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
All at once: Two conflicting characters, high H2 activation ability and low C=C hydrogenation ability, are achieved by heterogeneous ReOx-Ag/CeO2 catalyst, leading to relatively high deoxydehydration (DODH) activity and high selectivity to DODH products in the DODH of various polyols such as erythritol and sugar derivatives with H2 as a reducing agent.
一气呵成:多相 ReO x -Ag/CeO 2催化剂实现了高 H 2活化能力和低 C=C 加氢能力这两个相互矛盾的特性,从而导致相对较高的脱氧脱水 (DODH) 活性和对 DODH 产物的高选择性以H 2为还原剂的各种多元醇如赤藓糖醇和糖衍生物的DODH 。
Concise chemoenzymatic synthesis of methyl d-2,3-dideoxyriboside
作者:Juan C. Ramos、Paula Bracco、Mauro Mazzini、José R. Fernández、Daniela Gamenara、Gustavo A. Seoane
DOI:10.1016/j.tetasy.2010.05.039
日期:2010.4
The synthesis of methyl alpha- and beta-D-2,3-dideoxyriboside from a non-carbohydrate source is presented. The source of chirality is the microbial oxidation of halobenzenes to produce cyclohexadienediols, which are transformed into the final product in five steps with high chemical and enantiomeric purity. (C) 2010 Elsevier Ltd. All rights reserved.