Synthesis and catalytic properties of phenylene-bridged binuclear organolanthanide complexes

摘要

Using base-free Ln[N(SiHMe2)(2)](3) complexes as highly effective protodeamination reagents, the binuclear lanthanide complexes p-bis{eta(5)-(2,3,4,5-tetramethylcyclo-pentadienyl)Ln[N(SiHMe2)(2)](2)}phenylene [p-Ln(2)] (Ln = Y, La, Lu) and m-bis{eta(5)-(2,3,4,5-tetramethylcyclopentadienyl)La[N(SiHMe2)(2)](2)}phenylene [m-La-2] 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, antinoalkynes, and aminodienes, with turnover frequencies as high as 10 h(-1) at 60 degrees C.