卤代吡啶类化合物的合成及应用

介绍了吡啶和卤代吡啶的结构和性质,综述了五氯吡啶、3,5,6,-三氯吡啶-2-酚、2-氯-5-三氟甲基吡啶等几种氯代吡啶化合物的合成及其在农药、医药领域的应用,并对各种合成路线工业化前景作了评价。     

Synthesis,Characterization and Application of New Rhodium Complexes for Indirect Electrochemical Cofactor Regeneration

Electroenzymatic synthesis often suffers from electrochemical reaction steps which proceed slower than the coupled enzyme reaction. For indirect electrochemical cofactor regeneration, we here report two new mediators with superior properties compared to the established rhodium complex (2,2′‐bipyridyl)(pentamethylcyclopentadienyl)rhodium [Cp*Rh(2,2′‐bipyridine)]. After constructing a robotic system for fast and reliable cyclic voltammetry measurements, we screened twelve rhodium complexes with substituted 2,2′‐bipyridine ligands for their reduction potentials and catalytic activity towards the reduction of NADP. Promising complexes were investigated in more detail by cyclic voltammetry and under batch electrolysis conditions. The new complexes Cp*Rh(5,5′‐methyl‐2,2′‐bipyridine) and Cp*Rh(4,4′‐methoxy‐2,2′‐bipyridine) reduced NADP to NADPH three times faster than the established mediator, resulting in volumetric productivities of up to 136 mmol L⁻¹ d⁻¹ and turnover frequencies of up to 113 h⁻¹. This increased reaction rate of these new mediators makes indirect electrochemical approach significantly more competitive to other methods of cofactor regeneration. Abbreviations: ADH=alcohol dehydrogenase; Ag|AgCl=silver|silver chloride reference electrode; bpy=2,2′‐bipyridine; ci=current increase; Cp*=pentamethylcyclopentadienyl; CV=cyclic voltammetry; Ep=peak potential; equiv=equivalent; NADP/NADPH=nicotinamide adenine dinucleotide phosphate oxidised/reduced form.     

一类偶氮苯酚类化合物的合成及表征

以取代苯胺为原料,经重氮化后与取代苯酚偶联合成了5个偶氮苯酚类化合物,产物经FTIR、1 HNMR表征。结果表明,产物结构与预期一致。     

4-甲基-7-羟基-8-醛香豆素的合成与表征

采用间苯二酚和乙酰乙酸乙酯为原料,合成了4-甲基-7-羟基香豆素。4-甲基-7-羟基香豆素和六次甲基四胺在冰醋酸中反应,简单处理后得到4-甲基-7-羟基-8-醛基香豆素。对所合成的醛基香豆素采用IR、1HNMR进行了结构表征和确认。该反应操作简单,后处理简便,产率较高。     

双联苄类化合物中间体二苯醚类化合物的合成及表征

以酚类化合物和卤代芳香醛或卤代芳香酯类化合物为原料,通过醛保护和Ullmann反应合成系列二苯醚类化合物。考查了催化剂、缩合剂和混合缩合剂的比例对反应收率的影响,结果表明,当催化剂为氧化铜、缩合剂为混合碳酸钙和碳酸钾,投料比为n(酚类化合物)∶n(卤代化合物)∶n(氧化铜)∶n(碳酸钾)∶n(碳酸钙)=1∶1.05∶0.3∶1.6∶0.4,收率较理想。目标产物的结构通过MS和1H NMR确证。     

几种卤代吡啶类农药中间体的合成与应用

概述了3,5,6-三氯吡啶-2-醇、2,3-二氯吡啶、2-氯-5-氯甲基吡啶、2,3-二氟-5-氯吡啶和2,3-二氯-5-三氟甲基吡啶5种卤代吡啶类化合物的合成方法,并对其在农药工业中的应用做了简要介绍。     

新型手性大环多胺化合物的合成及表征

以2,5-二甲基吡嗪为原料合成吡嗪-2,5-甲醛,再通过与1R,2R-环己二胺合成一种新型的手性大环多胺类化合物L,通过1H NMR、FT-IR对所合成的物质的结构进行了表征。     

