Piano-Stool Lutetium Amido and Imido Compounds Supported by a Constrained Bis(oxazoline)cyclopentadienyl Ligand

{BoMCptet}­Lu­(CH2Ph)2 (1; BoMCptet = MeC­(OxMe2)2C5Me4;
OxMe2 = 4,4-dimethyl-2-oxazoline) was prepared in 95% yield
from the reaction of BoMCptetH and Lu­(CH2Ph)3THF3. Compound 1 reacts
with 1 or 2 equiv of H2NCH2R (R = C6H5, 1-C10H7) to give the corresponding
imido complexes [{BoMCptet}­LuNCH2R]2 (R = C6H5 (2a),
1-C10H7 (2b)) or amido complexes
{BoMCptet}­Lu­(NHCH2R)2 (R = C6H5 (3a), 1-C10H7 (3b)). Once isolated, the imido species
are insoluble in nonprotic organic solvents. Crystallographic characterization
reveals dimeric [{BoMCptet}­LuNCH2(1-C10H7)]2 in the solid state.
The reaction of 1 and NH3B­(C6F5)3 affords crystallographically characterized {BoMCptet}­Lu­{NHB­(C6F5)2}­C6F5. This species is proposed to form
via a transient lutetium imido, which undergoes C6F5 migration to the lutetium center.