Department of Health Technology, Technical University of Denmark, Ørsteds Plads, Building 349, 2800 Kgs, Lyngby, Denmark.
Chem Commun (Camb). 2020 Jun 11;56(46):6245-6248. doi: 10.1039/d0cc01756f. Epub 2020 May 6.
Lewis acids play key roles in many chemical reactions. Structural and functional (kinetic) detail in Lewis acid catalysed fructose conversion are derived herein by the combined use of conventional and dissolution dynamic nuclear polarization (D-DNP) NMR. Structural information obtained with D-DNP NMR was used to identify conditions that stabilize an elusive initial intermediate and to determine its chemical structure. Carbohydrate dehydration through this intermediate had been predicted computationally. Complementary kinetic NMR assays yielded rate constants spanning three orders of magnitude for the three biggest energy barriers in the catalytic cycle.
路易斯酸在许多化学反应中起着关键作用。通过常规和溶解动态核极化（D-DNP）NMR 的联合使用，本文获得了路易斯酸催化果糖转化的结构和功能（动力学）细节。使用 D-DNP NMR 获得的结构信息用于确定稳定难以捉摸的初始中间体的条件，并确定其化学结构。通过该中间体的碳水化合物脱水已通过计算进行了预测。补充的动力学 NMR 测定法为催化循环中的三个最大能量障碍提供了跨越三个数量级的速率常数。