苦基呋咱醚化合物的合成及表征

为了得到综合性能优良的高能量密度材料,通过将羟基硝基呋咱转化为相应的醇钠盐,分别与苦基氯（PcCl）和2,4-二氯-1,3,5-三硝基苯（DCPc）缩合得到苦基-（3-硝基呋咱基-4）醚（FOP）和双（3-硝基呋咱基-4）苦基醚（DFOP）,采用红外光谱、核磁共振、质谱及元素分析方法对其结构进行了表征。确定了最佳合成条件,FOP合成条件为：PcCl与硝基呋咱醇钠的摩尔比1．0：1．1,反应温度80℃,反应时间16h,以原料PcCl计产品收率达到31％以上;DFOP合成条件为：DCPc与硝基呋咱醇钠的摩尔比1．0：2．7,反应温度80℃,反应时间2h,以原料DCPc计产品收率达到42％以上。     

Pyridine Compounds with Antimicrobial and Antiviral Activities

In the context of the new life-threatening COVID-19 pandemic caused by the SARS-CoV-2 virus, finding new antiviral and antimicrobial compounds is a priority in current research. Pyridine is a privileged nucleus among heterocycles; its compounds have been noted for their therapeutic properties, such as antimicrobial, antiviral, antitumor, analgesic, anticonvulsant, anti-inflammatory, antioxidant, anti-Alzheimer’s, anti-ulcer or antidiabetic. It is known that a pyridine compound, which also contains a heterocycle, has improved therapeutic properties. The singular presence of the pyridine nucleus, or its one together with one or more heterocycles, as well as a simple hydrocarbon linker, or grafted with organic groups, gives the key molecule a certain geometry, which determines an interaction with a specific protein, and defines the antimicrobial and antiviral selectivity for the target molecule. Moreover, an important role of pyridine in medicinal chemistry is to improve water solubility due to its poor basicity. In this article, we aim to review the methods of synthesis of pyridine compounds, their antimicrobial and antiviral activities, the correlation of pharmaceutical properties with various groups present in molecules as well as the binding mode from Molecular Docking Studies.     

Heteropoly Acids and Related Compounds as Catalysts for Fine Chemical Synthesis

Catalysis by heteropoly acids (HPAs) and related compounds is a field of growing importance, attracting increasing attention worldwide, in which many new and exciting developments are taking place in both research and technology [1-111, HPAs are polyoxometalates incorporating anions (heteropolyanions) having metal-oxygen octahedra as the basic structural units [ll-141. Among a wide variety of HPAs those belonging to the so-called Keggin series are the most importance for catalysis. They include heteropolyanions (HPANs)     

Heteropoly Acids and Related Compounds as Catalysts for Fine Chemical Synthesis

Catalysis by heteropoly acids (HPAs) and related compounds is a field of growing importance, attracting increasing attention worldwide, in which many new and exciting developments are taking place in both research and technology [1–111, HPAs are polyoxometalates incorporating anions (heteropolyanions) having metal-oxygen octahedra as the basic structural units [ll-141. Among a wide variety of HPAs those belonging to the so-called Keggin series are the most importance for catalysis. They include heteropolyanions (HPANs)     

石墨层间化合物（GIC）的合成技术及其在催化反应中的应用

介绍了石墨层间化合物的结构特征及其合成方法，讨论了各种合成方法的优点、缺点，指出了国内外对GIC作为催化剂在各种有机反应中的研究和应用现状。     

Novel Function of CtXyn5A from Acetivibrio thermocellus: Dual Arabinoxylanase and Feruloyl Esterase Activity in the Same Active Site**

Enzymes’ uncharacterised side activities can have significant effects on reaction products and yields. Hence, their identification and characterisation are crucial for the development of successful reaction systems. Here, we report the presence of feruloyl esterase activity in CtXyn5A from Acetivibrio thermocellus, besides its well-known arabinoxylanase activity, for the first time. Activity analysis of enzyme variants mutated in the catalytic nucleophile, Glu279, confirmed removal of all activity for E279A and E279L, and increased esterase activity while removing xylanase activity for E279S, thus allowing the proposal that both reaction types are catalysed in the same active site in two subsequential steps. The ferulic acid substituent is cleaved off first, followed by hydrolysis of the xylan backbone. The esterase activity on complex carbohydrates was found to be higher than that of a designated ferulic acid esterase (E-FAERU). Therefore, we conclude that the enzyme exhibits a dual function rather than an esterase side activity.     

