Synthesis and Catalytic Properties of Phenylene-Bridged Binuclear Organolanthanide Complexes

Abstract

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