A Genetically Encodable Ligand for Transfer Hydrogenation
作者:Clemens Mayer、Donald Hilvert
DOI:10.1002/ejoc.201300340
日期:2013.6
Simple tripeptides are shown here to be versatile ligands for iridium-catalyzed transferhydrogenations affording large acceleration effects. A water-soluble iridium complex with Gly-Gly-Phe, for example, catalyzes the reduction of diverse ketones, aldehydes, and imines by formate with turnover frequencies rivaling or outperforming those of established ligand systems. Regioselective reduction of coenzyme
Electrocatalytic NAD<sup>+</sup> reduction <i>via</i> hydrogen atom-coupled electron transfer
作者:Fengyuan Liu、Chunmei Ding、Shujie Tian、Sheng-Mei Lu、Chengcheng Feng、Dandan Tu、Yan Liu、Wangyin Wang、Can Li
DOI:10.1039/d2sc02691k
日期:——
dinucleotide cofactor (NAD(P)H) is regarded as an important energy carrier and charge transfer mediator. Enzyme-catalyzed NADPH production in natural photosynthesis proceeds via a hydride transfer mechanism. Selective and effective regeneration of NAD(P)H from its oxidized form by artificial catalysts remains challenging due to the formation of byproducts. Herein, electrocatalytic NADH regeneration and the reaction
烟酰胺腺嘌呤二核苷酸辅因子(NAD(P)H)被认为是重要的能量载体和电荷转移介体。自然光合作用中酶催化的 NADPH 产生是通过氢化物转移机制进行的。由于副产物的形成,通过人工催化剂从氧化形式选择性有效地再生 NAD(P)H 仍然具有挑战性。本文研究了电催化NADH再生以及金属和碳电极上的反应机理。我们发现生物活性 1,4-NADH 在 Cu、Fe 和 Co 电极上的选择性相对较高,且不会形成常见报道的 NAD 2副产物。相反,碳电极形成更多的NAD 2副产物。ADP-核糖被证实是NAD +裂解反应产生的副产物。基于H/D同位素效应和电子顺磁共振分析,提出NADH在这些金属电极上的形成是通过氢原子耦合电子转移(H ad CET)机制进行的,而不是直接电子转移和NAD˙ 碳电极上的自由基路径,产生更多副产物 NAD 2。这项工作揭示了与生物催化不同的电催化 NADH 再生机制。
Chemo-bio catalysis using carbon supports: application in H<sub>2</sub>-driven cofactor recycling
作者:Xu Zhao、Sarah E. Cleary、Ceren Zor、Nicole Grobert、Holly A. Reeve、Kylie A. Vincent
DOI:10.1039/d1sc00295c
日期:——
reduction. These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared to metal/C catalysts. The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply
非均相生物催化加氢是清洁,对映选择性C X还原的有吸引力的策略。该方法依赖于由H 2驱动的NADH循环提供动力的酶。本文研究了可商购的碳负载金属(金属/ C)催化剂用于直接H 2驱动的NAD +还原。然后将选定的金属/ C催化剂用于H 2氧化,电子通过导电碳载体材料转移到NAD +的吸附酶上减少。与金属/ C催化剂相比,这些化学生物催化剂显示出在环境反应条件下产生生物活性NADH的改进的活性和选择性。金属/碳催化剂和碳载体材料(所有活性炭或炭黑)的特征在于探查哪些性质可能影响催化剂的活性。然后使用优化的化学生物催化剂将NADH提供给醇脱氢酶以减少对映选择性(> 99%ee)的酮,从而导致高的辅因子转换数以及Pd和NAD +还原酶活性分别为441 h -1和2347 h -1, 分别。该方法展示了将化学催化与生物催化结合在碳载体上的新方法,此处重点介绍了选择性氢化反应。