含双酰腙类新型席夫碱大环化合物的合成与表征

报道以草酸、邻苯二胺为原料,合成中间体N,N′-双(2-苯氨基)-乙二酰胺(1),然后中间体(1)再与乙酰丙酮反应,合成得到了新型席夫碱大环化合物(2)。并探讨了合成目标大环化合物的最佳合成条件:以50%乙醇做溶剂,在高度稀释下中间体(1)与乙酰丙酮投料比(摩尔比)为1∶1,反应液pH值7~8,于75~80℃条件下反应18 h。目标大环化合物通过元素分析、1H NMR、IR、UV-vis和MS进行组成和结构表征。     

Far‐Red Fluorogenic Probes for Esterase and Lipase Detection

Fluorogenic enzyme probes go from a dark to a bright state following hydrolysis and can provide a sensitive, real‐time readout of enzyme activity. They are useful for examining enzymatic activity in bacteria, including the human pathogen Mycobacterium tuberculosis. Herein, we describe two fluorogenic esterase probes derived from the far‐red fluorophore 7‐hydroxy‐9H‐(1,3‐dichloro‐9,9‐dimethylacridin‐2‐one) (DDAO). These probes offer enhanced optical properties compared to existing esterase probes because the hydrolysis product, DDAO, excites above 600 nm while retaining a good quantum yield (?=0.40). We validated both probes with a panel of commercially available enzymes alongside known resorufin‐ and fluorescein‐derived esterase substrates. Furthermore, we used these probes to reveal esterase activity in protein gel‐resolved mycobacterial lysates. These probes represent new tools for esterase detection and characterization and should find use in a variety of applications.     

偶氮四唑类高氮含能化合物的合成及表征

以5-氨基四唑为原料,合成了3种偶氮四唑类高氮含能化合物（偶氮四唑铵盐（AZT）、偶氮四唑胍盐（GZT）及偶氮四唑三氨基胍盐（TAGZT））,利用IR、NMR、DSC、熔点测试和元素分析鉴定了其结构,简要地介绍了其爆炸性能.研究表明,作为新型高氮含能材料,偶氮四唑盐具有高的正生成焓、成气量大、燃烧无烟或少烟、燃后剩余残渣少以及不吸湿等特点,且具有良好的爆炸性能,可作为新型气体发生剂、低特征信号推进剂、低烟或无烟烟火剂以及高能炸药的重要组分.     

偶氮苯甲酸类衍生物的合成、表征及光学性能研究

设计合成了三种偶氮苯甲酸类化合物,产率均达84%以上.通过元素分析、1H NMR、MS及红外光谱对产物进行了表征,结果与预期产物吻合.通过紫外光谱和荧光光谱研究化合物的光学性能,发掘偶氮苯甲酸类化合物的光学特性与应用.     

Increasing the Reaction Rate of Hydroxynitrile Lyase from Hevea brasiliensis toward Mandelonitrile by Copying Active Site Residues from an Esterase that Accepts Aromatic Esters

The natural substrate of hydroxynitrile lyase from rubber tree (HbHNL, Hevea brasiliensis) is acetone cyanohydrin, but synthetic applications usually involve aromatic cyanohydrins such as mandelonitrile. To increase the activity of HbHNL toward this unnatural substrate, we replaced active site residues in HbHNL with the corresponding ones from esterase SABP2 (salicylic acid binding protein 2). Although this enzyme catalyzes a different reaction (hydrolysis of esters), its natural substrate (methyl salicylate) contains an aromatic ring. Three of the eleven single‐amino‐acid‐substitution variants of HbHNL reacted more rapidly with mandelonitrile. The best was HbHNL‐L121Y, with a k_cat 4.2 times higher and high enantioselectivity. Site‐saturation mutagenesis at position 121 identified three other improved variants. We hypothesize that the smaller active site orients the aromatic substrate more productively.     

吡啶化合物的合成技术与应用进展

择要介绍了近期研究的、主要作为医药、农药等化工产品领域的一些吡啶化合物及其衍生物的合成和开发情况。这些化合物主要包括:2-氯-5-氯甲基吡啶,2-氯-3-氨基-4-甲基吡啶、2,3,5-三氯吡啶,五氯吡啶,2-氯-3-氰基吡啶,2-氯甲基-4-乙氧基吡啶盐酸盐、2-氯-5-甲基吡啶等。特别叙述了2,3-环戊烯并[b]吡啶、它具有抗溃疡、抗癌的重要生理活性,也是合成头孢匹罗等的重要原料。另外,对这些化合物的合成方法、基本性质、市场前景也作了简要讨论。     

2,4,6-三甲基吡啶合成工艺的研究

以丙酮与氨为原料在常压下反应合成 2 ,4,6-三甲基吡啶 ,较佳反应条件为 :反应温度为30 0°C,氨与丙酮摩尔比为 2 .2∶ 1 ,液体空速为 0 .2 5 h-1,收率可达 5 0 %以上。