Platinum complexes bearing phosphinous acids have efficiently promoted a tandem intermolecular sequence of [2+1]/[3+2] cycloaddition reactions. This process gave access to novel tricyclic systems and the cascade reactions were regio‐ and diastereoselective (see scheme; Cy=cyclohexyl). The [3+2] cycloaddition reaction was investigated further and two different alkyne partners were used.

International audienceAn efficient palladium-catalyzed [2 + 1]cycloaddition between ynamides and norbornenes or norbornadienes is reported. Both phosphapalla- dacycles and palladium/secondary phosphine oxide catalytic systems were found to be competent for the transformation allowing the preparation of ami- nomethylenecyclopropanes. The reaction showed general applicability to various functionalized bicyclo[2.2.1]hept-2-enes and ynamides. A chiral phosphapalladacycle was tested to carry out this transformation in an enantioselective fashion

Platinkomplexe von phosphinigen Säuren vermitteln eine effiziente intermolekulare Tandemsequenz aus [2+1]‐ und [3+2]‐Cycloadditionen. Diese Prozesse öffnen den Zugang zu neuartigen tricyclischen Systemen, und sie verlaufen zudem regio‐ und diastereoselektiv (siehe Schema; Cy=Cyclohexyl). Für die [3+2]‐Cycloaddition wurden weiterhin zwei verschiedene Alkinpartner eingesetzt.