A sub-stoichiometric tungsten-mediated Pauson–Khand reaction: Scope and limitations

Terminal alkynes do not partake in sequential [2+2+1]/benzoannulation reactions with Fischer carbene complexes and highly reactive and sterically hindered olefins; instead, they undergo a Fischer carbene complex-catalyzed Pauson–Khand reaction (PKR). This result has allowed the development, for the first time, of a tungsten-catalyzed PKR, although of limited scope.

An intermolecular Pauson–Khand reaction, a [2+2+1] cycloaddition leading to cyclopentenones, is catalyzed by tungsten carbonyl complexes. Its scope and limitations are established.Figure optionsDownload as PowerPoint slide