Bis(phosphinimino)methanide rare earth amides: Synthesis, structure, and catalysis of hydroamination/cyclization, hydrosilylation, and sequential hydroamination/hydrosilylation

A series of yttrium and lanthanide amido complexes [Ln[N(SiHMe2)(2)}(2){CH(PPh2NSiMe3)(2)}] (Ln = Y, La, Sm, Ho, Lu) were synthesized by three different pathways. The title compounds can be obtained either from [Ln{N(SiHMe2)(2)}(3)(thf)(2)] and [CH2(PPh2NSiMe3)(2)] or from KN(SiHMe2)(2) and [Ln(CH(PPh2NSiMe3)(2)} Cl-2](2), while in a third approach the lanthanum compound was synthesized in a one-Pot reaction starting from K{CH(PPh2NSiMe3)(2)}, LaCl3, and KN(SiHMe2)(2). All the complexes have been characterized by single-crystal Xray diffraction. The new complexes, [Ln{N(SiHMe2)(2)}(2){CH(PPh2NSiMe3)(2)}], were used as catalysts for hydroamination/cyclization and hydrosilylation reactions. A clear dependence of the reaction rate on the ionic radius of the center metal was observed, showing the lanthanum compound to be the most active one in both reactions. Furthermore, a combination of both reactions-a sequential hydroamination/hydrosilylation reaction-was also investigated.