Department of Chemical and Pharmaceutica Sciences, University of Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy.
Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via P. Gobetti, 101-40129, Bologna, Italy.
Chemistry. 2019 Nov 18;25(64):14701-14710. doi: 10.1002/chem.201903557. Epub 2019 Oct 21.
The application of N-heterocyclic carbene (NHC) catalysis to the polycondensation of diols and dialdehydes under oxidative conditions is herein presented for the synthesis of polyesters using fossil-based (ethylene glycol, phthalaldehydes) and bio-based (furan derivatives, glycerol, isosorbide) monomers. The catalytic dimethyl triazolium/1,8-diazabicyclo[5.4.0]undec-7-ene couple and stoichiometric quinone oxidant afforded polyester oligomers with a number-average molecular weight (M ) in the range of 1.5-7.8 kg mol as determined by NMR analysis. The synthesis of a higher molecular weight polyester (polyethylene terephthalate, PET) by an NHC-promoted two-step procedure via oligoester intermediates is also illustrated together with the catalyst-controlled preparation of cross-linked or linear polyesters derived from the trifunctional glycerol. The thermal properties (TGA and DSC analyses) of the synthesized oligoesters are also reported.
本文介绍了 N-杂环卡宾（NHC）催化在氧化条件下二醇和二醛的缩聚反应，用于使用化石基（乙二醇、邻苯二甲醛）和生物基（呋喃衍生物、甘油、异山梨醇）单体合成聚酯。催化的二甲基三唑鎓/1,8-二氮杂二环[5.4.0]十一-7-烯偶联物和化学计量醌氧化剂提供了数均分子量（M）在 1.5-7.8kgmol 范围内的聚酯低聚物，这是通过 NMR 分析确定的。还通过两步法通过低聚物中间体展示了 NHC 促进的更高分子量聚酯（聚对苯二甲酸乙二醇酯，PET）的合成，以及由三官能团甘油衍生的交联或线性聚酯的催化剂控制制备。还报告了合成低聚物的热性能（TGA 和 DSC 分析）。
