Discrete allyl complexes of group 3 metals and lanthanides

Allyl complexes based on group IIIb metals (Sc, Y, La) and lanthanides are reviewed. The diversity, synthesis, and main structural and reactivity features of discrete, well-defined homoleptic and pseudo-homoleptic neutral, anionic and cationic bis-, tris- and tetra(allyl)-lanthanide complexes, as well as heteroleptic allyl-lanthanidocenes and allyl-lanthanide complexes supported by non-Cp ligands are covered. Brief comments on the catalytic performances of some key compounds in polymerization processes are also provided.