was tested in 30 % [BMIm][Cl] for the synthesis of a rare, very costly commercially available sugar, d‐sedoheptulose, which was obtained in one step from d‐ribose with an isolated yield of 82 %. This biohybrid was reusable over four cycles with no loss of enzymatic activity. The particular activity of free and immobilized TKgst in [BMIm][Cl] holds promise to extend the applications of TKgst in other ionic
Productive sugar isomerization with highly active Sn in dealuminated β zeolites
作者:Jan Dijkmans、Dries Gabriëls、Michiel Dusselier、Filip de Clippel、Pieter Vanelderen、Kristof Houthoofd、Annelies Malfliet、Yiannis Pontikes、Bert F. Sels
DOI:10.1039/c3gc41239c
日期:——
A water-tolerant Lewis acid catalyst was synthesized by grafting SnIV in isopropanol under reflux onto dealuminated zeolites with the BEA (β) topology. This synthesis method allows the production of highly active Snβ-type catalysts without the need for long hydrothermal syntheses or hydrogen fluoride, while using cheap Sn-precursors, industrially available β zeolites and standard catalyst synthesis unit operations. Extensive characterization of the best catalyst shows highly dispersed Sn in the zeolite matrix (XRD, 29Si MAS NMR and 1H MAS NMR) without the formation of SnO2 (XRD and UV-Vis). The catalyst was tested for the model isomerization of sugars such as glucose to fructose. The catalytic activity proved to be purely heterogeneous and the catalyst was recycled and reused without significant loss in activity. Isomerization productivities above 4 kg product per kg of catalyst per hour are reported with appreciably low Sn loadings, corresponding to exceptionally high turnover frequencies, viz. 500 cycles per Sn per hour at 110 °C, which surpass the activity per Sn of the original hydrothermally synthesized Snβ.
一种耐水路易斯酸催化剂通过在异丙醇中回流方式合成,其方法是将SnIV插枝到去铝沸石(BEA(β)拓扑)上。这种合成方法使得能够生产高度活性的Snβ型催化剂,而无需长时间的水热合成或氟化氢,同时还使用便宜的Sn前驱体、工业上可获得的β沸石和标准催化剂合成单元操作。对最佳催化剂的广泛表征显示,在沸石基体中高度分散的Sn(XRD、29Si MAS NMR和1H MAS NMR),而未形成SnO2(XRD和UV-Vis)。该催化剂用于模型糖异构化反应,例如将葡萄糖转化为果糖。催化活性证明是纯粹的异相,并且催化剂在回收和再使用过程中没有显著的活性损失。报告的异构化产量超过每kg催化剂每小时4kg产物,且Sn负载显著低,相应地表现出异常高的周转频率,即在110°C时每小时每个Sn达到500个周期,这超出了原水热合成Snβ的每个Sn的活性。
Hydroxyapatite: catalyst for a one-pot pentose formation
作者:K. Usami、A. Okamoto
DOI:10.1039/c7ob02051a
日期:——
One of the possible synthetic routes to pentoses is the formose reaction pathway from C1 and C2 carbon sources, but preferential ribose generation in a one-pot reaction without any control of conditions has not been reported. We have tested a one-pot pentose formation and analyzed the products and mechanism in the reaction, using 1H-NMR and mass spectrometry. Hydroxyapatite (HAp), which consists of
戊糖可能的合成途径之一是来自C1和C2碳源的甲糖反应途径,但尚未报道在不影响任何条件的情况下在一锅反应中优先产生核糖。我们测试了一锅戊糖的形成并分析了反应中的产物和机理,使用11 H-NMR和质谱。由磷酸根和钙离子组成的羟基磷灰石(HAp)连续进行跨羟醛反应和Lobry de Bruyn-van Ekenstein转化,从甲醛和乙醇醛中产生核糖。仅在HAp催化剂存在下,连续反应在一个锅中于热水中进行,而无需在每个反应步骤中进行任何精细的pH控制或任何复杂的条件控制。HAp产生的核糖可能是在益生元世界中将戊糖主链掺入核酸的原因。
Synthesis of Cyclopentadiene and Methylcyclopentadiene with Xylose or Extracted Hemicellulose
作者:Zhenjie Yu、Zhufan Zou、Ran Wang、Guangyi Li、Aiqin Wang、Yu Cong、Tao Zhang、Ning Li
DOI:10.1002/anie.202300008
日期:2023.3.20
A highly integrated two-step strategy was developed for the selective synthesis of renewable cyclopentadiene (CPD) and methylcyclopentadiene (MCPD) with xylose or the hemicelluloses extracted from real biomass. Compared with the conventional fossil route, the new synthetic strategy has evident advantages in the renewability and higher availability of feedstock.
Environmental conditions drive self-organization of reaction pathways in a prebiotic reaction network
作者:William E. Robinson、Elena Daines、Peer van Duppen、Thijs de Jong、Wilhelm T. S. Huck
DOI:10.1038/s41557-022-00956-7
日期:2022.6
chemical reactions exhibit well-defined self-organization in response to varying environmentalconditions. This self-organization allows the compositional complexity of the reaction products to be controlled as a function of factors such as feedstock and catalyst availability. We observe how Breslow’s cycle contributes to the reactioncomposition by feeding C2 building blocks into the network, alongside
生命从前生命环境进化而来,需要一个逐步的化学进化过程,朝着更大的分子复杂性发展。已经建立了与生命组成部分有关的与益生元相关的详细合成路线。然而,目前尚不清楚功能化学系统是如何仅使用固有分子化学反应性与非生物环境之间的相互作用而随方向进化的。在这里,我们展示了复杂的化学反应系统如何在不同的环境条件下表现出明确的自组织。这种自组织允许反应产物的组成复杂性作为原料和催化剂可用性等因素的函数来控制。我们观察 Breslow 循环如何通过进料 C 对反应组成做出贡献网络中的2 个构建块,以及以甲醛驱动的链增长为主的反应途径。响应环境变化的有组织的化学反应系统的出现为化学进化过程提供了一种潜在的机制,该过程弥合了益生元化学构件与生命起源之间的差距。