10.1021/acs.macromol.8b00924.s002 Jianwen Hu Jianwen Hu Chao Kan Chao Kan Haobing Wang Haobing Wang Haiyan Ma Haiyan Ma Highly Active Chiral Oxazolinyl Aminophenolate Magnesium Initiators for Isoselective Ring-Opening Polymerization of <i>rac</i>-Lactide: Dinuclearity Induced Enantiomorphic Site Control American Chemical Society 2018 chiral magnesium complexes Active Chiral Oxazolinyl Aminophenolate Magnesium Initiators enantiomorphic site control racemic magnesium initiators investigation ROP Dinuclearity Induced Enantiomorphic Site Control enantiomorphic site control mechanism challenge isoselective magnesium complexes isotactic PLAs isotactic stereoblock PLA Isoselective Ring-Opening Polymerization chiral oxazolinyl aminophenolate ligands TOF magnesium lactate model complexes 2018-07-11 18:33:54 Dataset https://acs.figshare.com/articles/dataset/Highly_Active_Chiral_Oxazolinyl_Aminophenolate_Magnesium_Initiators_for_Isoselective_Ring-Opening_Polymerization_of_i_rac_i_-Lactide_Dinuclearity_Induced_Enantiomorphic_Site_Control/6807017 The most important challenge in ring-opening polymerization of <i>rac</i>-lactide today is to obtain isotactic PLAs with high molecular weights. The goal of our work is to address this important challenge by developing novel catalysts that enable precise control over stereoselectivity and produce high molecular weight PLAs at the same time. Here we report some rare examples of isoselective magnesium complexes toward the ROP of <i>rac</i>-LA, which are supported by chiral oxazolinyl aminophenolate ligands. Preliminary kinetic investigations confirmed that isotactic PLAs could be achieved via an enantiomorphic site control mechanism by using these chiral magnesium complexes. A pair of racemic magnesium initiators proved to integrate hyperactivity (TOF up to 54 000 h<sup>–1</sup> at 25 °C) with sufficient isoselectivity (<i>P</i><sub>m</sub> = 0.80) toward the ROP of <i>rac</i>-LA, leading to the formation of isotactic stereoblock PLA with high molecular weight (<i>M</i><sub>n</sub> = 461 kg mol<sup>–1</sup>) and a semicrystalline property (<i>T</i><sub>m</sub> = 164 °C). Detailed structural investigation on the magnesium lactate model complexes suggested that the high degree of enantiomorphic site control is derived from both the ligand chirality and the dinuclear feature of the magnesium active species.