Department of Chemistry, National Changhua University of Education, Changhua 500, Taiwan.
Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan.
Molecules. 2021 Dec 28;27(1):164. doi: 10.3390/molecules27010164.
A series of chelated dehydroacetic acid-imine-based ligands ~ was synthesized by reacting dehydroacetic acid with 2-t-butylaniline, ()-1-phenyl-ethylamine, 4-methoxylbenzylamine, and 2-(aminoethyl)pyridine, respectively, in moderate yields. Ligands ~ reacted with AlMe in toluene to afford corresponding compounds (), (), (), and (). All the ligands and aluminum compounds were characterized by IR spectra, H and C NMR spectroscopy. Additionally, the ligands ~ and corresponding aluminum derivatives , , and were characterized by single-crystal X-ray diffractometry. The catalytic activities using these aluminum compounds as catalysts for the ε-caprolactone ring-opening polymerization (ROP) and styrene oxide-CO coupling reactions were studied. The results show that increases in the reaction temperature and selective solvent intensify the conversions of ε-caprolactone to polycaprolactone. Regarding the coupling reactions of styrene oxide and CO, the conversion rate is over 90% for a period of 12 h at 90 °C. This strategy dispenses the origination of cyclic styrene carbonates, which is an appealing concern because of the transformation of CO into an inexpensive, renewable and easy excess carbon feedstock.
一系列螯合脱氢乙酸-亚胺基配体通过脱氢乙酸与 2-叔丁基苯胺、()-1-苯乙胺、4-甲氧基苄胺和 2-(氨乙基)吡啶分别反应中等产率合成。配体与 AlMe 在甲苯中反应得到相应的化合物()、()、()和()。所有配体和铝化合物均通过红外光谱、H 和 C NMR 光谱进行了表征。此外，配体和相应的铝衍生物、和通过单晶 X 射线衍射进行了表征。研究了这些铝化合物作为催化剂对 ε-己内酯开环聚合 (ROP) 和氧化苯乙烯-CO 偶联反应的催化活性。结果表明，升高反应温度和选择性溶剂可增强 ε-己内酯向聚己内酯的转化率。对于氧化苯乙烯和 CO 的偶联反应，在 90°C 下反应 12 小时，转化率超过 90%。这种策略省去了环状苯乙烯碳酸酯的生成，这是一个吸引人的关注点，因为 CO 转化为廉价、可再生且易于过量的碳原料。
