Efficient Asymmetric Synthesis of Ethyl (<i>S</i>)-4-Chloro-3-hydroxybutyrate Using Alcohol Dehydrogenase <i>Sm</i>ADH31 with High Tolerance of Substrate and Product in a Monophasic Aqueous System
Bioreductionscatalyzed by alcoholdehydrogenases (ADHs) play an important role in the synthesis of chiral alcohols. However, the synthesis of ethyl (S)-4-chloro-3-hydroxybutyrate [(S)-CHBE], an important drug intermediate, has significant challenges concerning high substrate or product inhibition toward ADHs, which complicates its production. Herein, we evaluated a novel ADH, SmADH31, obtained from
醇脱氢酶(ADHs)催化的生物还原在手性醇的合成中起重要作用。然而,重要的药物中间体((S)-4-氯-3-羟基丁酸乙酯([ S)-CHBE])的合成对于高底物或产物对ADH的抑制作用具有重大挑战,这使其生产变得复杂。本文中,我们评估了一种新的ADH,即Sm ADH31,它从嗜麦芽单胞菌的嗜麦芽孢杆菌基因组中获得,其可以耐受极高浓度(6 M)的底物和产物。的共表达的Sm ADH31和葡萄糖脱氢酶从枯草芽孢杆菌在大肠杆菌意味着高达660克L-在单相水性体系中,–1(4.0 M)4-氯乙酰乙酸乙酯已完全转化为(S)-CHBE,其ee值> 99.9%,时空产率高(2664 g L –1 d –1)。分子动力学模拟揭示了Sm ADH31的高活性和立体选择性。此外,由于Sm ADH31具有较宽的底物谱,因此还以高浓度(100–462 g L –1)合成了其他五种光学纯手性醇。所有这些化合物均充当重要的药物中间体,证明了Sm
Organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts: The first example of homogenization of inorganic-supported catalyst in asymmetric hydrogenation
In this article, we report the synthesis, structure, morphologies, and asymmetric catalytic properties of a series of novel organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts, which have a good organosolubility (0.1–0.5 g mL−1) in various solvents and mesoporous, filiform, and layered structures. Due to the organosoluble properties in various organic solvents
在本文中,我们报告了一系列新型有机可溶物的合成,结构,形态和不对称催化性能 磷酸锆纳米复合材料及其负载的手性钌催化剂,在各种溶剂和介孔,丝状和层状结构中均具有良好的有机溶解度(0.1–0.5 g mL -1)。由于在各种有机溶剂中的有机可溶特性,在催化领域实现了膦酸锆负载的催化剂的第一次均质化。在取代的α-酮酯的不对称氢化中,对映选择性(74.3–84.7%ee)和分离的产率(86.7–93.6%)高于相应的均相Ru(p -cymene)(S -BINAP)Cl 2由于膦酸锆骨架中剩余的中孔引起的限制作用。反应完成后,通过添加可轻松以定量收率回收负载型催化剂环己烷 离心后再重复使用五次,而催化活性没有明显损失。
Asymmetric hydrogenation of α-ketoesters on the Pt(111) surface
作者:Poonam Sharma、Rakesh K. Sharma
DOI:10.1039/c6nj02405j
日期:——
remarkable recent findings and advances in heterogeneous catalyst design based on facet rich Pt(111) on carbon materials. Platinum(111) hexagonal nanocrystals are prepared using Tween 20 as a facet directing agent via a simple, efficient and scalable thermolytic reduction process in air. These highly dispersed Pt(111) nanocrystals on carbon act as single site catalytic systems and exhibit exceptional
(R)- and (S)-α-hydroxy esters 5 are interconverted via their triflates 6 in high chemical as well as optical yields by reaction with dimethylformamide. The same triflates are efficiently converted into N-hydroxy-α-amino acid derivatives 7 of highopticalpurity.