Boryl Metal Complexes, Boron Complexes, and Catalytic (Hydro)boration

Boryl metal complexes are not old hat, as demonstrated by the great interest in this class of compounds in recent years. Today, the importance of these complexes lies mainly in their role as intermediates in borylations catalyzed by transition metals [Eq. (1)], for which there are numerous synthetic applications. With regard to new types of structures, the combinations metal complex/borane continues to produce many novelties, for example σ complexes of type 1.