Organometallic Compounds of the Lanthanides. 110.1 Donor-Functionalized Chiral Cyclopentadienyl Complexes of Calcium, Samarium(II), and Ytterbium(II). A New Class of Chiral Metallocenes

Twelve optically active metallocene complexes of Ca, Sm(II), and Yb(II) containing cyclopentadienyl systems with a chiral N- or O-substituted side chain as ligands are described. Specifically, the ligand systems ( S )-(2-methoxypropyl)cyclopentadienyl (( S )-C 5 H 4 CH 2 CH(Me)OMe)) and ( S )-(2-methoxy-2-phenylethyl)cyclopentadienyl (( S )-C 5 H 4 CH 2 CH(Ph)OMe)) and the novel ( S )-[2-(dimethylamino)propyl]cyclopentadienyl (( S )-C 5 H 4 CH 2 CH(Me)NMe 2 )) and ( S )-[2-(dimethylamino)-1-phenylethyl]cyclopentadienyl (( S )-C 5 H 4 CH(Ph)CH 2 NMe 2 )) systems were employed. The starting materials for their synthesis are ethyl ( S )-(−)-lactate, ( R )-(−)-2-methoxy-2-phenylethanol, ( S )-(+)-2-amino-1-propanol, and ( R )-(−)-2-phenylglycinol, respectively. Each of the cyclopentadienyl systems was converted by a 2:1 reaction of the potassium salt with the metal diiodide into the corresponding metallocene, [M{( S )-η 5:η 1 -C 5 H 4 (CH 2 CH(R)OMe)} 2 ] (R = Me, M = Ca ( 1a ), Sm ( 1b ), Yb ( 1c ); R = Ph, M = Ca ( 3a ), Sm ( 3b ), Yb ( 3c )), [M{( S )-η 5:η 1 -C 5 H 4 (CH 2 CH(Me)NMe 2 )} 2 ] (M = Ca ( 2a ), Sm ( 2b ), Yb ( 2c )), and [M{( S )-η 5:η 1 -C 5 H 4 (CH(Ph)CH 2 NMe 2 )} 2 ] (M = Ca ( 4a ), Sm ( 4b ), Yb ( 4c )). The novel compounds have been characterized by C, H, N analysis, mass spectrometry, NMR spectroscopy, and optical rotation. Additionally, an X-ray structural analysis of 2c, 3a, and 4a was performed.