[2+1] Cycloaddition Affording Methylene-and Vinylidenecyclopropane Derivatives: A Journey around the Reactivity of Metal- Phosphinito-Phosphinous Acid Complexes

International audienceMetal-phosphinito-phosphinous acid complexes are interesting catalysts exhibiting unique reactivities. In this account, we intend to provide a clear overview of palladium-and platinum-phosphinito-phosphinous acid complexes preparation starting from secondary phosphine oxides, and their applications in catalysis. They have been mainly used to develop [2+1] cycloadditions affording methylenecyclopropane derivatives using norbornenes and various alkynes as partners. As a function of the catalyst, the reaction conditions, or the nature of the reagents, different synthetic transformations have been observed: [2+1] cycloadditions giving rise to either alkylidenecyclopropanes or vinylidenecyclopropanes, tandem [2+1]/[3+2] cycloadditions… The mechanisms of these reactions have been studied to rationalize the different reactivities observed