Synthesis, Structure, and Catalytic Reactions of 1,2-Bis(indenyl)ethane-Derived Lanthanocenes

The synthesis and structure of meso -[ethylenebis(η 5 -indenyl)]ytterbium(III) bis(trimethylsilyl)amide ( 6 ) and the syntheses of rac- and meso -[[ethylenebis(η 5 -indenyl)]ytterbium(III) chloride][LiCl(Et 2 O) 2 ] ( 4, 5 ) and rac- and meso -[ethylenebis(η 5 -indenyl)lutetium(III) chloride][LiCl(Et 2 O) 2 ] ( 7, 8 ) are reported. The complexes are synthesized by the metathesis of dilithiated 1,2-bis(indenyl)ethane with either YbCl 3 or LuCl 3 in THF followed by solvent exchange with diethyl ether to give [[ethylenebis(η 5 -indenyl)]Ln III chloride][LiCl(Et 2 O) 2 ] (Ln = Yb, Lu) in yields of 43% and 30%, respectively. In the Yb case, the major diastereomer formed is meso, while in the lutetium reaction, the rac diastereomer predominated. Complex 6 is synthesized by reaction of meso -[[ethylenebis(η 5 -indenyl)]ytterbium(III) chloride][LiCl(Et 2 O) 2 ] with NaN(TMS) 2; this material was characterized by X-ray diffraction. Complex 6 catalyzes the cyclic hydroamination of primary amino olefins in excellent yields.