Synthesis, structure, and catalytic activity of titanium complexes with new chiral 11,12-diamino-9,10-dihydro-9,10-ethanoanthracene-based ligands

• Published in: Journal of organometallic chemistry Vol. 695; no. 17; pp. 1993 - 1999
• Main Authors: Zhang, Furen, Song, Haibin, Zi, Guofu
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier B.V 01.08.2010; Elsevier
• Subjects: 11,12-Diamino-9,10-dihydro-9,10-ethanoanthracene; Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Chiral titanium complexes; Crystal structure; Physical Sciences; Polymerization of rac-lactide; Science & Technology; Synthesis; Synthesis; 11,12-Diamino-9,10-dihydro-9,10-ethanoanthracene; Chiral titanium complexes; Polymerization of rac-lactide; Crystal structure; AG(I) COMPLEXES; DIELS-ALDER REACTIONS; REACTIVITY; ALDEHYDES; ENANTIOSELECTIVE ADDITION; DIETHYLZINC; X-RAY STRUCTURES; AMIDES
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2010.05.003

A new series of organo-titanium complexes have been prepared from the reaction between Ti(NMe 2) 4 and C 2-symmetric ligands, ( R, R)-11,12-bis(pyrrol-2-ylmethyleneamino)-9,10-dihydro-9,10-ethanoanthracene ( 1H 2), and ( R, R)-bis(diphenylthiophosphoramino)-9,10-dihydro-9,10-ethanoanthracene ( 2H 2), ( R, R)-11,12-bis(mesitylenesulphonylamino)-9,10-dihydro-9,10-ethanoanthracene ( 3H 2) and ( R, R)-bis(diphenylthiophosphoramino)-1,2-cyclohexane ( 4H 2). Treatment of Ti(NMe 2) 4 with 1 equiv of 1H 2 gives, after recrystallization from a benzene solution, the binuclear double helicate titanium amide ( 1) 2[Ti(NMe 2) 2] 2⋅( 5) in 71% yield. While under similar reaction conditions, reaction of Ti(NMe 2) 4 with 1 equiv of 2H 2, 3H 2 or 4H 2 gives, after recrystallization from a toluene or benzene solution, the mononuclear single helicate titanium amides ( 2)Ti(NMe 2) 2 ( 6), ( 3)Ti(NMe 2) 2 ( 7) and ( 4)Ti(NMe 2) 2 ( 8), respectively, in good yields. All new compounds have been characterized by various spectroscopic techniques, and elemental analyses. The solid-state structures of complexes 5– 8 have further been confirmed by X-ray diffraction analyses. The titanium amides are active catalysts for the polymerization of rac-lactide, leading to the isotactic-rich polylactides. A new series of chiral organo-titanium complexes have been prepared. They are active catalysts for the polymerization of rac-lactide, leading to the isotactic-rich polylactides. [Display omitted]