Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.
Current address: Institute of Materials Research and Engineering, 2 Fusionopolis Way, Singapore, 138634, Singapore.
Angew Chem Int Ed Engl. 2019 Apr 23;58(18):6007-6011. doi: 10.1002/anie.201901592. Epub 2019 Mar 28.
Polylactide (PLA) is a fully biodegradable and recyclable plastic, produced from a bio-derived monomer: it is a circular economy plastic. Its properties depend upon its stereochemistry and isotactic PLA shows superior thermal-mechanical performances. Here, a new means to control tacticity by exploiting rotaxane conformational dynamism is described. Dynamic achiral [2]rotaxanes can show high isoselectivity (P =0.8, 298 K) without requiring any chiral additives and enchain by a chain end control mechanism. The organocatalytic dynamic stereoselectivity is likely applicable to other small-molecule and polymerization catalyses.
聚乳酸（PLA）是一种完全可生物降解和可回收的塑料，由生物衍生的单体制成：它是一种循环经济塑料。其性能取决于其立体化学，而全同立构 PLA 则表现出优异的热机械性能。在这里，描述了一种通过利用轮烷构象动力学来控制立构规整性的新方法。动态非手性[2]轮烷可以表现出高的等规选择性（P=0.8，298 K），而不需要任何手性添加剂，并通过链端控制机制进行连接。有机催化动态立体选择性可能适用于其他小分子和聚合催化。
