推进氢键有机催化用于开环聚合

本期文章：《美国化学会志》：Online/在线发表

浙江大学张兴宏团队报道了推进氢键有机催化用于开环聚合——引发剂/链端的分子内活化。相关研究成果发表在2024年9月3日出版的《美国化学会杂志》。

内酯的有机催化开环聚合（ROP）是一种获得可再生和可生物降解聚酯的绿色方法。开发具有高活性和可控性的新型有机催化剂是该领域一个重大而具有挑战性的研究课题。

该文中，研究人员报告了一系列有机催化剂，以实现内酯的快速和可控的ROP。这些催化剂将（硫代）尿素和醇盐结合在一个分子中，并在ROP中充当引发剂。

如计算研究所示，这些催化剂能够有效地分子内活化引发剂/链端，从而比现有的（硫代）脲/醇盐二元体系具有更高的活性和更少的（硫）尿素负载。

这些有机催化剂表现出与金属配合物相当的超高活性，即周转数高达900，周转频率高达4860 min-1，为聚酯提供了量身定制的结构、预测的分子量、窄分散性、较少的差向异构化和最小的酯交换。催化剂合成简单且可扩展，可广泛调节ROP的活性。

附：英文原文

Title: Advancing H-Bonding Organocatalysis for Ring-Opening Polymerization: Intramolecular Activation of Initiator/Chain End

Author: Xiaowei Geng, Xiong Liu, Qinglei Yu, Chengjian Zhang, Xinghong Zhang

Issue&Volume: September 3, 2024

Abstract: Organocatalytic ring-opening polymerization (ROP) of lactones is a green method for accessing renewable and biodegradable polyesters. Developing new organocatalysts with high activity and controllability is a major and challenging research topic in this field. Here, we report a series of organocatalysts to achieve a fast and controlled ROP of lactones. These catalysts incorporate (thio)urea and alkoxide in one molecule and act as initiators in the ROP. Such catalysts enable an effective intramolecular activation of initiator/chain end, as revealed by computational studies, resulting in higher activity and fewer (thio)urea loads than existing (thio)urea/alkoxide binary systems. These organocatalysts exhibit ultrahigh activity comparable to metal complexes, i.e., turnover number up to 900 and turnover of frequency up to 4860 min–1, affording polyesters with tailor-made structure, predicted molecular weights, narrow dispersity, less epimerization, and minimal transesterification. The catalyst synthesis is simple and scalable, allowing widely tuned activities of the ROP.

DOI: 10.1021/jacs.4c09394

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c09394

期刊信息

JACS：《美国化学会志》，创刊于1879年。隶属于美国化学会，最新IF：16.383
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