Synthesis and Catalytic Properties of Phenylene-Bridged Binuclear Organolanthanide Complexes

Using base-free Ln[N(SiHMe2)2]3 complexes as highly effective protodeamination reagents, the binuclear lanthanide complexes p-bis{η5-(2,3,4,5-tetramethylcyclopentadienyl)Ln[N(SiHMe2)2]2}phenylene [p-Ln2] (Ln = Y, La, Lu) and m-bis{η5-(2,3,4,5-tetramethylcyclopentadienyl)La[N(SiHMe2)2]2}phenylene [m-La2] were synthesized from the corresponding phenylene-linked tetramethylcyclopentadienes. The resulting products serve as new types of multicenter homogeneous 4f catalysts. Reactivity studies reveal that these binuclear organolanthanide complexes efficiently catalyze the intramolecular hydroamination/cyclization of aminoalkenes, aminoalkynes, and aminodienes, with turnover frequencies as high as 10 h−1 at 60 °C.