Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, Avenue A. Savary, BP 47870, F-21078 Dijon, France.
Beilstein J Org Chem. 2013 Apr 3;9:647-54. doi: 10.3762/bjoc.9.73. Print 2013.
The ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) under solvent-free conditions and using 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2) as precatalyst is described. Linear and star-branched polyesters were synthesized by successive use of benzyl alcohol, ethylene glycol, glycerol and pentaerythritol as initiator alcohols, and the products were fully characterized by (1)H and (13)C{(1)H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating under vacuo (method A) or by addition of NaBPh4 (method B). Possible catalytic and deactivation mechanisms are proposed.
无溶剂条件下 1-正丁基-3-甲基咪唑-2-羧酸酯（BMIM-2-CO2）作为前催化剂引发ε-己内酯（ε-CL）和丙交酯（rac-LA）的开环聚合。通过连续使用苯甲醇、乙二醇、甘油和季戊四醇作为引发醇，合成了线性和星形支化聚酯，并通过（1）H 和（13）C{（1）H}NMR 光谱、凝胶渗透色谱（GPC）和差示扫描量热法（DSC）对产物进行了充分表征。BMIM-2-CO2 作为 N-杂环卡宾前体，通过真空加热（方法 A）或添加 NaBPh4（方法 B）原位脱羧形成。提出了可能的催化和失活机制。
