Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
Org Lett. 2017 Sep 1;19(17):4596-4599. doi: 10.1021/acs.orglett.7b02198. Epub 2017 Aug 21.
A high-yielding, one-pot simultaneous synthesis and full characterization of two regioisomeric C-symmetrical macrocycles 3a and 3b from triphosgene and readily available hexa-O-benzyl-6,6'-diaminosucrose 1 is reported. The efficient macrocyclization (90% overall yield, ∼1:1 ratio of 3a vs 3b) is attributed to favorable steric constraints and to a templation by a chloride anion. H NMR titration studies and theoretical predictions revealed that both receptors show similar affinity for acetate and benzoate anions and enhanced preference for chloride over HPO.
报道了一种高产、一锅法同时合成和全表征两种区域异构体 C 对称大环 3a 和 3b 的方法，原料为三光气和易得的六-O-苄基-6,6'-二氨基蔗糖 1。高效的大环化反应（总收率 90%，3a 与 3b 的比例约为 1:1）归因于有利的空间位阻和氯离子的模板作用。1H NMR 滴定研究和理论预测表明，两个受体对乙酸根和苯甲酸根阴离子表现出相似的亲和力，并对氯离子有增强的偏好，而不是 HPO。
