactones via intramolecular transesterification of β-lactones. The target structure was prepared in 15 steps for the longest linear sequence and 10% overall yield, 24 steps total. Copyright
