文献类型：期刊文献

英文题名：Magnesium complexes in diverse coordination patterns supported by tetradentate aminophenolate ligands: Synthesis, characterization and application in the stereocontrolled ring-opening polymerization of rac-LA

作者：Yang, Yang;Wang, Haobing[1];Ma, Haiyan[1]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China; East China Univ Sci & Technol, Lab Organometall Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2016

卷号：117

起止页码：569

外文期刊名：POLYHEDRON

收录：;EI(收录号：20233614668442);WOS:【SCI-EXPANDED(收录号:WOS:000384384500067)】；

基金：This work is subsidized by the National Natural Science Foundation of China (NNSFC, 21074032 and 21474028), the Program for New Century Excellent Talents in University (for H. Ma, NCET-06-0413) and the Fundamental Research Funds for the Central Universities (WD1113011). All the financial support is gratefully acknowledged. H. Ma also thanks the very kind donation of a Braun glove-box by the AvH foundation.

语种：英文

外文关键词：Magnesium; Aminophenolate ligand; Stereoselective catalysis; Rac-lactide; Ring-opening polymerization

摘要：A series of magnesium silylamido complexes supported by tetradentate aminophenolate ligands, LMgN (SiMe3)(2) (L = {(2-R-1)Ar-CH2N[(CH2)(2)R-2]CH2-(4-R-4-6-R-3)C6H2O-}, R-1 = NMe2, R-2 = (NPr2)-Pr-i, R-3 = R-4 = Cl (1), R-3 = R-4 = cumyl (2); R-1 = NMe2, R-2 = NEt2, R-3 = R-4 = cumyl (3), R-3 = CPh3, R-4 = Me (4); R-1 = NEt2, R-2 = NEt2, R-3 = CPh3, R-4 = Me (5); R-1 = NMe2, R-2 = (S)-1-butylpyrrolidine-2-yl, R-3 = R-4 = cumyl (6), R-3 = CPh3, R-4 = Me (7)), were synthesized and fully characterized, and their catalytic behaviors for the ring-opening polymerization (ROP) of rac-lactide (rac-LA) were explored. The monomeric nature and versatile coordination modes of these complexes in the solid state were further confirmed by X-ray diffraction studies on complexes 1, 3 and 7. In complex 1, the N,N-diisopropylamino group on the alkylamino side arm does not coordinate to the metal centre, whilst the remaining three donors of the aminophenolate ligand and the silylamido group bond with the magnesium centre. By contrast, in complexes 3 and 7, the arylamino moiety does not coordinate to the metal centre, while the alkylamino side arm coordinates. It is worth noting that the introduction of the N,N-dimethyl amino group to the pendant benzyl group realises the diastereoselective synthesis of multichiral aminophenolate magnesium complexes, which has not been achieved by the corresponding tridentate aminophenolate ligand. It was found that most of these magnesium complexes serve as highly active initiators for the ROP of rac-LA. The coordination pattern of the aminophenolate ligand exerted a considerable influence on the activity and stereoselectivity of the corresponding complex toward the polymerization of rac-LA, leading to the production of moderate to high heterotactic biased PLAs. The enantiopure complex 7 showed the highest heteroselectivity among these magnesium complexes (P-r = 0.80 in toluene, P-r = 0.82 in THF). (C) 2016 Elsevier Ltd. All rights reserved.