Mechanistic Study on Deoxydehydration and Hydrogenation of Methyl Glycosides to Dideoxy Sugars over a ReO<i><sub>x</sub></i>–Pd/CeO<sub>2</sub>Catalyst
作者:Ji Cao、Masazumi Tamura、Ryu Hosaka、Akira Nakayama、Jun-ya Hasegawa、Yoshinao Nakagawa、Keiichi Tomishige
DOI:10.1021/acscatal.0c02309
日期:2020.10.16
consecutive hydrogenation (DODH + HG) over a ReOx–Pd/CeO2 catalyst with gaseous H2. In the study, the reactivity of the methyl glycosides in DODH was clearly lower than that of simple cyclic vicinal diols, such as cis-1,2-cyclohexanediol and cis-1,2-cyclopentanediol, and the reactivity of the methyl glycosides was also different. Herein, we investigated the reactivity difference based on kinetic studies and
我们发现具有顺式-邻位OH基团的未保护的甲基糖苷可以在具有气态H 2的ReO x -Pd / CeO 2催化剂上通过脱氧脱水和连续氢化(DODH + HG)转化为相应的甲基二脱氧糖苷。在该研究中,DODH中甲基糖苷的反应性明显低于简单的环状邻位二醇,例如顺式-1,2-环己二醇和顺式-1,2-环戊二醇和甲基糖苷的反应性也不同。本文中,我们基于动力学研究和密度泛函理论(DFT)计算研究了反应性差异。动力学研究表明,甲基糖苷和简单二醇之间的反应性差异是由除顺式-邻位二醇之外的甲基糖苷的OH基团引起的,并且甲基糖苷之间的反应性差异将与取代基的构型有关与顺式邻位二醇相邻,而DODH的反应机理从底物浓度和H 2几乎相同的反应顺序来看,基本上是相似的所有基材的压力。吸附和过渡甲基α的状态-升-鼠李糖苷和甲基α-升(甲基α--fucopyranoside,它有一个大的反应速度差升-rhamnopyrano