Synthesis, Structure, and Diverse Catalytic Activities of [Ethylenebis(indenyl)]lanthanide(III) Amides on N−H and C−H Addition to Carbodiimides and ε-Caprolactone Polymerization

The simple silylamine elimination reaction of ethylenebis(indene) with the lanthanide amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 produced the [ethylenebis(η5-indenyl)][bis(trimethylsilyl)amido]lanthanide(III) complexes (EBI)LnN(TMS)2 (Ln = Y (1), Sm (2), Yb (3)), which exhibited diverse catalytic activities on the addition of the N−H bond of amines and the C−H bond of terminal alkynes to the carbodiimides and on the ring-opening polymerization of ε-caprolactone as well. The new complexes 1 and 2 were fully characterized by spectroscopic methods, elemental analyses, and X-ray crystallographic analyses. This work offers a straightforward, highly atom efficient route for the syntheses of substituted guanidines and propiolamidines, and it represents the first application of readily accessible lanthanocene amides to these reactions.