Efficient and Heteroselective Heteroscorpionate Rare-Earth-Metal Zwitterionic Initiators for ROP of <i>rac</i>-Lactide: Role of σ-Ligand
作者:Zehuai Mou、Bo Liu、Xinli Liu、Hongyan Xie、Weifeng Rong、Lei Li、Shihui Li、Dongmei Cui
DOI:10.1021/ma500209t
日期:2014.4.8
6-Me2-phenyl (HL5)) heteroscorpionate ligands were synthesized. Abstraction of the methide proton of these ligands by rare-earth-metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, afforded the corresponding zwitterionic bis(alkyl) complexes L1–5Ln(CH2SiMe3)2(THF) (L1, Ln = Y (1a), Lu (1b); L2, Ln = Y (2a), Lu (2b); L3, Ln = Y (3a), Lu (3b); L4, Ln = Y (4a), Lu (4b); L5, Ln = Y (5a), Lu (5b), while metathesis reaction
一系列的氧代膦(3,5-Me 2 Pz)2 CHP(R)2 O(Pz =吡唑; R = t Bu(HL 1),Cy(HL 2))和亚氨基膦(3,5-Me 2 Pz )2 CHP(R)2 NAr(R = Cy,Ar = Ph(HL 3); R = Ph,Ar = Ph(HL 4),Ar = 2,6-Me 2-苯基(HL 5))杂蝎子配体被合成。稀土金属三(烷基)s,Ln(CH 2 SiMe 3)3(THF)2提取这些配体的甲基化质子,得到相应的两性离子双(烷基)配合物L 1–5 Ln(CH 2 SiMe 3)2(THF)(L 1,Ln = Y(1a),Lu(1b); L 2,Ln = Y(2a) ,Lu(2b); L 3,Ln = Y(3a),Lu(3b); L 4,Ln = Y(4a),Lu(4b); L 5,Ln = Y(5a),Lu(5b) ,而LiL 3和LiL 4的锂盐与YCl的复分解反应3(THF)2或YBr