Ring-Opening Polymerization of ε-Caprolactone Utilizing Aluminum Alkyl Complexes Bearing Dianionic Scorpionate Ligands
作者:Elizabeth N. Cooper、Boris Averkiev、Victor W. Day、Peter E. Sues
DOI:10.1021/acs.organomet.1c00400
日期:2021.9.27
scorpionate ligands (Ar)2CHR (1–4) were synthesized and coordinated to aluminum to produce Al(CH2CH3)((Ar)2CHR) (5–8), where R = CH2OCH3 (1 or 5), CH2N(CH3)2 (2 or 6), imidazole (3 or 7), or N-methylimidazole (4 or 8), and Ar = 2,4-dimethylphenol (a) or 2-tert-butyl-4-methylphenol (b). The bisphenol compounds were generated using a Friedel–Crafts alkylation reaction starting with commercially available reagents
合成了一系列八个蝎形配体 (Ar) 2 CHR ( 1 – 4 ) 并与铝配位以产生 Al(CH 2 CH 3 )((Ar) 2 CHR) ( 5 – 8 ),其中 R = CH 2 OCH 3 ( 1或5 )、CH 2 N(CH 3 ) 2 ( 2或6 )、咪唑( 3或7 )或N-甲基咪唑( 4或8 ),Ar=2,4-二甲基苯酚(a ) 或 2-叔丁基-4-甲基苯酚 ( b )。双酚化合物是使用市售试剂开始的 Friedel-Crafts 烷基化反应生成的。所述蝎物种以探针的几何形状协调与三乙基铝随后被组合1 - 4。将得到的复合物5 - 8显示的扭曲的四面体结构与配体双酚作为三齿供体。唯一的例外是5a,它在固态下形成酚盐桥接二聚体。此外,复合体5 – 8被发现是ε-己内酯开环聚合的活性催化剂。烷基物种铝影响该转化具有和不使用醇助催化剂,但是,当1个当量的被视为更高的活性和清洁器激活我被