Structural and catalytic studies of lithium complexes bearing pendant aminophenolate ligands.
June 28th, 2008 | by admin |Structural and catalytic studies of lithium complexes bearing pendant aminophenolate ligands.
Lithium complexes bearing mono-anionic aminophenolate ligands are described. Reactions of ligand precursors HON(Me)Ph(OMe), HON(Me)Ph(SMe), HON(Me)C(OMe) or HON(Me)C(NMe2) [HON(Me)Ph(OMe) = (2-OMeC(6)H(4)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)Ph(SMe)= (2-SMe-C(6)H(4)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)C(OMe) = (MeOCH(2)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)C(NMe2) = (Me(2)NCH(2)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2))] with 1.1-1.3 molar equivalents of (n)BuLi in diethyl ether solution afford (LiON(Me)Ph(OMe))(2) (), (LiON(Me)Ph(SMe))(2) (), (LiON(Me)C(OMe))(2) () and (LiON(Me)C(NMe2))(2) () as dinuclear lithium complexes. The BnOH adduct of , (BnOH)(LiON(Me)C(OMe)) (), was prepared from the reaction of and BnOH in diethyl ether solution. The molecular structures are reported for ligand precursor HON(Me)Ph(SMe) and compounds and . These dinuclear lithium complexes show excellent catalytic activities toward the ring-opening polymerization of l-lactide in the presence of benzyl alcohol.
Huang CA, Ho CL, Chen CT.
Department of Chemistry, National Chung Hsing University, Taichung, 402, Taiwan. ctchen@dragon.nchu.edu.tw.